[MPlayer-users] number of yuv4mpeg frames does not match audio length.

[Maarten de Boer]

Hello,

Sorry for crossposting, but the problem I describe occurs with all three
applications, mplayer, mencoder and ffmpeg. I you respond for a specific
application, please use the respective mailinglist only.

I am trying to convert a VOB file to h264+aac in an mp4 container (using
x264, faac and MP4Box). I don't get the mp4 to be A/V sync (the
material has some very obvious points). Investigating this problem, I
found that the yuv4mpeg stream that I am using as input for x264 does
not have the expected number of frames. As a reference, I look at the
duration of the extracted audio:

mplayer -vo null -ao pcm test.vob

Duration    : 00:00:11.168

At my framerate of 29.97, this corresponds with 334.7 frames (not sure 
whether to round this up or truncate it)

However this is what I get with:

mplayer -harddup -noframedrop -vo yuv4mpeg -ao null test.vob

  333 frames

mencoder test.vob -vf-add harddup -vf-add =i420 -ovc raw -of rawvideo -nosound -o mencoder.420

  333 frames

ffmpeg -i test.vob -f yuv4mpegpipe ffmpeg.yuv

  342 frames (starting with 1 totally green frame)

Especially the ffmpeg output is quite surprising. I guess the mplayer/mencoder
output could be correct, and the sync problem is elsewhere, though this still
doesn't account for the missing frame...

Any advice would be greatly appreciated!

Maarten