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

[Måns Rullgård]

Michael Niedermayer <michaelni at gmx.at> writes:

> Hi
>
> On Sunday 08 May 2005 00:09, M?ns Rullg?rd wrote:
> [...]
>
>>
>> I'd still also like to know how to -acodec copy an AC3 stream from one
>> MPEG file to another, without --enable-a52.
>
> mpeg needs a decoder or parser to split things into packets and find the 
> timestamps for each, not to mention that stuff like the samplingrate is 
> stored in the AC3 stream
> there shouldnt be a problem with just extracting the raw AC3 stream without 
> --enable-a52, but putting it back into any file wont work, even for 
> mpeg-ps/ts you need to know the packet boundaries so the pts/dts values are 
> correct unless of course you somehow ensure that the same set of bytes which 
> was in a mpeg system packet ends up again in exactly one

Returning exactly one PES packet per AVPacket would make that
straigt-forward.

> thats not really a ffmpeg problem but a fundamental problem with
> mpeg-ps/ts, the easiest solution would be to make the existing ac3
> AVParser independant from the ac3 decoder

Parsing enough of the AC3 packets is quite simple, so that shouldn't
be too difficult.  Likewise for DTS, if anyone dares.

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