mpc8: convert to new channel layout API

Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>

libavformat/mpc8.c

@@ -230,6 +230,7 @@ static int mpc8_read_header(AVFormatContext *s)
     AVIOContext *pb = s->pb;
     AVStream *st;
     int tag = 0, ret;
+    int channels;
     int64_t size, pos;
 
     c->header_pos = avio_tell(pb);
@@ -273,7 +274,8 @@ static int mpc8_read_header(AVFormatContext *s)
     if ((ret = ff_get_extradata(s, st->codecpar, pb, 2)) < 0)
         return ret;
 
-    st->codecpar->channels = (st->codecpar->extradata[1] >> 4) + 1;
+    channels = (st->codecpar->extradata[1] >> 4) + 1;
+    st->codecpar->ch_layout.nb_channels = channels;
     st->codecpar->sample_rate = mpc8_rate[st->codecpar->extradata[0] >> 5];
     avpriv_set_pts_info(st, 64, 1152  << (st->codecpar->extradata[1]&3)*2, st->codecpar->sample_rate);
     st->start_time = 0;