[mythtv-users] Mythtv won't record sound, but everything else does!

[Arren Lex]

I have an ATI TV Wonder HD 600 USB tuner (no encoder chip). It
provides /dev/video0 and /dev/dsp1. I can watch TV perfectly in tvtime
with the sox workaround:

sox -r 48000 -w -c 2 -t ossdsp /dev/dsp1 -t ossdsp /dev/dsp

And I can transcode TV perfectly in mencoder:

mencoder tv:// -tv
driver=v4l2:width=640:height=480:outfmt=yuy2:input=0:device=/dev/video0:norm=NTSC:chanlist=us-cable:channel=13:adevice=/dev/dsp1:audiorate=48000
-ovc lavc -lavcopts vcodec=mpeg4:vbitrate=6400 -oac mp3lame -lameopts
cbr:br=128:mode=3 -ffourcc divx -o  foobar.avi

However, in mythtv, I absolutely CANNOT get sound, no matter how I configure it.

I have set up the card in mythbackend to use /dev/video0 and
/dev/dsp1. In the frontend, I have configured the audio to go out over
/dev/dsp using "default" passthrough. The frontend plays music files
file using these settings, but when I try to watch live TV, I get
video but no sound -- about every five seconds, for a tenth of a
second there is a blip of sound that sounds about right for what's
going on in the show, but other than that it is silent.

When I try to play the .nuv files in mplayer, I get perfect video but
no sound. MPlayer prints these errors over and over as it plays:

Too many video packets in the buffer: (149 in 8414073 bytes).
Maybe you are playing a non-interleaved stream/file or the codec failed?
For AVI files, try to force non-interleaved mode with the -ni option.


When I run mplayer with the -nosound switch, these errors disappear.
When I play the .nuvs in VLC, I again get video but no sound. When I
look at the stats, it says it has decoded tons of video frames, but 0
audio frames.

Looking at the backend output, I sometimes get things like:
NVR(/dev/video0) Error: Only read 336 bytes of 4096 bytes from '/dev/dsp1'.

And the frontend says things like:
NVP: Video is 30 frames ahead of audio, doubling video frame interval
to slow down.

(over and over)

So it looks a lot to me like the backend is messing up the files when recording.

Does anyone have any advice? Is this a bug?

This is mythbuntu 8.10,

myth at myth-desktop:/tmp$ mythbackend --version
Please include all output in bug reports.
MythTV Version   : 18722
MythTV Branch    : branches/release-0-21-fixes
Library API      : 0.21.20080304-1
Network Protocol : 40
Options compiled in:
 linux profile using_oss using_alsa using_arts using_jack
using_backend using_dbox2 using_dvb using_firewire using_frontend
using_hdhomerun using_iptv using_ivtv using_joystick_menu
using_libfftw3 using_lirc using_opengl_vsync using_opengl_video
using_v4l using_x11 using_xrandr using_xv using_xvmc using_xvmcw
using_xvmc_vld using_glx_proc_addr_arb using_bindings_perl
using_bindings_python using_opengl using_ffmpeg_threads
using_libavc_5_3 using_live

myth at myth-desktop:/tmp$ mythfrontend --version
Please include all output in bug reports.
MythTV Version   : 18722
MythTV Branch    : branches/release-0-21-fixes
Library API      : 0.21.20080304-1
Network Protocol : 40
Options compiled in:
 linux profile using_oss using_alsa using_arts using_jack
using_backend using_dbox2 using_dvb using_firewire using_frontend
using_hdhomerun using_iptv using_ivtv using_joystick_menu
using_libfftw3 using_lirc using_opengl_vsync using_opengl_video
using_v4l using_x11 using_xrandr using_xv using_xvmc using_xvmcw
using_xvmc_vld using_glx_proc_addr_arb using_bindings_perl
using_bindings_python using_opengl using_ffmpeg_threads
using_libavc_5_3 using_live

Thanks!
Alex