GNOME Bugzilla – Bug 644888
[alsasrc] set_hwparams: rate doesn't match (requested 44100Hz, get 0Hz)
Last modified: 2011-05-25 07:00:58 UTC
I have a usb webcam logitech c500(http://www.amazon.com/WEBCAM-C500-1-3MP-2-0BUILT-UNIV/dp/B0031ASY2M) which has a built-in mic: card 1: U0x46d0x807 [USB Device 0x46d:0x807], device 0: USB Audio [USB Audio] Subdevices: 1/1 Subdevice #0: subdevice #0 I use 'gstreamer-properties' to test the built-in mic. If I set the plugin as 'alsa', and set the device as 'USB audio', then press the test button, there is following error: The audio test fails and I get message " Could not get/set settings from/on resource. [gstalsasrc.c(437): set_hwparams (): /GstPipeline:pipeline1/GstAlsaSrc:alsasrc2" I tried the following 3 pipelines: this pipeline failed with error above printed: $ gst-launch-0.10 alsasrc device="hw:1,0" ! audioconvert ! audioresample ! autoaudiosink this pipeline succeed: $ gst-launch-0.10 alsasrc device="hw:1,0" ! audioresample ! audio/x-raw-int,rate=48000 ! autoaudiosink this pulseaudio pipeline also succeed: $ gst-launch-0.10 pulsesrc device="alsa_input.usb-046d_0807_3D92FE80-02-U0x46d0x807.analog-mono" ! audioconvert ! audioresample ! autoaudiosink
This problem also found reported in debian bugzilla, please refer to http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=578121 From the defect log, the problem is similiar as https://bugzilla.gnome.org/show_bug.cgi?id=455571, 455571 is about alsasink, the problem I met with is about alsasrc.
Could be USB-specific. The following pipeline works fine on my built-in ALSA device: gst-launch-0.10 alsasrc device="hw:0,0" ! audioconvert ! audioresample ! alsasink
Thanks for the reply. This pipeline also works well for my built-in MIC which is device 0, but failed to work for external MIC which is device 1. gst-launch-0.10 alsasrc device="hw:0,0" ! audioconvert ! audioresample ! alsasink Not sure whether it's related with USB, the pipeline below with resample rate can work well with the external USB MIC $ gst-launch-0.10 alsasrc device="hw:1,0" ! audioresample ! audio/x-raw-int,rate=48000 ! autoaudiosink
As it works with other alsa devices and this looks like your alsa driver for the USB device simply does not behave as it should, I think this is an alsa bug. Please report it against alsa again.