Original commit message from CVS:
* gst/audioconvert/gstaudioconvert.c: (gst_audio_convert_link),
(gst_audio_convert_channels):
create channel conversion matrix when linking
* gst/audioconvert/.cvsignore:
* gst/audioconvert/Makefile.am:
* gst/audioconvert/channelmixtest.c: (main):
add (ugly) test that ensures stereo <=> mono conversion works
correctly