2 files changed, 13 insertions, 0 deletions
diff --git a/libavcodec/audioconvert.c b/libavcodec/audioconvert.c
index b0a8afacb4..5842801093 100644
--- a/libavcodec/audioconvert.c
+++ b/libavcodec/audioconvert.c
@@ -153,6 +153,15 @@ void avcodec_get_channel_layout_string(char *buf, int buf_size, int nb_channels,
     }
 }
 
+int avcodec_channel_layout_num_channels(int64_t channel_layout)
+{
+    int count;
+    uint64_t x = channel_layout;
+    for (count = 0; x; count++)
+        x &= x-1; // unset lowest set bit
+    return count;
+}
+
 struct AVAudioConvert {
     int in_channels, out_channels;
     int fmt_pair;
diff --git a/libavcodec/audioconvert.h b/libavcodec/audioconvert.h
index 157bd44e21..46ba3d3929 100644
--- a/libavcodec/audioconvert.h
+++ b/libavcodec/audioconvert.h
@@ -73,6 +73,10 @@ void avcodec_get_channel_layout_string(char *buf, int buf_size, int nb_channels,
  */
 int64_t avcodec_guess_channel_layout(int nb_channels, enum CodecID codec_id, const char *fmt_name);
 
+/**
+ * @return the number of channels in the channel layout.
+ */
+int avcodec_channel_layout_num_channels(int64_t channel_layout);
 
 struct AVAudioConvert;
 typedef struct AVAudioConvert AVAudioConvert;