[MEncoder-users] transcoding from variable framerate MP4 to avi, a/v sync problem - video stream much shorter

[L. Lee]

On 7/30/11 3:01 PM, "SilentShade" <lifeemulation at gmail.com> wrote:

> Hello everybody.
> I'm trying make an all-in-one transcoder for any types of video, for web
> streaming. The output is AVC/AAC in MP4 container. For that i use the
> following techique:
> 1. Encode input to avc/aac and remux it to avi container. (mencoder)
> 2. Demux audio and video steams into separate files
> 3. Mux to mp4 with gpac MP4Box
> 
> I ran into problem with an input mp4 file having variable framerate.
> The sample command for stage 1 is:
> mencoder -af volnorm=2 -oac faac -faacopts br=98:mpeg=4:object=2 -channels 2
> -srate 44100 -ovc x264 -x264encopts
> bitrate=500:subq=5:frameref=6:cabac:threads=auto:bframes=3:b_pyramid=normal:we
> ight_b -ofps 30000/1001 -vf pp=hb/vb/lb,dsize=960:720:0,scale=-8:-8,harddup
> infile.mp4 -o tmp.avi
> 

Have you tried specifying a demuxer (-demuxer lavf, for example)?