Patent Publication Number: US-2015066999-A1

Title: Information processing device, information processing method, and program

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     The present application is a continuation of and claims the benefit under 35 U.S.C. §120 of U.S. patent application Ser. No. 12/475,900, titled “INFORMATION PROCESSING DEVICE, INFORMATION PROCESSING METHOD, AND PROGRAM,” filed Jun. 1, 2009, which claims the benefit under 35 U.S.C. §119 of Japanese Patent Application JP 2008-146009, filed in the Japan Patent Office on Jun. 3, 2008, each of which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to, for example, an information processing device used in creating contents, and sharing of the created contents, over a network, and to a method thereof. The present invention also relates to a program which the information processing device executes. 
     2. Description of the Related Art 
     SUMMARY OF THE INVENTION 
     As for one form of network usage, so-called content distribution and sharing of audio, video, and so forth, has widely come to be performed. For example, with a content distribution system, a great number of data files serving as contents to be distributed are saved and managed at a server. A user having an information processing terminal device such as a personal computer operates application software (client software) having a client function corresponding to content distribution, so as to download the desired content from the server. The data file serving as content that has been downloaded in this way is normally managed by being stored and saved in a storage device within the information processing terminal device by the client software. Subsequently, the user can listen to/view and enjoy this as sound and/or video, by performing an operation at the client software for playing the data file serving as the content stored in the information processing terminal device. 
     Also, with a content sharing system, a user of an information processing terminal, for example, uploads to a server data files serving as contents such as audio, video, and so forth. A server of such a sharing system has a site (Web page) for posting uploaded contents. A user of a general information processing terminal device can access this site and search for contents he/she is interested in, for example. Contents found by this searching are accessed and played, so as to be viewed/listened to, and thus are shared. 
     On the other hand, there is application software (editing software) capable of taking in audio data and video data and the like as material, so as to be modified, edited, and a new tune can be created, and in recent years in particular, there is widespread use thereof, from that which is easy to operate to complicated, by also common users as well. 
     As described above, such editing software can execute processing for changing actual data (audio/video data and so forth) serving as contents, for editing thereof. Accordingly, in the case of audio contents for example, modifying and editing or the like by taking in a part of original tune data as material, such as with so-called sampling, mash-ups, and so forth, can be easily performed. In fact, many tunes created by such techniques have been released by professional musicians or the like, for example. Description of such related art can be found in Japanese Unexamined Patent Application Publication No. 2000-113066 and Japanese Unexamined Patent Application Publication No. 2004-72502. 
     SUMMARY OF THE INVENTION 
     With a background such as described above, it can be thought that there would be a considerable number of common users who desire not only to simply play and enjoy the data of contents which can be obtained by content distribution and content sharing and so forth, but also creating new works by performing secondary editing using editing software, and publicly presenting (posting) the work. 
     Accordingly, the present invention proposes configuring a content sharing system on a network whereby general users for example can perform secondary use of contents held at the user terminal side and perform editing to create subsidiary contents, and can publicly present contents created in this way, by way of a server or the like. Thus, with this content sharing system, subsidiary contents existing on the network will be managed for content sharing. Enabling setting of the importance of each subsidiary content as one way of such managing would enable better service of the content sharing system, which would be advantageous. 
     With such a content sharing system, a great number of subsidiary contents for example, will exist on the server and be shared. To make things easier for the user with the content sharing system, there is demand to enable subsidiary contents which are appropriate for recommendation to each user to be found as efficiently as possible, from these subsidiary contents. 
     An information processing device according to an embodiment of the present invention includes: a storage management unit configured to store and manage a subsidiary content file including playback control information formed including content instructing playback of actual content data of a primary content file serving as source editing material; and 
     a subsidiary content selecting unit configured to select, from subsidiary content files managed by the storage management unit, subsidiary content files using at least a part of a primary content file serving as the source editing material, as recommended subsidiary contents to be recommended to the recommendation-receiving user. 
     With the above configuration, contents to be recommended are files. A subsidiary content file is a file created by secondary usage of one or more content files, and have a structure including playback control information for instructing playback of actual content data which a primary content file, serving as source editing material, has. 
     In recommending of such a subsidiary content file, a subsidiary content which uses held primary contents held by the recommendation-receiving user as source editing material contents in part or in all, is selected. Using a primary content which the recommendation-receiving user possesses as the source editing material means that the subsidiary content includes content matching the tastes of the recommendation-receiving user. 
     Thus, according to the above configuration, a subsidiary content which has the nature of being a secondary creation can be recommended to the user side so as to accurately match the tastes and so forth of each user. Accordingly, users can speedily and efficiently find subsidiary contents matching the tastes thereof, from a great number of subsidiary contents. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating a configuration example of a content creating/sharing system corresponding to an embodiment of the present invention; 
         FIG. 2  is a diagram illustrating a basic usage form of a content creating/sharing system according to an embodiment of the present invention, and procedure examples of system operations corresponding thereto; 
         FIG. 3  is a diagram schematically illustrating the flow of subsidiary content creation according to the embodiment; 
         FIG. 4  is a diagram schematically illustrating the flow of subsidiary content playing according to the embodiment; 
         FIGS. 5A through 5C  are diagrams illustrating a usage form example of editing material contents at the time of creating a subsidiary content; 
         FIG. 6  is a diagram illustrating an internal configuration example of a primary content server; 
         FIG. 7  is a diagram illustrating an internal configuration example of a subsidiary content server; 
         FIG. 8  is a diagram illustrating an internal configuration example of a communication content server; 
         FIG. 9  is a diagram illustrating an internal configuration example of a user information server; 
         FIG. 10  is a diagram illustrating an internal configuration example of a user terminal device; 
         FIG. 11  is a diagram illustrating an example of data contents to be stored in an HDD of the user terminal device; 
         FIG. 12  is a diagram illustrating a program configuration example serving as a content managing/creating tool of a content creating/sharing application; 
         FIGS. 13A and 13B  are diagrams schematically illustrating a structural example of a subsidiary content file and a primary content file; 
         FIG. 14  is a diagram illustrating examples of information items forming header information of a content file; 
         FIG. 15  is a diagram illustrating an example of information items forming present content related basic information, which is one of information items forming the header information; 
         FIG. 16  is a diagram illustrating a structural example of used source editing material content information and used editing material content information in a subsidiary content playback control file; 
         FIG. 17  is a diagram illustrating an example of what is in playback control information in a subsidiary content in a subsidiary content file; 
         FIG. 18  is a flowchart illustrating an example of reflecting the usage agreement range settings for editing material contents on a user interface at the time performing subsidiary content editing processing by the content creating/sharing application; 
         FIG. 19  is a flowchart illustrating an example of processing procedures up to the content creating/sharing application creating a subsidiary content file as subsidiary content editing processing; 
         FIG. 20  is a flowchart illustrating uploading subsidiary contents by the user terminal device, and an example of processing procedures by the subsidiary content server in response; 
         FIG. 21  is a flowchart illustrating downloading subsidiary contents by the user terminal device, and an example of processing procedures by the subsidiary content server in response; 
         FIG. 22  is a flowchart illustrating an example of playing processing procedures of subsidiary contents by the user terminal device; 
         FIG. 23  is a sequence diagram illustrating operations and processing performed with the content creating/sharing system in relation to recommendation of subsidiary contents; 
         FIG. 24  is a diagram illustrating a configuration example of user profile information; 
         FIG. 25  is a diagram illustrating an example of the structure of content profile information; 
         FIG. 26  is a diagram schematically illustrating a basic concept regarding extraction of recommended contents with the embodiment; 
         FIG. 27  is a flowchart illustrating an example of processing procedures for extracting recommended contents, executed by the subsidiary content server; 
         FIG. 28  is a flowchart illustrating an example of processing procedures for setting basic recommendation order in accordance with the number of lacking contents with regard to the extracted recommended contents; 
         FIG. 29  is a sequence diagram illustrating an example of operations of a system for obtaining information regarding potential audience users, executed between the user terminal device and user information server; 
         FIG. 30  is a flowchart illustrating an example of processing procedures for creating potential audience user information, executed at the user information server; and 
         FIG. 31  is a sequence diagram illustrating an example of operations and processing relating to content recommendation, as an extended example of the present embodiment. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  illustrates a configuration example of an information processing system, having information processing devices, according to an embodiment of the present invention. Note that the information processing system according to the present embodiment handles primary content files and subsidiary content files as content files, as will be described later. In the following, content files will be referred to simply as “content files” in the event that primary content files and subsidiary content files do not have to be distinguished. Also, in the case of describing contents in accordance with abstract concepts, primary content files will also be referred to as “primary contents”, and subsidiary content files will also be referred to as “subsidiary contents”. Moreover, contents will be referred to simply as “contents” in the event that primary contents and subsidiary contents do not have to be distinguished. 
     As shown in this drawing, the information processing system according to the present embodiment can first be viewed as being formed by connecting a primary content server  1 , a subsidiary content server  2 , a communication server  3 , a user information server  8 , and a great number of user terminal devices  4 , connected by a network  5 . The information processing system according to the present embodiment realizes a content creating/sharing system by such a device configuration. That is to say, so-called content distribution (distribution of primary contents) and sharing of contents created by users (subsidiary contents) among users, on a network, are realized. 
     Note that “contents” as used here primarily refer to audio contents corresponding to music, songs, and the like, or video contents which is moving images. Further, the content types of video contents may be considered to include still images, such as photographs and the like. Also, document data, programs to be executed by the information processing device, and so forth, can be handled as contents. 
     The primary content server  1  stores and manages in a database a great number of audio and video content data, in a predetermined format, as primary contents. The primary content server  1  is configured so as to externally transmit data which is specified primary contents to the requesting user terminal devices  4 , in response to download requests from the user terminal devices  4  via the network. Note that the primary contents here are, for example, videos or tunes or the like which artists and the like have created, provided from an affiliated record label. 
     The subsidiary content server  2  is capable of storing and managing data of a great number of subsidiary content files, which is data serving as subsidiary contents, in a database. As described later, a subsidiary content file is uploaded from a user terminal device  4  to the subsidiary content server  2  via the network. The subsidiary content server  2  stores the subsidiary content file uploaded in this way, handling as subsidiary contents. Also, a specified subsidiary content file is transmitted and output by the subsidiary content server  2  to a requesting user terminal device  4 , in response to a download request from the user terminal device  4  via the network. 
     The communication server  3  is a server having functions for providing inter-user communication services, such as for example, SNS (Social Networking Service), services for individuals to put information out which is also widely recognized as CGM (Consumer Generated Media) such as blogs, and so forth. 
     The user information server  8  stores information of predetermined contents relating to a user of a user terminal device  4  participating in the content creating/sharing system according to the present embodiment (user profile information), as a database for example. AS described later, the user information server  8  operates collaboratively with other servers and the like to execute predetermined operations for realizing a content recommending service. An example of user profile information will be described later. 
     A user terminal device  4  is a network device which a general user uses, and actually is a personal computer provided with network communication functions such as LAN or the like, for example. These user terminal devices  4  have installed an application program serving as a content creating/sharing application  100 , as described later. The user operates this content creating/sharing application  100 , and thus is enabled to perform such as downloading primary content files from the primary content server  1 , creating new subsidiary content due to editing work using the downloaded primary content file (and subsidiary content file), uploading the created subsidiary content file to the subsidiary content server  2 , downloading subsidiary content files from the subsidiary content server  2 , using SNS services, writing/browsing blogs using the communication server  3 , and so on. 
     Next, an example of basic operations relating to content distribution, of the information processing system according to the present embodiment assuming the configuration shown in  FIG. 1  described above, will be described with reference to  FIG. 2 , following a basic usage form example by a user of a user terminal device  4 . Note that in the description in  FIG. 2 , description will be made following the numbers of procedures and operations indicated by alphanumeric characters in the brackets [ ]. Also, here, user terminal devices  4 A and  4 B are shown as being used by two users A and B, respectively, as user terminal devices  4 . In this drawing, the network  5  which exists between the primary content server  1 , subsidiary content server  2 , communication server  3 , and user terminal devices  4  is omitted from the drawings. Further, with the present embodiment, the user information server  8  is also omitted from the drawing, since the user information server  8  does not function in an indispensable manner in basic distribution of contents. 
     Procedure 1 
     First, the user A accesses a content download site on the primary content server  1  with the user terminal device  4 A (content creating/sharing application  100 ), and then searches the content download side for primary contents which the user wants to download, and performs operations for downloading the searched primary contents. In response to this operation, the user terminal device  4 A transmits a download request to the primary content server  1 . 
     Now, we will say that with the content creating/sharing system according to the present embodiment, the downloading of primary contents is basically charged for, with the user A performing proper purchasing procedures at the time of transmitting a download request to the primary content server  1 . As far as purchasing procedures go, for example, this may be payment procedures for charges set individually in increments of contents or in increments of albums or the like, or may be subscriptions which have become widespread as of recent. Also, an arrangement may be conceived wherein primary contents are provided free of charge, an in this case, there are no purchasing procedures for the user A. 
     Upon receiving a download request as described above, the primary content server  1  first performs authentication regarding the requesting user for example, and so forth, and determines whether or not this is a legitimate download request. In the event that determination is made that this is a legitimate download, the primary contents (primary content file) specified at the time of the download request are searched for from the primary contents stored within itself, and data of the file serving as the searched primary contents is transmitted to the requesting user terminal device  4 . 
     Note that the actual entity of the primary content file which the primary content server  1  stores while managing in a database here is of a structure wherein main information serving as actual content data has header information attached thereto. “Actual content data” in this case refers to audio data, moving image data, and still image data according to a predetermined format (data for playing the actual content of the primary contents), as what the content of the contents is. That is to say, the primary content data according to the present embodiment is that from which contents can be played by performing audio signal processing and video signal processing and so forth. Also, header information includes, besides a unique identifier (content ID) for each content file, various types of metadata (tile, artist, title of album to which the data belongs, genre, data format, data size, etc.). 
     The primary content data transmitted from the primary content server  1  as described above is received at the user terminal device  4 A. The user terminal device  4 A (content creating/sharing application  100 ) stores and saves this received primary content data in a storage medium such as an internal HDD or the like. The content creating/sharing application  100  has functions for managing the primary content stored and saved in this way according to a predetermined form based on the header information for example, and executing playback control in accordance with user operations. 
     Thus, with this arrangement, primary content data stored in the primary content server  1  can be downloaded to user terminal devices  4 , by being purchased by the user as a general principle. That is to say, for procedure 1, so-called content distribution is performed. 
     Note that the primary content data stored and saved at the user terminal device  4 A can be played by the content creating/sharing application  100 , and output as images, audio, etc., with an AV (Audio-Visual) device or the like connected to the user terminal device  4 A, for example. 
     Procedure 2 
     Now, generally, with content distribution via network, usage of contents following downloading is restricted to use such as playback, with a certain level of copy restrictions of data being provided. In other words, a user who has obtained contents by downloading is normally only permitted usage within a certain range, and is not provided with rights to create new contents as secondary creations by performing editing based on the obtained audio contents that have been acquired, for example. 
     In comparison to this, with the present embodiment, the primary content is content regarding which using as material for secondary creation within a range set beforehand (secondary usage, secondary editing) has been permitted, as a matter of principle. Note that secondary usage of the primary content in the present embodiment is set within the range of rights which the writer of the primary content has authorized. 
     The content creating/sharing application  100  is capable of creating audio contents as a new tune, by executing editing processing in accordance with user operations to perform secondary usage of the primary contents managed in itself (locally stored and saved) as editing material. Also, at the time of editing such contents for example, plug-in data corresponding to predetermined special effects provided at an effect database  6  can be obtained, and editing performed using this. Also, in the same way, material such as audio, images, etc., provided at a material database  7  can be obtained, and editing performed by adding this. Note that the effect database  6  and material database  7  may be situated on a network, or may exist locally on the user terminal device  4 A. 
     With the present embodiment, contents created in this way are called subsidiary contents, and are distinguished from primary contents. As for the procedure 2, a certain subsidiary content is created by operating operations as to the user terminal device  4 A on which the content creating/sharing application  100  is running. 
     Note that the actual entity of the data serving as the subsidiary content created by this procedure 2 is not the digital audio data and video data having the tune content as with the primary content, but rather is generated with playback control information. That is to say, this is playback control information describing specification of effects (special effects), such as instructions of what portion of the digital audio data and digital video data serving as the secondarily used primary contents (editing material contents) is to be played and output at which timing. 
     Now,  FIG. 5  illustrates a concept of creating subsidiary contents with the content creating/sharing application  100 . As schematically illustrated in  FIG. 5 , the editing material contents A, B, and C which are objects of secondary use are used, and the user performs editing operations as to the content creating/sharing application  100  which reflect the intent of editing of the user. The content creating/sharing application  100  performs editing processing corresponding to the editing operations, and creates and outputs a subsidiary content file as a result. The structure of the subsidiary content file created in this way has the above-described playback control information as the main entity of the data. 
     The subsidiary content data serving as this playback control information (i.e., the subsidiary content playback control information) can be made markedly smaller in data size as compared to video data or audio data or the like, for example. Accordingly, the storage capacity of the storage medium such as the HDD or the like to store the subsidiary content data at the subsidiary content server  2  can be conserved and effectively used. Also, the amount of transmitted data is smaller at the time of transmission/reception of the subsidiary content data on the network, and accordingly does not make traffic heavier, for example. 
     Performing editing with already-existing contents as material, as with the secondary editing with the present embodiment, to create a secondary work as a new content, is called sampling, mash-up, and so forth, with professional musicians and the like also often performing this. In light of such, it is naturally conceivable that there is desire and demand of general people to create contents as secondary works in the same way. However, in reality, it is extremely difficult for general people to create contents as secondary works upon having properly cleared copyright issues. 
     Accordingly, as for the content creating/sharing system according to the present embodiment, an attempt has been made to increase the entertainment nature for the user, by first enabling general users to legally perform secondary editing using distributed contents. 
     To this end, the primary contents according to the present embodiment have been positioned as contents regarding which a user which has downloaded (purchased) is permitted to use secondarily in the range of rights which the copyright holder has authorized. That is to say, the content distribution service with the primary content server  1  according to the present embodiment is for distributing contents regarding which secondary usage has been proactively permitted. However, in the case of the present embodiment, the editing work which is secondary use of primary contents should be limited to user operations at the content creating/sharing application  100  developed for the content creating/sharing system according to the present invention at the least, and should be arranged such that the editing work is not performed by other editing software or the like unrelated to the content creating/sharing system according to the present embodiment. 
     Procedure 3 
     The data of the subsidiary content file created by the user A as described in Procedure 2 above is saved only at the user terminal device  4 A, with playback processing being performed by the playback functions of the content creating/sharing application  100  as described later with  FIG. 4 , and images/audio of the contents can be played as the subsidiary content. 
     With this in mind, the present embodiment further enables users who have the services of the content creating/sharing application  100  according to the present embodiment to share the subsidiary contents created by users, by making public on a network. 
     Now, let us say that the user A desires to share subsidiary contents created by the above Procedure 2. Accordingly, the user A performs predetermined operations as to the content creating/sharing application  100 , so as to upload the data of the subsidiary content file created by the Procedure 2 to the subsidiary content server  2 . This is Procedure 3. 
     Procedure 4 
     The subsidiary content server  2  saves the subsidiary content file transmitted as an upload as described above, so as to be newly registered in a database. At this time, the subsidiary content server  2  sets the saving location thereof (e.g., represented by an address such as a URL (Uniform Resource Locator)), and then performs saving processing of the subsidiary content file and registration thereof in the database. 
     Note that the subsidiary content server  2  has publishing functions with regard to the subsidiary content registered in the database. That is to say, the subsidiary content registered in Procedure 4 is subsequently published at the subsidiary content server  2 , can be downloaded in response to download requests from the user terminal device  4  (content creating/sharing application  100 ). 
     Procedure 5 
     Upon saving and managing the subsidiary content file as described above, the subsidiary content server  2  transmits, to the upload requesting user terminal device  4 A, an address indicating the saving location of the subsidiary content (subsidiary content file) that has been uploaded (saving location address), to notify the saving location thereof. 
     The content creating/sharing application  100  of the user terminal device  4 A receives the above saving location address, and stores and saves, and manages this in a predetermined storage medium. The user A can, at any time, output the saving location address of the subsidiary content which he/she has uploaded by Procedure 2, by performing a predetermined operation as to the content creating/sharing application  100 . 
     Procedure 6 
     As described earlier, the subsidiary content server  2  has a publishing function regarding the subsidiary contents registered in the database. Accordingly, the subsidiary content which the user A has created and uploaded this time can be browsed by users of an indeterminate number of user terminal devices  4  (content creating/sharing applications  100 ) accessing the content publishing site provided by the subsidiary content server  2 , as a general principle. Also, with the present embodiment, the user terminal devices  4  of all users can download desired subsidiary contents, as a general principle. With this understanding, the user A which has obtained the saving location address in Procedure 5 can announce to other users in several ways that his own subsidiary contents have been published at the subsidiary content server  2 . Procedure 6 corresponds to one of the publishing announcement methods, and is carried out by accessing the communication server  3  as shown in the drawing, and writing to his own page in an SNS, or his own blog or the like, for example, that the subsidiary contents created by himself have been published. At this time, the URL serving as the saving location address obtained in Procedure 5 is also copied in so as to be written in. 
     Procedure 7 
     Upon a user B for example operating the content creating/sharing application  100  installed in the user terminal device  4 B after the user A has written in as described above with Procedure 6 and accessing and browsing the page of the user A in the SNS or the blog of the user A, he/she knows that subsidiary content of the user A has been newly published. That is to say, in this case, the user B has indirectly received the announcement regarding the new publishing of the subsidiary content created by the user A, via the SNS or blog. Procedure 7 indicates such indirect announcement of subsidiary content publishing being performed. 
     Procedure 8 
     Procedure 8 will be given as another way for publishing announcement. As for this Procedure 8, the user B side is notified that the subsidiary content created by the user A has been disclosed by creating and transmitting mail using a mail function provided to the SNS, for example. This is a more direct form of announcement, as compared to the announcement according to the flow of the above-described Procedure 6 and Procedure 7. 
     Also, in the event of announcing by e-mail and so forth in this way, the saving location address of the subsidiary content is copied into the body for example, so as to be listed. 
     Procedure 9 
     In this way, the user B can indirectly or directly receive announcement and know that the subsidiary content created by the user A has been newly published. In the event that the user B desires to enjoy the subsidiary content of the user A that has been newly published, first, the subsidiary content is downloaded by the content creating/sharing application  100 . This is Procedure 9. 
     At the time of downloading the subsidiary content, a clicking operation or the like is performed as to the saving location address shown as a link in the body of the SNS diary page or blog, for example. Note that at the time of writing to an SNS diary page or blog, in the event the address information such as a URL is written in, this text string portion is presented as a link. 
     In response to performing a clicking operation as to the saving location address as described above, the content creating/sharing application  100  accesses this saving location address. That is to say, of the addresses on the subsidiary content server  2 , an address indicating the location where the file of the subsidiary content which the user A has created and published (subsidiary content file) has been saved, is accessed. The subsidiary content file saved at that saving location is then sent out to the user terminal device  4 B. The subsidiary content file set out in this way as received at the user terminal device  4 B, and saving and management is performed under control of the content creating/sharing application  100 . Accordingly, subsidiary content is downloaded. 
     Procedure 10 
     Upon the subsidiary content of the user A being saved and managed as described above, playing of the subsidiary content by the content creating/sharing application  100  of the user terminal device  4 B becomes available. Procedure 10 is a procedure for playing subsidiary content file, so that the content of the subsidiary contents are output as video, sound, and so forth, in accordance with playback instruction operations as to the content creating/sharing application  100  by the user B. 
       FIG. 4  shows a playback concept of subsidiary contents with the content creating/sharing application  100 . At the time of playing the subsidiary content, first, the content creating/sharing application  100  performs interpretation processing of the playback control information of the subsidiary content file which is the actual data. As a result of this interpretation, the content creating/sharing application  100  can recognize first, for example, which primary content file has the actual content data to be played (source editing material content), and also in the playing sequence, which portion of the actual content data (video data, audio data, etc.) of the source editing material contents have been used in what manner at what playing time, and so forth, for example. 
     In this diagram, an example of results is shown in a case that recognition has been made that source editing material contents A, B, and C have been used. Following the recognition results thereof, the content creating/sharing application  100  uses the actual contents of the primary content files serving as the source editing material contents A, B, and C, to execute playback control. Consequently, the content of the contents serving as the subsidiary content is played as images and sound. 
     According to the description of  FIG. 4  above, playing of the subsidiary content uses the actual content data of the source editing material content used for creating the subsidiary content. That is to say, with the present embodiment, in order to play subsidiary content file, the data of the source editing material contents has to exist at the same local location as the content creating/sharing application  100 , however temporarily. Accordingly, in the event that the source editing material contents are not locally saved as a primary content file at the time of attempting to play the subsidiary content, this should be obtained locally. 
     Procedure 11 
     Accordingly, in such a case as described above, procedures are performed for downloading and acquiring any editing material contents which are not locally available. Procedure 11 in  FIG. 2  is a procedure to be performed to this end in the process of playing contents with Procedure 10. 
     As can be understood from the description so far, the source editing material contents are actual content data, so as a principle, the source editing material contents are primary contents. Accordingly, in Procedure 11, the primary content server  1  is accessed by the user terminal device  4 B (content creating/sharing application  100 ) and primary contents used for playing the subsidiary content in this Procedure 10 but not existing locally are downloaded. Due to this downloading, the source editing material contents used for playing the subsidiary content all exist locally, and playback output can be properly executed as described with  FIG. 4 . 
     Note that several forms of data of the primary contents existing locally due to the downloading in Procedure 11 can be conceived. First, a form can be conceived wherein this is made to exist locally, in a state of being stored in saved as to an auxiliary storage device such as an HDD, in the same way as with the case of a normal download according to Procedure 1. As for another, a form can be conceived wherein this is temporarily held in a main storage device such as RAM, and is erased in response to the content creating/sharing application  100  no longer being in a state wherein the playback operation of the subsidiary content can be performed, for example. While primary contents have been described as being basically charged for, for example, operations can be conceived wherein in the case of temporary storage, these are free of charge, or fees are set cheaper than normal downloads, or the like. 
     Also, according to the description of  FIG. 2  above, with creating of subsidiary contents according to the present embodiment, primary contents are directly used as the contents of editing material (editing material contents), in a secondary usage manner. That is to say, the editing material contents in this case are primary contents of which the actual content data has to be used at the time of playing (also referred to as “source editing material contents”). 
     However, not only primary contents but also subsidiary contents can be included as the editing material contents which are subjected to secondary usage in the present embodiment. This point will be supplemented with reference to  FIGS. 5A through 5C , which each illustrate cases of creating one subsidiary content by editing with secondary usage of two editing material contents. 
     First,  FIG. 5A  illustrates a case wherein the editing material contents A and B are each primary contents, in the same way as with the example of creating subsidiary content described with  FIG. 2 . That is to say, this shows creating of subsidiary content by executing editing processing with a primary content A taken as editing material content A, and a primary content B which is a different primary content taken as editing material content B. The subsidiary content in this case includes at least a part of the primary content A and primary content B as for the contents thereof, as shown in the drawing. That is to say, the primary contents A and B are used as the contents which are the original editing material (i.e., source editing material contents). 
       FIG. 5B  illustrates creating a subsidiary content by editing with secondary usage of the editing material content A which is the same primary content as in  FIG. 5A , and editing material content C which is subsidiary content created using primary contents C and D secondarily. The subsidiary content in this case includes at least a part of the primary content A included in the editing material content A, and at least a part of each of the primary contents included in the editing material content C, as for the content of the contents thereof. That is to say, the primary contents A, C and D are used as the original editing material content, and accordingly, in the event of playing the subsidiary content shown in  FIG. 5B  here, the primary contents A, D, and D should be locally situated. 
       FIG. 5C  illustrates creating a subsidiary content by secondary usage of the two editing material contents C and D which are subsidiary contents. The subsidiary content newly created in this case includes at least a part of each of the primary contents C and D included in the editing material content C, and a part of each of the primary contents E and F included in the editing material content D, as for the content of the contents thereof. Accordingly, the primary contents C, D, E, and F should be locally situated in the event of playing the subsidiary content shown in  FIG. 5C . 
     Also, in the event of using subsidiary contents as editing material contents for creating subsidiary content as in the above  FIGS. 5B and 5C , first, the user performs download for example, and stores and saves at the user terminal device  4 , in order to situate the subsidiary content serving as the editing material contents locally, in the same way as with handling primary content as editing material content. 
     Also, in the event of the subsidiary content server  2  performing transmission of subsidiary content data in response to the download request for subsidiary content, in according with Procedure 9 in  FIG. 2 , the subsidiary content is encrypted. This encryption can be decrypted by an authorized content creating/sharing application  100 , but the content creating/sharing application  100  is arranged to operate such that only subsidiary content data decrypted by this encryption processing is played, and subsidiary content data not encrypted to begin with for example, or subsidiary content data encrypted by another format or algorithm, is not played. That is to say, the content creating/sharing application  100  only plays that downloaded and obtained from the subsidiary content server  2  with regard to externally-obtained subsidiary content data. 
     Accordingly, for example, even in the event that users directly exchange subsidiary content files between user terminal devices by direct communication such as P2P (Peer-to-Peer) network communication or e-mail file attachment or FTP (File Transport Protocol) or the like, or by direct exchange using removable media, files obtained by users in this way will not play properly since there is no encryption by the subsidiary content server  2 . That is to say, with the present embodiment, subsidiary content of others will not play properly unless downloaded from the subsidiary content server  2 . Accordingly, with the content creating/sharing system according to the present embodiment, circulation and reproduction of illegal subsidiary contents violating copyrights over the network is avoided. Thus, protection of the rights of copyright holders of the primary contents and subsidiary contents can be implemented. 
     As can be understood from the description in  FIGS. 2 through 5C , with the content creating/sharing system according to the present embodiment, first, primary contents are downloadable. That is to say, users can download (purchase) and enjoy contents which they like by normal content distribution. Based on this, usage rights are set whereby secondary usage to take the primary contents as editing materials is enabled, so users can perform editing with the primary contents as materials and create their own works. Further, subsidiary contents which are works created in this way can be publicly published using communication techniques such as SNSs and blogs and so forth. That is to say, general users can edit contents with copyrights as material and create new contents (subsidiary contents) and further publicly publish the subsidiary contents, in a proper manner, which has heretofore been considered legally difficult due to problems such as copyrights and so forth. 
     Also, with the present embodiment, the actual entity of the subsidiary contents are playback control information, formed including at least description instructing playing of primary contents which are the original editing material used by the subsidiary contents. 
     The content creating/sharing application  100  has playback functions of the subsidiary content, but also has editing functions for creating the subsidiary content. Accordingly, as a form of playback of the subsidiary contents, the content creating/sharing application  100  can not only execute processing for simple audio playback, but also reflect the editing history of the subsidiary content being played in the user interface of the editing function described above, for example. That is to say, as a benefit of the actual entity of the subsidiary content being taken as the playback control information, the user can use the editing functions of the content creating/sharing application  100  to find out in detail how the downloaded subsidiary content has been edited. 
     Next, an example of a technical configuration for realizing the operations as the content creating/sharing system according to the present embodiment described so far, will be described. 
     First,  FIG. 6  illustrates an internal configuration example of the primary content server  1 . As shown in this drawing, the primary content server  1  includes a control unit  11 , a storage unit  12 , an authentication processing unit  13 , a search processing unit  14 , a database management unit  15 , a settlement processing unit  16 , an encryption processing unit  17 , and a network interface  18 . 
     The control unit  11  is a member which centrally executes various types of control processing at the primary content server  1 , and is configured having a hardware configuration equivalent to the center of a computer system, formed of, for example, a CPU (Central Processing Unit), RAM (main storage device), and so forth. 
     The storage unit  12  is configured having an HDD or the like for example, and stores a primary content database  12   a . The primary content database  12   a  is information increments wherein data files serving as primary contents to be distributed have been databased. 
     The authentication processing unit  13  executes predetermined authentication processing regarding whether a valid user or not, in the event of a download request having been made for example, using the user ID and password and the like included in that request. Only in the event that the authentication processing results are OK is a primary content transmitted in response to the request. 
     The search processing unit  14  is a member which cooperates with the database management unit  15  to access the primary content database  12   a  and execute processing for searching for intended primary contents. 
     The database management unit  15  performs management with regard to the primary content database  12   a . For example, in the event that new primary contents are supplied, the new primary contents are registered to the primary content database  12   a  which is updated in response thereto. Also, in the event of deleting primary contents, deletion of the primary contents and updating of the database correspondingly is performed in the same way. 
     The settlement processing unit  16  executes processing such as settlement as to payment of charges at the user side, relating to pay primary contents. 
     The encryption processing unit  17  is a member which executes processing for subjecting primary contents to be transmitted from the primary content server  1  to a user terminal device  4  to predetermined encryption. 
     The network interface  18  is a member for performing communication via the network  5 , and reception of download requests and corresponding transmission of primary contents for example, are realized by the network interface  18  executing communication processing in accordance with the control of the control unit  11 . 
       FIG. 7  illustrates an internal configuration example of the subsidiary content server  2 . Here, the subsidiary content server  2  has a control unit  21 , a storage unit  22 , an authentication processing unit  23 , a search processing unit  24 , a recommended content extraction processing unit  25 , a content database management unit  26 A, a profile database management unit  26 B, a saving location setting processing unit  27 , an encryption processing unit  28 , an and a network interface  29 . 
     The control unit  21  is a member which centrally executes various types of control processing in the subsidiary content server  2 . This also has a hardware configuration equivalent to the center of a computer system, formed of, for example, a CPU, RAM (main storage device), and so forth. 
     The storage unit  22  is configured having an HDD or the like for example, and stores a subsidiary content database  22   a  and a content profile database  22   b . The subsidiary content database  22   a  is information increments wherein subsidiary content files, have been databased. The content profile database  22   b  is information increments formed by grouping content profile information corresponding to each of the subsidiary contents stored as the subsidiary content database  22   a  as a database. While an example of the content of content profile information will be described later, the content profile information is made up of certain information items serving as metadata, such as history information like the number of downloads, for example. 
     The authentication processing unit  23  executes predetermined authentication processing regarding whether a valid user or not, in the event of a download request for subsidiary content having been made for example, using the user ID and password and the like included in that request. 
     The search processing unit  24  is a member which cooperates with the content database management unit  26 A to access the subsidiary content database  22   a  and execute processing for searching for intended subsidiary contents. The search processing unit  24  also cooperates with the profile database management unit  26 B to access the content profile database  22   b  and execute processing for searching for information of content profiles to be used. 
     The recommended content extraction processing unit  25  executes processing for extracting recommended contents from the subsidiary contents stored in the subsidiary content database  22   a , and generating recommended content list information in which the extracted recommended contents are reflected. Note that recommended contents are subsidiary contents which are deemed to be appropriate and suitable for each user (user terminal device  4 ), and having value of recommending to that user. 
     The content database management unit  26 A performs management with regard to the subsidiary content database  22   a  in the storage unit  22 . For example, in the event that new subsidiary contents (subsidiary content files) are uploaded, the uploaded subsidiary contents are registered to the subsidiary content database  22   a  which is updated in response thereto. Also, in the event of deleting subsidiary contents (subsidiary content files), deletion processing to this end and updating of the database corresponding to the deletion results is performed in the same way. 
     The profile database management unit  26 B performs management regarding the content profile database  22   b  in the storage unit  22 . For example, updating corresponding to new loading of subsidiary contents (a subsidiary content file) or a deletion thereof, predetermined updating of history information in accordance with downloading of a subsidiary content file, and so forth, with regard to the content profile database  22   b , is performed. 
     The encryption processing unit  28  is a member which executes processing for subjecting the subsidiary content data to be transmitted from the subsidiary content server  2  to a user terminal device  4  to predetermined encryption. Also, depending on the system operation, subsidiary content data may be encrypted and transmitted from user terminal devices  4  at the time of uploading subsidiary contents, and in this case, the encryption processing unit  28  is arranged to execute processing for decrypting the encryption thereof as well. 
     The network interface  29  is a member for performing communication via the network  5 . Reception of uploaded subsidiary contents and download requests for example, and transmission of subsidiary content data corresponding to download requests (subsidiary content files) are realized by the network interface  29  executing communication processing in accordance with the control of the control unit  21 . 
       FIG. 8  illustrates an internal configuration example of the communication server  3 . As shown in the drawing, the communication server  3  includes a control unit  31 , an a storage unit  32 , authentication processing unit  33 , a blog running processing unit  34 , an SNS running processing unit  35 , and a network interface  36 . Note that the communication server  3  in this case provides communication services with blogs and SNSs. 
     The control unit  31  is a member which centrally executes various types of control processing in the communication server  3 , and also has a hardware configuration equivalent to the center of a computer system, formed of, for example, a CPU, RAM (main storage device), and so forth. 
     The storage unit  32  is configured having an HDD or the like for example, and stores a blog database  32   a  and SNS database  32   b . For example, the blog database  32   a  is information increments wherein data of a blog which the user has started have been databased. The SNS database  32   b  is information increments wherein page contents and the like of each SNS user have been databased. 
     The authentication processing unit  33  in this case executes authentication processing in response to logins for updating blogs, requests for SNS logins, and so forth, using the user ID and password and the like included in the requests. In the event that the authentication processing results are OK, the above login is successful. 
     The blog running processing unit  34  executes various types of predetermined processing for properly running a blog. For example, processing is executed such as transmission of blog screen data, transmission of blog posting screens, and so forth, in response to blog access requests from user terminal devices  4 , valid blog posting screen requests, and so forth. Also, processing for managing the blog database  32   a , such as updating the blog database  32   a  such that posts to the blog are reflected, is also executed. 
     In the same way, the SNS running processing unit  35  executes processing for properly running an SNS, such as processing for transmission of data of a page in response to SNS page access requests and database management beginning with updating the SNS database  32   b  such that posts such as diaries are reflected, and so forth. 
     The network interface  36  is a member for performing communication via the network  5 . This enables transmission of page data in response to access requests for blogs and SNSs, and so forth. 
     Note that while the communication server  3  is provided corresponding to SNSs and blogs, but separate servers may be configured for SNSs and blogs, for example. Also, a configuration may be made to provide more basic CGM related services which have been widespread even before SNSs and blogs, such personal sites and homepages, for example, whereby individual users can post information other than SNSs and blogs and the like. 
       FIG. 9  illustrates an internal configuration example of the user information server  8 . The user information server  8  here includes a control unit  51 , a storage unit  52 , an authentication processing unit  53 , a database management unit  54 , a search processing unit  55 , an encryption processing unit  56 , and a network interface  57 . 
     The control unit  51  is a member which centrally executes various types of control processing of the user information server  8 , and has a hardware configuration equivalent to the center of a computer system, formed of, for example, a CPU, RAM (main storage device), and so forth. 
     The storage unit  52  is configured having an HDD or the like for example, and stores a user profile database  52   a  here. The user profile database  52   a  is information increments formed by grouping user profile information for each user participating in the content creating/sharing system using the content creating/sharing application  100 , as a database. Specific examples of contents and examples of configurations of the user profile information will be described later. 
     The authentication processing unit  53  executes predetermined authentication processing using user ID and password and the like, such as whether a valid user or not, in a case of registering user profile information from a user terminal device  4  to the user information server  8 , for example. 
     The database management unit  54  performs management of the user profile database  52   a  in the storage unit  22 . For example, updating of the user profile database  52   a  is performed in response to new registration, updating registration, and deleting of user profile information. 
     The search processing unit  55  collaborates with the database management unit  54  for example, to execute processing for searching information from the user profile database  52   a.    
     The encryption processing unit  56  executes encryption of data to be transmitted from the user information server  8  to other servers or user terminal devices  4 , for example. The encryption processing unit  56  also executes decryption processing of encrypted data transmitted from other servers or user terminal devices  4 . 
     The network interface  29  is a member for performing communication with the other servers and user terminal devices  4  via the network  5 . 
       FIG. 10  illustrates an internal configuration example of the user terminal device  4 . Note that in this case, the hardware serving as the user terminal device  4  is a personal computer. 
     First, the user terminal device  4  has a network interface  44  in order to perform communication via the network  5 . Due to this network interface  44  having been provided, the user terminal device  4  can communication with, for example, the primary content server  1 , the subsidiary content server  2 , the communication server  3 , user information server  8 , and other user terminal devices  4  and so forth, via the network  5 . 
     A CPU (Central Processing Unit)  41  is capable of executing various types of processing following an OS (Operating System) and various types of applications programs installed in an HDD (hard disk drive)  48  for example, and programs held in ROM  42 . With the present embodiment, an application program serving as the content creating/sharing application  100  is to be installed. 
     RAM  43  is a work area for the CPU  41 , and suitably holds data and programs and the like for the CPU  41  to execute various types of processing. 
     An input/output interface  45  in this case has an input device  46  which is a keyboard or mouse or the like for example connected thereto, with operation signals being output from the input device  46  being converted into signals suitable for the CPU  41  and output to the CPU  41 . 
     Also, the input/output interface  45  has a media drive  47  connected thereto. This media drive  47  is a drive device configured such that data can be recorded to and played from removable media of a predetermined format. 
     Also, the input/output interface  45  has connected thereto an HDD  48  having a hard disk as a storage medium. The CPU  41  is arranged so as to be able to record or read out data and programs and the like to and from the hard disk of the hard disk drive  48 , via the input/output interface  45 . 
     Also, a display monitor  49  for displaying images is also connected to the input/output interface  45 . 
       FIG. 11  illustrates a data content example stored in the HDD  48  with relation to usage of the content creating/sharing system according to the present embodiment. 
     As shown in this drawing, with relation to the content creating/sharing system according to the present embodiment, first, the content creating/sharing application  100  is stored as data of an application program. Note that storing of the content creating/sharing application  100  as to the HDD  48  is performed by installation processing. Also, as application files, one or more primary content files (primary content file group  103 ) and one or more subsidiary content files (subsidiary content file group  104 ) are stored under the control of the content creating/sharing application  100 . 
     The content creating/sharing application  100  in this case can be viewed functionally as being generally configured of a program portion serving as a content managing/creating tool  101  and a program portion serving as a communication tool  102 . The content managing/creating tool  101  is arranged to execute downloading of primary content files and subsidiary content files, and file operations with regard to primary content files of the primary content file group  103  and subsidiary content files of the subsidiary content file group  104 . Also executed are editing processing in accordance with editing operations, subsidiary content file creating processing in response to editing results, and so forth. The communication tool  102  executes processing for accessing the communication server  3  and operating blogs and SNSs. 
       FIG. 12  is a schematic representation of the program configuration with regard to the content managing/creating tool  101  in increments of function blocks, and can be viewed of being made up of a communication control unit  111 , a primary content acquisition processing unit  112 , a primary content managing processing unit  113 , a subsidiary content acquisition processing unit  114 , a subsidiary content managing processing unit  115 , a content transfer processing unit  116 , a content creating processing unit  117 , a subsidiary content file generating/interpreting processing unit  118 , an encryption/decryption processing unit  119 , an playback output processing unit  120 , and a user profile managing processing unit  121 , as shown in the drawing. 
     The communication control unit  111  is a member made up primarily of programs for executing communication between the primary content server  1  and subsidiary content server  3  primarily with relation to content management/editing via the network. 
     The primary content acquisition processing unit  112  is a member made up of programs for downloading and acquiring primary contents. The primary content acquisition processing unit  112  provides a user interface for downloading primary contents. Also, control for issuing commands as download requests and causing transmission by the communication control unit  111 , processing for receiving handover of packets of the primary content data received at the communication control unit  111  and restoring to the data format as primary contents and so forth, are also executed by this primary content acquisition processing unit  112 . 
     The primary content managing processing unit  113  is a member for executing processing for saving the primary content files acquired by the primary content acquisition processing unit  112  in the HDD  48 , and processing for managing the saved primary content files. For example, the primary content managing processing unit  113  also realizes content management such as sorting in accordance with artist name, album units, genre, and so forth. 
     The subsidiary content acquisition processing unit  114  is a member made up of programs for downloading and acquiring subsidiary contents. 
     The subsidiary content managing processing unit  115  is a member for executing processing for saving subsidiary content files acquired by the subsidiary content acquisition processing unit  114  in the HDD  48 , and processing for managing the saved subsidiary content files. 
     The content transfer processing unit  116  executes control and processing such that data transfer of content files is executed properly via the communication control unit  111 , such as for uploading subsidiary content files to the subsidiary content server  2 , for example. 
     The content creating processing unit  117  is a member for executing processing relating to editing using the editing material contents shown in  FIG. 3 , i.e., creating the content of contents serving as subsidiary contents, in response to editing operations and the like performed by the user. Accordingly, a user interface for editing operations and so forth is also realized by this content creating processing unit  117 . 
     The subsidiary content file generating/interpreting processing unit  118  first executes processing for generating the data of subsidiary content files in which the tune contents serving as subsidiary contents created by the content creating processing unit  117  are reflected. Also, in the event of playing subsidiary contents, interpretation processing is executed regarding the playback control information in the subsidiary content file shown in  FIG. 4 , and a playback processing sequence is determined. 
     With the present embodiment, primary content files are encrypted and transmitted from the primary content server  1 . Also, encryption may be implemented at the time of transmitting subsidiary content files from the subsidiary content server  2  to a user terminal device  4  for downloading, and there are cases of transmitting with encryption in the case of uploading subsidiary content data from a user terminal device  4  to the subsidiary content server  2 . The encryption/decryption processing unit  119  executes processing for decrypting encryption in the event that a primary content file or a subsidiary content file that has been encrypted is used for operations for playing, editing, or the like. Also, processing for executing encryption is executed to perform encryption on the subsidiary content file and transmit, if this is the case. 
     The playback output processing unit  120  is a member for executing, in the signal processing process for playing primary content files and subsidiary content files as images, audio, and the like, predetermined signal processing which should be carried out at the digital signal format stage. For example, a primary content file has, as the actual entity of data, actual content data which is video data or audio data or the like of a predetermined format, for reproducing the content of the contents. Accordingly, in the event of the playback output processing unit  120  playing a primary content file, the playback output processing unit  120  executes digital signal processing for playing the video data or audio data or the like which is the actual content data. In the event that this primary content file has been subjected to compression encoding, decoding processing corresponding to this compression encoding is performed, and playback signal processing is performed regarding the digital video signals or digital audio signals. 
     Also, in the event of playing subsidiary contents, this executes playing processing serving as a sequencer, wherein the data portions of the used primary content files serving as source editing material contents are sequentially played following the sequence of playing processing determined by the aforementioned subsidiary content file generating/interpreting processing unit  118 . 
     The user profile managing processing unit  121  generates and updates user profile information, and also manages user profile information stored in the HDD  48 . Note that user profile information will be described later. Also note that the above-described content transfer processing unit  116  can also perform control for transmitting user profile information data to the user information server  8 , not being restricted to transferring of contents. 
     Now, at the time of playing subsidiary contents, the results of interpretation of the playback control information by the subsidiary content file generating/interpreting processing unit  118  can be reflected in an editing work screen which is a GUI provided by the content creating processing unit  117 . That is to say, the contents of playback instructions indicated by the playback control information can be displayed in a form which the user can recognized, on the editing work screen. The user can confirm in detail how that subsidiary contents was created, by viewing this. This means that how the creator created the subsidiary content can be obtained as accurate information. For example, in the case of general contents, in order for a general user to tell how the content has been created, only estimation can be made from the visual content or the acoustic content which can be actually played and viewed or listened to, or the like. In comparison with this, in the case of the present embodiment, how the subsidiary content has been created can be comprehended in further detail and more specifically. Sharing such subsidiary content among users can be expected to markedly improve the knowledge and skill of users using the content creating/sharing system according to the present embodiment with regard to content creating. The system according to the present embodiment has extremely high entertainment nature and usage value for users with interest in content creating. 
     Next, a structural example of content files (primary content files, subsidiary content files) corresponding to the present embodiment will be described with reference to  FIGS. 13A through 15 . First,  FIG. 13A  illustrates a configuration example of a subsidiary content file. As shown in  FIG. 13A , the subsidiary content file is configured of a header and body (main data portion). The header stores header information made up of a group of predetermined information items (metadata, added information) relating to the subsidiary content file. Accordingly, in the case of a subsidiary content file, playback control information is stored. 
       FIG. 13B  illustrates a configuration example of a primary content file. The primary content file is also configured of a header and body (main portion), with the header storing header information made up of a group of predetermined information items (metadata) corresponding to the primary content file. The body stores actual content data of a predetermined format as the actual data corresponding to the content of the contents. 
     Now,  FIG. 14  shows an example of the content of header information which the header of the subsidiary content file stores. In  FIG. 14 , the information items (metadata) making up the header information are present-content-related basic information, used source editing material content information, used editing material content information, present content usage agreement range information, and present content generation information. 
     The present-content-related basic information is basic information items (metadata) relating to the present content file.  FIG. 15  illustrates and example of an information item group making up the present-content-related basic information, with content ID, creator (name/user ID), content type, play time, date-and-time created, jacket data, genre, and so on, being shown. 
     The content ID here is an identifier uniquely given to each content serving as a subsidiary content. Note that with the present embodiment these content IDs are given to each content file by the content database management unit  26 A of the subsidiary content server  2 , for example. 
     The title is information indicating the title given to the subsidiary content file. 
     The creator is information of the name of the creator of the subsidiary content file (also can be called “writer”, “producer”, “artist”, or the like). 
     The content type is information indicating type, range, etc., of the content of the contents which the subsidiary content file has, such as movies, tunes, photographs (still images), and so forth. 
     Play time is information indicating the total play time of the content serving as the subsidiary content file. 
     Date-and-time created is information indicating the date and time at which the subsidiary content file was created. 
     There are cases wherein a content is provided with image data, such as a jacket of an album. Jacket data is such image data. 
     The genre is information indicating what the genre given to the content of the contents serving as the subsidiary content file. 
     Of course, information items other than those listed here may be included in the present-content-related basic information as well. 
     Used source editing material content information is information indicating what the source editing material content (which is the used source editing material content) to be used for playing the content of the contents serving as the subsidiary content file is. In other words, this is information indicating which primary content like or subsidiary content file has had the actual content data thereof used for creating the subsidiary content. 
     In correlation with  FIGS. 5A  though  5 C, the primary content file shown as making up the subsidiary content newly created by editing processing is the above-described used source editing material content information. Accordingly, in the case of  FIG. 5A , the primary contents A and B are shown in the usage primary contents information, in the case of  FIG. 5B , the primary contents A, B, and C are shown, and in the case of  FIG. 5C , the primary contents C, D, E, and F are shown. 
     Also, there may be a possibility that a certain primary content included in the editing material content may not be used at all in the content of the contents serving as the subsidiary content created by editing the editing material content. With the example of the case in  FIG. 5B , with the new subsidiary content obtained by performing editing using the editing material contents A and B for example, there may be a possibility that the contents will be that which uses at least a part of the primary contents A and C, but not using the primary content D at all. In this case, only the primary content A and C are actual content data of primary contents used for playing the subsidiary content, and the primary content D is unused. 
     With regard to how the contents of the used source editing material content information should be corresponding to such a case, there can be conceived one arrangement wherein the contents are such that only the primary contents A and C are shown and the primary content D is not shown, based on the idea that only primary contents actually used for playing the subsidiary content should be reflected. 
     As for another, there can be conceived another arrangement wherein the contents are such that all of the primary contents A, C, and D are shown. That is to say, this is based on an idea wherein, in this case, while the primary content D is not actually used, there has been the influence of the content of the contents serving as the primary content D to a certain extent in the process of creating the subsidiary content, and accordingly is equivalent to being used in an underlying manner. In this case, all primary contents which have been used even once up to the generation of the subsidiary content created this time are consequently included in the used source editing material. 
     As described later with reference to  FIG. 16 , the used source editing material content information also includes metadata of predetermined content, relating to the primary contents shown here. 
     Also, the used editing material content information is information indicating which editing material contents (used editing material contents, directly-used contents) have been directly used for creating the subsidiary content file. With the example in  FIGS. 5A through 5C , stored in the used editing material content information of the new subsidiary content shown in  FIG. 5A  is data indicating the actual primary content files serving as the editing material contents A and B. Also, in the case of the new subsidiary content shown in  FIG. 5B , data indicating the primary content file serving as the editing material content A, and the subsidiary content file serving as the editing material content C, is stored. Also, in the case of the new subsidiary content shown in  FIG. 5C , data indicating the subsidiary content files which are the serving as the editing material content C and D is stored as used editing material information. 
     Note that, as shown in  FIG. 16  which will be described later, the used editing material content information also has attached information of related predetermined contents for each of the editing material contents shown here. 
     The present content usage agreement range information is information of a usage agreement range set regarding the present content file. The structure should comply with the usage agreement range information of the configuration example described later with  FIG. 16 . 
     The present content generation information is information indicating what generation the present subsidiary content is, as a content created under the environment of the content creating/sharing system according to the present embodiment. 
       FIG. 16  illustrates structural examples of the used source editing material content information and used editing material content information. Note that here, the used source editing material content information and used editing material content information are shown as having a common basic structure. Accordingly, the content of  FIG. 16  is shown with both the used source editing material content information and used editing material content information being shown in common. As shown in  FIG. 16 , the used source editing material content information/used editing material content information primarily are made up of linked unit file information. Each unit file information corresponds to one used source editing material content information or used editing material content information. Note that in order to simplify description, both used source editing material content information and used editing material content information will be referred to simply as “used content” if there is no particular distinction therebetween. 
     For unit file information, for example, the items of content ID, creator, title, generation, and usage agreement range information are provided. 
     Here, content ID stores the content ID of the content file serving as the corresponding used content. 
     Creator stores the name of the writer of the corresponding used content, and the user ID of the creator. 
     Title indicates the tile of the corresponding used content as the name thereof. 
     The generation information item stores generation information. The generation information is information indicating what generation content the content is. With the content creating/sharing system according to the present embodiment, primary contents are defined explicitly as first-generation contents, while subsidiary contents are defined as being an N&#39;th generation according to predetermined rules, corresponding to the generation of the editing material contents. Accordingly, in the event that the used content information shown in  FIG. 16  is used source editing material content information, information indicating first generation will be stored in the time of generation information. Also, in the event that the used content information shown in  FIG. 16  is editing material content information, information indicating the generation which is actually set in accordance with each used content (primary content or subsidiary content) corresponding to the unit file information is stored. 
     The information of the usage agreement range (usage agreement range information) is formed of a group of one or more usage items 1 through n. 
     The usage items 1 through n are assigned such that predetermined usage contents related to editing (secondary use) of corresponding usage contents correspond to each. Examples of usage contents to be appropriated to usage items which can be conceived include the following.
         Contents relating to whether or not secondary usage of the present content is permitted   Contents relating to using contents of another creator from the present contents, with regard to other contents to be used as editing material   Contents relating to using contents of another album from that to which present contents belong, with regard to other contents to be used as editing material   Contents relating to using particular effects and special effects   Contents relating to using particular plug-in modules   Extracting a part from the entire content and using as editing material   Permission contents relating to the extracted actual content data portion in the event of extracting a part from the entire content and using as editing material   Number of usable generations (for example, in the event of permitting use for two generations, i.e., up to the grandchild generation (third generation), as primary content, child subsidiary content using this primary content and grandchild subsidiary content using the subsidiary content can be created, but editing of the grandchild subsidiary content is not permitted with regard to the portion using the corresponding primary contents)   Contents relating to number and type of contents regarding which secondary use can be performed in combination with the present content       

     Information indicating contents relating to usage authorization set for each usage item, beginning with permitted/not-permitted for example, is described for each of the these usage items. As for the information of the usage agreement range, generalizing the usage setting contents described for each of these usage items indicates the usage agreement range for the corresponding usage content. 
     With regard to the content of the header information of the primary content file, particular description by way of reference to the drawings will be omitted, and it should be noted that it is sufficient to have information defining the primary content file as being used. However, with the present embodiment, an arrangement wherein the header information of the primary content files have a common structure with those of the subsidiary content files can be considered to be appropriate. With such a primary content file header information structure, the header structure is standardized between primary contents and subsidiary contents, and which can be expected to lead to improved efficiency in content file management with the content creating/sharing system according to the present embodiment. One example thereof is that the primary content files will have present content usage agreement range information, so a usage agreement range which more accurately reflects the decisions and ideas of the writers can be set of the primary contents which are first-generation contents. 
     It should be noted though, that primary content files are not created secondarily using other contents. Accordingly, no meaningful information has to be stored regarding the used source editing material content information and used editing material content information shown in  FIG. 16 , in the header of the primary content files, for example. 
     Next, playback control information in subsidiary content files will be described. Playback control information is unit information made up describing a processing sequence for playing the content of contents serving as current subsidiary content, in a predetermined language, unlike actual content data. Elements of the description contents forming this playback control information include, for example, first, a description indicating primary content serving as actual content data used for playback, description indicating a data portion to be used for actual playing subsidiary content from the actual content data serving as this primary content, and description indicating the time for playing this data portion. Also, description for applying effects or special effects, such as fade-in, fade-out, overlap, equalizing (tone adjustment), playback speed rate, reverberation, delay, and so forth, for example, is performed. 
       FIG. 17  illustrates an example of the content of playback control information. In this drawing, the description portions between the brackets [ ] indicate the playback control content for one primary usage content (source editing material content). 
     An example of playback control content of a usage primary content unit shown in  FIG. 17  will be described. First, as for the playback control content as unit of used content shown at the head in the drawing, [file_id=AAAAAA; time=00:00-00:10; position=vv-zz] is described. This specifies that the used content is specified by the content ID=AAAAAA (the descriptor of file_id here), and that the play time of the current subsidiary content using this usage content is 00:00 (start time)-00:10 (play time 10 seconds), and that the data section (section of actual content data) of the usage content used during this play time is a range corresponding to address vv through address zz. 
     For the playback control content of the subsequent used content unit, [file_id=AAAAAA; time=00:10-00:15; position=ss-tt] is described. This specifies that the usage content is specified by the content ID=AAAAAA, and that the play time of the current subsidiary content using this usage content is 00:10-00:15, and that the data section of the usage content used during this play time is a range corresponding to address ss through address tt. 
     For the playback control content of the subsequent used content unit, [file_id=BBBBBB; time=00:15-00:20; position=pp-uu] is described. This specifies that the usage content is specified by the content ID=BBBBBB, and that the play time of the current subsidiary content using this usage content is 00:15-00:20, and that the data section of the usage content used during this play time is a range corresponding to address pp through address uu. 
     For example, the playback output processing unit  120  of the content creating/sharing application  100  according to the present embodiment thus sequentially interprets the playback control contents of the usage content units in the brackets [ ], and executes actual playback control in accordance with the interpretation results, thereby playing and outputting the subsidiary content as video signals, audio signals, and so forth. 
     Next, an example of procedures relating to the primary processing relating to editing of subsidiary contents will be described with reference to the flowcharts in  FIGS. 18  and  19 . Note that the processing shown in  FIGS. 18 and 19  is realized by execution of a program serving as the content managing/creating tool  101  in the content creating/sharing application  100 , for example. 
     Now, let us say that for example, a user of a user terminal device  4  has activated the content managing/creating tool  101  of the content creating/sharing application  100  and is ready to edit subsidiary content. Let us say that operations are performed such that content to use as material for creating subsidiary content is searched, and this is registered (finalized) as editing material content. In accordance with this, the processing shown in  FIG. 18  is executed by the content creating processing unit  117  of the content managing/creating tool  101 . 
     In  FIG. 18 , first, in step S 101 , taking in of data of content registered as editing material content is executed. Note that in the event that the registered editing material content is a primary content, the data of the primary content file corresponding thereto is taken in, and in the event of a subsidiary content, the data of a subsidiary content file corresponding thereto is taken in. 
     In step S 102 , reading in of information of the usage agreement range is further executed from the data taken in by the above step S 101 . Thus, various contents relating to the usage agreement set with regard to the content registered this time as editing material content is recognized based on the content of the usage items 1 through n in the usage agreement range information. Accordingly, in the following step S 103 , the contents of the usage agreement recognized in correspondence with the above step S 102  is set so as to be reflected on a user interface (UI) for subsidiary content editing. Due to this processing, the content creating processing unit  117  operates such that editing operations of content exceeding the usage agreement range set in the editing material content beforehand are unavailable. 
       FIG. 19  illustrates a basic processing procedure example relating to generating of a subsidiary content file which is the actual entity of data serving as the subsidiary content. The processing shown in this drawing is also realized by the CPU  41  executing a program serving as the content managing/creating tool  101 , for example. 
     Here, first in step S 201 , appropriate editing processing in accordance with operation input for editing is executed. For example, the content creating processing unit  117  provides a GUI (Graphical User Interface) for the user to perform editing operations for creating subsidiary content, with the program thereof. The user performs editing operations for creating subsidiary content using this GUI, and the processing in step S 201  is executed in accordance with this operation. 
     In the process of performing editing processing as described above, upon determination being made in step S 202  that operations have been performed for saving the editing results so far, the flow proceeds to step S 203 . In step S 203 , a subsidiary content file corresponding to the content of contents obtained by the editing results so far is generated. At the time of generating the subsidiary content file, header information and playback control information reflecting the results of editing so far are generated, and these are combined to generate the file. 
     Control is executed in step S 204  so as to save this subsidiary content file created as described above in an appropriate directory in the HDD  48  for example. Upon the procedure of step S 204  having ended, the flow returns to step S 201 . 
     Note that when creating the subsidiary content file, the content of the present content usage agreement range information is also generated. As for how to set the contents of the present content usage agreement range information, an arrangement may be conceived to automatically set (contents for each usage item) following predetermined rules, in a range not exceeding a minimum determined summarizing the usage agreement range information for each primary content which is the source editing material, for example. Also, an arrangement may be conceived for settings are made corresponding to specification operations relating to the contents of the present content usage agreement range information which the user has performed, so that the intent of the user is reflected. However, even in the event of setting in accordance with user operations in this way, setting is performed in a range not exceeding a minimum determined summarizing the usage agreement range information for each primary content which is the source editing material, so that setting of usage agreement range (contents for each usage item) exceeding this is unavailable. 
     Note that while not shown in the drawing here, the processing shown in this drawing is left and the flow transits to other processing, in response to operations being performed to close the GUI screen for creating subsidiary content for example, or the like. 
     Next, a basic processing procedure example relating to uploading of subsidiary content by the user terminal device  4 , and a processing procedure example of the subsidiary content server  2  in accordance with this uploading, will be described with reference to the flowchart in  FIG. 20 . The processing at the user terminal device  4  side in the drawing is realized primarily by programs serving as the subsidiary content managing processing unit  115  and content transfer processing unit  116 . The processing at the subsidiary content server  2  is executed by the members shown in  FIG. 7  operating in cooperation, but in reality, can be viewed as being realized by the computer system (CPU) making up the subsidiary content server  2  executing programs. 
     The user terminal device  4  side in step S 301  is awaiting obtaining of a command instructing uploading of a subsidiary content file. Now, let us say that the user selects, as an operation as to the GUI provided by the content managing/creating tool  101 , one or more subsidiary contents regarding which uploading is desired, and performs an upload execution operation. In response to this upload execution operation, a command is generated which instructs uploading of the subsidiary content file corresponding to the subsidiary content selected at the GUI, and the flow proceeds to step S 302 . Note that the subsidiary content for this upload is subsidiary content created by the content creating/sharing application  100  and stored in the HDD  48  as an application file of the content creating/sharing application  100 . 
     In step S 302 , the subsidiary content regarding which uploading has been specified, i.e., the subsidiary content file, is read in from the directory where it is stored. In the following step S 303 , control is executed such that the data of the subsidiary content file which has been read in is transmitted and output to the subsidiary content server  2  via network along with an upload request. 
     The subsidiary content server  2  is standing by in step S 401  for reception of an upload request, and upon the upload request being received, the procedures from 5402 and on are executed. Note that in order to actually transition to step S 402  after receiving an upload request, confirmation is made that this is a request from a valid user, by way of authentication processing for example, but such processing procedures are omitted here. 
     In step S 402 , a saving location (URL) for the subsidiary content file received along with the upload request is set. The functions of the saving location setting processing unit  26  at the subsidiary content server  2  for example, are used for this URL setting. 
     In step S 403 , communication processing for notifying the saving location of the subsidiary content file set in step S 402  is performed as to the user terminal device  4  which is the originator of the upload request this time. 
     At the user terminal device  4  side which has performed in upload request in step S 303  is awaiting reception of information of the saving location in step S 304 . Upon receiving information of the saving location, in step S 305  information of the received saving location (URL) is saved in an appropriate directory. Thus, hereafter, the information of the saving location of the subsidiary content can be called up by performing a predetermined operation as to the content managing/creating tool  101 . In the event that the saving location is a URL, a text string as the URL can be displayed, for example, depending on the call operation. 
     The flowchart in  FIG. 21  illustrates a processing procedure example relating to downloading of the subsidiary content by the user terminal device  4 , and a processing procedure example at the subsidiary content server  2  corresponding thereto. The processing at the user terminal device  4  in the drawing as well is primarily realized by programs serving as the subsidiary content managing processing unit  115  and content transfer processing unit  116 . 
     First, in step S 501 , the user terminal device  4  side is awaiting obtaining of a command instructing downloading of a subsidiary content file. Here, let us say that for example, the user accesses a download site (Web site) proceeded by the subsidiary content server  2  for download of the subsidiary content, as an operation as to the content managing/creating tool  101 , and causes display of a list of downloadable (shared) subsidiary contents. Further, let us say that the user selects one or more subsidiary contents which the user desires to download from the list, and performs operations for executing downloading. In response to this, a positive determination result will be obtained in step S 501 , and the flow proceeds to step S 502 . 
     In step S 502 , a download request is transmitted to the subsidiary content server  2  in response to a download instructing having been obtained. Note that as for this download request, information equivalent to specifying the directory (saving location) of the subsidiary content selected at the time of operation of the download execution instruction for example, is also included. Note that an arrangement may be conceived wherein instead of the saving location, a download request is made specifying the subsidiary content ID of the subsidiary content file which is the actual entity of the subsidiary content and so forth, for example. 
     The subsidiary content server  2  is awaiting for a download request to be received in step S 601 , and upon an download request being received, executes the procedures in step S 602 . Note that in order to actually transition to step S 602  after receiving a download request as well, authentication processing and the like transpires, but such processing procedures are omitted here as well. 
     In step S 602 , the subsidiary content database  22   a  of the storage unit  22  is accessed and the specified subsidiary content file is searched for, and the searched subsidiary content file is transmitted to the requesting user terminal device  4  in step S 604 . 
     The user terminal device  4  which has transmitted the download request in step S 502  awaits in step S 503  for the subsidiary content file according to the download request to be received. Upon determining that the subsidiary content file has been received, in step S 504 , the received subsidiary content file is saved and managed in an appropriate directory. 
     The flowchart in  FIG. 22  illustrates a processing procedure example of the user terminal device  4  to play the subsidiary content obtained by downloading (saved in HDD  48 ), and the processing of the user terminal device  4  in this drawing is realized by programs primarily serving as the subsidiary content managing processing unit  115 , encryption/decryption processing unit  119 , and playback output processing unit  120 . 
     First, in step S 701 , obtaining of a playback start instruction regarding the subsidiary content file saved in the HDD  48  is awaited. Now, let us say that for example, as an operation as to the GUI provided by the subsidiary content managing processing unit  115 , one subsidiary content is selected from the subsidiary contents saved in the HDD  48 , and an instruction is given to start playing. In response to this, a positive determination result is obtained in step S 701 , and the flow proceeds to step S 702 . 
     In step S 702 , the subsidiary content file corresponding to the specified subsidiary content is read in from the HDD  48 . Here, the subsidiary content data obtained by downloading is saved in the HDD  48  with the encryption at the time of transfer left. Accordingly, in the next step S 703 , processing for decrypting the read in subsidiary content data is executed by the encryption/decryption processing unit  119 . 
     In step S 704 , determination is made regarding whether or not the encryption decrypting processing in the above step S 703  has been successful. For example, in the event that the subsidiary content data regarding which starting of playing has been specified this time in step S 701  has been legitimately downloaded from the content server  2 , the decrypting processing in step S 703  will be successful and proper subsidiary content data will be restored. 
     Conversely, in the event that the subsidiary content data has been obtained by some way other than downloading from the subsidiary content server  2  for example, either encryption has been performed with another method or algorithm, or no encryption has been performed. In this case, depending on the decrypting processing in step S 703 , either proper subsidiary content data is not restorable, or decrypting processing is inapplicable. That is to say, as for the results of the decrypting processing in step S 703 , this can be viewed as failing, including cases that decrypting processing is inapplicable. 
     In the event that positive determination results have been obtained that the decrypting processing has been successful in step S 704 , the flow proceeds to step S 705 , and playback control processing regarding the subsidiary content is started. That is to say, the generating/interpreting processing unit  118  interprets the playback control information to be played and determines a playing sequence, and controls the playback signal processing of the playback output processing unit  120  such that the actual content data portion of the primary content is sequentially played following the playing sequence. 
     Conversely, in the event that a negative decryption result has been obtained in step S 704  that the decrypting processing has failed, the flow proceeds to step S 706 , and error handling processing is executed. As for this error handling processing, first, playback control processing regarding the subsidiary content regarding which playback has been specified this time is kept from being started, and thereupon for example, control processing for notifying on a GUI that the subsidiary content regarding which playback has been specified this time is unauthorized and unplayable, and so forth, is executed. 
     By such processing being executed for example, with the present embodiment, only subsidiary content information externally obtained which has been legitimately downloaded and obtained from the subsidiary content server  2  is played at the user terminal device  4 , whereby the copyright of the primary content or subsidiary content is fully protected. 
     Note that as for an arrangement for playing and outputting only subsidiary content legitimately downloaded from the subsidiary content server  2 , other arrangements can be conceived. For example, a configuration may be conceived wherein encryption is decrypted beforehand at the point of the user terminal device  4  receiving and obtaining as a download, and is stored in the HDD  48  with the decryption result information attached thereto, and at the time of playing, the attached information of the decryption results is referred to, so as to make determination regarding whether or not to play the subsidiary content. Also, an arrangement may be made wherein a special code indicating that transmission has been made for downloading is embedded in the subsidiary content as processing at the subsidiary content server  2  side at the time of transmission from the subsidiary content server  2 , and at the time of playing, presence/absence of this code, and the content thereof and so forth is confirmed at the user terminal device  4  side, so as to determine whether or not to start playing. 
     As described so far, the content creating/sharing system according to the present embodiment realizes a basic usage form such as described with  FIG. 2 , for example. However, with a content creating/sharing system such as with the present embodiment, the number of subsidiary contents shared among users, i.e., the number of subsidiary content files which the subsidiary content server  2  stores and manages, can be massive. 
     Also, as described earlier, with the content creating/sharing system according to the present embodiment, even if there is no notification for introducing subsidiary contents from users who are friends, or the like, as described above, the download site of the subsidiary content serve can be accessed and desired subsidiary contents can be downloaded. 
     Taking such into consideration, it can be said that with the content creating/sharing system according to the present embodiment, how efficiently the user is going to be able to find suitable subsidiary contents from the massive number of subsidiary contents is important. 
     Accordingly, a configuration is proposed for the content creating/sharing system according to the present embodiment so to be able to efficiently select subsidiary contents suitable and appropriate for each user, and to be able to present these to the user. This will be described next. 
     Note that to “present subsidiary contents suitable and appropriate for each user” according to the present embodiment means to recommend subsidiary content which would have value for listening/viewing for that user. That is to say, the following description can be said to be regarding a configuration for recommending subsidiary contents suitable of the user for each user. Also, in light of this, we will also so refer to subsidiary contents selected as being suitable of a certain user as “recommended contents”. 
       FIG. 23  illustrates an example of operations and processing performed with the content creating/sharing system in relation to recommendation of subsidiary contents. 
     First, step S 801  is processing which the user terminal device  4  and user information server  8  execute regularly at predetermined timings. In this step S 801 , user profile information stored and managed in the HDD  48  is uploaded to the user information server  8  by the content managing/creating tool  101  of the content creating/sharing application  100  at the user terminal device  4 , for example. The user information server  8  registers the received user profile information newly in the user profile database  22   b  of it is new. Also, in the event that user profile information of the same user (user ID) has already been registered, the registered user profile information is rewritten (updated) with the received user profile information. 
     The user profile information is made up from predetermined information relating to an individual user using the content creating/sharing application  100 . A group of the user profile information makes up the user profile database  52   a  in the user information server  8 . 
       FIG. 24  shows an example of what is in the user profile information corresponding to one user. First, as shown in (a) in  FIG. 24 , the user profile information is made up of basic user information, held content list information, and an individual content information list. 
     The basic user information has predetermined information items indicating basic information about the user, starting with the user ID for example, and including name, age, and so on. The held content list information (held primary content information) is information presenting a list of primary contents which the user possesses, i.e., primary content files (held primary contents) deemed to be held under management of the content creating/sharing application  100  corresponding to the user. 
     Note that “held” or “possessed” as used here firstly refers to a state wherein a primary content file is stored and managed in a state where it can be viewed as being local as to the content creating/sharing application  100  (user terminal device  4 ), for example. Also, this implies a state wherein, even if not locally existing, but existing on a server or the like, the content file can be accessed and played by the content creating/sharing application  100  by streaming or the like, for example. Examples of such primary contents include those which can be streamed or downloaded from a server under a content viewing/listening contract such as a subscription, and locally saved. This can also be said to be contents which the user does not have to pay for separately at the time of starting playing, but rather which the user has the right to play. 
     For example, the held content list information is compiled as a list of content IDs of relevant primary content files, as shown in (b) in  FIG. 24 . Note that content IDs are identifiers unique to each content file. The number of content IDs stored in the held content list information corresponds to the number of primary content files which the user holds. Also, the content IDs themselves allow identification of what primary content files the user holds. 
     The individual content information list is, in this case, a compiled list of a group of individual content information corresponding to individual contents, as shown in (c) in  FIG. 24 . The individual content information is made up of metadata in the form of predetermined definition for each primary content file (held primary content) indicated by the held content list information. Here, metadata includes content ID, total number of times played, number of times played within time limit, rating, and so forth. 
     In the individual content information, the content ID stores a value serving as the content ID of the primary content file to which the individual content information corresponds. The content ID within the individual content information, and the held primary content in the hold content list information, correspond on a one-to-one basis. 
     The total number of times played indicates the number of times played so far under management of the content managing/creating tool  101 , for example. The number of times played within time limit indicates the number of times played under management of the content managing/creating tool  101  within a predetermined period from the current point-in-time, for example. For example, the number of times played within a time limit indicates which held primary contents have been played with a high frequency as of recent. In other words, this can be said to be information indicating the trend of the held primary contents which the user has recently played. 
     The rating stores a value of a rating which the user has given to the corresponding content (such as an indicator of how favorite, for example). For example, the content managing/creating tool  101  can set a rating according to a predetermined scale for each held primary content file and subsidiary content file, in accordance with user operations. 
     For example, the content managing/creating tool  101  stores and manages user profile information by the user profile managing processing unit  121 , and updates the held content list information in accordance with additions or deletions of held primary contents. Also, the total number of times played, the number of times played within time limit, and the rating, and so forth are updated in accordance with playing of held primary contents, setting of ratings, and so forth. 
     The content managing/creating tool  101  first uploads user profile information in accordance to step S 801  (transmission to the user information server  8 ) in the event of new registration of user profile information. Also, user profile information is uploaded at a suitable predetermined timing even after new registration is performed. Accordingly, the user profile information stored at the user terminal  4  side and the user profile information stored at the user information server  8  side are synched. 
     Also, the processing illustrated as step S 802  is processing which the subsidiary content server  2  performs independently, and continuously updates the content profile information as described below. 
     The subsidiary content server  2  stores and manages the content profile database  22   b  in the storage unit  22 . The content profile database  22   b  is a group of content profile information corresponding to each subsidiary content which has been databased.  FIG. 25  shows an example of content profile information. The content profile information shown in  FIG. 25  is made up of the information items of content ID, total number of downloads, total rating, total number of times played, and date-and-time of upload. 
     The content ID represents the value of a content ID provided to the subsidiary content corresponding to the present content profile information. 
     The total number of downloads indicates the number of times that the subsidiary content corresponding to the present content profile information has been downloaded. Alternatively, this may be the number of users who have downloaded the subsidiary content corresponding to the present content profile information. 
     As described earlier, the user ran set a rating for each subsidiary content file which the user has locally held, by operating the content managing/creating tool  101 . The total rating is a value reflecting the rating set for the subsidiary content corresponding to the present content profile information by the user who holds the subsidiary content. For example, one conceivable way to obtain the total rating is to total all of the ratings which the user has set regarding the subsidiary content corresponding to the present content profile information. Alternatively, an average value may be obtained. Another way would be to obtain with a predetermined computation expression, taking into consideration distribution of ratings for each user. 
     Also, in order to obtain the total rating, the subsidiary content server  2  has to obtain information of the rating which the user has set. To this end, an arrangement can be conceived wherein the content managing/creating tool  101  transmits information to the rating values locally set at a predetermined timing or opportunity to the subsidiary content server  2 , in a manner correlated with the subsidiary content (content ID). 
     Another conceivable technique is for the user terminal device  4  (content managing/creating tool  101 ) to create the held content list information and individual content list shown in  FIG. 24  to include not only that corresponding to the primary content files but also corresponding to the subsidiary content files, and manage as a user profile database  52   a  at the user information server  8 . With this arrangement, the subsidiary content user  2  transfers rating information of the subsidiary content extracted from the user profile information (information correlating the directly used content ID and rating) at a predetermined timing or opportunity from the user information server  8 . 
     The subsidiary content  2  can stream the subsidiary content file data to the client (user terminal device  4 ) side to be played, instead of transmitting the subsidiary content by downloading, for example. The total number of times played indicates the number of times that the data of the subsidiary content corresponding to the present content profile information has been streamed so that the contents are played at the client side, for example. 
     Now, these three, i.e., total number of downloads, total rating, and total number of times played, can be said to be total information relating to usage of subsidiary contents by the user, and accordingly can be collectively referred to as “total usage information”. 
     The date-and-time of upload indicates the date and time (yyyy/mm/dd/hh/mm, for example) that the subsidiary content file corresponding to the present content profile information has been uploaded. 
     In step S 802 , each time a directly used content download, streaming transmission, rating information acquisition, etc., is performed, for example, the subsidiary content server  2  updates the predetermined content profile information in the content profile database  22   b  in accordance with the results thereof. 
     The following operations and processing of steps S 803  through S 811  in  FIG. 23  are for presenting (recommending) recommended contents to the user side at the user terminal device  4 . First, to give an overview, with the present embodiment, we will assume the communication serve  3  has prepared a recommended content service side (hereafter referred to as “recommending site”) which is a Web site for presenting recommended contents. The communication tool  102  of the content creating/sharing application  100  at the user terminal device  4  obtains information regarding recommended contents by accessing the recommending site, and displays information of recommended contents by a visually-perceivable format to the user, for example. 
     In step S 803 , the communication tool  102  of the user terminal device  4  accesses the recommending site of the communication server  3 , and makes notification of user ID at the time of this access. Note that hereafter, a user corresponding to the user ID notified in this step S 803 , i.e., a user which can be viewed as having accessed recommended contents, will be referred to as “recommendation-receiving user”. 
     Upon having received the user ID transmitted form the user terminal device  4  in accordance with step S 803 , in step S 804  the communication server  3  transmits a recommended content list information request to the subsidiary content server  2 . At the time of transmission of this recommended content list information request, the user ID received from the user terminal device  4  in step S 803  is also notified (transmitted). 
     In step S 805 , the subsidiary content server  2  which has received the recommended content list information request notifies the user information server  8  of the user ID notified (transmitted) in step S 804 , and also transmits a user profile information request. Note that such transmission processing can be viewed as being realized by the control unit  21  controlling the network interface  29 , for example. 
     The user information server  8  which has received the user profile information request, first, in step S 806 , searches the user profile information corresponding to the user ID notified along with the user profile information request, from the user profile database  22   b . As shown in  FIG. 24 , the user profile information includes the user ID in the basic user information, for example. The searched user profile information is then returned to the subsidiary content server  2  as a response as to the recommended content list information request. 
     The subsidiary content server  2  receives the user profile information transmitted as described above with the network interface  29 , and the control unit  21  acquires it, for example. The subsidiary content server  2  which has received and obtained the user profile information then executes processing in step S 807  to extract (select) subsidiary contents from the subsidiary contents stored in the subsidiary content database  22   a , those to serve as recommended contents. Recommended content list information is made up of predetermined information regarding recommended contents is created in accordance with the extraction results. Note that the extraction processing of the recommended contents will be described later. 
     In step S 808 , the subsidiary content server  2  which has created the recommended content list information transmits the recommended content list information as a response to the recommended content list request in step S 804 . 
     In step S 809 , the communication server  3  uses the recommended content list information received in step S 808  to create a recommended content list page. The contents in the recommended content list page are page contents of the recommending site, and a page design suitable for presenting the user with recommended contents is used. The actual entity of the recommended content list page is a file or data or the like described in a predetermined markup language such as HTML (Hyper TextMarkupLanguage) or XML (eXtensible Markup Language) or the like. 
     The communication server  3  then in step S 810  transmits the data of the created recommended content list page to the user terminal device  4 , as a response to the access in step S 803 , for example. 
     The user terminal device  4  (communication tool  102 ) which has received the data of the recommended content list page in this way performs display of a Web page using the data of the received recommended content list page, as the processing of step S 811 . That is to say, the recommended content list page is displayed. 
     Now, the processing for extracting recommended contents in step S 807  in step S 23  will be described in detail. First, the basic concept of recommended content extraction according to the present embodiment will be described with reference to  FIG. 26 . 
     Looking at the Venn diagram here, the set A is a set which takes as components thereof all subsidiary contents stored in the subsidiary content server  2  as the subsidiary content database  22   a . The set B is a set which takes as components thereof, of the subsidiary contents belonging to set A (subsidiary contents stored at the subsidiary content  2 ), the subsidiary contents of which at least one of the primary contents used as source editing material (used source editing material contents) is a primary content held by the recommendation-receiving user. Further, the set C is a set which takes as components thereof, of the subsidiary contents belonging to set B, the subsidiary contents of which at all of the primary contents used as source editing material are primary contents held by the recommendation-receiving user. 
     With the present embodiment, an idea implemented is that, of the subsidiary contents stored in subsidiary content server  2 , those with as many held primary contents as source editing material as possible have the highest value of recommendation to the user of the held primary contents. 
     The reason is thus. The held primary contents of a recommendation-receiving user are most likely a collection made in accordance with the preferences and tastes of the user. This means that we can estimate that the more held primary contents a subsidiary content has as the source editing material contents thereof, the more interest the recommendation-receiving user will be likely to have in the subsidiary content, and the subsidiary content will also most likely match the tastes of the recommendation-receiving user. 
     Also, with the present embodiment, at the time of the user obtaining primary contents by downloading or the like, the user pays for the contents as a rule. Held primary contents are contents which the user has already obtained, so the more held primary contents included in a subsidiary content, the fewer primary contents the user has to purchase, meaning that the cost is lower for the user. 
     Accordingly, with the present embodiment, we will say that subsidiary contents using one or more held primary contents as the source editing material contents will be extracted (selected) as recommended contents. In correlation with  FIG. 26 , subsidiary contents belonging to set B (including set C) will be extracted as recommended contents. 
     On the other hand, we can estimate that as for subsidiary contents of the set A which are a complement to set B, i.e., subsidiary contents which do not use even one held primary content as source editing material content, the recommendation-receiving user will likely have little interest in the subsidiary content, and the subsidiary content will also likely not match the tastes of the recommendation-receiving user. Moreover, such subsidiary contents will cost the user more. 
     It should be noted that the basis for subsidiary contents to be extracted as recommended contents described above is only an example, and an arrangement may be conceived wherein subsidiary contents of which all source editing material contents are held primary contents, i.e., the subsidiary contents belonging to set C in  FIG. 26 , are extracted as recommended contents. Further, an arrangement may be conceived wherein subsidiary contents of which two or more source editing material contents are held primary contents are extracted as recommended contents. 
     Description will be made regarding a procedure example of the recommended content extracting processing which is step S 807  in  FIG. 23 , to be executed by the subsidiary content server  2 , with reference to  FIGS. 27 and 28 . This processing can be viewed as being executed by the recommended content extraction processing unit  25  in correlation with  FIG. 7 . Also, with the recommended content extracting processing in  FIGS. 27 and 28 , recommended contents are first extracted following basic selection standards regarding recommended contents described in  FIG. 26 , as will be understood from the following description. Thereupon, the order of recommendation values (recommendation order) is determined regarding the extracted recommended contents, based on several factors. 
     In  FIG. 27 , first, in step S 901 , held content list information (hereafter referred to as “held primary content information”) is obtained from the user profile information received and obtained in step S 806  in  FIG. 23  (hereafter referred to as recommendation-receiving user profile information”). 
     Now, it should be noted that the user profile information serving as the source for obtaining the held content list information in step S 901  above corresponds to the user of the user terminal device  4  (content creating/sharing application  100 ) which has accessed the recommendation site of the communication server  3  in step S 803  in  FIG. 23 , i.e., a recommendation-receiving user. Accordingly, the held content list information obtained in step S 901  is a list indicating primary content files (held primary content files) which the recommendation-receiving user holds. 
     In the following step S 902 , subsidiary contents including the primary contents indicated in the held content list information obtained in step S 901  as the source editing material thereof are searched from the subsidiary content database  22   a . This search can be made by referencing the used source editing material content information ( FIG. 16 ) for each subsidiary content in the subsidiary content database  22   a . A subsidiary content which has one or more primary content (content ID) shown in the used source editing material content information is a matching subsidiary content. The primary contents found matching the search conditions are the recommended contents according to the present embodiment. That is to say, step S 902  is processing for extracting recommended contents from all subsidiary contents stored and managed in the subsidiary content server  2 . Note that the n recommended contents searched (extracted) here are indicated by numbers 1 through n following a predetermined rule. 
     In step S 903 , processing is performed for setting a basic recommendation order based on the number of lacking contents, for each of the recommended contents 1 through n extracted in step S 902  above. Note that “lacking contents” refer to primary contents used for playing the subsidiary contents as recommended contents (i.e., source editing material contents) which are not shown in the held content list information obtained in step S 901 , i.e., primary contents which are not held primary contents of the recommendation-receiving user. 
     Also, the number of lacking contents can be said to represent how much the held primary contents are used in the primary contents serving as source editing material, i.e., the usage state. With the present embodiment, setting of the recommendation order of the recommended contents is performed with the usage state of held primary contents as the source editing material being the most important factor. This is because the usage state of held primary contents are in a close relation with the concept of extracting recommended contents according to the present embodiment, described with reference to  FIG. 26 . Accordingly, the recommendation order set based on the number of lacking contents is the most important and basic factor, and should be handled as a basic recommendation order. 
       FIG. 28  illustrates an example of procedures regarding setting of basic recommendation order in accordance with the number of lacking of contents, in step S 903  above. 
     First, in  FIG. 28 , in step S 1001  initialization is performed by substituting 1 into the variable n indicating the No. of recommended contents. 
     In step S 1002 , the subsidiary content database  22   a  is accessed, and file operations for opening the subsidiary content file which is the recommended content n is performed. This file opening operation is for reading out the used source editing material content information in the header information. Accordingly, in the event that an arrangement has been made with a subsidiary content database  22   a  structure wherein the used source editing material content information for each subsidiary content can be referred to even without opening the file, a processing for reading out the used source editing material content information of the subsidiary content which is the recommended content n may be performed instead of this file opening processing. 
     In step S 1003 , the source editing material contents which are the primary contents used in the recommended content n are identified by referring the used source editing material content information corresponding to the recommended content n. Note that the m identified source editing material contents are denoted by numerals 1 through m following a predetermined rule. 
     Steps S 1004  and S 1005  are initialization processing for steps S 1006  through S 1009 . In step S 1004 , 1 is substituted into the variable m indicating the No. of identified source editing material contents. In step S 1005 , 0 is substituted into the variable Fn representing the number of lacking contents for the recommended contents n. 
     In step S 1006 , determination is made regarding whether or not the source editing material content m is included in the primary contents indicated by the held content list information obtained in step S 901  in  FIG. 27 . In the event that a positive determination result is obtained here, the step s 1007  is skipped and the flow advances to step S 1008 . 
     Conversely, in the event that a negative determination result is obtained, the variable Fn is incremented in step S 1007  and the flow proceeds to step S 1008 . 
     In step S 1008 , determination is made regarding whether or not the current variable m has reached the maximum value or higher. The maximum value of the variable m is the number of source editing material contents identified in step S 1003 . 
     In the event that a negative result is obtained in step S 1008 , this means that there remain source editing material contents regarding which determination has to be made regarding whether or not included in the held content list information (held primary contents), so the variable m is incremented in step S 1009  and the flow returns to step S 1006 . Accordingly, determination is made in step S 1006  regarding the source editing material contents 1 through m, and in the event that a negative editing result is obtained here, the variable Fn is incremented. 
     As a result of determination being performed in step S 1006  regarding all source editing material contents 1 through m, a positive determination result is obtained in step S 1008 , and the flow proceeds to step S 1010 . In the event that a positive determination result is obtained in step S 1008 , this finalizes the number of lacking contents Fn regarding the recommended contents n. 
     In step S 1010 , determination is made regarding whether the variable n has reached the maximum value or higher. In the event that a negative determination result is obtained here, this means that there are recommended contents remaining regarding which the number of lacking contents has not yet been obtained. In this case, the variable n is incremented in step S 1011  and the flow returns to step S 1002 . Accordingly, the number of lacking contents is obtained for each of the recommended contents 1 through n. Upon the number of lacking contents having been obtained for all of the recommended contents 1 through n, a positive determination result is obtained in step S 1010 , and the flow advances to step S 1012 . 
     Upon reaching step S 1012 , the number of lacking contents F1 through Fn for the recommended contents 1 through n have already been obtained. Accordingly, in step S 1012 , a basic recommendation order is set among the recommended contents 1 through n, based on the number of lacking contents F1. Various ideas can be conceived regarding how to set this basic recommendation order, is description of specific examples will be omitted here. As a basic rule, subsidiary contents with fewer lacking contents are set with a higher recommendation order. 
     Note that with the processing in step S 903 , description has been made that the basic recommendation order is to be set based simply on the number of lacking contents, but an arrangement may be conceived wherein the percentage or ratio of lacking contents in the primary contents used as the source editing material in the subsidiary contents is set as the basic recommendation order. That is to say, it is sufficient with the present embodiment that the basic recommendation order be set based on the usage state of the held primary contents as source editing material, and specific algorithms thereof are not restricted to that in  FIG. 28 . 
     Returning to  FIG. 27 , with the present embodiment, the usage state of lacking contents in the source editing material contents should be the most important setting factor regarding setting of the recommendation order with the present embodiment, and the recommendation order set in this way is the basic recommendation order. However, with the present embodiment, an arrangement is made such that after setting the basic recommendation order, in the subsequent step S 904  and following steps, coefficients are set based on order setting factors other than the usage state (weighting factors), and these factors are used to obtain a final total recommendation order reflecting the other order setting factors as well. 
     After performing the processing in  FIG. 28  which is step S 903 , the processing of step S 904  in  FIG. 27  is performed. 
     The recommended contents according to the present embodiment include held primary contents of the recommendation-receiving user as source editing material. Accordingly, in step S 904 , processing is executed for obtaining individual content information regarding the held primary contents of the recommendation-receiving user to be used as source editing material contents, for each of the recommended contents 1 through n, from the recommendation-receiving user profile information. 
     In step S 905 , the coefficients B1 through Bn (first weighting coefficients) corresponding to each of the recommended contents 1 through n are obtained and set as factors for total recommendation order setting, based on what is in the individual content information obtained in step S 904 . 
     AS shown in (c) in  FIG. 24 , the individual content information includes the overall number of times played locally, number of times played within time limit, rating, and so forth, which can be viewed as indicating the evaluation of recommendation-receiving users regarding the primary contents. 
     That is to say, the greater the number of times played overall is, the more the user must like that primary content, and accordingly the higher the evaluation value thereof can be said to be. Also, the higher the number of times played within time limit is, the higher the evaluation of the content can be said to be particularly as of recent. Also, the higher the rating is, the higher the user can be said to be evaluating the primary content. A high user evaluation of a source editing material content in the recommended contents means that the order for recommendation to the user should be high as well. 
     In step S 905 , the coefficients B1 through Bn are obtained regarding the recommended contents 1 through n by algorithms or computation or the like, following predetermined rules, based on the above reasoning. The coefficients B1 through Bn set in steps S 905  and S 906  can be said to be based on content evaluation made by the recommendation-receiving user himself/herself. 
     The following steps S 906  and S 907  are processing for obtaining coefficients C1 through Cn which are factors for setting the recommendation order for each of the recommended contents 1 through n in accordance with the newness of the recommended contents. For example, it can be through that the newer the recommended contents are, the higher the value for recommendation to the recommendation-receiving user is, and the steps S 906  and S 907  follow this idea. 
     In step S 906 , the content profile database  22   b  is accessed, and information of the date-and-time of upload is obtained from the content profile information corresponding to each of the recommended contents 1 through n individually registered. That is to say, the date-and-time of upload is recognized for each subsidiary content serving as the recommended contents 1 through n. 
     In step S 907 , coefficients C1 through Cn (third weighting coefficient) are set for each of the recommended contents 1 through n, based on the information of the date-and-time of upload. The closer the date-and-time of upload is to the current date-and-time, the newer the subsidiary content is, so basically, the coefficients C1 through Cn are set such that the later the date-and-time of upload is, the higher the value is. For example, setting of the coefficients A1 through An according to generation related information  22   c  in step S 904  described earlier can be said to be representing the evaluation of subsidiary contents by “users in general who are creators”. 
     Steps S 908  and S 909  are processing for setting coefficients D1 through Dn as recommendation order setting factors, in accordance with the overall evaluation of subsidiary contents by users of the content creating/sharing system according to the present embodiment. 
     An arrangement may be conceived regarding setting of the recommendation order of subsidiary contents as recommended contents, in which the evaluation by the great number of users in general besides the recommendation-receiving user is factored in. For example, overall evaluation by the great number of users in general is a fair third-party opinion, as viewed from the recommendation-receiving user. Steps S 906  and S 907  follow the idea that taking the opinion of others into consideration in this way can yield a more accurate recommendation order. On the other hand, the coefficients B1 through Bn set in steps S 904  and S 905  can be said to be based on the evaluation of contents of the individual recommendation-receiving user. Either of these can be applied as effective factors to recommendation order setting. 
     In step S 908 , the content profile database  22   b  is accessed, and total usage information is obtained from the content profile information corresponding to each of the recommended contents 1 through n individually registered. Total usage information is information of the total number of downloads, total rating, and total number of times played, in the content profile information, as described earlier with reference to  FIG. 25 . Each of these can be viewed as being results of information representing overall evaluation made by users in general regarding the corresponding subsidiary contents. 
     Accordingly, in step S 909 , the coefficients D1 through Dn (second weighting coefficient) are obtained based on total usage information regarding the recommended contents 1 through n obtained in step S 909  by algorithms or computation or the like, following predetermined rules. In this case as well, we can say that the greater the total number of downloads, total rating, and total number of times played, the higher the subsidiary content is evaluated among the users, so basically, the higher the total number of downloads, total rating, and total number of times played are, the higher a coefficient value is set. Also, in this case, the three of the total number of downloads, total rating, and total number of times played, are used as total usage information, and an arrangement can be conceived wherein the coefficients D1 through Dn are set by weighting the three information items according to the importance and so forth thereof. Alternatively, independent coefficients may be set for each of the total number of downloads, total rating, and total number of times played. 
     In step S 910 , with the basic recommendation order set in step S 903  above as a starting point, the total recommendation order of the recommended contents 1 through n is set based on the coefficients B1 through Bn, C1 through Cn, and D1 through Dn, set in the procedures of steps S 904  through S 909 . 
     That is to say, points for example, are set for each basic recommendation order set in step S 902  earlier, so as to be in descending order, with the points decreasing following a predetermined rule. For example, with regard to a recommended content 1 for example, the points provided to the recommended content 1 in accordance with the above basic recommendation order and the coefficients B1, C, and D1 are computed, and a recommendation evaluation value V1 is obtained. The same is performed for the other recommended contents 2 through n, using the points provided to the respective recommended contents 2 through n, and the coefficients B2 through Bn, C2 through Cn, and D2 through Dn, so as to obtain recommendation evaluation values V2 through Vn. The total recommendation order is then set among the recommended contents 1 through n, based on the score of the recommendation evaluation values V1 through Vn. 
     At this time, for example, points to serve as a starting point for basic recommendation order are weighted heavier than the values of the coefficients. The coefficients then are used for weighting in accordance with importance and the like for each of the order setting factors (evaluation of recommendation-receiving users of the primary content which is a source editing material, the newness of the subsidiary content file, the evaluation of the subsidiary content file by users in general) serving as a basis for setting the coefficients, for example. Obtaining evaluation values using these points and coefficients enables a total recommendation order to be set by giving a basic recommendation order the greatest weight, but correcting the recommendation order taking into consideration other order setting factors. 
     Note that instead of setting the basic recommendation order in step s 903 , and arrangement may be made wherein points or coefficients are obtained which are equivalent to the basic recommendation order. Thereupon, the total recommendation order is finally set taking into consideration the coefficients B1 through Bn, C1 through Cn, and D1 through Dn, as well. 
     In step S 911 , recommended content list information showing the recommended contents 1 through n is created so as to reflect the total recommendation order set in step S 910 . 
     Now, as for the structure of the recommended content list information, an arrangement can be conceived wherein predetermined additional metadata for each recommended content is stored, for example. The metadata can be obtained by the header information of subsidiary content files which are recommended contents. Also, metadata which the content creating/sharing application  100  itself adds to the subsidiary contents and manages may also be used. 
     The recommended content list information created in such a way is transmitted from the subsidiary content server  2  to the communication server  3  in step S 808  in  FIG. 23 . The recommended content list information ultimately is displayed on the user terminal device  4  of the recommendation-receiving user in step S 811  in  FIG. 35 . That is to say, the recommendation-receiving user can visually confirm and comprehend the recommendation order of the recommended contents selected as suitable for himself/herself. 
     According to  FIGS. 27 and 28 , extraction processing of the recommended contents according to the present embodiment first involves selection of subsidiary content including held primary contents of the recommendation-receiving user as source editing material, as a prerequisite. Techniques for recommending contents include, for example, a widely-used one based on content evaluation by users in general (e.g., a hit chart or the like). Also, Japanese Unexamined Patent Application Publication 2004-72502 discloses a technique by which contents can be recommended based on title, keyword, genre, and so forth. 
     However, with such techniques according to the related art, accurately extracting contents matching the user for recommendation of recommended contents to the user may be difficult. For example, even if we set the evaluation of users in general, such as with a hit chart, as the extraction conditions, this does not mean that there will be primary contents included therein that the recommendation-receiving user holds. In considering the relation between subsidiary contents and primary contents, if a primary content which the recommendation-receiving user holds is not used as the source editing material, there is a high likelihood that the recommendation-receiving user will not be interested in that subsidiary content at all. In the same way, due to the nature of subsidiary contents being secondary creations using the primary contents as the source editing material, even if title, keyword, genre, and the like are set as extraction conditions, we still have the possibility that no primary contents which the recommendation-receiving user has are included in the extracted subsidiary contents. 
     Conversely, with an arrangement such as with the present embodiment, where subsidiary contents including primary contents held by the recommendation-receiving user are first selected as recommended contents, extraction and selection of contents suitable for recommendation can be performed in light of the nature of subsidiary contents being secondary creations using the primary contents as the source editing material. Also, the subsidiary contents selected as recommended contents are based on primary contents which the user holds, and accordingly will match the tastes of the individual user. 
     With this understanding, the basic recommendation order is first set according to the number of lacking contents (S 902 , S 903 ) with the present embodiment. This allows the user to efficiently narrow down the presented recommended contents are compared with a case wherein recommended contents are simply presented without any recommendation order set. 
     Also, with the present embodiment, the basic recommendation order is corrected and the total recommendation order is obtained at the end. Accordingly, the ultimately obtained recommendation order (total recommendation order) is higher in reliability, and allows the recommended contents to be narrowed down even more efficiently. 
     Also, at the time of correcting the basic recommendation order, evaluation by the recommendation-receiving user regarding the held primary contents used as source editing material (S 904 , S 905 ), newness of recommended contents (S 906 , S 907 ), and evaluation of subsidiary contents by users in general as an audience (S 908 , S 909 ), are used. This is an attempt to correct the recommendation order with factors of various aspects. Accordingly, a more accurate estimation order can be obtained as compared to a case of correcting the recommendation order with too much weight on a certain factor, for example. 
     However, correcting the basic recommendation order is not indispensable with the present embodiment. That is to say, the basic recommendation order set in step S 903  may be used as the total recommendation order as it is, without correction. In this case, the procedures of steps S 904  through S 910  are omitted. 
     Also, even in cases of correcting the basic recommendation order to obtain a total recommendation order, the coefficients B1 through Bn, coefficients C1 through Cn, and coefficients D1 through Dn do not all have to be used, and one may be sufficient. Also, other coefficients obtained using conditions which can be used to correct the recommendation order may be applied besides the coefficients B1 through Bn, coefficients C1 through Cn, and coefficients D1 through Dn. 
     Now, according to the example described above with reference to  FIGS. 23 through 28 , the user profile information of the recommendation-receiving user is used to extract a recommended content list and create recommended content list information at the subsidiary content server  2 . Thereupon, the subsidiary content server  2  obtains user profile information from the user information server  8 . 
     However, a system operation may be realized wherein the content creating/sharing application  100  transmits user profile information of the corresponding user and also requests recommended content information. In the case of such a configuration, an arrangement may be made wherein, in the same way as the example described above, the content creating/sharing application  100  of the user terminal device  4  accesses the recommending site of the communication server  3 , and transmits user profile information instead of user ID at this time. In this case, the subsidiary content server  2  just has to extract the recommended contents using the user profile information transferred from the communication server  3 , and create the recommended content list information. 
     Alternatively, an arrangement may be made wherein the content creating/sharing application  100  of the user terminal device  4  makes a request to the subsidiary content server  2  for the recommended content list information by directly transmitting user profile information thereto. In any case, if user profile information is to be transmitted from the user terminal device  4  for obtaining recommended content list information, user profile information does not have to be sent from the user information server  8 . However, in actual practice, the user information server  8  is provided to centrally manage user profile information of all users, enabling various services which are valuable to user to be provided besides recommendation of contents for example, and user management at the system operating side, so the usefulness thereof is not lost. 
     Also, with the processing for recommending subsidiary contents described with reference to  FIGS. 23 through 28 , extraction of recommended contents and setting of recommendation order are performed based on the user profile information of the recommendation-receiving user, thereby creating the recommended content list. The user profile information can be viewed as metadata regarding each held primary content, for example. Also, the recommended content list is made up of metadata of recommended contents, as described earlier. That is to say, we can say that processing for recommending subsidiary contents according to the present embodiment uses metadata as a key for extracting recommended contents, and also returns the extraction results in metadata relating to recommended contents. 
     Now, the basic idea for the above-described recommended content extracting is that “the greater the number, percentage, or ratio, of primary contents held by the recommendation-receiving user, in a subsidiary content is, the higher the value of that subsidiary content is to the recommendation-receiving user”. As an application of this idea, an arrangement may be made with the content creating/sharing system according to the present embodiment wherein a user (creator) which has created a subsidiary content can tell, when the subsidiary content is uploaded and is ready for distribution, how may users will view/listen to the subsidiary content, for example. The configuration for this will be described next. Note that in the following description, users which may view/listen to the created subsidiary content will be referred to as “potential audience users”. 
       FIG. 29  illustrates an example of operations of the system enabling information regarding potential audience users to be obtained by the creator of the subsidiary content. First, the creator operates the content managing/creating tool  101  to specify, of the subsidiary contents created by himself/herself and locally held at the user terminal device  4 , a subsidiary content regarding which the creator desires to obtain information of potential audience users. An operation for requesting information of potential audience users regarding the specified subsidiary content is then executed. In step s 1101 , in response to this operation, a potential audience user information request is transmitted from the user terminal device  4  (content managing/creating tool  101 ) to the user information server. 
     At the user information server  8  which has received the potential audience user information request, potential audience user information is created in step S 1102 . An example of procedures for the potential audience user information creating processing in step S 1102  is shown in  FIG. 30 . 
     In  FIG. 30 , first, in step S 1201 , source editing material contents 1 through n are identified from the used source editing material content information stored in the header information received along with the potential audience user information request. This identifying processing can be performed in actual practice by obtaining the content IDs of primary contents serving as the source editing material contents, from the used source editing material content information, for example. 
     In step S 1202 , initialization is performed wherein 1 is substituted into the variable n representing the No. of the source editing material contents identified by step S 1201  (and No. of user group G). 
     In step S 1203 , a user holding a source editing material content 1 is searched from a user group Gn−1. A set of users thus searched will be recognized as a user group Gn. Note that in the event that the variable n=1, the user group Gn−1 is G0. Here, the user group G0 is stipulated as a group made up of all users registered in the user profile database  52   a  of the user information server  8 . 
     Accordingly, in step S 1203  which is the first step executed after step S 1201 , users holding the source editing material content 1 are searched from all registered users, and a user group thus searched is set as a user group G1. 
     Also, the searching in step S 1203  is performed by searching for a content ID the same as that of the source editing material content n. Thus, the found user profile information matches the users holding the source editing material content 1. 
     Upon executing the searching processing of user group Gn in step S 1203 , in step S 1204  determination is made regarding whether or not the current variable n has reached the maximum value or higher. In the event that a negative determination result is obtained here, this means that there are yet remaining source editing material contents to be used for searching of the user group Gn. In this case, in step S 1205  the variable n is incremented, and the flow is returned to step S 1203 . 
     Thus, the search for the user group Gn is performed sequentially for each of the source editing material contents 1 through n identified in step S 1201 , which can be viewed as being a processing sequence for narrowing down user groups holding all of the source editing material contents 1 through n. 
     Upon the search of the user group Gn for all of the source editing material contents 1 through n ending in step S 1203 , a positive determination result is obtained in step S 1204 , and the flow proceeds to step S 1206 . At the stage of reaching step S 1206 , a user group Gn which is made up of only of users holding all of the primary contents which are the source editing material contents 1 through n identified in step S 1201 . 
     Thus, users holding all of the primary contents which the subsidiary content uses as the source editing material will have a high likelihood of the subsidiary content matching the tastes thereof. Accordingly, once the subsidiary content is uploaded, it can be said that these uses will very likely download and view/listen to the subsidiary content. Based on this, with the present embodiment, all users holding the primary contents which are the source editing material contents 1 through n are handled as potential audience users. That is to say, everyone in the user group Gn ultimately searched is a potential audience user. In other words, the processing of steps S 1201  through S 1204  is processing for searching for potential audience users from the users registered in the user profile database  52   a.    
     In step S 1206 , potential audience user information is crated using the final search results of the user group Gn. A simplest form of the subsidiary content information which can be conceived is to show the number of potential audience users. Additionally, information such as the total number of times played, number of times played within a time limit, rating, and so on, in the user profile information, may be reflected therein. That is to say, information can be added regarding how often the potential audience users play the source editing material contents 1 through n, and how they are rating them. 
     Returning to  FIG. 29 , in step S 1103 , the potential audience user information created based on the results obtained by the processing in  FIG. 30  is transmitted from the user information server  8  to the requesting user terminal device  4 . 
     In step S 1104 , at the user terminal device  4 , the content managing/creating tool  101  performs control to use the received potential audience user information so as to present information relating to potential audience users. 
     The user, which is the creator, can view the information relating to potential audience users which is displayed, and use it as reference for creating subsidiary contents. As one example, let us say that the number of potential audience users is very small. Since the creator wants as many users as possible to view/listen to the subsidiary content, the creator may decide to remake the subsidiary content by not using primary contents used as source editing material of the subsidiary content held by few users. 
     Note that the processing illustrated exemplarily in  FIG. 30  shows only used source editing material content information being used in the header information received by the user information terminal  8 . Accordingly, in this case, an arrangement may be made regarding step S 1101  in  FIG. 29  wherein not all header information is transmitted as metadata, but only metadata made up of the used source editing material content information, which is one part thereof, is transmitted. 
     Also, as described earlier, the processing for subsidiary content recommendation described with reference to  FIGS. 23 through 28  for example, is understood to be “using metadata of a primary content (held primary content) as a key for extracting recommended contents, and returning the extracting results thereof as metadata relating to the subsidiary contents which are recommended contents, as well”. 
     Based on this, with the present embodiment, a system configuration can be conceived wherein metadata not restricted to user profiles can be used as a key for extracting recommended contents, and the recommended contents to be extracted are not restricted to subsidiary contents and can include primary contents as well. 
     For reference, an extended configuration for content recommendation will be described with reference to the sequence diagram in  FIG. 31 . Note that in the description of  FIG. 31 , the communication server  3  provides recommended sites for both primary contents and subsidiary contents. In  FIG. 31 , the steps S 1301  and S 1302  are the same as the steps S 801  and S 802  in  FIG. 23 , and accordingly description thereof will be omitted. 
     Step S 1303  is a procedure for the communication tool  102  of the user terminal device  4  to access the recommendation site of the communication server  3 . Accessing the recommendation site involves notifying the user ID of the recommendation-receiving user, in the same way as with step S 803  in  FIG. 23 . 
     The recommended site in the extended example may be a site corresponding to primary contents and a site corresponding to subsidiary contents which are independently with different URLs, or may be configured as an integrated site corresponding to both primary contents and subsidiary contents. 
     In the case of the extended example, the recommendation-receiving user can select desired contents presented at the accessed recommended site in step S 1303 . The user can select one of the contents for example, and perform an operation for receiving presentation of recommended contents relating to the selected content (recommendation source content), i.e., an operation for a recommended content request. 
     In response to this recommended content request operation, the communication server  3  transmits a recommended content list information request to the primary content server  1  or the subsidiary content server  2  in step S 1304 . Note that in the event that the recommendation source content is a primary content, in the processing of step S 1304  the communication server  3  transmits the recommended content list information request to the primary content server  1 . On the other hand, in the event that the recommendation source content is a subsidiary content, the communication server  3  transmits the recommended content list information request to the subsidiary content server  2 . 
     In the case of this extended example, at the time of transmission of the recommended content list information request, one metadata for example is selected from the metadata added to the recommendation source content and transmitted as a recommended content extracting key, along with the user ID of the recommendation-receiving user. 
     While several ideas can be conceived on how to select metadata to serve as the key for the recommended content extracting, one example is to display a list of metadata (keywords) added to a content on the recommendation site, and then have the recommendation-receiving user to select a metadata therefrom so as to serve as a key for the recommended contents extracting. 
     The primary content server  1  or subsidiary content server  2  which has received the recommended content list information request in step S 1304  transmits a user profile information request to the user information server  8  in step S 1305 . This step S 1305  is similar to step S 805  in  FIG. 23 . The user information server  8  searches the user profile information in step S 1306  in response to reception of the user profile information request, and returns this to the primary content server  1  or the subsidiary content server  2 . 
     The primary content server  1  or the subsidiary content server  2  which has received the user profile information in this way performs processing for extracting recommended contents in step S 1307 . 
     In this processing, in the case of the primary content server  1  for example, the primary content server  1  searches for primary contents stored in the primary content database  12   a  that match, or have a certain similarity or higher to, the metadata received in step S 1302 . 
     For example, if we say that the keyword in the metadata is “ocean”, primary contents having “ocean” as the metadata are selected, and further, primary contents having similar words, such as “seaside”, “marine”, and so forth, can also be extracted. 
     Thereupon, the primary content server  1  performs recommendation order setting processing regarding the primary contents searched above with the metadata as the search key. While several ways can be conceived for this processing, one example is to use the user profile information obtained in step S 1306 , for example. 
     An example of recommendation order setting of primary contents, which uses user profile information, will be described. The user profile information of a recommendation-receiving user shows the held primary contents thereof. Accordingly, the primary content server  1  extracts the metadata attached to these held primary contents in the primary content database  12   a , analyzes the metadata, and recognizes the preferences of the recommendation-receiving user. 
     One example is to use genre metadata, wherein the order of genres in held primary contents is obtained as the result of analyzing genres for each held primary content. The above-described example had primary contents with metadata relating to “ocean” being extracted from various genres, meaning that the contents are extracted regardless of genre. Here, primary contents extracted as having metadata relating to “ocean” can have the genre of the held primary contents reflected in the order thereof, thereby setting a recommendation order. 
     Also, in the case of the subsidiary content server  2  performing the extracting processing of recommended contents as step S 1307 , this can following the example described in step S 807  in  FIG. 23 . Also, metadata such as keywords, genre, etc., added to the subsidiary content, may be aggressively used as with the case of the above-described primary content. 
     The following steps S 1308  through S 1311  are similar to steps S 808  through S 811 , and accordingly description thereof will be omitted here. 
     Note that multiple keywords (search keys) which are metadata may be transmitted at the time of requesting the recommended content list in step S 1304 . In this case, in step S 1307 , the content searching processing can be performed for extracting recommended contents by fitting the multiple metadata into appropriate conditional expressions. 
     Also, the configuration of the primary content server  1 , subsidiary content server  2 , communication server  3 , user information server  8 , and user terminal device  4  are but one example, and may actually be changed as appropriate. Also, a configuration may be made wherein at least one of the above servers is dispersed among multiple server, or conversely, where at least two or more of these servers are integrated. 
     The elements of the invention according to the embodiment of the present invention may be included in the subsidiary content server  2  in correspondence with the present embodiment, but other arrangements may be made wherein components corresponding to the elements of the invention are dispersed in other servers as appropriate, and the configuration of an information processing device according to the present invention is realized by cooperation with these servers. 
     Also, while no specific example of a GUI screen or the like has been shown for the content creating/sharing application  100  has been described so forth, various GUI configurations can be conceived for the content creating/sharing application  100 . 
     Also, the functional configuration of the content creating/sharing application  100  also is not restricted to that described with reference to  FIGS. 11 and 12 , and so forth, and various configurations can be conceived. 
     Also, the structure of the subsidiary content files shown in  FIGS. 13A through 17  is only an example, and a conceptual one at that, so various modifications and developments therefrom may be made based thereupon. 
     Also, the processing procedures shown in the flowcharts, i.e., program configurations, are only examples, and may be changed as appropriate in actual practice. 
     Also, the programs executed by the primary content server  1 , subsidiary content server  2 , communication server  3 , user information server  8 , and user terminal device  4 , may be written to and stored in a storage region such as an internal HDD, storage unit, or the like, as described above, or may be stored in a removable storage medium and installed (including updates) from the storage medium to the storage region. Also, an arrangement may be conceived wherein programs can be installed under the control of other host devices via a predetermined data interface. Further, an arrangement may be conceived wherein programs are stored on a storage device on the network, and can be downloaded and obtained from the storage device by the networking functions of the primary content server  1 , subsidiary content server  2 , communication server  3 , user information server  8 , and user terminal device  4 . 
     The present application contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2008-146009 filed in the Japan Patent Office on Jun. 3, 2008, the entire content of which is hereby incorporated by reference. 
     It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.