audio: map channels=1,channel-mask=0 to MONO instead of NONE

Fixes problem in audioconvert, which would end up using
a mixmatrix when converting between different mono format
because it thinks MONO positioning is different from
unpositioned channels, which is not the case in this
special case. The mixmatrix would end up being 0.0 so
audioconvert would convert to silence samples.

https://bugzilla.gnome.org/show_bug.cgi?id=724509

diff --git a/gst-libs/gst/audio/audio-info.c b/gst-libs/gst/audio/audio-info.c
index a9740da..26b96dd 100644 (file)
--- a/gst-libs/gst/audio/audio-info.c
+++ b/gst-libs/gst/audio/audio-info.c
@@ -219,7 +219,7 @@ gst_audio_info_from_caps (GstAudioInfo * info, const GstCaps * caps)
     goto no_channels;
 
   if (!gst_structure_get (str, "channel-mask", GST_TYPE_BITMASK, &channel_mask,
-          NULL)) {
+          NULL) || (channel_mask == 0 && channels == 1)) {
     if (channels == 1) {
       position[0] = GST_AUDIO_CHANNEL_POSITION_MONO;
     } else if (channels == 2) {