GNOME Bugzilla – Bug 613852
Audio loopback at 16khz produces "clicks"
Last modified: 2010-05-11 09:25:53 UTC
On several HW/OS combinations, the following pypeline breaks produces "clicks" rather than the expected loopback from the microphone to the speaker: gst-launch-0.10 alsasrc ! audio/x-raw-int,rate=16000,channels=1,depth=16 ! wavenc ! decodebin ! autoaudiosink Works on: * Lenovo x200s, Fedora 12 x86-64, gstreamer-0.10.28-2.fc12.x86_64 Breaks on: * OLPC XO-1, Fedora 11, gstreamer 0.10.26 * OLPC XO-1, Fedora 11, gstreamer 0.10.28 * Netbook with Intel HDA sound, running Ubuntu Karmic, gstreamer 0.10.28 * Laptop with Intel HDA sound, running Ubuntu Jaunty, gstreamer 0.10.25 I'm not sure whether this is a gstreamer bug, alsa bug or sound driver bug. This bug affects recording sound in a Sugar activity called Record. The bug is described in detail here: http://bugs.sugarlabs.org/ticket/1244
You can't decode the wav while still recording it. Can you do e.g. gst-launch-0.10 alsasrc ! audio/x-raw-int,rate=16000,channels=1,depth=16 ! tee name=t ! queue ! wavenc ! filesink location record.wav t. ! queue ! autoaudiosink This way you get recording + monitoring. If you want to show a level meter or spectrum analyzer you would plug them in the monitor chain 8that goes to autoaudiosink).
Thanks, we've applied a similar workaround. Though I don't understand why the same code was working fine on my laptop with Fedora 12 and not on the XO with Fedora 11.
Changing from FIXED to NOTABUG, since nothing was really 'fixed'.