Red Hat Bugzilla – Bug 468695
Spits out errors for USB webcam mic
Last modified: 2009-02-04 05:43:45 EST
W: alsa-util.c: Device hw:1 doesn't support 44100 Hz, changed to 16000 Hz.
W: alsa-util.c: Device hw:1 doesn't support 2 channels, changed to 1.
W: module-alsa-source.c: Your kernel driver is broken: it reports a volume range from 18.00 dB to 18.00 dB which makes no sense.
The device is a UVC webcam, and the device uses USB audio.
$ cat /proc/asound/cards
0 [ICH7 ]: ICH4 - Intel ICH7
Intel ICH7 with AD1981B at irq 23
1 [U0x46d0x990 ]: USB-Audio - USB Device 0x46d:0x990
USB Device 0x46d:0x990 at usb-0000:00:1d.7-2, high speed
$ amixer -c 1
Simple mixer control 'Mic',0
Capabilities: cvolume cswitch cswitch-joined
Capture channels: Mono
Limits: Capture 0 - 3072
Mono: Capture 1536 [50%] [18.00dB] [on]
Yepp. PA is right. Your dB range is 3072 steps between 18 to 18 dB. Which of course is bogus. Your USB hardware apparently exports bogus dB information. The USB kernel driver should detect bogus dB data and not export that to userspace.
Reassigning to kernel, since this should be filtered out by the kernel drivers, not by PA.
This is an alsa problem, not a v4l problem, re-assigning.
This bug appears to have been reported against 'rawhide' during the Fedora 10 development cycle.
Changing version to '10'.
More information and reason for this action is here:
*** This bug has been marked as a duplicate of bug 469416 ***