[Ffmpeg-cvslog] Re: ffmpeg-cvslog Digest, Vol 20, Issue 22
Thu Nov 9 09:41:04 CET 2006
Steve Lhomme <steve.lhomme at free.fr> writes:
>> From: M?ns Rullg?rd <mru at inprovide.com>
>> Steve Lhomme <steve.lhomme at free.fr> writes:
>>> 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.
>> Oh boy. So much fluff from someone who can't even quote an email
> Personal attack... (blame Thunderbird for not being able to quote with
> signatures, which happen a lot in Digest MLs)
And who should be blamed for you using thunderbird?
>>> 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).
>> The rather large size of all known matroska demuxers seems to
>> contradict that statement.
> Can you give examples instead of just waving things in the air ?
$ cd ~/src/tcvp/src/demuxer
$ wc -l avi/*.c
$ wc -l matroska/*.c
$ wc -l mpeg/mpegps.c
$ wc -l mpeg/mpegts.c
$ wc -l ogg/*.c
$ cd ~/src/ffmpeg/libavformat
$ wc -l avidec.c gxf.c matroska.c mov.c mpeg.c mpegts.c mxf.c
1824 mpeg.c # includes muxer
>>> 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).
>> The spec on the web fails to mention this.
> The codec page on the site was never up to date. Only Mosu and Haali
> know exactly about all the ones used (and looking in their OSS code,
> of course), but they aren't willing to update the specs. They are free
> to answer questions though.
mru at inprovide.com
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