amr: set channel_layout

libavformat/amr.c

@@ -25,6 +25,8 @@ Write and read amr data according to RFC3267, http://www.ietf.org/rfc/rfc3267.tx
 Only mono files are supported.
 
 */
+
+#include "libavutil/channel_layout.h"
 #include "avformat.h"
 #include "internal.h"
 
@@ -97,6 +99,7 @@ static int amr_read_header(AVFormatContext *s)
         st->codec->sample_rate = 8000;
     }
     st->codec->channels   = 1;
+    st->codec->channel_layout = AV_CH_LAYOUT_MONO;
     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
     avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);