[PlanetCCRMA] sound issue with webcam

Nigel Henry cave.dnb2m97pp at aliceadsl.fr
Tue Feb 19 14:26:01 2008

On Tuesday 19 February 2008 17:57, Tom Poe wrote:
> I'm running FC8, with planetccrma, and have logitech Pro 9000 webcam.  I
> can record video, but audio is not working.  I tracked the issue this far:
> "The webcam audio interface must be initialised before the video
> interface. Linux will by default initialise the video interface first,
> so you need to remove the uvcvideo.ko module from the /lib/modules
> subdirectory where it gets loaded automatically, and load it manually
> after plugging the webcam."
> Can anyone help me translate this quote into specific steps with
> commands?  I learn best with really big crayolas.  :)

Hi Tom. I think you'll need the big crayolas. According to the quote above the 
uvcvideo is loaded automatically. Assuming that the webcam is a USB one, and 
the webcam is unplugged, the uvcvideo module would not be loaded as the USB 
device wasn't present.

For example. I have a cheapo webcam (ov511 driver). If it's unplugged the 
ov511 module doesn't load. This webcam doesn't have integrated sound on the 
USB, but comes with a separate mic/earpiece, with jacks that plug into the 
soundcard, so the sound is totally distanced from the video, which is on the 
USB. The ov511 driver is only loaded when I plug the webcam in.

I've looked on all the kernels on F8, that I have installed, but can't find 
the uvcvideo module, but I am at this time downloading planetccrma -core. 
Perhaps this module is on planetccrma's realtime kernel. Time will tell (I'm 
on dialup).

Would you plugin the webcam, reboot, then post the output of /sbin/lsmod. Also 
post the output from:
cat /proc/asound/cards
And also the output from /sbin/lsusb.

I have a usb midi keyboard, and have allways had to add lines for it 
in /etc/modprobe.conf, as below.
alias snd-card-1 snd-usb-audio
options snd-usb-audio index=1
Otherwise the usb midi keyboard ends up being set as card0, and I have no 
sounds, which is due to the USB being started early in the boot process, and 
the keyboard is wrongly detected as an actual soundcard.

This is presuming that you only have one actual soundcard, and that is set as 
> I've found some stuff on rmmod, lsmod, insmod, modprobe, but just feel
> overwhelmed.  Any help appreciated.

I'm guessing here, and wish I had your webcam so that I could try out what I'm 
going to suggest. By the way the planetccrma kernel is now installed, and has 
the uvcvideo module available.

Not having the webcam available doesn't help, but I think the way I'd go about 
this, is to plug the webcam in, then reboot.

You say you have video from the webcam working, so the uvcvideo module is 
presumably loaded, but no sound from the webcam.

I think now I'd su to root on the command line, and do a rmmod uvcvideo, 
followed by a rmmod snd-usb-audio.

I don't like guessing for resolving problems, without having the hardware 
available, but I'd now do a modprobe snd-usb-audio, followed by a modprobe 

Sorry if I've been of no help whatsoever, but it's all I can suggest without 
having the hardware available.


> Tom
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