[mythtv-users] strange sound issue (with ivtv) depending on recording profiles

[Joachim Gehweiler]

Dear all,

after upgrading to 0.12, nearly all sound- and transcoding-related 
problems were solved, but there was still some strange problem left:

- live tv worked fine
- recording from live tv (keys o, and then r) worked, too
- recordings scheduled with mythTV also worked,
- but recordings scheduled via mythWeb did NOT work (the sound was missing)

after days searching for errors and testing with different recording 
profiles with and without transcoding, I finally noticed, that the sound 
was missing if and only if the recording profile was NOT NULL (if you 
don't choose the profile manually in the advanced recordings screen, it 
is set to 'NULL', not 'Default' in the database by mythTV, whereas 
mythWeb sets it to 'Default' and doesn't offer the 'unspecified' 
(='NULL') option)

amazingly, I could finally solve the problem by changing my 
modules.conf; until now it looked like the following (as suggested e.g. 
in the "Step-by-step guide to building a MythTV box under Red Hat Linux 
9 w/ATrpms"):

...
# Start IVTV
alias char-major-61 lirc_i2c
alias char-major-81 videodev
alias char-major-81-0 ivtv
options ivtv debug=0 mpg_buffers=30
options tuner type=14
options msp3400 once=1 simple=1
add below ivtv tuner msp3400 saa7115
add above ivtv lirc_dev lirc_i2c
# IVTV End
...

by moving the msp3400 and saa7115 modules to 'above' it worked:

...
# Start IVTV
alias char-major-61 lirc_i2c
alias char-major-81 videodev
alias char-major-81-0 ivtv
options ivtv debug=0 mpg_buffers=30
options tuner type=14
options msp3400 once=1 simple=1
add below ivtv tuner
add above ivtv msp3400 saa7115 lirc_dev lirc_i2c
# IVTV End
...


At least, it seems to work now (before the change it did not work every 
time, and now it worked during all my tests).


Now my question: is this just a lucky coincidence, or this there some 
reason behind it?

If there is a reason, what is it?

If this problem is not specific to my case, I think we should make a faq 
out of it and change the install guides, as it may concern many other users.

Best,
   Joachim