[MPlayer-users] audio half-speed in mencoder v4l TV recording

[Jindrich Makovicka]

On Thu, Nov 28, 2002 at 12:17:23PM -0500, D Richard Felker III wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> On Thu, Nov 28, 2002 at 02:49:57PM +0800, Mike Holland wrote:
> > [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> > Folks,
> >  I am recording from a BT878 TV card, and find the audio at
> > half-speed on playback, with corresponding drop in pitch and volume. Its
> > the same when playing back under assorted windoze players. If I play back
> > with 'mplayer -speed 2', the audio sounds OK, but video doesnt speed up
> > much. They soon get out of sync.
> >    Video is fine. I'm very impressed to see full-res PAL in real-time.
> > 
> >   I'm new here and not sure what to try next. Have browsed the last couple 
> > of months of this list from the archives, read the docs, tried the source 
> > (almost no comments). Is a video driver problem likely in this case?
> >    I tried to get btaudio working, but no sucess yet.
> > 
> > Hardware: nvidia nForce motherboard with i810_audio ; PixelView PlayTV 
> > pro. ; Duron 1.2 ; 256MB DDR; fast hdd.
> > Software: RedHat 7.3, linux 2.4.18, mplayer-0.90pre10
> > 
> > % mencoder -v  -tv 
> > on:driver=v4l:width=768:height=576:device=/dev/video0:input=1 -o tv.avi \
> >     -ovc lavc  -vop pp=lb -oac mp3lame
> > 
> > Output includes:
> >   Opening audio decoder: [pcm] Uncompressed PCM audio decoder
> >   AUDIO: 44100 Hz, 1 ch, 16 bit (0x10), ratio: 88200->88200 (705.6 kbit)
>                     ^^^
> 
> For some reason your audio device is only recording mono! You should
> play around with the -tv options to let it know you're recording mono,
> or else fix this (probably requires trashing your junky onboard sound
> that doesn't support stereo :).

try to specify the audio mode with "amode" and eventually use the
"forcechan" option. mencoder tells you if it finds it may be necessary.

-- 
Jindrich Makovicka