Patent Publication Number: US-11659062-B2

Title: Remote access of media items

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/250,455, filed on Aug. 29, 2016, entitled “Remote Access of Media Items”, which in turn is a continuation of U.S. patent application Ser. No. 14/796,713, filed on Jul. 10, 2015, entitled “Remote Access of Media Items,” which in turn is a continuation of U.S. patent application Ser. No. 13/895,010, filed on May 15, 2013, entitled “Remote Access of Media Items,” which in turn is a continuation of U.S. patent application Ser. No. 11/701,823, filed Feb. 2, 2007, entitled “Remote Access of Media Items” all of which are hereby incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to the access of media items and, more particularly, to the remote access of media data associated with media items. 
     Description of the Related Art 
     Many users purchase media items such as songs or movies online and store them on a network device such as a personal computer. However, users often own and use multiple devices. For instance, many users own portable electronic devices that they use to play media items, which may be referred to as “media players.” 
     A media player can store media items, such as audio tracks, that can be played or displayed on the media player. One example of a portable media player is the iPod® media player, which is available from Apple Computer, Inc. of Cupertino, Calif. Often, a media player acquires its media items from a host computer that enables a users to manage media their items. In managing media items, a user can create playlists for audio tracks. These playlists can be created at the host computer. Media items identified within the play lists can then be copied to the media player. More particularly, media items are typically downloaded from a host computer when the media player is physically connected to the host computer by way of cable (e.g., a USB cable). 
     Unfortunately, downloading media items from a host computer to a media player can be a time-consuming process. As a result, many users find themselves without the media items they would like on their portable devices. 
     In view of the above, it would be desirable if the desired media items could be accessed via an electronic device such as a portable electronic device without requiring the user to download all of the media items onto the electronic device when the media player is physically connected to the host computer. 
     SUMMARY OF THE INVENTION 
     The invention pertains to methods and systems that facilitate data delivery to electronic devices such as, for example, media players. In one embodiment, media item metadata associated with a plurality of media items can be obtained from a second network device and stored on a first network device. In addition, media item content data associated with a first subset of the plurality of media items can be obtained from the second network device and stored on the first network device. In this manner, media item metadata associated with a second subset of the plurality of media items can be stored on the first network device. The second subset of media items may be referred to as “virtual media items.” 
     In accordance with another embodiment, information identifying the virtual media items can be displayed for selection by the user via the first network device. As a result, the user perceives that the virtual media items may be available on the first network device. In this manner, the virtual capacity of an electronic device may be increased. 
     In accordance with another embodiment, a graphical user interface can display a listing of a media library on an electronic device such as, for example, a mobile network device. The listing can include each of a plurality of media items in the media library. However, the electronic device may only store media content associated with a subset of the plurality of media items in the media library. 
     In accordance with yet another embodiment, one or both of the network devices can be a portable device such as a media player. Thus, media item content data associated with the virtual media items can be accessed and downloaded remotely. Similarly, a virtual media item can be played remotely. 
     In accordance with yet another embodiment, the electronic devices and network devices can be coupled to one another via a communications link that may use a network such as a wired or wireless local area network (LAN), wide area network (WAN), or a cellular network. In accordance with one embodiment, in order to enable the network devices to retrieve media item content data from one another, the network devices remain on and connected to the network. For instance, a personal computer can be turned on and connected to the Internet to enable a portable device to access the media items stored on the personal computer. 
     In accordance with yet another embodiment, when a media item is played, the corresponding media item content data can be deleted from the network device. Media item content data of another media item can then be retrieved and downloaded in the memory that has been released. 
     In accordance with another embodiment of the invention, it is possible that the media items that are available from the second network device can change over time. More particularly, a media item stored on the second network device can be deleted from the second network device. Similarly, a new media item can be stored on the second network device. The second network device can then send a notification to the first network device, where the notification indicates that a media item has been deleted from the second network device or stored on the second network device. The first network device can then store metadata associated with a newly added media item or delete metadata associated with a deleted media item (e.g., where the corresponding media item content data is not already stored locally). 
     In accordance with another embodiment, a computer-implemented method for managing a mobile media library on a mobile network device includes (a) determining whether the mobile network device has access to a media repository via a network; (b) determining whether the mobile media library is to be updated; (c) determining update data to be provided to the mobile media library; (d) acquiring the update data from the media repository via the network; and (e) storing the acquired update date to the mobile media library on the mobile network device, wherein the determining (c), acquiring (d) and storing (e) steps are performed when determining (a) determines that the mobile network device has access to the media repository and determining (b) determines that the mobile media library is to be updated. 
     Another embodiment of the invention pertains to the dynamic and/or automatic update of a mobile media library residing on a mobile device. The update to the mobile media library can be influenced by user configurations, preferences or settings. The update to the mobile media library can also be influenced by user history with respect to the mobile device. Still further, the dynamic update can be dependent on the availability of a network connection (wired or wireless). Still another implementation can operate to retain or remove media items differently based on their type. Still further, usage history, user ratings, policies or rules can be utilized to influence when and how updates to a mobile media library are performed. 
     According to another embodiment of the invention, updates to a mobile media library can be influenced by conditions of a mobile device. Since the update to the mobile media library involves the transmission of data to the mobile device, in one implementation, the transmission of the data, and thus the update to the mobile media library, can be paused or stopped in various conditions. For example, if the mobile device is a wireless communication device for its user, and if a wireless communication is incoming or present, then data transmission for the update to the mobile media library can be paused or stopped. In another implementation, if the network bandwidth currently available is deemed low, the amount or degree of update to the mobile media library being performed can be altered. For example, smaller and/or higher priority items can be transferred, while other larger or lower priority items can be deferred. 
     The invention can be implemented in numerous ways, including as a method, system, device, apparatus (including graphical user interface), or computer readable medium. Several embodiments of the invention are discussed below. 
     Other aspects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which: 
         FIG.  1 A  is a block diagram illustrating a specific system in which embodiments of the invention can be implemented. 
         FIG.  1 B  is a process flow diagram illustrating a method of updating data stored in a media library in accordance with one embodiment of the invention. 
         FIG.  1 C  is a process flow diagram illustrating a method of updating media content stored in a media library in accordance with one embodiment of the invention. 
         FIG.  2    is a general process flow diagram illustrating a specific method of implementing the present invention in accordance with one embodiment of the invention. 
         FIG.  3    is a process flow diagram illustrating a specific method of fetching media items in accordance with one embodiment of the invention. 
         FIG.  4    is a process flow diagram illustrating a method of playing a media item via the first network device in accordance with one embodiment of the invention. 
         FIG.  5    is a process flow diagram illustrating a method of playing a selected media item in accordance with one embodiment. 
         FIG.  6    is a process flow diagram illustrating a method of playing a selected media item locally as shown at  512  of  FIG.  5    in accordance with one embodiment of the invention. 
         FIG.  7    is a process flow diagram illustrating a method of identifying the next media item to download as shown at  612  in accordance with one embodiment of the invention. 
         FIG.  8    is a process flow diagram illustrating an example of one implementation of the method of  FIG.  7   . 
         FIG.  9    is a process flow diagram illustrating a method of fetching additional media items where the network device has remaining unused memory as shown at  210  of  FIG.  2   . 
         FIG.  10    is a process flow diagram illustrating a method of downloading media item content data as shown at  912  of  FIG.  10   . 
         FIGS.  11 A- 11 B  together illustrate an illustrative method of modifying media item metadata and/or content stored on a network device corresponding to contents stored on another network device as shown at  212  of  FIG.  2   . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     There are a variety of types of media that can be delivered, downloaded and/or played. Generally, a media item can have associated therewith media item metadata and media item content data. Media item metadata can include information, such as a file name, URL, and/or other information, such as the size of the file containing the media item content data. Media item metadata may also include information that may be used to identify or organize the media items such as title, author, album name, album art, genre, history of use, media type, bit rate, sample rate, date modified, play count, last played, format, channels, ratings, rankings, public assessments, etc. The media item content data refers to the media data, which is typically stored in a media file. 
     Media item content data (i.e., media data) are digital data that can pertain to audio, video, and/or images that can be played. Some examples of specific forms of media data (which can be referred to as “media items”) include, but are not limited to, songs, albums, audiobooks, playlists, movies, television shows, music videos, photos, computer games, audio and/or video clips or presentations, news reports, sports updates, and podcasts. 
     Various embodiments of the invention enable a user to access a plurality of media items via an electronic device, even where the media item content data for all of the media items is not stored on the network device. More particularly, by storing the media item metadata associated with the media items on the electronic device, it can appear to the user that the media item content data for all of the media items is stored on the electronic device, thereby increasing the “virtual capacity” of the electronic device. Upon selecting a media item for which only metadata is stored, the media item content data can be retrieved and played, as will be described in further detail below. 
     Exemplary embodiments of the invention are discussed below with reference to  FIGS.  1 A- 11 B . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes as the invention extends beyond these limited embodiments. 
       FIG.  1 A  is a block diagram illustrating exemplary system  100  in which embodiments of the invention can be implemented. Media exchange system  100  permits the transfer of data such as media item data (e.g., media item content data and media item metadata) between various different electronic devices. As set forth above, media item data can refer to media such as music, video, podcast episodes, TV shows, photos, games, and the like. 
     Media exchange system  100  facilitates exchange of data such as media item data between electronic devices using various wired and/or wireless communications links. The data exchange environment can pertain to exchange of media item data, in which case the data exchange environment can be considered a media exchange environment. At a minimum, the electronic devices are capable of receiving and storing digital data, and may also be capable of transferring digital data. Still further, these electronic devices can also process, display, present, play, or otherwise utilize digital data. 
     Media exchange system  100  can include central media server  101  and network  102  such as a wired data network. In this example, central media server  101  couples to wired data network  102 . Wired data network  102  can be a global network, a wide area network, or a local area network. In one example, wired data network  102  pertains to some portion of the World Wide Web. A network device such as personal computer  104  can couple to network  102 . Wireless data network  106  can also couple to wired data network  102 . Wireless data network  106  can include one or more wireless data networks, such as cellular networks, WiFi networks, WiMAX networks, etc. 
     Central media server  101  stores or has access to numerous media items. In addition, media exchange system  100  supports one or more additional network devices such as portable media devices  110 ,  116  and  120 . Portable media devices  110 ,  116  and  120  can communicate with personal computer  104  over wired link  112  or wireless link  114 . As an example, wired link  112  can correspond to a cable (e.g., USB cable) that, if available, can interconnect portable media device  110  to personal computer  104 . Wireless link  114  can be provided by a wireless capability, such as Bluetooth, infrared, etc. Typically, the portable media device  110  would be capable of communicating with personal computer  104  using either wired link  112 , wireless link  114 , or both. 
     Portable media device  116  can couple to the wireless data network  106  over a wireless link  118 . Similarly, portable media device  120  can couple to wireless data network  106  over a wireless link  122 . In this regard, portable media devices  116  and  120  can access central media server  101  via wireless data network  106 . In addition, portable media devices  110 ,  116  and  120  can wirelessly access each other, thereby exchange media item data between portable media devices. 
     In one embodiment, one or more of the mobile devices, such as mobile devices  110 ,  116  or  120  illustrated in  FIG.  1 A , can pertain to media devices. More particularly, the media devices can pertain to media players, such as the iPod® media player from Apple Computer, Inc. These mobile devices can include a media management application that operates on the mobile device. One example of a media management application is iTunes®, available from Apple Computer, Inc. Given the portability of mobile devices, mobile devices are smaller and have less resources (e.g., storage capacity). Consequently, a media management application designed for use on a mobile device can offer less features and capabilities than would a counterpart media management application operating on a larger, more powerful computing device, e.g., a personal computer. Given that the mobile devices have wireless access to central media server  101 , the mobile devices can interact with media server  101  to request and/or receive media item data (or other data). In this regard, a media management application operating on the mobile devices can communicate with the media server  101  to perform various tasks, including: navigating available media content at the server (such as navigation of a media store), receiving a periodic delivery of media content to media devices (such as a daily pushing of media item data from a server to a media device), etc. 
     According to another aspect of the invention, mobile devices (e.g., portable media devices) can communicate with one another. This type of communication can be referred to as peer-to-peer interaction. In this regard, one mobile device can communicate (e.g., unicast) directly with another mobile device. In another example, one mobile device can communicate (e.g., broadcast, anycast or multicast) to a plurality of other mobile devices. 
     In the peer-to-peer environment, one mobile device can communicate with one or more other electronic devices (whether mobile or stationary) in the immediate vicinity. Data sharing can be performed when such communication is available. 
     Data transfer could be between a mobile device and a computing device, such as a home computer or another mobile device. Typically, the mobile device and the computing device would be associated with a particular user. For example, when the mobile device is within range of a home computer (or a home network), data transfer can be performed between the mobile device and the home computer. Data transfer could also be between two or more mobile devices, or between two or more non-mobile devices. The data transfer can be automatic without any user action or can alternatively require manual approval by a user. The network devices can be associated with one another via an identification number or other suitable mechanism. In one embodiment, the data transfer can be part of a synchronization operation. For additional details on synchronization, particularly in a wireless manner, see e.g., U.S. application Ser. No. 10/987,649, filed Nov. 12, 2004, and entitled “WIRELESS SYNCHRONIZATION BETWEEN MEDIA PLAYER AND HOST DEVICE”, which is hereby incorporated herein by reference. 
     Additional synchronization methods that may be used with this invention include, for example: (1) U.S. Application No. 883541, Publication No. US20060069809A1, entitled “State Based Synchronization” by Bertrand Serlet, filed Jan. 7, 2004; (2) U.S. application Ser. No. 10/853,306, entitled “A Method of Synchronizing Between Three or More Devices” by Toby Paterson and Jerome Lebel, filed May 24, 2004; (3) U.S. application Ser. No. 10/852,926, entitled “A Method of Synchronizing” by Toby Patterson and Jerome Lebel, filed May 24, 2004; (4) application Ser. No. 11/157,647, entitled “Apparatus And Method For Peer-To-Peer N-Way Synchronization In A Decentralized Environment,” filed Jun. 21, 2005; (5) N-Way Synchronization of Data,” by M. Scott Marcy and Brent Eric Knight, filed Jan. 8, 2007 and having Ser. No. 11/621,033; and (6) “Wide Area Peer-To-Peer Synching In A Decentralized Environment,” by Bruce Nilo, Gordie Freedman, and Toby Paterson, filed Jan. 5, 2007 and having Ser. No. 11/620,618, which are incorporated herein by reference for all purposes. Additional information concerning wireless communication, media devices, content updates, synchronization and the like are provided in the following: (i) U.S. patent application Ser. No. 11/485,142, filed Jul. 11, 2006, and entitled “WIRELESS COMMUNICATION SYSTEM,” which is hereby incorporated herein by reference; (ii) U.S. patent application Ser. No. 11/324,863, filed Jan. 3, 2006, and entitled “REMOTE CONTENT UPDATES FOR PORTABLE MEDIA DEVICES,” which is hereby incorporated herein by reference; (iii) U.S. Patent application Ser. No. 11/210,172, filed Aug. 22, 2005, and entitled “AUDIO SAMPLING AND ACQUISITION SYSTEM,” which is hereby incorporated herein by reference; (iv) U.S. application Ser. No. 10/987,649, filed Nov. 12, 2004, and entitled “WIRELESS SYNCHRONIZATION BETWEEN MEDIA PLAYER AND HOST DEVICE,” which is hereby incorporated herein by reference; and (v) U.S. application Ser. No. 10/423,490, filed Apr. 25, 2003, and entitled “MEDIA PLAYER SYSTEM,” which is hereby incorporated herein by reference. 
     In the work environment or other network environment, as a user comes into an employer&#39;s office to work, the user&#39;s mobile device can transfer data to the user&#39;s work computer or to a network server for the office. The data transfer can be automatic without any user action or can alternatively require manual approval by a user. The user of the mobile device can also communicate with mobile devices of coworkers or other users of the network to exchange data. Methods and systems for supporting such communication are disclosed in (1) U.S. Application No. US2004000862115, Publication No. US20050273790A1, entitled “Networked Media Station,” filed Jun. 4, 2004; (2) U.S. application Ser. No. 11/306,557, entitled “System and Method For Synchronizing Media Presentation At Multiple Recipients,” by Bob Bradley and Robert Dale, filed Jan. 2, 2006; and (3) U.S. application Ser. No. 11/530,855, entitled “Network Media Device,” By Jeff Robbin and Dave Heller, filed Sep. 11, 2006, which are incorporated herein by reference for all purposes. In some embodiments, authentication may be required before such exchange takes place. For example, the media item metadata may include additional information, which may be used to facilitate such authentication. 
     Additional information concerning communication among network devices, playlists and authentication are provided in: (1) U.S. Application No. US200500021313, U.S. Publication No. US20060155914A1, entitled “Highly Portable Media Device”, by Steve Jobs, Anthony Fadell and Jonathan lye, filed Aug. 24, 2005; and (2) U.S. Application No. US200500021555, U.S. Publication No. US20060153040A1, entitled “Techniques For Improved Playlist Processing On Media Devices,” which are incorporated herein by reference for all purposes. 
     A mobile device or non-mobile device capable of receiving, transmitting and/or storing data may be referred to as a “data device.” The manner by which the data arrives at the data device can depend upon implementation. For example, the data can be directly transferred to the data device, or the data can be indirectly transferred to the data device. For example, the data transfer can be between one data device to another data device. Alternatively, one data device can cause another data device to transfer desired data to a recipient data device. 
     The shared data can be transferred to a recipient device by file transfer or streaming. The data transferred can be received by one or more data devices. Examples of data devices include a media player, PDA, a speaker unit, a wireless transmitter/receiver unit, etc. Users of data devices can also create and distribute content through data sharing. The streaming can be limited so as to restrict the number of data devices simultaneously receiving the data. On the other hand, if the users of the data devices are subscribers to the streaming content (i.e., have a subscription), then the streaming can be unlimited as to subscribers. Storing some portion of the media item content associated with the media item metadata may also be done to facilitate the streaming of media item content. For example, a user could begin playing such a previously stored portion of the media item content before streaming of the remaining content even begins. 
     Data can be shared after being purchased. For example, a recipient could purchase data from a remote server. The remote server would then cause the purchased data to be delivered to the recipient&#39;s data device. The purchase can be performed in real-time or can be deferred until a later point in time. Thereafter, the purchased data can be shared from the recipient&#39;s data device to another data device. 
     Regardless of the particular environment, the data transfer can be wireless. The wireless data transfer can be facilitated by a wireless network. One mobile device could wirelessly transmit data in a unicast fashion from one mobile device to another mobile device or stationary computing device. Still further, one mobile device could wirelessly transmit data in a multicast or broadcast fashion to a plurality of other mobile devices. 
     According to one aspect of the invention, a media device, such as a mobile device, can periodically receive updates from a media server. In one embodiment, when a media device such as a mobile device is within an available network that facilitates connection to the media server, the update can be performed. In one implementation, the update can be automatically performed. 
       FIG.  1 B  is a flow diagram of a media library update process  150  according to one embodiment of the invention. Media library update process  150  is, for example, performed by a media device, such as media device  110 ,  116  or  120  illustrated in  FIG.  1   . Media library update process  150  can begin with decision  152  that determines whether a network is available to the media device. The network can be a wired or wireless network that facilitates the media device in acquiring data communication with a media server. When decision  152  determines that the network is not available, a delay  153  can be imposed. Delay  153  serves to provide a delay before processing is again performed to determine whether a network is available. Following delay  153 , media library update process  150  returns to repeat block  152 . 
     On the other hand, when decision  152  determines that a network is available to a media device, decision  154  determines whether a mobile media library (MML) residing on the media device should be updated. Decision  154  can make use of one or more criteria in determining whether the mobile media library should be updated. The criteria can include policies, rules or conditions. When decision  154  determines that the mobile media library should not be updated, then delay  156  can be performed. Delay  156  serves to provide a delay before processing is again performed to determine whether an update to the mobile media library should be subsequently retried. Alternatively, when decision  154  determines that the mobile media library should be updated, update data can be determined at  158 . Next, the update data can be requested  160 . For example, the media device can send an update request to a media server to retrieve and return the update date to the media device via the network previously determined to be available: After update data has been requested at  160 , decision  162  can determine whether the requested update data has been received. When decision  162  can determine that the requested update data have or have not been received, media library update process  150  can return to repeat decision  162  so as to await the requested update data. A time-out can be used to prevent waiting for an excessive period of time. When decision  162  determines that the requested update data is or has been received, the received update data can be stored  164  to the mobile media library. Thereafter, decision  166  can determine whether the update to the mobile media library is complete. For example, the update to the mobile media library can be deemed complete when the requested update data has been received and stored. When decision  166  determines that the update to the mobile media library is not complete, then media library update process  150  can return to repeat decision  162  so as to await receipt of the remaining portion of the requested update data. On the other hand, once decision  166  determines that the update to the mobile media library is complete, media library update process  150  returns to repeat decision  152  so that the media library can be subsequently updated in a similar manner. In this manner, a media library can be updated periodically and automatically, or as the network becomes available. 
       FIG.  1 C  is a flow diagram of mobile device content update process  300  according to one embodiment of the invention. Mobile device content update process  300  can, for example, be performed by a mobile device. Mobile device content update process  180  can initially receive  182  metadata updates for a mobile media library (MML) residing on the mobile device. For instance, the metadata updates can be received while the mobile device is physically connected to a media server, as well as when the mobile device has roamed to another location. Next, mobile device can obtain  184  content update policies. For example, the mobile device can store one or more update policies that govern when and how content updates are to be performed. The mobile device then determines  186  content data to be acquired for the mobile media library (e.g., using the content update policies). Thereafter, the mobile device operates to acquire  188  the content data for the mobile media library. In one embodiment, acquisition  188  of the content data involves a request by the mobile device to the mobile server for the content data, and then the return of the requested content data to the mobile device via a network. After the content data has been acquired  188  at the mobile device, the mobile device can store  190  the content data. Here, storage  190  of the content data can be within the mobile device. In one embodiment, content data is stored  190  within the mobile media library of the mobile device. 
       FIG.  2    is a general process flow diagram illustrating a specific method of implementing the present invention. One or more policies with respect to acquisition and retention of data for a media library can be configured at  202 . More particularly, a particular policy can be hard-coded, configured (e.g., by a system administrator) or user-selected. These policies may be referred to as “content update” policies. 
     One aspect of the invention is that user preferences or settings can be utilized to configure operation of a device such as a mobile device with respect to acquisition and retention of data for a media library. For instance, one or more policies can be used to select media items to be obtained (e.g., pre-fetched) and/or to determine the order in which media items are downloaded (e.g., cached), as well as deleted. As one example, a policy can specify that the oldest media items are to be downloaded before newer media items. More particularly, a policy can be associated with a type of media. As another example, such a policy can be associated with television episodes based upon the assumption that the user would like to watch the episodes in chronological order. Similarly, a policy associated with movies can specify that the newest movies are to be downloaded before older movies, based upon the assumption that a user would rather watch newly released movies before older movies. 
     Content update policies can be implemented via various algorithms or processes. For instance, such algorithms or processes can include those that analyze the history of use of various media items. For example, such processes can analyze data for a particular period of time and/or for a specific type of media item. From the analysis, various decisions can be made. 
     A set of media items can be “pre-fetched” at  206 . More particularly, media item metadata associated with a plurality of media items is obtained and stored, while media item content data associated with only a subset of the plurality of media items is stored. One method of pre-fetching media items will be described in further detail below with reference to  FIG.  3   . 
     Typically, a network device such as a mobile device can also play back the various media items within the media library (e.g., mobile media library). Thus, a user can choose to play a media item at  208 . A method of playing a selected media item will be described in further detail below with reference to  FIG.  4   . 
     In some instances, it can be desirable to fetch additional media items according to various content update policies (e.g., where the network device has remaining unused memory) at  210 . In this manner, the media items can be downloaded slowly as a background process. However, in other instances, it can be undesirable to perform downloading when other tasks are in process, as the downloading can slow other processes. For example, if the user is watching a television show or web-browsing, downloading can temporarily discontinue. One method of fetching additional media items will be described in further detail below with reference to  FIG.  9   . It can also be desirable to modify media item metadata and/or content stored on a network device corresponding to contents stored on another network device at  212 . One method of performing such a modification will be described in further detail below with reference to  FIGS.  11 A- 11 B . 
       FIG.  3    is a process flow diagram illustrating a specific method of fetching media items as shown at  206  of  FIG.  2    in accordance with one embodiment of the invention. A plurality of media items to which access via the first network device is to be enabled can be directly or indirectly identified. This can be accomplished via one or more user settings at  302 . More particularly, in order to select the media items to be “fetched,” a user can establish a user setting associated with a particular type of media item. For instance, the type of media item can be a podcast episode, television episode, movie, or song. The user can choose all of the media items of that type. Alternatively, the user can choose a subset of the media items of that type. For instance, the user can choose media items having associated therewith a date (e.g., release date or date that the media item has been stored) that is after a specified date. As another example, the user can choose songs associated with the last three bands that have been played. In this manner, it is possible to identify the media item(s) of a particular media type to retrieve. 
     In addition to user-established settings, it is also possible to identify one or more policies and/or a history of use that can be used to identify a plurality of media items. Any settings, policies and/or history of use can therefore be applied at  304  to identify a plurality of media items to download to the first network device. 
     Since the memory on the first network device may not be able to accommodate all of the media items desired, media item metadata and media item content data for a portion (e.g., first subset) of the identified media items can be downloaded to the first network device at  306 . More particularly, media item metadata and media item content data for the portion of the identified media items can be obtained from a second network device and stored on the first network device. In this case, only media item metadata for the remaining identified media items are downloaded to the first network device at  308 . More particularly, only media item metadata for the remaining identified media items (e.g., second subset) are obtained from the second network device and stored on the first network device. In other words, media item content data for the remaining identified media items is not necessarily downloaded to the first network device. In accordance with one embodiment, step  308  can be performed when the first network device is physically connected to the second network device. 
     One aspect of the invention relates to a graphical user interface. For instance, the graphical user interface can be used by a user when interacting with a media library (e.g., mobile media library) residing on a network device, such as a mobile device. The graphical user interface can gain access to metadata stored within the mobile media library. In one embodiment, since the mobile media library may store most or all of the available metadata for the mobile media library, the graphical user interface can give the user the impression that the entire mobile media library is in existence on the mobile device. For instance, a list of all of the media items can be presented in a track listing area of the graphical user interface. However, typically, only a subset of the content data for the mobile media library is present on the mobile device. As noted above, the various conditions or operations of the mobile device can influence what subset of the content data is present on the mobile device at any given point in time. One mechanism for implementing a user interface is described in U.S. patent application Ser. No. 11/620,545, entitled “Adaptive Acceleration of Mouse Cursor,” by Howard A. Miller and Frank Doepke, which is incorporated herein by reference for all purposes. 
     A list of the media items that are available to the user via the first network device (e.g., mobile device) can be presented in a graphical user interface via a display associated with the first network device at  310 . Such a graphical user interface could assist a user of the device in interacting with the device. For example, the user interface could facilitate navigation of locally stored media as well as the access of remotely stored media. More particularly, it can be desirable to display the actual and/or virtual media items present on the first network device. As one example, only those media items for which media item content data is stored on the first network device are presented via the display. As another example, it can be desirable to present each of the plurality of media items via the display, enabling the user to select and play any of the media items. As a result, the user can perceive that all of the media items have been downloaded to the network device. Of course, it can be desirable to distinguish the media items for which media content has already been obtained from “virtual” media items for which only metadata has been obtained. For instance, the two sets of media items can be distinguished via highlighting or color distinctions. In accordance with one embodiment, the user can access a menu enabling the user to view all media items and/or only those media items that have been stored locally on the network device. 
     Once the first network device is disconnected from the second network device, the user can play a selected media item via the first network device.  FIG.  4    is a process flow diagram illustrating a method of playing a media item via the first network device as shown at  208  of  FIG.  2    in accordance with one embodiment of the invention. A user can select a media item to play at  402 . However, the media item that has been selected may not be stored on the first network device. Thus, upon receiving a request to playa selected media item, it can be determined whether the media item content data associated with the selected media item is stored on the first network device at  404 . If the media item content data associated with the selected media item is stored locally on the first network device at  406 , the media item content data is played at  408 . One method of playing media item content data locally will be described in further detail below with reference to  FIG.  6   . 
     If the media item content data associated with the selected media item is not present on the first network device at  406 , it can be determined whether the media item content data is currently remotely accessible at  410 . More particularly, it can be determined whether the media item content data can be accessed via the second network device. In some embodiments, it can be determined whether the media item content data can be accessed via another network device such as a server associated with an online media store. Thus, if the second network device cannot be accessed to retrieve the media item content data, it is possible to retrieve the media item content data from another network device. For instance, a song can be obtained from an online media store. Upon verification of the user&#39;s prior purchase history, the song can be provided free of charge. Alternatively, the user can be charged for a re-purchase of the song. Of course, it is possible that such a retrieval of media item content data can be supported by a service provided by a service provider. In this instance, the user can simply pay a monthly service fee for such media item content data retrieval service. 
     If the media item content data cannot be accessed remotely from another network device at  412 , an error message can be provided to the user at  414  indicating that the selected item cannot be played at that time. However, if the media item content data is remotely accessible, the media item content data can be played remotely (e.g., via the second network device) or the media item content data can be downloaded from the second network device and played locally via the first network device at  416 . One method of playing media item content data that is remotely accessible will be described in further detail below with reference to  FIG.  5   . 
       FIG.  5    is a process flow diagram illustrating a method of playing a selected media item in accordance with one embodiment. As shown at  502 , it can be determined whether the current location of the first network device is local to the network in which the media item is stored. For instance, the first network device can be a portable device that is no longer within the same network as the second network device on which the media item that has been requested is stored. 
     In accordance with one embodiment, the first network device is a mobile media device (e.g., portable media player). If a user decides to play a particular media item when in the presence of a wireless network that facilitates Internet connectivity, it can be determined whether a wireless network is available. In other words, it can be determined whether the mobile media device is in the presence of a wireless network such that the mobile media device can utilize the wireless network. Thus, it can be determined whether the mobile media device is within range of the second network device. 
     In addition, the type of connection via which the first network device is connected to the network and therefore the second network device (or online media store) can be ascertained at  504 . For instance, the connection can be a network connection such as a connection to a wireless LAN, a telephone connection, cable connection, DSL connection, etc. Upon determining the type of connection, the bandwidth and/or speed of the network connection can be ascertained. 
     The location of the network device and/or the type of connection can be used to determine whether to play the media item content data remotely at  506 . For instance, if the first network device is within the same network as the second network device on which the media item content data is stored and the connection provides sufficient bandwidth or speed, the media item can be played remotely via the second network device. More particularly, the media item content data can be streamed from the remote location to the first network device at  508 . 
     However, if the first network device is no longer within the same network as the second network device and/or the connection does not provide sufficient bandwidth to play the media item content data remotely in real-time, the media item content data can be downloaded (e.g., retrieved from another network device and stored on the first network device) at  510  and the media item content data can be played locally via the first network device at  512 . 
       FIG.  6    is a process flow diagram illustrating a method of playing a selected media item locally as described above with reference to  512  of  FIG.  5    in accordance with one embodiment of the invention. When a media item has been played locally, it can be desirable to delete the media item to make room for another media item. Thus, one or more settings and/or policies can be used to determine whether to delete the media item that has been played at  602 . For instance, the user may have established via a setting that once a media item of a particular type has been played, the media item content data should be deleted (or should not be deleted). More particularly, a setting or policy can establish that when a movie has been played, the media item content data should be deleted. However, another setting or policy can establish that when a song has been played, the media item content data should not be deleted. 
     When it is determined that the media item should not be deleted at  604 , the process can end at  606 . However, if it is determined that the media item should be deleted, the process can continue at  608  to delete the media item content data. In addition, it may be desirable to delete the media item metadata. 
     Once a media item has been deleted, memory has been freed to retrieve one or more additional media items. As a result, the first network device now has memory to store the media item content data of another media item. Thus, a set of one or more media items for which only metadata is stored can be identified at  610 . A next media item in the set of media items can be identified for downloading using one or more settings, policies and/or history of use at  612 . One method of identifying the next media item to download will be described in further detail below with reference to  FIG.  7   . The media item content data of the identified media item can then be downloaded at  614 . More particularly, the media item content data of the identified media item can be retrieved from another network device and stored on the first network device. The identified media item can be retrieved remotely where the first network device is not physically connected to the network device from which the identified media item is being retrieved. 
       FIG.  7    is a process flow diagram illustrating a method of identifying the next media item to download as shown at  612  in accordance with one embodiment of the invention. The type of media item to be downloaded can be identified at  702 . For instance, the type of the media item can be the same as the type of the media item for which the media item content data has recently been deleted. Thus, if an episode of a television show were deleted, the media item content data of another episode of a television show (e.g., the same show or a different show) can be downloaded. Similarly, if a song has been deleted, the media item content data of another song can be downloaded. 
     One or more settings, one or more policies, and/or history of use associated with the identified type of media item can be identified at  704 . The identified setting(s), policies and/or history of use can then be applied to identify the next media item to download at  706 . For instance, where a song has been deleted, it can be established that the user wants to listen to a song by the same musician as the song that has been deleted. As another example, the user may wish to watch the next television episode of the television show that has been deleted. 
       FIG.  8    is a process flow diagram illustrating an example of one implementation of the method of  FIG.  7   . As shown at  802 , the type of media item to retrieve is ascertained (e.g., by identifying the type of the media item that has been deleted). Where the type of media item to retrieve is a television show at  804 , the settings, policies and/or history of use can indicate that the media item content data for the oldest episode of the television show should be retrieved at  806 . Similarly, where the type of media item to retrieve is a movie at  808 , the settings, policies and/or history of use can indicate that the media item content data for the newest movie (e.g., the movie having the most recent release date) should be retrieved at  810 . Where the type of media item to retrieve is a song at  812 , the settings, policies and/or history of use can indicate that the media item content data for the newest song (e.g., the song having the most recent release date) should be retrieved at  814 . 
       FIG.  9    is a process flow diagram illustrating a method of fetching additional media items where the network device has remaining unused memory as shown at  210  of  FIG.  2   . It can be determined at  902  whether the network device has more memory to store media items at  902 . If the network device does not have more unused memory at  904 , the process can end at  906 . However, if the network device has unused memory at  904 , a set of media items for which only metadata is stored on the network device can be identified at  908 . A next media item in the set of media items to be downloaded can be identified at  910  using one or more settings, one or more policies, and/or history of use. The media item content data of the identified media item can then be downloaded at  912 . More particularly, the media item content data can be retrieved from another network device and stored. 
       FIG.  10    is a process flow diagram illustrating a method of downloading media item content data as shown at  912  of  FIG.  10   . Metadata associated with the media item for which media item content data is to be retrieved can be obtained at  1002 . It can be determined whether the media item content data for the item identified by the metadata can be retrieved from the second network device at  1004 . It the media item content data can be retrieved from the second network device at  1006 , the media item content data can be retrieved from the second network device at  1008 . 
     If the media item content data cannot be retrieved from the second network device at  1006 , it is possible that the first network device (or the second network device from which the media item content data is being retrieved) has roamed to a location that cannot be accessed (e.g., where the two network devices are in two different networks). Thus, there are two possibilities for accessing the media item content data. The media item content data can be retrieved presently at  1010  from another location (e.g., network device), such as via an online media store at  1012 . Alternatively, the media item content data can be retrieved later at  1014  by waiting to retrieve the media item content data from the second network device at a later time at  1016 . For instance, when the first network device roams back into the network area of the second network device, the first network device can retrieve the media item content data from the second network device. 
     Even if the second network device can be accessed, it is still possible that the media item can no longer be retrieved from the second network device. For instance, the media item can have been deleted from the second network device. As a result, it may be impossible to download the media item content data from the second network device. Accordingly, it may be desirable to notify the first network device when modifications have been made to the media items that are stored on the second network device. 
       FIGS.  11 A- 11 B  together illustrate a method of modifying media item metadata and/or content stored on a network device corresponding to contents stored on another network device as set forth above with reference to  212  of  FIG.  2   . More particularly,  FIG.  11 A  represents processes performed by the second network device, while  FIG.  11 B  represents processes performed by the first network device. 
     It is possible to delete a media item from the second network device or add a media item to the second network device as shown at  1102 . More particularly, when a new media item has been added to the second network device, media item content data and corresponding metadata are stored on the second network device. Similarly, when a media item has been deleted from the second network device, the media item content data and corresponding metadata can be deleted from the second network device. 
     If a new media item has been added to the second network device at  1104 , it may be desirable to notify the first network device that the media item has been added to the second network device. This can be accomplished, for example, by sending the media item metadata to the first network device at  1106 . If a media item has been deleted from the second network device at  1108 , it may be desirable to notify the first network device that the media item has been deleted from the second network device. This can be accomplished by sending a notification to the first network device at  1110  to delete the corresponding metadata, thereby preventing the first network device from attempting to retrieve the corresponding media item content data from the second network device. Of course, if the first network device has already downloaded the media item content data, it may be undesirable to delete the corresponding metadata (or media item content data). As a result, the metadata can be deleted if the corresponding media item content data is not stored locally on the first network device. The process ends at  1112 . 
     As shown in  FIG.  11 B , if the first network device receives notification from the second network device that a new media item has been downloaded at  1120 , this notification can include the corresponding media item metadata. The first network device can then store this media item metadata at  1122 . Similarly, if the first network device receives notification from the second network device that a media item has been deleted from the second network device at  1124 , the corresponding media item metadata can be deleted from the first network device at  1126 . As set forth above, if the corresponding media item content data has already been stored locally on the first network device, the media item metadata need not be deleted. However, if the media item content data for that media item has not yet been retrieved from the second network device, it may be desirable to delete the media item metadata from the first network device to prevent the first network device from attempting to retrieve the media item content data from the second network device. The process ends at  1128 . 
     The various aspects, embodiments, implementations or features of the invention can be used separately or in any combination. 
     The invention can be implemented by software, hardware or a combination of hardware and software. The invention can also be embodied as computer readable code on a computer readable medium. The computer readable medium is any data storage device that can store data which can thereafter be read by a computer system. Examples of the computer readable medium include read-only memory, random-access memory, CD-ROMs, DVDs, magnetic tape, optical data storage devices, and carrier waves. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. 
     The advantages of various embodiments of the invention are numerous. Different aspects, embodiments or implementations can yield one or more of the following advantages. One advantage of the invention is that data, such as media item data, can be provided to (or from) a portable media device by way of a wired or wireless network, (e.g., a local wireless network). The wireless data exchange can be one-way or two-way. 
     The many features and advantages of the present invention are apparent from the written description. For instance, the embodiments and aspects described herein can be utilized separately or in any combination. Further, since numerous modifications and changes will readily occur to those skilled in the art, the invention should not be limited to the exact construction and operation as illustrated and described. Hence, all suitable modifications and equivalents can be resorted to as falling within the scope of the invention.