static int flac_header (AVFormatContext * s, int idx) { struct ogg *ogg = s->priv_data; struct ogg_stream *os = ogg->streams + idx; AVStream *st = s->streams[idx]; GetBitContext gb; int mdt; if (os->buf[os->pstart] == 0xff) return 0; init_get_bits(&gb, os->buf + os->pstart, os->psize*8); get_bits(&gb, 1); /* metadata_last */ mdt = get_bits(&gb, 7); if (mdt == 0x7f) { skip_bits(&gb, 4*8); /* "FLAC" */ if(get_bits(&gb, 8) != 1) /* unsupported major version */ return -1; skip_bits(&gb, 8 + 16); /* minor version + header count */ skip_bits(&gb, 4*8); /* "fLaC" */ /* METADATA_BLOCK_HEADER */ if (get_bits_long(&gb, 32) != FLAC_STREAMINFO_SIZE) return -1; skip_bits(&gb, 16*2+24*2); st->codec->sample_rate = get_bits_long(&gb, 20); st->codec->channels = get_bits(&gb, 3) + 1; st->codec->codec_type = CODEC_TYPE_AUDIO; st->codec->codec_id = CODEC_ID_FLAC; st->codec->extradata = av_malloc(FLAC_STREAMINFO_SIZE + FF_INPUT_BUFFER_PADDING_SIZE); memcpy (st->codec->extradata, os->buf + os->pstart + 5 + 4 + 4 + 4, FLAC_STREAMINFO_SIZE); st->codec->extradata_size = FLAC_STREAMINFO_SIZE; st->time_base.num = 1; st->time_base.den = st->codec->sample_rate; } else if (mdt == 4) { vorbis_comment (s, os->buf + os->pstart + 4, os->psize - 4); } return 1; }
static int flac_read_header(AVFormatContext *s, AVFormatParameters *ap) { uint8_t buf[ID3v2_HEADER_SIZE]; int ret, metadata_last=0, metadata_type, metadata_size, found_streaminfo=0; uint8_t header[4]; uint8_t *buffer=NULL; AVStream *st = av_new_stream(s, 0); if (!st) return AVERROR(ENOMEM); st->codec->codec_type = CODEC_TYPE_AUDIO; st->codec->codec_id = CODEC_ID_FLAC; st->need_parsing = AVSTREAM_PARSE_FULL; /* the parameters will be extracted from the compressed bitstream */ /* skip ID3v2 header if found */ ret = get_buffer(s->pb, buf, ID3v2_HEADER_SIZE); if (ret == ID3v2_HEADER_SIZE && ff_id3v2_match(buf)) { int len = ff_id3v2_tag_len(buf); url_fseek(s->pb, len - ID3v2_HEADER_SIZE, SEEK_CUR); } else { url_fseek(s->pb, 0, SEEK_SET); } /* if fLaC marker is not found, assume there is no header */ if (get_le32(s->pb) != MKTAG('f','L','a','C')) return 0; /* process metadata blocks */ while (!url_feof(s->pb) && !metadata_last) { get_buffer(s->pb, header, 4); ff_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_VORBIS_COMMENT: buffer = av_mallocz(metadata_size + FF_INPUT_BUFFER_PADDING_SIZE); if (!buffer) { return AVERROR_NOMEM; } if (get_buffer(s->pb, buffer, metadata_size) != metadata_size) { av_freep(&buffer); return AVERROR_IO; } break; /* skip metadata block for unsupported types */ default: ret = url_fseek(s->pb, metadata_size, SEEK_CUR); 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 */ ff_flac_parse_streaminfo(st->codec, &si, st->codec->extradata); /* set time base and duration */ if (si.samplerate > 0) { av_set_pts_info(st, 64, 1, si.samplerate); if (si.samples > 0) st->duration = si.samples; } } else { /* STREAMINFO must be the first block */ if (!found_streaminfo) { av_freep(&buffer); return AVERROR_INVALIDDATA; } /* process supported blocks other than STREAMINFO */ if (metadata_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) { if (vorbis_comment(s, buffer, metadata_size)) { av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n"); } } av_freep(&buffer); } } return 0; }