Only test the first frame for missing aac_adtstoasc bistream filter.

Many players ignore broken aac frames, so don't abort mov or flv
muxing when encountering one, just print a warning instead.

Fixes ticket #2380.

libavformat/flvenc.c

@@ -493,10 +493,13 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
                 return ret;
     } else if (enc->codec_id == AV_CODEC_ID_AAC && pkt->size > 2 &&
                (AV_RB16(pkt->data) & 0xfff0) == 0xfff0) {
+        if (!s->streams[pkt->stream_index]->nb_frames) {
         av_log(s, AV_LOG_ERROR, "Malformed AAC bitstream detected: "
                "use audio bitstream filter 'aac_adtstoasc' to fix it "
                "('-bsf:a aac_adtstoasc' option with ffmpeg)\n");
         return AVERROR_INVALIDDATA;
+        }
+        av_log(s, AV_LOG_WARNING, "aac bitstream error\n");
     }
 
     if (flv->delay == AV_NOPTS_VALUE)

libavformat/movenc.c

@@ -3185,8 +3185,11 @@ int ff_mov_write_packet(AVFormatContext *s, AVPacket *pkt)
         }
     } else if (enc->codec_id == AV_CODEC_ID_AAC && pkt->size > 2 &&
                (AV_RB16(pkt->data) & 0xfff0) == 0xfff0) {
+        if (!s->streams[pkt->stream_index]->nb_frames) {
         av_log(s, AV_LOG_ERROR, "malformated aac bitstream, use -absf aac_adtstoasc\n");
         return -1;
+        }
+        av_log(s, AV_LOG_WARNING, "aac bitstream error\n");
     } else {
         avio_write(pb, pkt->data, size);
     }