Multiple channel support on OS X (#212)

* fix typo

* Add cubeb_channel_map_to_layout

* Implement audiounit_get_preferred_channel_layout

* Implement audiounit_layout_init

* Create auto_channel_layout to replace raw operation of AudioChannelLayout

* Apply cubeb_channel_map_to_layout in cubeb_pulse.c

* Use enum instead of bool to indicate input or output

* Show input/output, preferred or not in error message for channel layout

* Replace Boolean writable by nullptr

* Null the raw pointer(layout) after freeing it

* Use fieldOffset to calculate size of AudioChannelLayout

* Return CUBEB_ERROR when preferred layout is non-SMPTE format

* Check layout is undefined when cubeb_get_preferred_channel_layout returns ERROR

1 files changed, 7 insertions, 0 deletions

diff --git a/src/cubeb_mixer.h b/src/cubeb_mixer.h
index 1527483..466b597 100644
--- a/src/cubeb_mixer.h
+++ b/src/cubeb_mixer.h
@@ -52,6 +52,13 @@ static cubeb_channel const CHANNEL_INDEX_TO_ORDER[CUBEB_LAYOUT_MAX][CHANNEL_MAX]
   { CHANNEL_LEFT, CHANNEL_RIGHT, CHANNEL_CENTER, CHANNEL_LFE, CHANNEL_RLS, CHANNEL_RRS, CHANNEL_LS, CHANNEL_RS }  // 3F4_LFE
 };
 
+typedef struct {
+  unsigned int channels;
+  cubeb_channel map[CHANNEL_MAX];
+} cubeb_channel_map;
+
+cubeb_channel_layout cubeb_channel_map_to_layout(cubeb_channel_map const * channel_map);
+
 bool cubeb_should_upmix(cubeb_stream_params const * stream, cubeb_stream_params const * mixer);
 
 bool cubeb_should_downmix(cubeb_stream_params const * stream, cubeb_stream_params const * mixer);