Mailing List Archive: Live TV

Live TV - no sound

Apr 28, 2003, 9:24 PM

Post #1 of 4 (1381 views)

I can view live TV but without sound. I can record...also no sound

is this a permissions issue with /dev/dsp???

user: bob
group: audio

read write for both user and group

I'm running front and backend as the user bob and NOT as root.

alsa is working..I think. If i set line in at capture and mute then the
sound does not come out.

If I set line in at capture and unmute, then i get sound but it's
obviously delayed. assuming this is analog.

pause works, rewind..record. i'm very close i think.

sh-2.05b$ mythbackend
Starting up as the master server.
Probed: /dev/video0 - Television
Probed: /dev/video0 - Composite1
Probed: /dev/video0 - S-Video
Probed: /dev/video0 - Composite3
adding: bob.chrisrickert.com as a player 1
adding: bob.chrisrickert.com as a player 0
adding: bob.chrisrickert.com as a player 0
adding: bob.chrisrickert.com as a remote ringbuffer
Changing from None to WatchingLiveTV
Cannot open DSP '', dying.
Could not detect audio blocksize
audio volume set to '32768'
Cannot open DSP '', exitingChanging from WatchingLiveTV to None

Re: Live TV - no sound [ In reply to ]

marc.deleenheer at pandora

Apr 29, 2003, 2:51 AM

Post #2 of 4 (1362 views)

Permalink

> I can view live TV but without sound. I can record...also no sound
>
> is this a permissions issue with /dev/dsp???
>
> user: bob
> group: audio
>
> read write for both user and group
>
> I'm running front and backend as the user bob and NOT as root.

This shouldn't be a problem.

>
> alsa is working..I think. If i set line in at capture and mute then the
> sound does not come out.
>
> If I set line in at capture and unmute, then i get sound but it's
> obviously delayed. assuming this is analog.

Check if you really have plugged in the patch cable in LINE IN, and not MIC.

>
> pause works, rewind..record. i'm very close i think.
>
> sh-2.05b$ mythbackend
> Starting up as the master server.
> Probed: /dev/video0 - Television
> Probed: /dev/video0 - Composite1
> Probed: /dev/video0 - S-Video
> Probed: /dev/video0 - Composite3
> adding: bob.chrisrickert.com as a player 1
> adding: bob.chrisrickert.com as a player 0
> adding: bob.chrisrickert.com as a player 0
> adding: bob.chrisrickert.com as a remote ringbuffer
> Changing from None to WatchingLiveTV
> Cannot open DSP '', dying.

This may be because another process has grabbed /dev/dsp. Look at the HOWTO:

http://www.mythtv.org/docs/mythtv-HOWTO-18.html#ss18.11

> Could not detect audio blocksize
> audio volume set to '32768'
> Cannot open DSP '', exitingChanging from WatchingLiveTV to None

On a related note, I have a question also. Anyone know why the sound is
VERY quiet when watching LiveTV or recordings (MythMusic, MythVideo and
MythGame don't have these problems). If I turn on ALL channels (in ALSA
and in Myth) to a 100%, I still need to pump up the volume of my TV set to
about 50-75%, whereas watching TV without Myth only required 25-40%.
I have a CMedia 8738 (driver cmipci) and ALSA 0.9.2.

mdl

Re: Live TV - no sound [ In reply to ]

antti.boman at mindcom

Apr 29, 2003, 3:17 AM

Post #3 of 4 (1358 views)

Permalink

Marc De Leenheer wrote:
> On a related note, I have a question also. Anyone know why the sound is
> VERY quiet when watching LiveTV or recordings (MythMusic, MythVideo and
> MythGame don't have these problems). If I turn on ALL channels (in ALSA
> and in Myth) to a 100%, I still need to pump up the volume of my TV set to
> about 50-75%, whereas watching TV without Myth only required 25-40%.
> I have a CMedia 8738 (driver cmipci) and ALSA 0.9.2.

Just to let you know, I have the same chip (and driver), and I have the
problem you mentioned, too. Haven't looked for a solution yet, though.

-a

Re: Live TV - no sound [ In reply to ]

chris.rickert at mchsi

Apr 29, 2003, 5:14 PM

Post #4 of 4 (1362 views)

Permalink

On Tue, 2003-04-29 at 04:51, Marc De Leenheer wrote:
> > I can view live TV but without sound. I can record...also no sound
> >
> > is this a permissions issue with /dev/dsp???
> >
> > user: bob
> > group: audio
> >
> > read write for both user and group
> >
> > I'm running front and backend as the user bob and NOT as root.
>
> This shouldn't be a problem.
>
> >
> > alsa is working..I think. If i set line in at capture and mute then the
> > sound does not come out.
> >
> > If I set line in at capture and unmute, then i get sound but it's
> > obviously delayed. assuming this is analog.
>
> Check if you really have plugged in the patch cable in LINE IN, and not MIC.
>
> >
> > pause works, rewind..record. i'm very close i think.
> >
> > sh-2.05b$ mythbackend
> > Starting up as the master server.
> > Probed: /dev/video0 - Television
> > Probed: /dev/video0 - Composite1
> > Probed: /dev/video0 - S-Video
> > Probed: /dev/video0 - Composite3
> > adding: bob.chrisrickert.com as a player 1
> > adding: bob.chrisrickert.com as a player 0
> > adding: bob.chrisrickert.com as a player 0
> > adding: bob.chrisrickert.com as a remote ringbuffer
> > Changing from None to WatchingLiveTV
> > Cannot open DSP '', dying.
>
> This may be because another process has grabbed /dev/dsp. Look at the HOWTO:
>
> http://www.mythtv.org/docs/mythtv-HOWTO-18.html#ss18.11
>
> > Could not detect audio blocksize
> > audio volume set to '32768'
> > Cannot open DSP '', exitingChanging from WatchingLiveTV to None
>

follwing the howto mentioned above, this is what happens when playing
audio of Xawtv to /dev/sound/dsp

[root@bob bob]# aplay /dev/sound/dsp
Playing raw data '/dev/sound/dsp' : Unsigned 8 bit, Rate 8000 Hz, Mono
xrun!!! (at least 0.104 ms long)
aplay: pcm_write:968: write error: Input/output error

chris