[FFmpeg-devel] About guess_correct_pts / AVFrame.best_effort_timestamp

[Luca Barbato]

On 02/17/2011 09:48 PM, Nicolas George wrote:
> Le nonidi 29 pluvi?se, an CCXIX, Luca Barbato a ?crit :
>> I don't see why. Cramming half demuxer in libavcodec doesn't sound
>> correct.
> 
> That is the other way around: determining the PTS when there is none
> requires cramming a significant part of a decoder (the parser) in the
> parser.
> 
> Do you agree with the following principle:
> 
> A demuxer that decodes perfectly the information in its supported format but
> does not examine the payload data at all should be acceptable.

Depends on the container. Broken containers exist...


>> The main flaw is assuming that libavcodec, with the data it has, can do
>> something reliable.
> 
> Why should lavf be able to do it then? lavc has more information than lavf,
> since it has all information extracted by lavf plus everything in the
> payload.

because h264 in nut or h264 in mkv shouldn't be interpreted as h264 in
avi just to name one...

If you want to extract information from the codec and use it to help
getting valid information to sync streams you should do that in a place
in which you are aware of ALL the information available, this place
usually it's outside the decoder...

lu

-- 

Luca Barbato
Gentoo/linux
http://dev.gentoo.org/~lu_zero