[MPlayer-dev-eng] Re: h264+aac in lavf mp4

[Rich Felker]

On Sun, Mar 19, 2006 at 04:27:00PM +0100, Baptiste COUDURIER wrote:
> Erik Slagter wrote:
> >Hi,
> >
> >Just, asking, is putting h264 and aac in mp4 using the lavf muxer mp4
> >supposed to work at the moment, or maybe it's known broken?
> >
> >Some additional info: when I try this, the resulting file plays only
> >audio in mplayer, video says: "Error while decoding frame". I must admit
> >this an improvement since Michael's audio chunk patch, because the audio
> >now works.
> 
> I bet fourcc is H264, changing fourcc to avc1 will make it work.
> 
> >If I do exactly the same, but choose avi as container, all is OK... 
> >
> >I was testing with b frames forced to 0, btw.
> >
> >Afaik there is an issue with the lavf muxer and b frames, are there more
> >known issues in this area?
> 
> lavf muxer was fixed recently to reformat nals when muxing into mp4, it 
> should be working fine. It should also generate correct avcc atom, and 
> ctts to handle B frames. I don't know any issue about it yet.

No!! IT ABSOLUTELY DOES NOT WORK WITH B FRAMES!
The problem is fundamental, that the timestamps are WRONG. If you make
files with B frames using the lavf muxer they will be hopelessly
incorrect. Some incorrect players may play them correctly, but the
files muxed in this way have valid semantics that SHOULD be played
totally out-of-order by any correct player.

Rich