[FFmpeg-cvslog] lavu/channel_layout: document the semantic of layouts.

[Nicolas George]

ffmpeg | branch: master | Nicolas George <nicolas.george at normalesup.org> | Wed Nov 28 12:05:24 2012 +0100| [2cb227f6a2a0aa04da8fbcfd4c7a6069c0cb4c36] | committer: Nicolas George

lavu/channel_layout: document the semantic of layouts.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=2cb227f6a2a0aa04da8fbcfd4c7a6069c0cb4c36
---

 libavutil/channel_layout.h |    8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/libavutil/channel_layout.h b/libavutil/channel_layout.h
index e1a6d28..2906098 100644
--- a/libavutil/channel_layout.h
+++ b/libavutil/channel_layout.h
@@ -36,6 +36,14 @@
 
 /**
  * @defgroup channel_masks Audio channel masks
+ *
+ * A channel layout is a 64-bits integer with a bit set for every channel.
+ * The number of bits set must be equal to the number of channels.
+ * The value 0 means that the channel layout is not known.
+ * @note this data structure is not powerful enough to handle channels
+ * combinations that have the same channel multiple times, such as
+ * dual-mono.
+ *
  * @{
  */
 #define AV_CH_FRONT_LEFT             0x00000001