Comment 12 for bug 19254

Comparing plughw:
gst-launch-0.8 gnomevfssrc location=/pub/music/albums/Radiohead/OK\
Computer/Subterranean\ Homesick\ Alien.mp3 ! spider ! volume ! audioscale !
audioconvert ! alsasink device=plughw:0,0

to dmix:
gst-launch-0.8 gnomevfssrc location=/pub/music/albums/Radiohead/OK\
Computer/Subterranean\ Homesick\ Alien.mp3 ! spider ! volume ! audioscale !
audioconvert ! alsasink device=dmix

Shows the problem exists only with dmix.

There is also a click before audio output starts when using the dmix device that
does not occur with the direct hardware device. I'd never bothered about it,
but this experiment makes it obvious.

This issue is also a problem if the system becomes so busy it can't service the
audio events (or possibly read the input audio file).

The other thing I notice is that dmix plays catchup: sometimes when resuming the
process, a mixture of weird sound is first emitted before normal playback. This
weird sound at the start sounds like semi-random frames from the source file.
Maybe it's all the buffered audio at a much higher rate.

Thanks to Daniel's suggestion, I think we've been able to narrow this down to a
dmix bug.

Setting package to libasound2.