+static int extract_extradata_init(AVStream *st)
+{
+ AVStreamInternal *i = st->internal;
+ const AVBitStreamFilter *f;
+ int ret;
+
+ f = av_bsf_get_by_name("extract_extradata");
+ if (!f)
+ goto finish;
+
+ /* check that the codec id is supported */
+ if (f->codec_ids) {
+ const enum AVCodecID *ids;
+ for (ids = f->codec_ids; *ids != AV_CODEC_ID_NONE; ids++)
+ if (*ids == st->codecpar->codec_id)
+ break;
+ if (*ids == AV_CODEC_ID_NONE)
+ goto finish;
+ }
+
+ i->extract_extradata.pkt = av_packet_alloc();
+ if (!i->extract_extradata.pkt)
+ return AVERROR(ENOMEM);
+
+ ret = av_bsf_alloc(f, &i->extract_extradata.bsf);
+ if (ret < 0)
+ goto fail;
+
+ ret = avcodec_parameters_copy(i->extract_extradata.bsf->par_in,
+ st->codecpar);
+ if (ret < 0)
+ goto fail;
+
+ i->extract_extradata.bsf->time_base_in = st->time_base;
+
+ /* if init fails here, we assume extracting extradata is just not
+ * supported for this codec, so we return success */
+ ret = av_bsf_init(i->extract_extradata.bsf);
+ if (ret < 0) {
+ av_bsf_free(&i->extract_extradata.bsf);
+ ret = 0;
+ }
+
+finish:
+ i->extract_extradata.inited = 1;
+
+ return 0;
+fail:
+ av_bsf_free(&i->extract_extradata.bsf);
+ av_packet_free(&i->extract_extradata.pkt);
+ return ret;
+}
+
+static int extract_extradata(AVStream *st, AVPacket *pkt)
+{
+ AVStreamInternal *i = st->internal;
+ AVPacket *pkt_ref;
+ int ret;
+
+ if (!i->extract_extradata.inited) {
+ ret = extract_extradata_init(st);
+ if (ret < 0)
+ return ret;
+ }
+
+ if (i->extract_extradata.inited && !i->extract_extradata.bsf)
+ return 0;
+
+ pkt_ref = i->extract_extradata.pkt;
+ ret = av_packet_ref(pkt_ref, pkt);
+ if (ret < 0)
+ return ret;
+
+ ret = av_bsf_send_packet(i->extract_extradata.bsf, pkt_ref);
+ if (ret < 0) {
+ av_packet_unref(pkt_ref);
+ return ret;
+ }
+
+ while (ret >= 0 && !i->avctx->extradata) {
+ int extradata_size;
+ uint8_t *extradata;
+
+ ret = av_bsf_receive_packet(i->extract_extradata.bsf, pkt_ref);
+ if (ret < 0) {
+ if (ret != AVERROR(EAGAIN) && ret != AVERROR_EOF)
+ return ret;
+ continue;
+ }
+
+ extradata = av_packet_get_side_data(pkt_ref, AV_PKT_DATA_NEW_EXTRADATA,
+ &extradata_size);
+
+ if (extradata) {
+ i->avctx->extradata = av_mallocz(extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
+ if (!i->avctx->extradata) {
+ av_packet_unref(pkt_ref);
+ return AVERROR(ENOMEM);
+ }
+ memcpy(i->avctx->extradata, extradata, extradata_size);
+ i->avctx->extradata_size = extradata_size;
+ }
+ av_packet_unref(pkt_ref);
+ }
+
+ return 0;
+}
+