[mythtv-users] Mythsqueezebox Volume Control Doesn't Work

[Robert]

Robert wrote:
> George Galt wrote:
>> On Sun, Mar 15, 2009 at 5:22 PM, Robert <RobertCL at iname.com> wrote:
>>> Hi,
>>>
>>> I've managed to get the mythsqueezebox plugin compiled and working on
>>> Gentoo.  All seems well, except the volume control doesn't actually 
>>> change
>>> the volume.
>>>
>>> I can "appear" to change the volume using either the volume buttons 
>>> on my
>>> remote (I see the volume bar in mythsqueezebox move on-screen) or 
>>> using the
>>> volume control from squeezecenter (web interface) but the actual 
>>> volume of
>>> playback never changes.
>>>
>>> I've looked in mythfrontend logs, but there are no obvious errors.  I'm
>>> thinking of buying some squeezebox hardware, so I'd like to get this 
>>> working
>>> so I can use it with that.
>>>
>>> Where should I start looking?
>>>
>>> (just to be clear, I do hear the music I've added to the playlist being
>>> played, it's just that chaning the volume doesn't work)
>>>
>>> Thanks,
>>> Robert.
>>>
>>> Mythtv-0.21_p19961 (-fixes?)
>>> media-libs/portaudio-19_pre20071207
>>> Linux version 2.6.28.7 (root at quad) (gcc version 4.1.2 (Gentoo 4.1.2 
>>> p1.1))
>>>
>>> _______________________________________________
>>> mythtv-users mailing list
>>> mythtv-users at mythtv.org
>>> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>>>
>>
>> Robert:
>>
>> What output are you using?  It seems that somehow there is a conflict
>> with how the plugin uses portaudio and using anything other than the
>> standard "stereo" audio out on the soundcard (using something like the
>> SPDIF out).  If this is the case, try using the standards "stereo" out
>> for sound to see if this fixes it.  I'm not suggesting you leave it
>> this way -- obviously, this is something that will have to be fixed.
>>
>> I've been considering dropping portaudio altogether, but it is a
>> bigger project than I've got time for right now, so it will take some
>> time.
>>
>> George
> 
> Hi,
> 
> MythTV is setup to use:
>     Audio Output Device: ALSA:default
>     Mixer Device: ALSA:default
>     Mixer Controls: PCM
> 
> However, if I change to:
>     Audio Output Device: /dev/pcm
>     Mixer Device: /dev/mixer
> 
> Then volumne control doesn't work at all in Myth :-(  So I guess there 
> is some problem on my system as a whole in that /dev/mixer doesn't work 
> properly.
> 
> It looks like PortAudio is using OSS ??  So I'm guessing it's using 
> /dev/mixer by default and hence why it doesn't work.
> 
> So "all" I need to do is fix /dev/mixer....  Hmm.  I've never really got 
> to grips with alsa config, it's kind of just worked...
> 
> Robert.

Ok, some success, I installed aumix to test the OSS mixer and noticed I 
didn't have a PCM device.

I confirmed this by looking in /proc/asound/card0/oss_mixer which said 
'PCM "" 0'.  So after some googling found that I should

	echo 'PCM "PCM" 0' > /proc/asound/card0/oss_mixer

Doing this made aumix show a PCM mixer (that works) and this seems to 
have made the volume control work in mythsqueezebox :-))

So it all seems to be working ok.

I hope you find time to develop this plugin further, because it seems 
like it would be a useful addition.

Robert.