[mythtv-users] Sound Problems

Stephen Kitchener stephen at g6dzj.demon.co.uk
Wed May 24 11:40:01 UTC 2006


Hi List,

I hope someone can help and at least give an insight where my problem might 
be..

I am using Fedora 4, mythtv from yum and ivtv 0.6.2 and a Hauppage 150.


My problem is that until I change channel I have no sound on LiveTV.

What I have checked.

1. restarting alsa does have an effect, but more often then not I get an error 
saying that on sound devices can be found, so sticking a restart of alsa in 
rc.local won't work.

2 If I play the live tv mpg before I kick the sound into life, there is no 
sound on the mpg. When I do change channels and play the mpg, there is sound.

3. mpg's of scheduled programs do have sound. I set up a recording to be the 
same as the startup channel, so to avoid changing channels ( and thereby 
kicking the sound into life). this appears to be ok, but later thought that 
Mythtv couldn't assume that the tuner was on any particular channel, so it 
would issue a change channel even though it might be on the right channel 
anyway.

4. If I use ivtv's untils on their own, even before starting mythtv for the 
first time and getting sound, so that I tune to a known channel and record 
the stream with cat and play that thought mplayer, I have sound, so I don't 
think is an ivtv problem.

5. If I play a recorded program, after initial startup of Mythtv (ie the sound 
hasn't been kicked into life by changing channels). I get sound from the 
recording.  but going to livetv I have no sound.

6. If I enable sounds for opening windows and stuff, they all play fine, but I 
still have no initial sound on mythtv.

7. when I change channels to get some sound, there is a small 'pop' before the 
sound is there.

I have looked for muting

ivtvctl -d /dev/video0 -Y
ioctl: VIDIOC_QUERYCTRL
Brightness = 127
Contrast = 63
Saturation = 63
Hue = 0
Volume = 58880
Balance = 32768
Bass = 32768
Treble = 32768
Mute = 0

I have used v4lctl to look also, but the output from v4lctl list dosn't 
change.

I have disabled artsd, as it was reported that it might get in the way, though 
it appears that something clearly is....

So, my questions are, why does changing channel kick the sound into life ??

Why should it effect livetv only

Why is there no sound on the mpg of livetv even though, as I understand it, 
the mpg stream is taken directly off the card and saved to disk. The sound 
system should have nothing to do with it. (am I wrong here ??)

I have checked to see if the list of modules changes between boot - 
startingmythtv - or having sound on Mythtv, no change.

I have swapped the 150 to a working setup (running .18 and 0.4.0 ivtv, and it 
works fine, I have even changed from using the built in sound hardware to a 
soundblaster card and I still have the problems described.

Nothing appears to have started or complained in the system or Mythtv logs.

Can I supply more information, do more checks ??

I'm lost as to what I can try next .,........ HELP Please.

Any help appreciated.

Sorry for the long post, but this is really bugging me!


Steve


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