binkaudio: set channel layout

libavcodec/binkaudio.c

@@ -28,6 +28,7 @@
  *  http://wiki.multimedia.cx/index.php?title=Bink_Audio
  */
 
+#include "libavutil/channel_layout.h"
 #include "avcodec.h"
 #define BITSTREAM_READER_LE
 #include "get_bits.h"
@@ -87,6 +88,8 @@ static av_cold int decode_init(AVCodecContext *avctx)
         av_log(avctx, AV_LOG_ERROR, "too many channels: %d\n", avctx->channels);
         return -1;
     }
+    avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO :
+                                                   AV_CH_LAYOUT_STEREO;
 
     s->version_b = avctx->extradata && avctx->extradata[3] == 'b';