idroqdec: set channel layout

libavformat/idroqdec.c

@@ -27,6 +27,7 @@
  *   http://www.csse.monash.edu.au/~timf/
  */
 
+#include "libavutil/channel_layout.h"
 #include "libavutil/intreadwrite.h"
 #include "avformat.h"
 #include "internal.h"
@@ -175,7 +176,14 @@ static int roq_read_packet(AVFormatContext *s,
                 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
                 st->codec->codec_id = AV_CODEC_ID_ROQ_DPCM;
                 st->codec->codec_tag = 0;  /* no tag */
-                st->codec->channels = roq->audio_channels = chunk_type == RoQ_SOUND_STEREO ? 2 : 1;
+                if (chunk_type == RoQ_SOUND_STEREO) {
+                    st->codec->channels       = 2;
+                    st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
+                } else {
+                    st->codec->channels       = 1;
+                    st->codec->channel_layout = AV_CH_LAYOUT_MONO;
+                }
+                roq->audio_channels    = st->codec->channels;
                 st->codec->sample_rate = RoQ_AUDIO_SAMPLE_RATE;
                 st->codec->bits_per_coded_sample = 16;
                 st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *