+ /* if fLaC marker is not found, assume there is no header */
+ if (avio_rl32(s->pb) != MKTAG('f','L','a','C')) {
+ avio_seek(s->pb, -4, SEEK_CUR);
+ return 0;
+ }
+
+ /* process metadata blocks */
+ while (!s->pb->eof_reached && !metadata_last) {
+ avio_read(s->pb, header, 4);
+ avpriv_flac_parse_block_header(header, &metadata_last, &metadata_type,
+ &metadata_size);
+ switch (metadata_type) {
+ /* allocate and read metadata block for supported types */
+ case FLAC_METADATA_TYPE_STREAMINFO:
+ case FLAC_METADATA_TYPE_CUESHEET:
+ case FLAC_METADATA_TYPE_VORBIS_COMMENT:
+ buffer = av_mallocz(metadata_size + FF_INPUT_BUFFER_PADDING_SIZE);
+ if (!buffer) {
+ return AVERROR(ENOMEM);
+ }
+ if (avio_read(s->pb, buffer, metadata_size) != metadata_size) {
+ av_freep(&buffer);
+ return AVERROR(EIO);
+ }
+ break;
+ /* skip metadata block for unsupported types */
+ default:
+ ret = avio_skip(s->pb, metadata_size);
+ if (ret < 0)
+ return ret;
+ }
+
+ if (metadata_type == FLAC_METADATA_TYPE_STREAMINFO) {
+ FLACStreaminfo si;
+ /* STREAMINFO can only occur once */
+ if (found_streaminfo) {
+ av_freep(&buffer);
+ return AVERROR_INVALIDDATA;
+ }
+ if (metadata_size != FLAC_STREAMINFO_SIZE) {
+ av_freep(&buffer);
+ return AVERROR_INVALIDDATA;
+ }
+ found_streaminfo = 1;
+ st->codec->extradata = buffer;
+ st->codec->extradata_size = metadata_size;
+ buffer = NULL;
+
+ /* get codec params from STREAMINFO header */
+ avpriv_flac_parse_streaminfo(st->codec, &si, st->codec->extradata);
+
+ /* set time base and duration */
+ if (si.samplerate > 0) {
+ avpriv_set_pts_info(st, 64, 1, si.samplerate);
+ if (si.samples > 0)
+ st->duration = si.samples;
+ }
+ } else if (metadata_type == FLAC_METADATA_TYPE_CUESHEET) {
+ uint8_t isrc[13];
+ uint64_t start;
+ const uint8_t *offset;
+ int i, chapters, track, ti;
+ if (metadata_size < 431)
+ return AVERROR_INVALIDDATA;
+ offset = buffer + 395;
+ chapters = bytestream_get_byte(&offset) - 1;
+ if (chapters <= 0)
+ return AVERROR_INVALIDDATA;
+ for (i = 0; i < chapters; i++) {
+ if (offset + 36 - buffer > metadata_size)
+ return AVERROR_INVALIDDATA;
+ start = bytestream_get_be64(&offset);
+ track = bytestream_get_byte(&offset);
+ bytestream_get_buffer(&offset, isrc, 12);
+ isrc[12] = 0;
+ offset += 14;
+ ti = bytestream_get_byte(&offset);
+ if (ti <= 0) return AVERROR_INVALIDDATA;
+ offset += ti * 12;
+ avpriv_new_chapter(s, track, st->time_base, start, AV_NOPTS_VALUE, isrc);
+ }