+ } else if (st->codecpar->codec_id == AV_CODEC_ID_AC3 && !ts_st->dvb_ac3_desc) {
+ AC3HeaderInfo *hdr = NULL;
+
+ if (avpriv_ac3_parse_header(&hdr, pkt->data, pkt->size) >= 0) {
+ uint8_t number_of_channels_flag;
+ uint8_t service_type_flag;
+ uint8_t full_service_flag = 1;
+ DVBAC3Descriptor *dvb_ac3_desc;
+
+ dvb_ac3_desc = av_mallocz(sizeof(*dvb_ac3_desc));
+ if (!dvb_ac3_desc) {
+ av_free(hdr);
+ return AVERROR(ENOMEM);
+ }
+
+ service_type_flag = hdr->bitstream_mode;
+ switch (hdr->channel_mode) {
+ case AC3_CHMODE_DUALMONO:
+ number_of_channels_flag = 1;
+ break;
+ case AC3_CHMODE_MONO:
+ number_of_channels_flag = 0;
+ break;
+ case AC3_CHMODE_STEREO:
+ if (hdr->dolby_surround_mode == AC3_DSURMOD_ON)
+ number_of_channels_flag = 3;
+ else
+ number_of_channels_flag = 2;
+ break;
+ case AC3_CHMODE_3F:
+ case AC3_CHMODE_2F1R:
+ case AC3_CHMODE_3F1R:
+ case AC3_CHMODE_2F2R:
+ case AC3_CHMODE_3F2R:
+ number_of_channels_flag = 4;
+ break;
+ default: /* reserved */
+ number_of_channels_flag = 7;
+ break;
+ }
+
+ if (service_type_flag == 1 || service_type_flag == 4 ||
+ (service_type_flag == 7 && !number_of_channels_flag))
+ full_service_flag = 0;
+
+ dvb_ac3_desc->component_type_flag = 1;
+ dvb_ac3_desc->component_type = (full_service_flag << 6) |
+ ((service_type_flag & 0x7) << 3) |
+ (number_of_channels_flag & 0x7);
+ dvb_ac3_desc->bsid_flag = 1;
+ dvb_ac3_desc->bsid = hdr->bitstream_id;
+ dvb_ac3_desc->mainid_flag = 0;
+ dvb_ac3_desc->asvc_flag = 0;
+
+ ts_st->dvb_ac3_desc = dvb_ac3_desc;
+ }
+ av_free(hdr);