+static int mkv_check_new_extra_data(AVFormatContext *s, AVPacket *pkt)
+{
+ MatroskaMuxContext *mkv = s->priv_data;
+ mkv_track *track = &mkv->tracks[pkt->stream_index];
+ AVCodecParameters *par = s->streams[pkt->stream_index]->codecpar;
+ uint8_t *side_data;
+ int side_data_size = 0, ret;
+
+ side_data = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA,
+ &side_data_size);
+
+ switch (par->codec_id) {
+ case AV_CODEC_ID_FLAC:
+ if (side_data_size && s->pb->seekable) {
+ AVCodecParameters *codecpriv_par;
+ int64_t curpos;
+ if (side_data_size != par->extradata_size) {
+ av_log(s, AV_LOG_ERROR, "Invalid FLAC STREAMINFO metadata for output stream %d\n",
+ pkt->stream_index);
+ return AVERROR(EINVAL);
+ }
+ codecpriv_par = avcodec_parameters_alloc();
+ if (!codecpriv_par)
+ return AVERROR(ENOMEM);
+ ret = avcodec_parameters_copy(codecpriv_par, par);
+ if (ret < 0) {
+ avcodec_parameters_free(&codecpriv_par);
+ return ret;
+ }
+ memcpy(codecpriv_par->extradata, side_data, side_data_size);
+ curpos = avio_tell(mkv->tracks_bc);
+ avio_seek(mkv->tracks_bc, track->codecpriv_offset, SEEK_SET);
+ mkv_write_codecprivate(s, mkv->tracks_bc, codecpriv_par, 1, 0);
+ avio_seek(mkv->tracks_bc, curpos, SEEK_SET);
+ avcodec_parameters_free(&codecpriv_par);
+ }
+ break;
+ default:
+ if (side_data_size)
+ av_log(s, AV_LOG_DEBUG, "Ignoring new extradata in a packet for stream %d.\n", pkt->stream_index);
+ break;
+ }
+
+ return 0;
+}
+