[mythtv-users] 0.24 no sound with Alsa multi pcm - channels setup problem

[Matt Taylor]

Hi,

I use a custom asound.conf to give me output over optical (for my
receiver) and analogue simultaneously so that I can have sound in
another room at the same time, this uses the alsa multi pcm. This setup
worked fine with 0.23 (and is fine in mplayer, mpd etc.) but with 0.24
release and 0.24-fixes svn I cannot produce sound using this output. I
get an error like this one when trying to use ALSA:default:

2010-11-16 21:12:30.186 Opening ALSA audio device 'default'.
2010-11-16 21:12:30.233 ALSA, Error: Channels count 2 not available:
Invalid argument
2010-11-16 21:12:30.233 ALSA, Error: Unable to set ALSA parameters:
Invalid argument
2010-11-16 21:12:30.265 AudioOutput Error: Aborting reconfigure
2010-11-16 21:12:30.265 AudioPlayer: Disabling Audio, reason is:
Aborting reconfigure

If I disable the channel configuring stuff by changing
mythtv/libs/libmyth/audiooutputalsa.cpp

#define OPEN_FLAGS (SND_PCM_NO_AUTO_RESAMPLE|SND_PCM_NO_AUTO_FORMAT|\
SND_PCM_NO_AUTO_CHANNELS

to:

#define OPEN_FLAGS (SND_PCM_NO_AUTO_RESAMPLE|SND_PCM_NO_AUTO_FORMAT)

The sound works fine using this output and I have sound in both rooms.

(Sound also works in 0.24 accessing just optical directly, or by using
ALSA:default changing asound.conf not to use the multi pcm, but this
doesn't give me what I want.)

For the moment I am happy using the hack I have outlined above but is
there a way to implement a cleaner solution to this problem?

Thanks,

Matt