avformat/adtsenc: allow only AAC streams

The ADTS muxer will silently (attempt to) mux any audio stream passed to it.
Patch adds a codec check.
Signed-off-by: James Almer <jamrial@gmail.com>

libavformat/adtsenc.c

@@ -99,6 +99,10 @@ static int adts_init(AVFormatContext *s)
     ADTSContext *adts = s->priv_data;
     AVCodecParameters *par = s->streams[0]->codecpar;
 
+    if (par->codec_id != AV_CODEC_ID_AAC) {
+        av_log(s, AV_LOG_ERROR, "Only AAC streams can be muxed by the ADTS muxer\n");
+        return AVERROR(EINVAL);
+    }
     if (par->extradata_size > 0)
         return adts_decode_extradata(s, adts, par->extradata,
                                      par->extradata_size);