[mythtv-users] Audio lags when transcoding 720p from cable box firewire

[Stephen Sassman]

I have been trying to transcode some 720p video captured from the
firewire of my cable box (motorolla 6200 series). I am transcoding to
x264 to a matroska container which works perfectly with my ivtv
recordings. The problem that I am having is that the audio track lags
behind the video, and it gets worse as the video progresses. By the end
of a 90min movie, the audio can end up more than 10 sec behind the
video. I have tried using avidemux, mencoder, and ffmpeg with the same
result. Here is the command line that I'm using in mencoder:

mencoder file.mpg -vf crop=944:688:168:16 -ovc x264 -x264encopts
subq=6:me=umh:8x8dct:partitions=all:bframes=3:frameref=3:mixed_refs:dct_decimate:threads=0:weight_b:crf=23
-oac copy -o file.mkv


I use similar settings with ffmpeg and avidemux. The original mpeg has
no issues with audio sync. I have seen mention of similar problems, but
never a clear solution. Any idea?