[mythtv] Work Around for SAA7134 Intial Sound Problems
d.williams at paradise.net.nz
d.williams at paradise.net.nz
Tue Aug 12 11:45:58 EDT 2003
Hi,
When looking into some other sound issues i was having with my FlyVideo 3000
card (SAA7134 based card), I think I've found the cause of the problem with
Mythtv and no recording of sound untill you watch live tv a couple of times,
(which a few people have noticed)
Basically the driver's hardcoded to mute it's output on startup.
I enabled the audio_debug module param for the saa7134 V4l2 module, and noticed
the following:
What xawtv appears to do on startup:
mute the card
unmute the card
What myth appears to do:
Nothing, assumes that the sound is enabled.
I don't know what the BTTV driver does (as I don't have a card that needs it),
so don't know if BTTV is muted by default or not!
I would have thought it would be a good idea for Myth to make sure the card is
in the state that it expects. (I would do it, but don't have the skills to do
it!)
I haven't managed to trace through the recording process (I'm not a C++ Coder)
to see if Myth attempts to make sure the card is not muted.
To work around /fix the issue:
In saa7134-video.c, function saa7134_video_init
change the line:
dev->ctl_mute = 1;
To:
dev->ctl_mute = 0;
(This is based off the snapshot on the 6th August - but does appear to be in).
Now when mythtv starts, I get audio with no messing about. 8-)
(say goodbye to the biggest problem I had with myth - next stop getting the
remote working properly 8-) ).
I've posted this to both the user + developer lists
Oh - and also - it appears the the current method of getting sound working,
going into live tv a couple time doesn't work under CVS anymore (at least not
for me !)
Cheers
Daniel
P.s Thanks to all the guys/girls who are doing the coding for mythtv, VERY
much appeciated.
More information about the mythtv-dev
mailing list