[MPlayer-users] yum4mpeg audio sync broken

[Juergen Hammelmann]

I have created several video with no lag between syncronisation of audio and 
video. Another problem is, if you convert ntsc videos you have 24 frames/sec
instead of 25 frames/sec at pal videos. To recognice this, you have to give 
some more parameters... If not set correctly, the gap is increasing...

Am Freitag, 2. Januar 2004 23:11 schrieb Fredrik Hubinette:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
>
> No, that's not the answer. Because in my particular case, I have a
> movie where the sound is offsetted by ~2 seconds from the video.
>
> If I play the video to the screen, mplayer quickly adjust the video
> to sync up with the audio, but when I use yuv4mpeg audio and the
> -framedrop flag, the code below actually *prevents* mplayer from
> syncing the audio to the video.
>
> I've read mencvcd, and I'm reasonably certain that mencvcd would
> create a video with a 2 second lag between the audio and video,
> just like my script does. (Unless you use --sync 2.0 or some other
> manual fix.)
>
>         /Hubbe
>
> "Jürgen Hammelmann" <Juergen.Hammelmann at gmx.de> writes:
> > [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> > Hi,
> >
> > for encoding with yuv4mpeg you have to disable frame dropping in
> > mplayer!!! Look at my TOOLS/mencvcd script how to do it.
> >
> > Ciao, Jürgen Hammelmann
> >
> > > [Automatic answer: RTFM (read DOCS, FAQ), also read
> > > DOCS/bugreports.html]
> > >
> > > I'm writing a script that uses mplayer as a first step in converting
> > > movies of various formats to DVDs. However, I'm having various problems
> > > with the audio sync, and while reading mplayer.c I came across this
> > > code:
> > >
> > >
> > >          } else {
> > >              /*
> > >              Well, no blitting is needed, but some devices (such as
> > > yuv4mpeg) m\
> > > ust output frame
> > >              otherwise A/V desync will occur. -- Alvieboy
> > >              */
> > >             if (vo_config_count)
> > >                 video_out->control(VOCTRL_DUPLICATE_FRAME, NULL);
> > >          }
> > >
> > >
> > > As far as I can tell, this code is wrong. Frame dropping is done
> > > specifically
> > > to *preserve* A/V sync, and the code above prevents that from working.
> > > I also noticed that there doesn't seem to be any code that can generate
> > > extra frames if the audio should fall behind the video.  The code for
> > > this seems to exist in mencoder, but unfortunately mencoder cannot
> > > output yuv4mpeg...
> > >
> > > In my script I currently have a workaround that reads the "ct:" part of
> > > the mplayer output and drops frames if ct becomes too large, but it's
> > > a really really really ugly workaround.
> > >
> > >   /Hubbe
>
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