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

[Baptiste COUDURIER]

Rich Felker wrote:
> 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.

It seems extradata from x264 is not passed to lavf muxer. avcC atom is 
empty.

>>> 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.
> 

I was more referring to mp4 muxing in lavf. Mencoder does not pass 
correct dts to lavf muxer ? May I suggest to use ffmpeg then ?

-- 
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