libavcodec/opus.c:362: error: Buffer Overrun L1
  Offset: 20 Size: 19.

libavcodec/opus.c:289:9: <Length trace>
287. }
288. 
289. av_cold int ff_opus_parse_extradata(AVCodecContext *avctx,
             ^
290.                                     OpusContext *s)
291. {

libavcodec/opus.c:289:9: Array declaration
287. }
288. 
289. av_cold int ff_opus_parse_extradata(AVCodecContext *avctx,
             ^
290.                                     OpusContext *s)
291. {

libavcodec/opus.c:312:9: Assignment
310.         }
311.         default_extradata[9] = (avctx->channels == 1) ? 1 : 2;
312.         extradata      = default_extradata;
             ^
313.         extradata_size = sizeof(default_extradata);
314.     } else {

libavcodec/opus.c:362:26: Array access: Offset: 20 Size: 19
360. 
361.         streams        = extradata[19];
362.         stereo_streams = extradata[20];
                              ^
363.         if (!streams || stereo_streams > streams ||
364.             streams + stereo_streams > 255) {
