- From: Thierry MICHEL <tmichel@w3.org>
- Date: Tue, 21 Sep 2010 16:22:50 +0200
- To: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
- CC: "public-media-annotation@w3.org" <public-media-annotation@w3.org>
http://www.w3.org/2008/WebVideo/Annotations/drafts/ontology10/CR/test.php?table=containerOGG Le 21/09/2010 16:00, Silvia Pfeiffer a écrit : > Hi Thierry, > > I saw the two sections and my reply was indeed targeted at the container > format section. As I said: skeleton should be regarded as part of the > container format and because Skeleton includes metadata, it should be > counted (see > http://github.com/cpearce/OggIndex/blob/master/Skeleton-4.0-Index-Specification.txt). > My point was that all of the information you are after is already included > in the previous table everywhere where it says "skeleton". I guess in this previous metadata table, all these information which are now redondant with the OGG container table, should be removed. OGG container table: http://www.w3.org/2008/WebVideo/Annotations/drafts/ontology10/CR/test.php?table=containerOGG thierry. > > Anyway, happy to help - here is the table: > > <table class="ta20" border="1"> > > <tbody> > <tr class="ro-header"> > <th class="col-mawg">MAWG</th> > > <th class="col-relation">Relation</th> > <th class="col-attribute">OGG</th> > > <th class="col-how">How to do the mapping</th> > > > <th class="col-datatype">Datatype</th> > <th class="col-xpath">XPath</th> > > </tr> > <tr class="ro-header"> > <td class="ma" colspan="6">Descriptive Properties (Core Set)</td> > > </tr> > <tr class="ro-header"> > > > <td class="col-mawg" colspan="6"><em>Identification</em></td> > > </tr> > <tr class="ro-even"> > <td class="ma">ma:identifier</td> > > <td>exact</td> > <td>Name</td> > <td>Name field in skeleton header (new)</td> > > <td>String</td> > > <td>N/A</td> > </tr> > > <tr class="ro-header"> > <td class="col-mawg" colspan="6"><em>Content description</em></td> > > </tr> > <tr class="ro-even"> > <td class="ma">ma:description</td> > > <td>related</td> > > <td>Title</td> > <td>Title field in skeleton header (new)</td> > > <td>String</td> > <td>N/A</td> > </tr> > > <tr class="ro-header"> > <td class="col-mawg" colspan="6"><em>Technical Properties</em></td> > > </tr> > > <tr class="ro-even"> > <td class="ma">ma:frameSize</td> > > <td>N/A at container level</td> > <td></td> > <td></td> > > <td></td> > <td></td> > </tr> > > <tr class="ro-odd"> > <td class="ma">ma:compression</td> > > <td>exact</td> > <td>Content-type</td> > <td>Content-type field of Skeleton header</td> > > <td>MIME type</td> > <td>N/A</td> > </tr> > > <tr class="ro-even"> > <td class="ma">ma:duration</td> > > <td>exact</td> > <td></td> > <td>calculate as duration = last_sample_time - > > first_sample_time of OggIndex header of skeleton</td> > <td>Float (or rather: rational - rational)</td> > > <td>N/A</td> > </tr> > > <tr class="ro-odd"> > > <td class="ma">ma:format</td> > <td>exact</td> > > <td>Content-type</td> > <td>Content-type field of Skeleton header</td> > > <td>MIME type</td> > <td>N/A</td> > </tr> > > <tr class="ro-even"> > <td class="ma">ma:samplingRate</td> > > <td>exact</td> > <td></td> > <td>calculate as granulerate = granulerate_numerator / > > granulerate_denominator of Skeleton header</td> > <td>Rational (or rather int / int)</td> > <td>N/A</td> > > </tr> > > <tr class="ro-odd"> > <td class="ma">ma:frameRate</td> > > <td>exact</td> > <td></td> > <td>calculate as granulerate = granulerate_numerator / > > granulerate_denominator of Skeleton header</td> > <td>Rational (or rather int / int)</td> > <td>N/A</td> > > </tr> > > <tr class="ro-even"> > <td class="ma">ma:averageBitRate</td> > > <td>exact</td> > <td></td> > <td>calculate as bitrate = length_of_segment / duration from > > OggIndex headers of skeleton</td> > <td>Float</td> > <td>N/A</td> > > </tr> > > <tr class="ro-odd"> > <td class="ma">ma:numTracks</td> > > <td>N/A on container level</td> > <td></td> > <td></td> > > <td></td> > <td></td> > </tr> > > </tbody> > </table> > > Cheers, > Silvia. > > > On Tue, Sep 21, 2010 at 11:22 PM, Thierry MICHEL<tmichel@w3.org> wrote: > >> Silvia, >> >> I think you are misunderstanding/missing what we have decided during our >> last F2F in Sophia. >> >> Your contribution is still included in the latest draft of the Ontology >> specification >> >> >> http://dev.w3.org/2008/video/mediaann/mediaont-1.0/mediaont-1.0.html#d0e8203 >> >> Your OGG table is included in the following section >> 5.2.2 Multimedia metadata formats mapping tables >> >> but we have created a new section for >> 5.2.3 Multimedia container formats mapping tables >> >> where we have added these containers: 3gp, flv, mov, mp4, ogg, webm >> >> Feel free to update the OGG container table, if you have expertize on this >> container, >> the file is at: >> >> http://dev.w3.org/2008/video/mediaann/mediaont-1.0/mappings/container-OGG.htm >> >> Thierry. >> >> >> >> >> >> >> Le 21/09/2010 14:55, Silvia Pfeiffer a écrit : >> >> I think you misunderstand some of the way in which Ogg works. Skeleton is >>> actually part of the container format and thus all the metadata that >>> skeleton supports has to be attributed to Ogg. See: >>> >>> http://github.com/cpearce/OggIndex/blob/master/Skeleton-4.0-Index-Specification.txt >>> >>> May I ask what happened to the Ogg mapping table that I previously >>> contributed and why that is not being used? I have contributed a mapping >>> table for Ogg files, which I think is now at >>> >>> http://dev.w3.org/2008/video/mediaann/mediaont-1.0/mediaont-1.0.html#d0e8203 >>> . >>> It includes the skeleton metadata, which should be counted as >>> container-level metadata. >>> >>> Cheers, >>> Silvia. >>> >>> >>> >>> On Tue, Sep 21, 2010 at 8:28 PM, Thierry MICHEL<tmichel@w3.org> wrote: >>> >>> >>>> I have investigated into the OGG container to fill our OGG mapping table >>>> [1] >>>> >>>> Ogg does not know anything about the content it carries and leaves it to >>>> the media mapping of each codec to declare and describe itself. There is >>>> no >>>> meta information available at the Ogg level about the content tracks >>>> encapsulated within an Ogg physical bitstream. >>>> >>>> read more at >>>> http://www.xiph.org/ogg/doc/skeleton.html >>>> >>>> >>>> >>>> Ogg does not replicate codec-specific metadata into the mux layer in an >>>> attempt to make the mux and codec layer implementations 'fully >>>> separable'. >>>> Things like specific timebase, keyframing strategy, frame duration, etc, >>>> do >>>> not appear in the Ogg container. The mux layer is, instead, expected to >>>> query a codec through a centralized interface, left to the >>>> implementation, >>>> for this data when it is needed. >>>> >>>> Though modern design wisdom usually prefers to predict all possible needs >>>> of current and future codecs then embed these dependencies and the >>>> required >>>> metadata into the container itself, this strategy increases container >>>> specification complexity, fragility, and rigidity. >>>> >>>> read more at >>>> http://www.xiph.org/ogg/doc/oggstream.html >>>> >>>> Therfore I guess there is not much to fill in our OGG mapping table. >>>> >>>> Thierry >>>> >>>> >>>> [1] >>>> >>>> http://dev.w3.org/2008/video/mediaann/mediaont-1.0/mediaont-1.0.html#d0e12764 >>>> >>>> >>>> >>>
Received on Tuesday, 21 September 2010 14:23:18 UTC