[MEncoder-users] a/v sync problems

Jon Drukman jdrukman at gmail.com
Tue Feb 3 01:22:32 CET 2009

I'm trying to convert videos from many different sources into H.264/AAC 
that can be played on the web (in flash player) and on the iphone. 
Ideally one file would serve both purposes.

I've got a recipe that works for lots of different types of videos, 
using mplayer/mencoder to extract the video and audio and convert to 
H.264.  I use MP4Box to recombine the streams.

It is falling down a lot on certain .mov files.  The most recent 
problematic example are videos taken with the "Photo Booth" app on Mac 
OS.  It seems like the video is actually 15fps, but mplayer identifies 
it as something totally random.  It plays fine if I just watch the 
original with mplayer, but converting it usually causes the video to run 
too fast.

the script looks something like this:

mencoder "$input" -o "temp.264" -vf scale=-10:368:noup=1,harddup -ssf 
lgb=0.2 -ovc x264 -x264encopts 
  -of rawvideo -nosound  -ofps 30000/1001

mplayer "$input" -ao pcm:fast:waveheader:file="temp.wav" -vc null -vo dummy
faac -q 80 -o temp.aac temp.wav

MP4Box -add temp.264#video:fps=29.97 out.m4v
MP4Box -add $input#audio out.m4v

I've tried various combinations of -fps, -ofps, -mc, -noskip, but 
nothing is working.  Any ideas?  I can supply a test clip if necessary.


More information about the MEncoder-users mailing list