29 Jun
2008
29 Jun
'08
9:14 p.m.
Nick Urban wrote:
Hello,
I just joined the list, so I hope this is the right place for this question..
I have a M-Audio Firewire solo which I use with jack and firebob to
record audio.
I was thinking about making a little video with my Quickcam 9000 Pro,
but because the audio quality of its built-in mic is poor, I wanted to
use my nice studio mic instead. I am currently using guvcview to
record with the camera, and it has a selection of input options, on
which, when jack is running, an extra option appears: "system". I
thought, wow, maybe this actually supports jack! But when I try using
that option it just crashes. Oh well, I didn't expect that to work
anyway.
Welcome Nick.
If you can reproduce this with guvcview while recording with other
software works, you should report this on the Forum of guvcview or check
their Wiki for the problem - it might be easy to solve. I don't know
much about guvcview but I'm not aware that luvcview has JACK support.
I'm gonna check out the latest version now ;)
But I thought, okay, maybe I can set up a virtual ALSA
device that
somehow connects to jack. Then I could record for that device, which
would actually just be a jack sink (which I would have connected my
mic input to). I can't figure out any way to do that, though. I
searched around for ALSA jack clients, couldn't find anything. I tried
running two different jack instances (one with alsa, one with
freebob), but they didn't seem to be aware of each other when I looked
at the connections panel in qjackctl.
Does anyone have any suggestions here?
You can try gstreamer. I once toyed around with it and got a
jack-audio-port recording in sync with a v4l usb webcam @30fps with a
simple gstreamer pipeline. It's quite straight forward: you use
'gstreamer-properties' to set up your audio and video devices and check
the gstreamer-wiki on how to make a recording eg:
http://www.linuxtv.org/v4lwiki/index.php/Gstreamer#Record_to_ogg_theora
In my experience gstreamer is the quickest solution, but there are
plenty of alternatives, depending on where and how far you want to go:
As you mentioned ffmpeg or maybe guvcview should work using a
virtual-JACK-ALSA device setup in $HOME/.asoundrc - see:
http://www.alsa-project.org/main/index.php/Asoundrc#JACK_plugin
or you might even be able to fire up http://lives.sf.net/ which has JACK
support, or use a puredata+gem patch to do the trick..
Another reason I'd like jack
and ALSA to play together is so that I can use my speakers (which are
connected to my PCI sound card) to play audio from Ardour while I am
working on takes with my firewire interface.
Every reason to use JACK is a good one, but this is an exception ;) You
can not use two sound-cards in the same jack-server at the same time
[unless you resample with netjack's alsa_in/out].
You could run two independent jack-servers, but they can not share any
clients or I/O ports.
#robin