[MPlayer-users] Accurate a/v sync in mencoder

[T]

Hi, 

What is the recommend way to have a (near) perfect a/v sync using mencoder?

I'm follwing this guide 
http://www.linux.com/article.pl?sid=06/04/17/2058219
to convert my video to DVD format. I.e., 

 mencoder -oac lavc -ovc lavc -of mpeg -mpegopts format=dvd -vf scale=720:576,harddup \
 -srate 48000 -af lavcresample=48000 \
 -lavcopts vcodec=mpeg2video:vrc_buf_size=1835:vrc_maxrate=9800:vbitrate=5000:keyint=15:aspect=16/9:\
 acodec=ac3:abitrate=192 -ofps 25 -o your_video.mpg your_video

But some of the converted mpg files have a/v sync problem -- a/v diff by
half or nearly a whole second at the later half. Some results audio come
before the video, some after.

I've looked into the problem, but was not able to interpret what I read.
E.g.

>From http://forum.doom9.org/archive/index.php/t-83039.html

,-----
| OK, that's a problem with mencoder's A/V sync algorithm, which is common
| when encoding from VOBs. It's not related to x264. If you know the source is
| good, use "-noskip -mc 0". If you need to let mencoder "correct" A/V sync,
| use "-vf harddup".
`-----

>From http://lists.mplayerhq.hu/pipermail/mplayer-dev-eng/2004-May/026323.html

,-----
| I propose we make -mc 0 the default in mencoder. ... If there are no
| objections (or more people for it than against) by late next week I'll
| commit!
`-----

So, here are my questions. 

- How can I tell if my source is good?

I saw lots of "1 duplicate frame(s)!" or such in the output while
converting, meanwhile mencoder reports there is no a/v sync difference:

 Pos:2253.6s  54519f (88%) 119.62fps Trem:   1min 317mb  A-V:0.000 [795:192]

- all files play fine in mplayer, perfect a/v sync. So are they good or bad?

- what's the differece between mplayer a/v sync method and mencoder's? I
presume that they should be almost the same but apparently mplayer
knows/utilizes more than mencoder?

- is current mencoder '-mc 0' by default? Else, will '-mc 0' improve my
current situation? How about -noskip?

- regarding the above converting script, is the MEncoder's frame-skip 
  code disabled?

I looked back and forth in map page trying to understand the following,
but still don't know exactly what it meant for me to do.

,-----
| when generating MPEG files, it is advisable to disable MEncoder's frame-skip
| code (see -noskip, -mc as well as the harddup and softskip video filters).
`-----

thanks

PS. the video that I am converting is real media.

-- 
Tong (remove underscore(s) to reply)
  http://xpt.sourceforge.net/