Patent Publication Number: US-2010124405-A1

Title: Playback apparatus for stored content and playback method for stored content

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2008-294674, filed on Nov. 18, 2008, the entire contents of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     This invention relates to a playback apparatus for a stored content and a playback method for a stored content to playback the content such as video/audio content used for a broadcast program from a storage medium such as a hard disk drive. 
     DESCRIPTION OF THE BACKGROUND 
     In a broadcast of a program, it is general to playback a program recorded in a storage medium from a broadcasting start point, and it is necessary to cue the storage medium at the broadcasting start point of the program (hereinafter called as “cue up”) before broadcasting. In the case that a plurality of programs are recorded in one storage medium, the broadcasting start point is provided for each program, and the storage medium is automatically stopped at the broadcasting start point of the next program when the program is broadcasted (playbacked). By this, the playback apparatus can cue up to the broadcasting start point of the next program. 
     Conventionally, a magnetic tape has been generally used to record the program. The magnetic tape has a characteristic that a few seconds are required to actually stop after outputting a stop instruction. For this reason, in order to automatically stop the magnetic tape at the broadcasting start point of the program, it was necessary to record the data called as a stop code for a few frames at a few seconds before the broadcasting start point of the program. When the playback apparatus discriminates the stop code during the playback of the magnetic tape, the playback apparatus starts to perform the stop operation of the magnetic tape and automatically stops the magnetic tape at the few frames after discriminating the stop code, that is, at the broadcasting start point of the program. 
     As shown in  FIG. 4 , a conventional playback apparatus  2  using a magnetic tape is provided with a medium unit  21 , a playback unit  22  and a control unit  23 . In order to realize to stop automatically the magnetic tape at a broadcasting start point of the program, the playback apparatus  2  is further provided with an external apparatus  3 . A detection unit  31  recognizes a stop code from the data playbacked by the playback unit  22  and controls to stop playback unit  2 . For this reason, the conventional playback apparatus  2  can not recognize the stop code without using the external apparatus  3 . 
     In addition, as the magnetic tape is a storage media in which random access is impossible, in order to recognize the stop code, the playback apparatus needs the playback operation of the magnetic tape to search the stop code. In the case that the present playback position is distant from the position where the stop code is recorded, a lot of time is required to cue up. 
     As a prior art relating to this kind of playback apparatus, Patent Document 1 shows the construction to share the data by associating the control data with the video data via an absolute time. In addition, Patent Document 2 shows the construction which associates and records the content and the metadata. However, the playback apparatuses described in these Patent Documents 1 and 2 do not relate to stopping the content or cuing up. 
     [Patent Document 1] JP, P2007-235668A 
     [Patent Document 2] JP, P2001-216726A 
     As described above, as the conventional playback apparatus for the stored content uses the magnetic tape as the storage medium, in order to recognize the stop code, the playback operation of the magnetic tape for searching the stop code is required. In addition, in the case that the present playback position is distant from the position where the stop code is written, a lot of time is required to cue up. 
     SUMMARY OF THE INVENTION 
     An object of the invention is to provide a playback apparatus for a stored content and a playback method for a stored content which can automatically perform the stop processing for one or a plurality of content data stored in a storage medium without recognizing a stop code by playbacking the storage medium. 
     A playback apparatus for a stored content according to the invention include a storage medium to store a content data of a frame structure; a stop code memory unit to store a stop code so as to stop playbacking the content data at an arbitrary position; a discrimination unit to discriminate a stop position for the content data based on the stop code obtained from the stop code memory unit when the content data is playbacked from the storage medium; and a stop control unit to stop playbacking the content data during the playback based on a discrimination result by the discrimination unit. 
     A playback method for a stored content to playback a content data from a storage medium which stores the content data of a frame structure according to a playback instruction, according to the invention includes a step to store a stop code for stopping playbacking the content data at an arbitrary position in a stop code memory unit; a step to obtain the stop code from the stop code memory unit and to discriminate a stop position for the playback of the content data when the content data is playbacked from the storage medium; and a step to stop the playback of the content date based on the discrimination result of the stop position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a playback apparatus for a stored content according to an embodiment of the present invention. 
         FIG. 2  is a flow chart showing a playback control procedure of a control unit in the embodiment. 
         FIG. 3  is a timing chart in the case of playbacking the content data in the playback apparatus for the stored content of the embodiment. 
         FIG. 4  is a block diagram showing a conventional playback apparatus using a magnetic tape and an external apparatus. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Hereinafter, embodiments of this invention will be described with reference to the drawings. In  FIG. 1 , a playback apparatus  1  for a storage content is a tape-less playback apparatus. The playback apparatus  1  is provided with a medium unit  11 , a playback unit  12  and a control unit  13 . The medium unit  11  is provided with storage medium  11 A capable of random accessing, such as a HDD (Hard Disk Drive), and a medium control unit  11 B. In addition, the control unit  13  is provided with a CPU (Central Processing Unit)  14  and a memory  15 , and a program for executing each processing is stored in the memory  15 . Each of the processing functions executed by the program is described in  FIG. 1  as a content transfer control unit  16 A, a metadata transfer control unit  16 B, a playback control unit  16 C, a stop control unit (a stop code control unit)  16 D and a discrimination unit  16 E. In addition, an operating input terminal (not shown), such as a key board and a mouse, is connected to the control unit  13 . 
     The storage medium  11 A in the medium unit  11  preliminarily stores a plurality of video content data which are encoded by compressing the program to be broadcasted. The content data has a frame structure. According to the content transfer control given from the content transfer control unit  16 A, the medium control unit  11 B reads out the designated content data from the storage medium  11 A by a predetermined transfer unit and sends the read out content data to the playback unit  12 . A playback mode of the playback unit  12  is designated by the playback control preliminarily given from the playback control unit  16 C. The playback control designates the playback mode, such as, an ordinary playback, a slow playback, a double speed playback and a reverse playback. The playback unit  12  decodes the inputted content data, playbacks the content in a designated playback mode and outputs a playback signal from the playback apparatus  1 . 
     In addition, the storage medium  11 A stores the non-compression coded content relevant information (hereinafter, called as “metadata”) differently from the content data. The metadata includes an identification code (ID), a format information, the number of the audio channels, a stop code and so on. The stop code includes an information of a stop position to stop playbacking the content data, and the stop position is represented by a frame number of the content data, for example. The stop code is inputted by the operating input terminal connected to the control unit  13  while editing the content data, and is stored in the storage medium  11 A. In addition, in the case that the storage medium  11 A is removable from a main body of the playback apparatus  1 , the storage medium  11 A in which the content data and the metadata including the stop code are preliminarily stored by other apparatus may be loaded in the playback apparatus  1 . In addition, an offset value for displacing the stop position may be added to the stop code. 
     Hereinafter, a playback processing of the content data by using the stop code will be described. 
     A plurality of content data of the programs are stored in the storage medium  11 A. The control unit  13  controls such that these plurality of content data are read out in a preliminary determined order and the read out content data are transferred to the playback unit  12 . 
     In the case of playbacking the content data, the metadata transfer control unit  16 B executes the metadata transfer control to the medium unit  11 , and obtains the metadata including the stop code from the medium unit  11 . The discrimination unit  16 E analyzes the metadata to take out the stop code and discriminates the ID of the content data and the frame number of the stop position of the content data. 
     When the discrimination unit  16 E discriminates the ID of the content data and the stop position of the content data, the content transfer control unit  16 A executes the content transfer control to the medium unit  11 , and in addition, discriminates whether or not the data to be transferred includes the frame data of the stop position. In the case that the data to be transferred includes the data of the stop position, the stop control unit  16 D executes the stop control to playback unit  12  so as to stop playbacking at the frame of the stop position. In the case that the data to be transferred does not include the data of the stop position, stop control unit  16 D does not execute the stop control to the playback unit  12 . 
     In the content transfer control, the ID of the content data and the range of the data to be transferred are designated, and transferring of the data by a predetermined transfer unit is indicated to the medium unit  11 . The medium unit  11  reads out the designated data from the storage medium  11 A, and transmits the read out designated data to the playback unit  12 . The playback unit  12  decodes the content data transmitted from the medium unit  11  to playback, however, the playback unit  12  stops the playback at the frame of the designated stop position when the playback unit  12  receives the stop control. In addition, in the case that the data to be transferred includes the data of the stop position, as the playback is stopped at the predetermined stop position, the subsequent content transfer control is not executed. 
     On the other hand, in the case that the data to be transferred does not include the data of the stop position, the next content transfer control is subsequently executed. The content transfer control unit  16 A executes the content transfer control to the medium unit  11  for the next data, and in addition, discriminates whether or not the data to be transferred includes the data of the stop position. Subsequently, the same operation as described above is repeated to playback the content data. 
     As described above, the playback unit  12  stops the playback at the frame of the designated stop position during playbacking the content data transferred from the medium unit  11 . In addition, content transfer control unit  16 A stops the content transfer control at the position where the content transfer control for the data of the transfer unit including the data of the stop position is executed. By this, the automatic stop of the playback of the program content (the cue up for the next program) is executed. 
     In addition, a function which is realized with the magnetic tape playback apparatus and playbacks further the content data by a few frames after entering in the stop operation can be realized by adding an offset value to the stop code information. That is, the frame number which is displaced by only the offset value from the frame number designated by the stop code is treated as the stop position, and the content transfer control and the stop control are executed. Thereby, the content data can be further playbacked by the offset value, and then the playback can be stopped. In this case, it is necessary for the stop code to record the frame number of the data before only the number of the offset frames from the broadcasting start point of the program, as the stop position. 
       FIG. 2  is a flow chart showing a playback control procedure of control unit  13 . 
     First, control unit  13  judges whether a playback instruction input is given from the operating input terminal (step ST 3   a ). In the case that the playback instruction is given, the control unit  13  executes the metadata transfer control to the medium unit  11 . And, the control unit  13  obtains metadata from medium unit  11  (step ST 3   b ). The control unit  13  analyzes the metadata, extracts the stop code included in the metadata, and discriminates the stop position to stop playbacking the content data. 
     Next, the control unit  13  judges whether or not the offset value is added to the stop code information (step ST 3   d ). In the case that the offset value is added, the control unit  13  judges that a position that is behind only the offset value from the stop position shown by the stop code is the stop position to stop the playbacking. 
     After the stop position is discriminated, the above-described content transfer control to the medium unit  11  and the above-described stop control to the playback unit  12  are executed. By this, the content data is read out from storage medium  11 A and is playbacked in the playback unit  12 . In addition, in the playback unit  12 , the playback is stopped at the predetermined stop position. In the case that the offset value is not added to the stop code, the playback stops at the stop position designated by the stop code (step ST 3   f ). 
     In the case that the offset value is added to the stop code, the content transfer control and the stop control are executed by assuming that the position added by the offset value is the stop position. By this, the playback is stopped at the position elapsed by the frames designated by the offset value from the stop position designated by the stop code (step ST 3   e ). As shown in  FIG. 3 , the playback unit  12  stops the playback of the content data at the position elapsed by the offset value (in  FIG. 3 , three frames) from the stop position designated by the stop code. 
     According to the above-described construction, the playback apparatus  1  stores the stop code in the storage medium  11 A as the metadata differently from the content data. As the playback apparatus  1  uses storage medium capable of random accessing and uses the stop code obtained from the metadata independent from the present stop position, the playback apparatus  1  can cue up or move to the broadcasting start point of the program by only random accessing the frame designated by the stop code, without playbacking the content data. 
     That is, the control unit  13  obtains the metadata from the storage medium  11 A and discriminates the stop position for the playback at the discrimination unit  16 E. Content transfer control unit  16 A makes the medium unit  11  read out the content data of the predetermined transfer unit including the data of the stop position from the storage medium  11 A by random accessing the storage medium  11 A and transfer the read out content data to the playback unit  12 . The playback unit  12  stops the playback at the prescribed position based on the stop control. As the content data of the transfer unit to be transferred includes the data of the stop position, the content transfer control unit  16 A does not execute the content transfer control after this content transfer control, but stops reading out the content data from the storage medium  11 A. By this, to cue up or to move to the broadcasting start point of the program can be executed and to read out and to playback the content data from the storage medium is stopped at the position. 
     Therefore, since the playback apparatus  1  can recognize the stop code without playbacking the content data unlike the playback apparatus using the magnetic tape, to cue up or to move to the broadcasting start point of the program can be executed in a short time. 
     In addition, by giving the offset value to the stop code as a parameter, the tape-less playback apparatus  1  can execute the operation of stopping the playback at the position where only a number of the frames designated by the offset value were playbacked, after playbacking the frames of the content data designated by the stop code. 
     The above-described embodiment explains the example which adds the offset value to the stop code information. But, the offset value is not necessary to be store preliminarily in the storage medium  11 A as the metadata by addition to the stop code information. When the content data is playbacked, the offset value may be inputted to the control unit  13  from the operating input terminal and the control unit  13  may hold the offset value in the memory  15 , for example. In this case, the control unit  13  acquires the frame number which shows the stop position designated by the stop code information included in the metadata from the medium unit  11 , and the control unit  13  adds the frame number designated by the stop code information and the offset value. Then the control section  13  executes the stop control using the added frame number as a stop position. By this, even in the case that the storage medium  11 A which stores the content data and the stop code to which the offset value is not added is loaded to the playback apparatus  1 , the offset value can be added at the time of the playback without editing the metadata. 
     Other embodiments or modifications of the present invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and example embodiments be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following.