[mythtv-users] Volume Settings/WinTV Go Plus Output

[Dan]

I'm so close to having MythTV running properly on FC4, but I've
reached an impasse when configuring the audio. The problem - I can't
hear anything unless I do some silly hack which Myth doesn't seem to
like. Let me explain.

I have a WinTV Go-Plus card with an 878 chip and an Audio output. My
SB Audigy 2 soundcard appears to be located at /dev/dfs, there is an
Intel card (which doesn't seem to exist, and doesn't work) at
/dev/dfs1, and I believe the Audio output from the WinTV is /dev/dfs2.
I believe the Audigy card is properly configured (it seems to play
sounds), and when connected, the WinTV audio output produces the
tuner's sound as well.

In the MythTV tuner card setup, I selected /dev/dfs2 as the audio
device. This produces no sound and an error message in my
"mythbackend" shell to the effect that it can't open /dev/dfs2. When I
open the BT878 tab in KMix, the "Capture" volume can be adjusted but,
instead of the green icon, there is a red icon with a "pause" symbol
above the "Capture" mix. I can't figure out why.

So.

I opted for route 2. I ran a cable from the WinTV Go audio output into
the mic input on my Audigy card. In the alsamixer I muted "Mic" in
playback and muted everything but "Mic" in capture. I opened up mythtv
and - echoes!

Upon checking the alsamixer again, I saw that the "PCM" volume in
capture was set to the same value as the "PCM" volume in playback.
Changing the volume in mythtv seems to change not only the playback
PCM, but also the capture PCM, creating a nasty echo loop that makes
mythtv all but unusable. I can put PCM capture volume back to zero,
and the echoes go away, but even changing the channel in mythtv resets
both PCM volumes to mythtv's current level in the alsamixer.

I can think of two solutions, neither of which I seem to be capable of
doing. First, I could just get the BT878 audio output in /dev/dfs2
working properly, perhaps using btaudio. If this is the best solution,
could someone give me compilation instructions, because I can't get it
running with the traditional make/make install commands.

Second, I could just make it so MythTV changes the Master volume,
instead of the PCM. There is no Master volume in capture, so it seems
to me that this would work. The problem is that I can't find any
settings to change this in any graphical mythtv config, and I dare not
touch the volumecontrol.cpp file (yet).

So please, if you can, help me take this almost perfect MythTV box to
the next level. I appreciate your time and effort, because God knows
it's taken me plenty of each to get to this point.

- Dan Wahl
- drwahl at gmail.com