[Ffmpeg-devel] Containers (was: On2 Flix Engine uses memcoder in commerical Flix Engine)

[Steve Lhomme]

M?ns Rullg?rd wrote:
> Steve Lhomme <steve.lhomme at free.fr> writes:
> 
>> Rich Felker wrote:
>>> On Fri, Apr 28, 2006 at 06:17:39PM +0200, Steve Lhomme wrote:
>>>>> Matroska is overly complicated and bloated.
>>>> What do you find complicated ?
>>>>
>>>> Given 3 developers wrote their own parser simply based on the one
>>>> HTML page of specs.
>>> And how many lines of code is their parser? It's fucking huge!!
>>> Even if it were simple, a parser is only a tiny part of a demuxer. The
>>> complicated part is the semantics.
>> Haali's splitter (used in the official DShow splitter and in TCPMP) is
>> smaller than the parser in FFMPEG and handles far more semantics and
>> codecs.
> 
> That sentence alone is proof that matroska is a flawed format.  A
> demuxer should not need any specific handling of different codecs
> beyond a simple table of codec identifiers.

Well, I spend a lot of time thinking about what a container is. And I 
came to a different conclusion. Apparently I'm not alone since in 
GStreamer ID3 tags are considered a container and I think they are 
right, it's probably the most minimalist container.

> If you think lines of code are important, consider these line counts
> for a few demuxers I have written myself purely based on the specs:
> 
> matroska 1808
> avi      1094
> ogg      1147
> mpeg ps   688
> mpeg ts   842
> 
> The matroska demuxer handles only the basics (reading and seeking),
> and makes no attempts to recover from errors in the file.  The others
> are complete with error recovery.
> 
> I'm not claiming that my code is particularly efficient or well
> written, but I suspect that all code I write is of similar quality.  I
> thus believe that the line counts may indicate something about the
> complexity of those formats.

Given ogg is unusable without parsing the codec data I don't think it's 
fair to compare it. And I wouldn't compare containers as they have 
different designs, goals, good sides and bad sides. For example in that 
list only AVI and matroska have seek entry (optional in matroska as most 
of it) and can do chapters (theoretical in AVI).

Steve

-- 
robUx4 on blog <http://robux4.blogspot.com/>