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== A proposal for adding free codecs as optional Media Format Profiles to the DLNA specification ==

The [http://upnp.org UPnP] specification relies on the mimetype - ''audio/mpeg'' or ''image/jpeg'' - to provide information to the clients about which
media format the exported data is encoded in.

As this most of the time isn't specific enough - just think of mobile clients with little decoding power, or mimetypes that describe containers formats that may contain media in various different encodings - 
[http://dlna.org DLNA] introduced Media Format Profiles to clearly identify the media formats used in the image, audio and AV media classes.

The Media Format Profile is stored in the DLNA.ORG_PN extension - ''DLNA.ORG_PN=MP3'' or ''DLNA.ORG_PN=JPEG_SM'' - equivalent to the mimetypes mentioned above, but in case of the image this profile states that it must not exceed 640 pixels in width and 480 pixels in height.

Albeit [http://gxben.wordpress.com/2008/08/24/why-do-i-hate-dlna-protocol-so-much/ one could argue] that this kind of bureaucracy overshoot the mark, but it definitely allows a much more fine-grained characterization of the media data - native or transcoded - held ready by a MediaServer and the media a MediaRenderer actually is able to handle. 

Anyway, there are mandatory  (JPEG_SM,LPCM,MP3,AVC_MP4_BL_CIF15_AAC_520,...) - and optional Media Format Profiles (JPEG_LRG,PNG_LRG,...). Mandatory are the ones a DLNA-certified device __must__ understand - the least common denominator - and the optional ones are profiles a device __could__ implement. Having that common ground is imho a very important thing, and on the other hands nothing prevents devices to handle codecs and formats that aren't defined there.

Unfortunately there are no free codecs included in the initial and in the extended set of Media Format Profiles, offering especially open source implementations a Hobson's choice.

So this document is about defining optional Media Format Profiles for some of the free codecs - [http://www.vorbis.com OGG Vorbis] and [http://diracvideo.org/ Dirac] are chosen as initial candidates for this task.

To get these proposals accepted for review by the DLNA organisation, we have to fulfill these requrements:

 * test content representative in terms of sampling frequency and any other parameters
 * reference document used for basis for both codec & container
 * market wise information on both of these
 * if applicable a separation of profile, if some are applicable only to a MHD (Mobile Handheld Device) and other to a HND (Home Network Device)


=== OGG Vorbis ===

Driven by [http://blogs.gnome.org/uraeus Christian Schaller] I've started with the [attachment:"DLNA Vorbis proposal v2.odt" a document] proposing the audio codec Vorbis.

==== Tasks ([/newticket?component=DLNA%20Vorbis%20proposal&type=task new...]) ====

[[TicketQuery(component=DLNA Vorbis proposal&status=new|assigned|closed)]]

=== Dirac ===

==== Tasks ([/newticket?component=DLNA%20Dirac%20proposal&type=task new...]) ====

[[TicketQuery(component=DLNA Dirac proposal&status=new|assigned|closed)]]