[Ffmpeg-cvslog] Re: ffmpeg-cvslog Digest, Vol 20, Issue 22

Steve Lhomme steve.lhomme
Thu Nov 9 09:07:37 CET 2006


> From: Nico Sabbi <nicola_sabbi at fastwebnet.it>
> 
> Steve Lhomme wrote:
> 
>> Let me see, Matroska handles more formats than any other format, 
>> handles attachment,
> 
> attachments? external files look much more attractive to me

Album/DVD covers ? Fonts ? These are all in use today and for good reasons.

>> 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
> 
> yes, now that the mess is made...
> The fact remains that in order to handle just the most basic elements 
> (audio and video
> id and extradata) there's a scarily huge amount of code and special cases.

Can you give an example of the huge amount of special cases ?

> And people say that matroska "just works", LOL. Maybe, but at what cost.

You must be right and people must be wrong then.

> 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
> properly...

Personal attack... (blame Thunderbird for not being able to quote with 
signatures, which happen a lot in Digest MLs)

>> 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 ?

>> 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.

Steve

PS: What's the policy on flamewars and trolls around here ?





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