[Ffmpeg-devel] [PATCH] configure.c: CONFIG_ENCODERS

[Måns Rullgård]

"Fran?ois Revol" <revol at free.fr> writes:

>> Rich Felker <dalias at aerifal.cx> writes:
>> 
>> > On Sat, May 07, 2005 at 09:32:20PM +0200, Roine Gustafsson wrote:
>> >> 
>> >> On May 7, 2005, at 8:19 PM, M?ns Rullg?rd wrote:
>> >> 
>> >> >Roine Gustafsson <roine at users.sourceforge.net> writes:
>> >> >
>> >> >>Patch sets CONFIG_ENCODERS and CONFIG_DECODERS depending on 
>> > > > > wether the
>> >> >>user has added any encoders or decoders.
>> >> >>The idea is to use CONFIG_[EN|DE]CODERS for libavformat and use
>> >> >>CONFIG_<x>_[EN|DE]CODER for libavcodec.
>> >> >>Then libavformat would have no 'encoders' (muxers) if libavcodec 
>> > > > > has
>> >> >>no encoders at all.
>> >> >
>> >> >You might still want the ability to mux streams from other
>> >> >encoders, or copied from the input.
>> >> 
>> >> You might have misunderstood: If there are ANY decoders, it will
>> >> enable ALL demuxers, and similar for encoders.
>> >
>> > Yes, this is wrong. There's no reason you need decoders to use
>> > demuxers, and no reason you need encoders to use muxers.
>> 
>> The requirement of decoders for demuxers is a design flaw in
>> libavformat.  Fixing it now will not be easy.
>> 
>
> The requirement of containers to parse encoded data to retrieve basic 
> infos such as frame rate is a design flaw in those containers (see NSV 
> and many others). Do you plan on fixing the file format themselves too?

A file format is broken, if parsing the file depends on the contained
data.  This is not the same as allowing the container to omit some
information that the decoder can fill in later.

-- 
M?ns Rullg?rd
mru at inprovide.com