Transcode matrix

A transcode architecture determines if a media source file needs to be transcoded for playback on a target playback device, and if so, the proper format needed for transcoding the source file. A transcode architecture includes a transcode manager, a transcode matrix, a transcode engine and a cache for storing transcoded media files. A media library stores media source files and device capabilities information. The transcode manager controls a transcode process in which the transcode matrix generates a profile for a media source file and accesses device capabilities that indicate playback capabilities for a target playback device. The transcode matrix compares parameters of the source profile with the device capabilities to decide whether the source file must be transcoded to enable playback of the file on the target playback device, and if so, the proper format needed for transcoding the source file.

TECHNICAL FIELD

The present disclosure generally relates to synchronizing media content between a source device and a target playback device, and more particularly to determining a format for transcoding the media content if transcoding the media content is necessary for playback on the target device.

BACKGROUND

As digital media technology continues to advance and the cost of storage continues to decline, users increasingly host and consume digital media on their own primary computers (e.g., desktop PCs). Examples of such digital media include music, video, still pictures, and so on.

In addition, a corresponding increase in the availability of portable media playback devices such as personal digital assistants (PDAs), hand-held computers, laptop computers, and smart phones is providing users more ubiquitous access to information than ever. As users rely more and more on such portable devices, there is a growing need for applications that effectively transfer digital media from source devices, such as primary computers, to the portable playback devices.

Transcoding is a way of altering a media file through one or more transcoding processes so the file can be played back on a particular playback device. Thus, transcoding converts a source media file having certain characteristics into a target media file having different characteristics. Such transcoding processes can include, for example, converting a media file from one format to another (e.g., MP3 to WMA), changing the codec of the file, down-sampling the file to a lower bit rate to reduce the amount of storage space needed on the playback device, adapting the screen size of the file (i.e., height/width) so video appears correctly on the playback device, and so on.

Deciding whether a source media file needs to be transcoded for playback on a particular target playback device and what format to transcode the source file to based on the target playback device's capabilities are important steps in the transcoding process. That is, a source media file on a source device may be formatted correctly for playback on one target playback device, but may need to have one or more parameters reformatted before it can be played back on a different target playback device. There is a continual need to improve the transcoding process through such decision steps in order to ensure that source files are properly and timely transcoded for transfer and playback on different target playback devices.

SUMMARY

A system and methods are described for determining if a media source file needs to be transcoded for playback on a target playback device and, if so, the proper format needed for transcoding the source file. The source file can then be transcoded and transferred to the target playback device.

In a described embodiment, a system provides a transcode architecture that includes a transcode manager, a transcode matrix, a transcode engine and a cache for storing transcoded media files. The system also includes a media library to store media source files and device capabilities information. In the described embodiment, the transcode manager controls a transcode process in which the transcode matrix generates a profile for a media source file and accesses device capabilities that indicate playback capabilities for a target playback device. The transcode matrix compares parameters of the source profile with the device capabilities to decide whether the source file must be transcoded to enable playback of the file on the target playback device. If the source file needs to be transcoded, the transcode matrix generates a target profile containing target parameters determined to match, and/or fall within acceptable ranges of, corresponding parameters indicated in the device capabilities. The transcode matrix hands off the target profile to the transcode engine, which transcodes the source file according to the target profile. The transcoded source file is then saved in a memory and can be transferred to the target playback device at an appropriate time, such as when the target playback device is connected to the source device during a synchronization process.

DETAILED DESCRIPTION

Introduction

The following discussion is directed to a system and methods for determining whether a media source file needs to be transcoded to enable playback of the file on a target playback device, and the manner in which such transcoding will be implemented with respect to various parameters of the source file. The system and methods described herein for determining the transcoding requirements of a source media file to play back on a target playback device, facilitate and improve transcoding in general, regardless of whether the transcoding is performed before or during transferring/synchronizing of the media file to the target playback device.

Exemplary Environment

FIG. 1illustrates an exemplary environment100suitable for determining whether a digital media source file needs to be transcoded and what format the file should be transcoded to if needed. The exemplary environment100generally illustrates a media content synchronization scenario in which a target playback device104is coupled to a source device102for the purpose of transferring pre-transcoded media content from the source device to the target device. In a typical scenario, media content received by source device102and destined for synchronization with a target playback device104is fully transcoded prior to the time the target device104is connected to the source device. Thus, copying media content from the source device102to the target playback device104is uninhibited by the transcoding process, and the time for synchronizing/copying the content is significantly reduced.

It is noted that the hardwire coupling between the source device102and target playback device104as shown in the exemplary environment100ofFIG. 1is intended by way of example only, and not by way of limitation, to illustrate one manner of facilitating content synchronization/transfer from source device102to target playback device104. Various other known methods for coupling the target playback device104for synchronization are also contemplated, including for example, coupling through a synchronization port that includes a docking cradle for the playback device104, coupling through a wireless infrared port, coupling via a network using a wireless and/or modem/cellular-based Internet and VPN (virtual private network), and so on. Thus, physical coupling of target playback device104to source device102for content synchronization is not necessary.

Source computing device102is typically implemented as a user's primary computing device, such as a desktop personal computer (PC). However, source device102might also be implemented as various other conventional computing devices generally configured to receive and render multi-media content from various sources, and/or to reformat such content for synchronization and playback on a target playback device104. An example of a source computing device102is depicted inFIG. 8and described in greater detail below in the Exemplary Computing Environment section.

Target media playback device104may be implemented as any one of numerous digital media player devices available from various manufacturers, a general computing device such as a desktop PC, or any other suitable media playback device. Such devices are typically configured with audio and/or video subsystems capable of rendering digital media (audio/video) files such as MP3 (MPEG-1 Audio Layer 3) files, .WAV (Windows® Wave) files, .WMA (Windows® Media Audio) files, .WMV (Windows® Media Video) files, MPEG (Moving Picture Experts Group) files, .jpg files, .gif files, and the like. Accordingly, by way of example and not limitation, a target media playback device104may include various general-purpose laptop and notebook computers configured to playback media content, in addition to devices that are more specifically designed to play back various forms of multimedia, such as Rio's Rio Riot and Rio Karma, Archos' Jukebox Recorder 20 and AV320 Pocket Audio/Video Recorder, Creative's Jukebox Zen and Portable Media Center Zen, Apple's iPod, ZVUE's MP4 Video Player, and so on.

EXEMPLARY ENVIRONMENT

FIG. 2illustrates a block diagram representation of an exemplary source device102that is suitable for determining whether a media source file needs to be transcoded for playback on a target playback device, and the manner in which various parameters of the source file should be transcoded if necessary. Various components of source device102facilitate the retrieval and management of media content for the general purpose of rendering the content on source device102and/or synchronizing the content with target playback device104. These components include an operating system200, one or more media source applications202, a media player application204, a media content synchronization program module206, a media library208, and a transcode architecture210embodied on one or more processor-readable media (seeFIG. 8and Exemplary Computing Environment section below). Although these components are illustrated separately on source device102, it is noted that any one or more of these components may be implemented on source device102as part of a multimedia software product, the operating system200, or as stand-alone components.

A media source application202may be one or more of various applications and/or tools configured to receive media content. For example, media source application202may be an interactive TV service application that facilitates the recording of video (e.g., TV programming) directly off of a cable and/or satellite feed, a video capture component to transfer home video footage from a digital video recorder onto source device102, a Web browser application that facilitates downloading media off the Internet, and so on. Such media source applications202typically supply various forms of media content212to media library208on source device102. Thus, source files214within media content212stored in media library208may include, for example, audio files in the form of MP3 and WMA files, video files in the form of DVR-MS, AVI and MOV files, image files in the form of GIF and JPEG files, and so on. Media library208additionally includes device capabilities216(B) acquired from a target playback device104as discussed in greater detail herein below.

In addition to the configurations noted above, a media source application202may also include or be part of a media player application204. A media player application204is typically a desktop based application player that manages a broad range of multimedia related tasks. For example, a media player application204may handle streaming audio and video, CD/DVD playback, MP3 and WMA support, encoding, CD/DVD burning, Internet radio, and the like. A media player application204may also offer Web browser integration so it can be embedded in a browser enabling multi-tasking during streaming video. Like other media source applications202, a media player application204may supply various forms of media content212(i.e., source files214as audio files, video files, image files, etc.) to a media library208on source device102.

Synch module206may be configured as part of a media player application204, the operating system200, or as a stand-alone component, and provides a user-configurable model for facilitating the transfer of media source files214to a target playback device104from the media library208on source device102. As noted above, examples of media content212stored in media library208may include source files214in the form of audio, video, text, or image files. Media content212may also include a static or automated playlist of files (e.g., audio, video, and images) or any grouping of files or data. Some source files214in the media library208may be more or less important to a user than others, and the synch module206may assign a transfer priority to files in the library to indicate their relative importance or desirability as indicated by the user.

Components of transcode architecture210interact with synch module206and other components of source device102to facilitate transcoding of source files214(i.e., media content212). The transcoding of source files214is preferably performed as a background process on source device102in anticipation of a synchronization process that transfers media content to a target device104when the target device104is coupled to the source device102. However, transcoding may also be performed concurrently with such a synchronization process during the transfer of media content to a target device104.

Transcoding is generally managed by the transcode architecture210, which includes transcode manager216, transcode matrix220, transcode engine222, and a transcode cache224for storing transcoded media content (i.e., transcoded source files226). Transcode manager218retrieves device capabilities216(A) from a target device104(e.g., by querying the target device) upon an initial coupling of the target device104with source device102. Device capabilities216are an object or report from the target device104regarding what types of media content the device can play back successfully. A device capabilities216object or report contains a list of profile collections keyed by a format code. The format code is an indicator of content format loosely based on the extension of the file. A profile collection is a collection of profiles all having the same format code. A profile, in general, represents a type of file, either as source content or as content that a target device can play. Therefore, source profiles and device profiles are discussed throughout this disclosure. A profile includes codec information, and various content parameters such as bitrates, sample rates, number of channels, and so on. The parameter values in a profile are keyed by parameter name and they can be enumerated, ranged, or unrestricted.

Once device capabilities216(A) are retrieved by transcode manager218, they may be serialized into XML format and saved as device capabilities216(B) in the media library208in a row that represents that particular target device104. In addition, each component of the device capabilities216(i.e., including the profile collection, device profiles, and parameter values) may be serialized by itself, resulting in a combined XML. Sample device capabilities and sample serialized device capabilities are shown below in the Appendix section of this disclosure. The samples in the Appendix provide examples of device capabilities for a particular target playback device104and examples of what serialized device capabilities may look like.

The transcode manager218caches device capabilities216(B) in media library208so that they are accessible by transcode matrix220and other applications. In general, caching device capabilities216(B) enables the transcode architecture210to perform background transcoding of newly acquired media source files214(e.g., video/TV files, audio files) that match a target playback device's synchronization rules, even when the target device is not coupled to source device102. This minimizes the delay incurred at transfer time since source files214can be transcoded ahead of time. Transcode manager218monitors the media content212in the media library208for newly acquired media source files214. When a media source file214is stored in the media library208(e.g., by a media source application202, media player application204, etc.), the transcode manager218determines if the media source file214is destined to be transferred to a target device104. If so, the transcode manager218hands the source file path (i.e., location of source file within media library208) to the transcode matrix220and asks the transcode matrix220to determine whether the media source file214needs to be transcoded for playback on the target playback device104, and if so, how the source file214should be transcoded.

In order to determine if a media source file214needs to be transcoded for a particular target playback device104, the transcode matrix220first generates a source profile for the source file214that catalogues source file information such as the source file codec, parameters and their values, and so on. For an audio source file214, the parameters in the source profile typically include an audio bitrate, a sample rate, the number of channels, the audio bit depth, and the audio codec (e.g., WAVE codec). For a video source file214, the parameters in the source profile typically include a video bitrate, a height, a width, a frame rate, and the video codec (e.g., FOURCC codec). The transcode matrix220searches for the parameters of the source file214in the media library, according to the file path provided by transcode manager218. If this search fails, the transcode matrix220inspects the source file itself, for example, by opening the source file using a file format SDK to gain access to the source file parameters. If this also fails, the transcode matrix220will assign an artificial profile to the source file214. After accessing the source file parameters, the transcode matrix220generates the source profile for the source file. The transcode matrix220can then use the source profile for comparison with the device capabilities216(B) of a target playback device as discussed below with reference toFIG. 3.

FIG. 3illustrates a block diagram representation of an exemplary process for comparing a source profile300with the device capabilities216(B) of a target playback device104in order to determine if a source file214needs to be transcoded, and how various parameters of the source file should be transcoded if necessary. InFIG. 3, a source file214is shown with its corresponding source profile300generated by transcode matrix220as discussed above. It is noted that source profile300is illustrated inFIG. 3as a part of source file214only for the purpose of this discussion, to indicate that a source profile300is an inherent part of a source file214. However, after its generation by transcode matrix220, as discussed above, a source profile300may actually be stored in media library208or in some other memory on source device102.

There are several steps the transcode matrix220takes to determine if a source file214needs to be transcoded. The first is selecting a profile collection in the device capabilities216(B) that matches the format code of the source profile300. As noted above, a profile collection is a collection of device profiles that all have the same format code. The format code is an indicator of file content format that is loosely based on the file extension. For example, a format code for a WMA file will be selected from the device capabilities216(B) (assuming it exists in the device capabilities216(B)) if the source profile300is associated with a WMA source file. If a profile collection is not found in the device capabilities216(B) that matches the format code of the source profile300, then the source profile300is not supported, and the source file214is not playable on the target playback device104. Therefore, no transcode of the source file214would be necessary.

In the case where a profile collection is found in the device capabilities216(B) that does not contain any device profiles301, then the format code is supported with no restrictions, and the source file214also does not need to be transcoded. In this case, however, where a target device104does not specify any restrictions in its device capabilities216(B), artificial restrictions will be imposed while the device capabilities are being retrieved. For example, a 32-160 kbps (kilobits per second) bitrate and 0-44100 KHz sample rate may be imposed on the target device104.

In the case where a profile collection is found in the device capabilities216(B) that contains one or more device profiles301, then the transcode matrix220determines if the source file214needs to be transcoded by checking each device profile301to see if it matches the source profile300. Matching is done by comparing each parameter in the source profile300with the corresponding parameter found in the device profile301of the device capabilities216(B).FIG. 3shows the transcode matrix220making comparisons between example parameter values in a source profile300and corresponding parameter values in the device profile301of device capabilities216(B) (i.e., parameters A, B, and C). If a source profile parameter matches an enumerated value of the corresponding parameter in the device profile301of the device capabilities216(B), or if it falls into the range specified by the same parameter in the device profile301, then there is a match. If all parameters match between the source profile300and the device profile301, then the transcode matrix220determines that the target device104supports the source profile300. In this case, the transcode matrix220again concludes that there is no need to transcode the source file214because the source file214can be played back on the target device104in its current format.

However, if there are one or more parameters from the source profile300that do not match the corresponding parameters in the device profile301of the device capabilities216(B), then the transcode matrix220determines that the source file214needs to be transcoded. As discussed in more detail below, there are other scenarios in which the transcode matrix220may also determine that a source file214needs to be transcoded, such as when a user specifies a preference or when a device has a total bitrate restriction.

As shown inFIG. 3, if the transcode matrix220determines that the source file214needs to be transcoded, it normalizes the source profile300by generating a target profile302based on the comparison of parameters between the source profile300and the device profile301of the device capabilities216(B). In general, a profile containing ranged or enumerated parameters (e.g., from device capabilities216can be normalized to a profile that has unique parameters by achieving a closes parameter match. For each parameter, therefore, the transcode matrix220determines a target value for the target profile302by comparing each parameter from the source profile300with its corresponding parameter in the device profile301. If a source profile300parameter value matches that of the device profile301(i.e., is the same as or within the same range as), then the transcode matrix220will set the target profile302parameter value to be the same as the source profile parameter value, which will be a single-valued enumeration containing this value. That is, if the source profile parameter and the device profile parameter match, the source profile parameter is not changed, but remains the same in the target profile302.FIG. 3provides an example of this with parameter A. The value of parameter A in the source profile300is 4, while the acceptable range for parameter A in the device profile301is 1-5. Therefore, because parameter A falls within the acceptable range in the device capabilities216(B), the transcode matrix220sets the target value to 4 for parameter A in the target profile302.

If a source profile300parameter value does not match that of the device profile301in the device capabilities216(B) (i.e., is not the same as or within the same range as), then the transcode matrix220sets the target profile302parameter value to a value that is as close as possible to the source profile300parameter value while also being within the acceptable range for the device capabilities216(B). Referring to theFIG. 3example, parameter B of the source profile300is 11, while the acceptable range for parameter B in the device profile301of the device capabilities216(B) is 6-10. As shown in the target profile302, the transcode matrix220sets the target value for parameter B to 10, which is the closest possible value to the source profile value of parameter B, while still being within the acceptable device capabilities range for parameter B. The case is similar for parameter C shown inFIG. 3.

After generating the target profile302, the transcode matrix220hands off the target profile302to the transcode engine222. As shown inFIG. 3, the transcode engine222transcodes the source file214in accordance with target parameter values within the target profile302. The transcode engine222generates a transcoded source file304whose parameters match those of the target profile302. Therefore, the transcoded file304inFIG. 3is illustrated as containing the target profile302.

After the source file214is transcoded, the transcoded file304is typically stored on source device102in a transcode cache224and/or made available to target device104either directly or at some later time when the target device104is coupled to the source device102, as shown inFIG. 3. The transcoded file is typically maintained in a memory on source device102in the event that the same format of the source file is suitable for another target device104at some later time.

FIG. 4shows the block diagram representation and exemplary process ofFIG. 3using several exemplary parameters that better illustrate how the transcode matrix220determines target values for the target profile302by comparing parameters from the source profile300with corresponding parameters in the device profile301of the device capabilities216(B). In the source profile300ofFIG. 4, a bitrate parameter value is 256 kbps (kilobits per second) while the corresponding bitrate parameter in the device profile301indicates that the acceptable playback range for the device capabilities216(B) is between 0-128 kbps. The resulting target value for the bitrate parameter set by the transcode matrix220will be 128 kbps, as shown in the target profile302ofFIG. 4. This is the closest value to the source profile value that is within the acceptable range of the device capabilities216(B). A sample rate parameter value in the source profile300ofFIG. 4is 22 KHz. Because this value already falls within the acceptable range of the corresponding sample rate parameter value in the device capabilities216(B) (i.e., 0-48 KHz), the transcode matrix220sets the target value for the sample rate parameter at 22 KHz. Likewise, the source profile300indicates that the source file214has 2 channels, while the device profile301of the device capabilities216(B) show that acceptable (enumerated) values for the number of channels parameter are 1, 2, and 6. Because 2 channels is an enumerated value in the device profile301, the transcode matrix220sets the target value for the number of channels parameter to 2.

Another step the transcode matrix performs following normalization as described above, is a “reduction” step. For example, there can be multiple candidate target profiles contending to be chosen, such as the following:

Profile 1 is a better choice because the sample rate in profile 1 is closer to that of the source file.

The reduction process works by sorting the profiles by a single parameter at a time, and only retaining those profiles that are the best match. In the example above, if bitrate is the first parameter, then the 3rd profile will be eliminated because 128 kbps is a better match to the source bitrate than 64 kbps. If the next parameter is sample rate, then the 2nd profile will be eliminated because profile 1 provides a better match.

However, in the case where neither profile matches the source exactly (as profile 1 does in the example above), then the lowest closest value takes precedence. That is, if the source parameter is 1000 and the choices on the target are 800, 900, 1050 and 1100, the order of preference would be 900, 800, 1050, 1100.

As noted briefly above, the transcode matrix220may determine that a source file214needs to be transcoded for reasons other than finding that one or more parameters from the source profile300do not match the corresponding parameters in the device capabilities216(B). A user preference is one such reason where transcoding is required even if the target device104can support the source file214in its original format. If a user specifies a preference (i.e., an override) for a parameter (e.g., audio and/or video bitrate), the transcode matrix220will substitute the preferences into the source profile and effectively set the target value for that parameter in the target profile302to the preference specified by the user, or at least to a closest match to the user preference. During the determination of transcode need, the source file's audio and video bitrates, for example, are inspected and compared to the user-preferred bitrates specified for the device. If the source profile300shows that the source file214has a higher bitrate, then a transcode is needed. During the generation of the target profile302, the transcode matrix220seeks a closest match to the user preference. This is done by modifying the source profile300and setting the audio and/or video bitrate to the user-preferred bitrate(s). If the device profile301of the device capabilities216(B) indicate that the target device104does not support the user preference, the transcode matrix220then finds the closest match to the user preference that is within the acceptable range provided by the device profile301. For example, if a user prefers that all content be transcoded to an audio bitrate of 192 kbps, but the device only supports up to 160 kbps, then the content will be transcoded to 160 kbps. However, if a user selects a higher bitrate than that of a source file, the source file will not be transcoded if it is supported as is on the target device.

Another reason the transcode matrix220may determine that a source file214needs to be transcoded is if the target device places a restriction on the total bitrate. A device may place a restriction on total bitrate (i.e., the sum of audio bitrate and video bitrate) on a per profile basis. Thus, there can exist a device profile301that declares support for an audio bitrate of 0-320000 and a video bitrate of 0-700000. However, the total bitrate may be limited to 800000. Thus, a combination of audio bitrate of 320000 and video bitrate of 700000 is not allowable. The transcode matrix220therefore checks device profiles to see if the sum of the audio and video bitrates does not exceed the specified total (if a restriction is specified). If the sum of the audio and video bitrates exceeds a specified total, the device profile is skipped, and the transcode matrix220continues to the next device profile. If no profiles are found as a result, the profile with the lowest audio bitrate above a certain threshold (32000) is selected, and the video bitrate is adjusted in order to fit within the total restricted bitrate. The lowest audio bitrate is chosen in order to give preference to video bitrate.

Exemplary Methods

Example methods for determining if a media source file needs to be transcoded for playback on a target playback device and, if so, the proper format needed for transcoding the source file, will now be described with primary reference to the flow diagrams ofFIGS. 5-7. The methods apply to the exemplary embodiments discussed above with respect toFIGS. 1-4. While one or more methods are disclosed by means of flow diagrams and text associated with the blocks of the flow diagrams, it is to be understood that the elements of the described methods do not necessarily have to be performed in the order in which they are presented, and that alternative orders may result in similar advantages. Furthermore, the methods are not exclusive and can be performed alone or in combination with one another. The elements of the described methods may be performed by any appropriate means including, for example, by hardware logic blocks on an ASIC or by the execution of processor-readable instructions defined on a processor-readable medium.

A “processor-readable medium,” as used herein, can be any means that can contain, or store, instructions for use or execution by a processor. A processor-readable medium can be, without limitation, an electronic, magnetic, optical, electromagnetic or semiconductor system, apparatus or device. More specific examples of a processor-readable medium include, among others, a portable computer diskette (magnetic), a random access memory (RAM) (magnetic), a read-only memory (ROM) (magnetic), an erasable programmable-read-only memory (EPROM or Flash memory), a rewritable compact disc (CD-RW) (optical), and a portable compact disc read-only memory (CDROM) (optical).

At block502of method500, a transcode matrix220receives a file path for a media source file214. A transcode manager218sends the transcode matrix a file path for a media source file each time a media source file is stored in a media library and is destined to be transferred to a target playback device104. The transcode manager generally sends the file path to the transcode matrix and requests that the transcode matrix determine whether the media source file needs to be transcoded for playback on the target playback device, and if so, how the source file should be transcoded.

At block504, the transcode matrix locates the media source file in the media library according to the file path received from the transcode manager. The transcode manager retrieves parameters for the media source file from the media library as shown at block506. The transcode manager first tries to access the parameters directly from the media library as shown at block508. If this attempt fails, the source file itself is inspected, for example, by opening the source file with a Format SDK to retrieve the source file parameters as shown at block510. Then at block512, if opening the media source file also fails, the transcode matrix assigns artificial parameters to the media source file.

In addition, as shown at block514, retrieving source file parameters for the media source file can include accessing a bitrate preference or other user preference for the target device that has been expressed by a user. If a bitrate preference (e.g., audio and/or video bitrate) or other user preferences are provided by a user, they are substituted for corresponding parameters of the media source file as shown at block516. At block518, the transcode matrix generates a source profile based on the parameters retrieved as discussed above regarding block506.

At block520, device capabilities216are retrieved or accessed from the target playback device. This is generally accomplished by the transcode manager218querying the target playback device for the device capabilities. Optionally, as shown at block522, after device capabilities216(A) are retrieved by transcode manager218, they can be serialized into XML format and then saved as device capabilities216(B) in the media library208so that the transcode matrix and other applications have access to them. In addition, each component of the device capabilities216(i.e., including the profile collection, device profiles, and parameter values) can be serialized by itself, resulting in a combined XML. The Appendix section shown below, provides sample device capabilities and sample serialized device capabilities. The samples in the Appendix provide examples of device capabilities for a particular target playback device104and examples of what serialized device capabilities may look like.

In the event the device capabilities do not indicate any restrictions for the target playback device104, artificial restrictions will be imposed as shown at block524. For example, where no bitrate or sample rate restrictions are indicated in the device capabilities, a 32-160 kbps (kilobits per second) bitrate and 0-44100 KHz sample rate may be imposed on the target device104.

The method500continues fromFIG. 5toFIG. 6, at block526. At block526, the transcode matrix compares the device capabilities with the source profile. Specifically, the transcode matrix compares parameters in a device profile with like parameters in the source profile. At block528, a profile collection from the device capabilities is selected that matches the format code of the media source file. At decision block530, the transcode matrix determines if there are any profile collection in the device capabilities that match the format code of the media source file. If not, the transcode matrix determines that no transcode is needed, because the target device supports the media source file, as shown at block536. At decision block530, if the transcode matrix determines that there is a profile collection that matches the format code of the media source file, then the transcode matrix determines if the matching profile collection contains any device profiles (decision block532). If there are no device profiles in the matching profile collection, the transcode matrix again determines that no transcode is needed and that the target device supports the media source file (block536). However, if there are one or more device profiles in the matching profile collection, the transcode matrix determines, at decision block534, if all the parameters in the source profile match (or fall within range of) corresponding parameters in the device profile. If all the parameters in the source profile match (or fall within range of) corresponding parameters in the device profile, then the transcode matrix again determines that no transcode is needed and that the target device supports the media source file (block536). However, if any of the parameters in the source profile do not match (or fall within range of) corresponding parameters in the device profile, then the transcode matrix determines that the media source file must be transcoded, as shown at block538.

The method500continues with block540ofFIG. 7. At block540, the transcode matrix generates a target profile302that has target parameter values that match enumerated values of the device profile, or that fall within an acceptable range of the corresponding parameters in the device profile. As shown at block542, when setting target parameter values, the transcode matrix selects target values that fall within acceptable parameter ranges indicated in the device profile, but it selects those target values to be as close to the parameter value of the source profile as possible. Thus, where an acceptable range of values in the device profile is 2-10, for example, and the source profile value is 6, then the selected target profile value will be set at 6 also.

At block544, the transcode matrix sends the target profile to the transcode engine. At block546, the transcode engine transcodes the media source file according to target parameter values specified in the target profile received from the transcode matrix. As shown at blocks548and550, respectively, a copy of the transcoded file is then maintained in memory on the source device102and transferred to the target playback device at an appropriate time, such as when the target playback device is coupled to the source device for a content synchronization process.

Exemplary Computing Environment

FIG. 8illustrates an exemplary computing environment for implementing a source computing device102suitable for suitable for determining if a media source file needs to be transcoded for playback on a target playback device and, if so, the proper format needed for transcoding the source file, such as discussed above with reference toFIGS. 1-4. Although one specific configuration is shown inFIG. 8, a source computing device102may also be implemented in other computing configurations.

The computing environment800includes a general-purpose computing system in the form of a computer802. The components of computer802may include, but are not limited to, one or more processors or processing units804, a system memory806, and a system bus808that couples various system components including the processor804to the system memory806.

The system bus808represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. An example of a system bus808would be a Peripheral Component Interconnects (PCI) bus, also known as a Mezzanine bus.

Computer802includes a variety of computer-readable media. Such media can be any available media that is accessible by computer802and includes both volatile and non-volatile media, removable and non-removable media. The system memory806includes computer readable media in the form of volatile memory, such as random access memory (RAM)810, and/or non-volatile memory, such as read only memory (ROM)812. A basic input/output system (BIOS)814, containing the basic routines that help to transfer information between elements within computer802, such as during start-up, is stored in ROM812. RAM810contains data and/or program modules that are immediately accessible to and/or presently operated on by the processing unit804.

Computer802may also include other removable/non-removable, volatile/non-volatile computer storage media. By way of example,FIG. 8illustrates a hard disk drive816for reading from and writing to a non-removable, non-volatile magnetic media (not shown), a magnetic disk drive818for reading from and writing to a removable, non-volatile magnetic disk820(e.g., a “floppy disk”), and an optical disk drive822for reading from and/or writing to a removable, non-volatile optical disk824such as a CD-ROM, DVD-ROM, or other optical media. The hard disk drive816, magnetic disk drive818, and optical disk drive822are each connected to the system bus808by one or more data media interfaces825. Alternatively, the hard disk drive816, magnetic disk drive818, and optical disk drive822may be connected to the system bus808by a SCSI interface (not shown).

Any number of program modules can be stored on the hard disk816, magnetic disk820, optical disk824, ROM812, and/or RAM810, including by way of example, an operating system826, one or more application programs828, other program modules830, and program data832. Each of such operating system826, one or more application programs828, other program modules830, and program data832(or some combination thereof) may include an embodiment of a caching scheme for user network access information.

A user can enter commands and information into computer system802via input devices such as a keyboard834and a pointing device836(e.g., a “mouse”). Other input devices838(not shown specifically) may include a microphone, joystick, game pad, satellite dish, serial port, scanner, and/or the like. These and other input devices are connected to the processing unit804via input/output interfaces840that are coupled to the system bus808, but may be connected by other interface and bus structures, such as a parallel port, game port, or a universal serial bus (USB).

A monitor842or other type of display device may also be connected to the system bus808via an interface, such as a video adapter844. In addition to the monitor842, other output peripheral devices may include components such as speakers (not shown) and a printer846which can be connected to computer802via the input/output interfaces840.

Computer802may operate in a networked environment using logical connections to one or more remote computers, such as a remote computing device848. By way of example, the remote computing device848can be a personal computer, portable computer, a server, a router, a network computer, a peer device or other common network node, and the like. The remote computing device848is illustrated as a portable computer that may include many or all of the elements and features described herein relative to computer system802.

Logical connections between computer802and the remote computer848are depicted as a local area network (LAN)850and a general wide area network (WAN)852. Such networking environments are commonplace in offices, enterprise-wide computer networks, intranets, and the Internet. When implemented in a LAN networking environment, the computer802is connected to a local network850via a network interface or adapter854. When implemented in a WAN networking environment, the computer802includes a modem856or other means for establishing communications over the wide network852. The modem856, which can be internal or external to computer802, can be connected to the system bus808via the input/output interfaces840or other appropriate mechanisms. It is to be appreciated that the illustrated network connections are exemplary and that other means of establishing communication link(s) between the computers802and848can be employed.

In a networked environment, such as that illustrated with computing environment800, program modules depicted relative to the computer802, or portions thereof, may be stored in a remote memory storage device. By way of example, remote application programs858reside on a memory device of remote computer848. For purposes of illustration, application programs and other executable program components, such as the operating system, are illustrated herein as discrete blocks, although it is recognized that such programs and components reside at various times in different storage components of the computer system802, and are executed by the data processor(s) of the computer.

APPENDIX

Sample Device Capabilities

The following samples represent device capabilities returned to a media player application204on source device102for an example target playback device104that supports audio (including WMA Professional Lossless content with high bitrate), video in WMV format, and still pictures in JPG format. The properties returned by actual target playback devices will differ from these device capabilities according to the actual capabilities of such devices.

Sample Serialized Device Capabilities

The following samples are based on the above sample device capabilities, serialized to XML (i.e., what is saved in the media library208after stripping off the irrelevant content).

CONCLUSION