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

[D Richard Felker III]

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 :).

Rich