avformat/mpegts: Also parse the FMC descriptor if the codec has not been identified yet

Fixes Detecting AAC with such descriptor if the parts needed for detection
are later in the stream
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/mpegts.c

@@ -1591,7 +1591,9 @@ int ff_parse_mpeg2_descriptor(AVFormatContext *fc, AVStream *st, int stream_type
         if (get16(pp, desc_end) < 0)
             break;
         if (mp4_descr_count > 0 &&
-            (st->codec->codec_id == AV_CODEC_ID_AAC_LATM || st->request_probe > 0) &&
+            (st->codec->codec_id == AV_CODEC_ID_AAC_LATM ||
+             (st->request_probe == 0 && st->codec->codec_id == AV_CODEC_ID_NONE) ||
+             st->request_probe > 0) &&
             mp4_descr->dec_config_descr_len && mp4_descr->es_id == pid) {
             AVIOContext pb;
             ffio_init_context(&pb, mp4_descr->dec_config_descr,