[vox-tech] Record my desktop - how to record app sounds?

[Bill Kendrick]

On Thu, Sep 25, 2008 at 03:00:41PM -0700, Scott Miller wrote:
> qjackctl is the GUI control for jack. Jack lets you record from one
> thing to another- internally in Linux. So send sounds from program X
> into Audacity, and record. It works rather well! You can send midi
> from one program to another as well.

Ok, so I'm staring blankly at this, searching Google, reading Jack's and
RecordMyDesktop's docs, and am able to get horrible, screeching feedback
from my system if I connect either 'capture' device to a 'playback' device
(if my KMix shows my Input Source as "Mic", being my laptop's built-in
microphone).

If I set it to "Front line", no screeching.  Makes sense.


So here's where I'm baffled.

(1) Instructions here http://www.linuxplanet.com/linuxplanet/tutorials/6491/1
    suggest that once I start "recordMyDesktop" and tell it to use Jack,
    I should see a pair of "recordMyDesktop" input ports appear in Jack's
    connections dialog.  I do not.

(2) When Jack is running, no application (I tried Amarok and Tux Paint)
    can open a sound device, meaning they can't make sound.  Kind of
    meaningless, if that's the case.

I feel like I've got about 75% a recipe for a dish I've never cooked before.
What the heck am I missing?


For what it's worth, when I run qjackctl (I told it to start jackd for me),
when I go to "Connect" I see:

  Readable Clients / Output Ports:
  + system
    capture_1
    capture_2

  Writable Clients / Input Ports
  + system
    playback_1
    playback_2

The "Connections" dialog also has MIDI and ALSA tabs.  The latter sounds
promising, except the ports seem MIDI-related.  I'm not running MIDI apps. :^/

When connections are made (e.g., capture_1 to playback_1) and my mixer volume
is way up, I can hear a little 'computer background noise' static.  Otherwise,
I get silence.


In gtk-recordMyDesktop, when I go to "Advanced" and click the "Sound" tab,
I've got "Use Jack for audioo capture" checked.  Available ports are:

  system:capture_1
  system:capture_2
  system:playback_1
  system:playback_2

I tried capture_1 and capture_2, as per the screenshot on LinuxPlanet, to
no avail.  Then out of curiosity (while writing this email), I tried
playback_1 and 2.  Then Jack seemed to show the additional 'recordMyDesktop'
Writeable clients, like the other screenshot on LinuxPlanet!

And now... not so much.  WTF?


So my big questions are:

(1) How do I convince apps to actually make _noise_, when Jack is running,
    such that Jack can even _send_ them to recordMyDesktop?

(2) What do I need to do to (consistently) get Jack to even notice rMD?

:^(

Yergh!

-bill!