[MEncoder-users] mencoder skipping frames.

[Rich Felker]

On Tue, Jul 26, 2005 at 09:38:06AM -1000, AaronL wrote:
> Rich Felker wrote:
> 
> >On Thu, Jul 07, 2005 at 08:14:28PM -0500, Mike Hodson wrote:
> > 
> >
> >>try -vf filmdint, -fps 29.970 -ofps 23.976
> >>this should force input fps to be treated as 29.97 with a telecine,
> >>and the filmdint plugin will take it down to progressive 24fps aka
> >>23.976. i've had good luck with these options before.
> >>   
> >>
> >
> >
> >-fps should not be used for cases like this. it will either do nothing
> >or cause a/v desync. second, 29.97 and 23.976 are _wrong_. the numbers
> >are 30000/1001 and 24000/1001.
> >
> >and... please do not top post!
> >
> >rich
> >
> > 
> >
> 
> Sorry for the long discontinuity.  It's been a while since I have time 
> to do some more tests.  So far I've tried "-mc 0" and the skip frame 
> problem goes away but that causes a/v desync.
> I've also tried "-vf pullup,softskip" and this still cause skip frames.
> 
> Finally, I tried using the "-vf filmdint" option, but the video still 
> skips frames.  Here's my command line.
> 
> mencoder dvd://1 -fps 30000/1001 -ofps 24000/1001 -oac mp3lame -lameopts 
                   ^^^^^^^^^^^^^^^
Did you read what I said above? DO NOT USE -FPS! EVER! Unless you
understand what it does.

> abr:br=128 -vf filmdint,crop=720:352:0:62,scale=576:240 -ovc lavc 
> -lavcopts vcodec=mpeg4:vbitrate=768:v4mv:mbd=1:aspect=2.4:vpass=1 -aid 
> 128 -o output.avi
> 
> It looks like mencoder is trying to keep a/v sync by skipping frames, 
> but forcing mencoder to not skip frames cause a/v desync...i don't know 
> what else to try...am I the only one with this problem?

Well you're mixing different problems. Try the above command line with
-fps nonsense removed and with -oac copy and see if the a/v desync
goes away. If so, try with lame. If a/v sync is back, it's a bug in
lame and you can work around it with splitting the audio and video and
remuxing after encoding.

Rich