[MPlayer-users] A/V sync problems whendDigitizing old VHS tapes with mencoder

[Josef Wolf]

Hello folks,

Is there anybody out there to help me? I am almost about to give up :-((

For more than a month I am trying to digitize those VHS tapes via a BT848
card and a standard sound card.

No matter what I do, I keep getting bad A/V sync. The problem seems to be
caused by those empty/broken/muted/whatever video frames that are sent by
the VHS recorder when it gets tracking problems (e.g. whenever there is a
switch from one recording to the next on the same VHS tape).

I have tried virtually every possible combination of the -noskip, -forceidx,
-noidx, -framedrop, -hardframedrop, -mc, and whatever options I could think
of. But I could not come up with a combination that works properly.

I even tried the hack that was suggested in

  http://lists.mplayerhq.hu/pipermail/mencoder-users/2009-November/010945.html

on this list to stop the capturing process and run

  mencoder -forceidx -ovc copy -oac copy capture.avi fixed.avi

while it is halted. Still bad sync.

In mplayer, the result looks like the bad video frames are played about
double as fast as they should be played and audio is played with correct
speed. In reality, there are not enough video frames captured during the
tracking period, I guess. I can confirm this from the debug output of the
capturing process. The fps value drops to about 12fps when I capture such
line noise.

Here is what I use to capture:

  mencoder tv:// -tv outfmt=yv12:driver=v4l2:input=1:fps=25:quality=100:norm=pal:buffersize=100:forceaudio:alsa:adevice=hw.0,0,0:amode=1:immediatemode=0:width=768:height=576 -noskip -oac copy -ovc copy -of avi -o outfile.avi

Any ideas ?