[MEncoder-users] how I solved A/V sync problems

[Carlos F Lange]

Hi,

I was working on two videos, one MJPG from my Fulifilm S6000 camera and 
one TV clip on DVD I received from a local TV station.

In both cases I wanted to transcode them to MPEG-4 and I got a 
progressive synchronization problem, i.e. they both start synchronized, 
but they grew out of sync as time passed. The camera video had a sound 
acceleration and it was 1 second ahead after 2 minutes. The TV clip had 
a progressive sound delay and the sound track was about 1 second behind 
after 5 minutes. Both cases could not be solved with -audio-delay, 
because the delay changed with time. The same problem occurred whether 
I used "-oac copy" or encoding with mp3lame.

I tried several options and recommendations from the mailing-list, 
including -mc 0, -noskip, -skiplimit 0, but they had no effect. Before 
submitting my question I wanted to try all options and I hit one that 
finally solved the synchronization problem in both cases:
-vf harddup

The resulting AVIs have a few tiny hick-ups in the playback, which is 
probably where the desync problems occurred and grew, but these are 
minor annoyances in my case for the huge benefit of having the audio 
synchronized with the images throughout.

Since this killed two flies with one swat for me, I thought I would post 
it here.

-- 
Carlos FL

Who is General Failure, and why is he reading my disk?