static int flac_read_header(AVFormatContext *s) { int ret, metadata_last=0, metadata_type, metadata_size, found_streaminfo=0; uint8_t header[4]; uint8_t *buffer=NULL; FLACDecContext *flac = s->priv_data; AVStream *st = avformat_new_stream(s, NULL); if (!st) return AVERROR(ENOMEM); st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; st->codecpar->codec_id = AV_CODEC_ID_FLAC; st->need_parsing = AVSTREAM_PARSE_FULL_RAW; /* the parameters will be extracted from the compressed bitstream */ /* 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 (!avio_feof(s->pb) && !metadata_last) { avio_read(s->pb, header, 4); 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_PICTURE: case FLAC_METADATA_TYPE_VORBIS_COMMENT: case FLAC_METADATA_TYPE_SEEKTABLE: buffer = av_mallocz(metadata_size + AV_INPUT_BUFFER_PADDING_SIZE); if (!buffer) { return AVERROR(ENOMEM); } if (avio_read(s->pb, buffer, metadata_size) != metadata_size) { RETURN_ERROR(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) { uint32_t samplerate; uint64_t samples; /* STREAMINFO can only occur once */ if (found_streaminfo) { RETURN_ERROR(AVERROR_INVALIDDATA); } if (metadata_size != FLAC_STREAMINFO_SIZE) { RETURN_ERROR(AVERROR_INVALIDDATA); } found_streaminfo = 1; st->codecpar->extradata = buffer; st->codecpar->extradata_size = metadata_size; buffer = NULL; /* get sample rate and sample count from STREAMINFO header; * other parameters will be extracted by the parser */ samplerate = AV_RB24(st->codecpar->extradata + 10) >> 4; samples = (AV_RB64(st->codecpar->extradata + 13) >> 24) & ((1ULL << 36) - 1); /* set time base and duration */ if (samplerate > 0) { avpriv_set_pts_info(st, 64, 1, samplerate); if (samples > 0) st->duration = 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_ERROR(AVERROR_INVALIDDATA); offset = buffer + 395; chapters = bytestream_get_byte(&offset) - 1; if (chapters <= 0) RETURN_ERROR(AVERROR_INVALIDDATA); for (i = 0; i < chapters; i++) { if (offset + 36 - buffer > metadata_size) RETURN_ERROR(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_ERROR(AVERROR_INVALIDDATA); offset += ti * 12; avpriv_new_chapter(s, track, st->time_base, start, AV_NOPTS_VALUE, isrc); } av_freep(&buffer); } else if (metadata_type == FLAC_METADATA_TYPE_PICTURE) { ret = ff_flac_parse_picture(s, buffer, metadata_size); av_freep(&buffer); if (ret < 0) { av_log(s, AV_LOG_ERROR, "Error parsing attached picture.\n"); return ret; } } else if (metadata_type == FLAC_METADATA_TYPE_SEEKTABLE) { const uint8_t *seekpoint = buffer; int i, seek_point_count = metadata_size/SEEKPOINT_SIZE; flac->found_seektable = 1; if ((s->flags&AVFMT_FLAG_FAST_SEEK)) { for(i=0; i<seek_point_count; i++) { int64_t timestamp = bytestream_get_be64(&seekpoint); int64_t pos = bytestream_get_be64(&seekpoint); /* skip number of samples */ bytestream_get_be16(&seekpoint); av_add_index_entry(st, pos, timestamp, 0, 0, AVINDEX_KEYFRAME); } } av_freep(&buffer); } else { /* STREAMINFO must be the first block */ if (!found_streaminfo) { RETURN_ERROR(AVERROR_INVALIDDATA); } /* process supported blocks other than STREAMINFO */ if (metadata_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) { AVDictionaryEntry *chmask; ret = ff_vorbis_comment(s, &s->metadata, buffer, metadata_size, 1); if (ret < 0) { av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n"); } else if (ret > 0) { s->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED; } /* parse the channels mask if present */ chmask = av_dict_get(s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0); if (chmask) { uint64_t mask = strtol(chmask->value, NULL, 0); if (!mask || mask & ~0x3ffffULL) { av_log(s, AV_LOG_WARNING, "Invalid value of WAVEFORMATEXTENSIBLE_CHANNEL_MASK\n"); } else { st->codecpar->channel_layout = mask; av_dict_set(&s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0); } } } av_freep(&buffer); } } ret = ff_replaygain_export(st, s->metadata); if (ret < 0) return ret; reset_index_position(avio_tell(s->pb), st); return 0; fail: av_free(buffer); return ret; }