[jokosher-devel] Recording Problems...

[Luke Tilley <sinisterguy gmail com>]

Hello All,

As some of you may know, I have been having recording problems with
Jokosher (Both 0.1 and latest svn). Until recently, I couldn't get
anything at all to record under linux. I recently found the solution on
the alsa mailing list. With a Creative SoundBlaster Live! (my card), you
must turn down AC97 output to 0, turn up AC97 Capture to 100, turn up
Capture and set it to record and finally, turn up whatever you want to
record and set it to record. complicated to say the least.

Anyways, what would happen then was that I'd set up everything properly,
but nothing would be recorded in Jokosher. I fired up audacity and it
worked though. Strange to say the least. Long story short, I finally
isolated the problem: Jokosher was muting AC97 Capture every time I
tried to record. I further narrowed the problem down to these lines in
JokosherApp.py:

for track in mixer.list_tracks():
    if track.flags & gst.interfaces.MIXER_TRACK_INPUT:
        mixer.set_record(track, False)
    #Most cards incapable of multiple simultanious input have a channel called 'Capture' which must be enabled along with the actual input channel
    if track.label == 'Capture':
        mixer.set_record(track, True)


I'm not entirely sure what the 'if track.flags...' part does, but it
seems to mute everything except the channels armed for recording. Then
the Capture channel is armed, but that only does half of the work. For
my sound card AC97 needs to be enabled as well.

The quick and dirty fix is obvious: just add:

if track.label == 'AC97 Capture':
    mixer.set_record(track, True)

However, this is quite unelegant as not all sound cards have an 'AC97
Capture'. A marginally better way I think, would be to check to see if
the sound card is indeed one which needs this hack, but like I said,
that would only be marginally better. What do you guys think?

-Lukas