audioconvert: add av_get_standard_channel_layout().

Also bump minor version and add APIchanges entry.

doc/APIchanges

@@ -15,6 +15,10 @@ libavutil:     2011-04-18
 
 API changes, most recent first:
 
+2012-07-30 - xxxxxxx - lavu 51.66.100
+  Add av_get_channel_description()
+  and av_get_standard_channel_layout() functions.
+
 2012-07-20 - xxxxxxx - lavc 54.43.100
   Add decode_error_flags field to AVFrame.
 

libavutil/audioconvert.c

@@ -243,3 +243,13 @@ uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
     }
     return 0;
 }
+
+int av_get_standard_channel_layout(unsigned index, uint64_t *layout,
+                                   const char **name)
+{
+    if (index >= FF_ARRAY_ELEMS(channel_layout_map))
+        return AVERROR_EOF;
+    if (layout) *layout = channel_layout_map[index].layout;
+    if (name)   *name   = channel_layout_map[index].name;
+    return 0;
+}

libavutil/audioconvert.h

@@ -188,6 +188,18 @@ const char *av_get_channel_name(uint64_t channel);
  */
 const char *av_get_channel_description(uint64_t channel);
 
+/**
+ * Get the value and name of a standard channel layout.
+ *
+ * @param[in]  index   index in an internal list, starting at 0
+ * @param[out] layout  channel layout mask
+ * @param[out] name    name of the layout
+ * @return  0  if the layout exists,
+ *          <0 if index is beyond the limits
+ */
+int av_get_standard_channel_layout(unsigned index, uint64_t *layout,
+                                   const char **name);
+
 /**
  * @}
  */

libavutil/version.h

@@ -39,7 +39,7 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR 51
-#define LIBAVUTIL_VERSION_MINOR 65
+#define LIBAVUTIL_VERSION_MINOR 66
 #define LIBAVUTIL_VERSION_MICRO 100
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \