Not necessarily an Ubuntu-specific question but I wasn't sure where else to ask. I have an AverMedia DVD EZMaker 7 which plugs into USB and works well on Ubuntu 12.04. I downloaded and installed the official drivers without error. However, when I try:
gst-launch alsasrc device="hw:1,0" ! alsasink device="hw:0,0"
it tells me:
Setting pipeline to PAUSED ... Pipeline is live and does not need PREROLL ... Setting pipeline to PLAYING ... New clock: GstAudioSrcClock
which is the normal output, however there is no audible sound. Trying the command again doesn't help. If I run gstreamer-properties and close it right away (don't need to touch any controls), THEN the gst-launch command works. If I unplug the device and plug it back in or restart the computer, I have to run gstreamer-properties again.
What is gstreamer-properties doing that enables the audio?