[Ffmpeg-cvslog] Re: ffmpeg-cvslog Digest, Vol 20, Issue 21

Steve Lhomme steve.lhomme
Wed Nov 8 22:51:17 CET 2006


Alex Beregszaszi <alex at fsn.hu> writes:

 > Hi,
 >
 >> Log:
 >> add support for AAC in matroska
 >
 > Why matroska has to be so complicated? :)

 > I think it was one of the design goals.
 >
 > --
 > M?ns Rullg?rd

 > From: Nico Sabbi <nicola_sabbi at fastwebnet.it>
 > indeed: in every single mmedia program I've seen so far
 > the demuxer for matroska is by far the largest and most
 > full of special cases to handle separately

Oh boy. Not again...

Let me see, Matroska handles more formats than any other format, handles 
attachment, chapters, VFR, compressed data, subtitles, index-less 
playback, fast seeking, gaps, tags, interactive playback (DVD menus), 
seamless file linking and recently 3D/stereo files, all that with the 
lowest overhead. So yes, it may take some code to achieve that.

It can take very little code to actually handle basic matroska files, 
once you have the EBML layer working. (MOV and AVI hide this code in 
riff.c in lavf).

And yes, the AAC codec was a mess so far in matroska as some codec 
"information" were given by the codec ID. Now "A_AAC" alone should be 
used with setting the common MPEG4 extradata (3 or 5 bytes). But old 
files should still be handled...

Steve





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