/* * Raw FLAC demuxer * Copyright (c) 2001 Fabrice Bellard * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "libavcodec/flac.h" #include "avformat.h" #include "flac_picture.h" #include "internal.h" #include "rawdec.h" #include "oggdec.h" #include "vorbiscomment.h" #include "replaygain.h" #include "libavcodec/bytestream.h" 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; AVStream *st = avformat_new_stream(s, NULL); if (!st) return AVERROR(ENOMEM); st->codec->codec_type = AVMEDIA_TYPE_AUDIO; st->codec->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 (!url_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: 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) { 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) { FLACStreaminfo si; /* 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->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_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 { /* 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; if (ff_vorbis_comment(s, &s->metadata, buffer, metadata_size)) { av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n"); } /* 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->codec->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; return 0; fail: av_free(buffer); return ret; } static int flac_probe(AVProbeData *p) { if (p->buf_size < 4 || memcmp(p->buf, "fLaC", 4)) return 0; return AVPROBE_SCORE_EXTENSION; } static av_unused int64_t flac_read_timestamp(AVFormatContext *s, int stream_index, int64_t *ppos, int64_t pos_limit) { AVPacket pkt, out_pkt; AVStream *st = s->streams[stream_index]; AVCodecParserContext *parser; int ret; int64_t pts = AV_NOPTS_VALUE; if (avio_seek(s->pb, *ppos, SEEK_SET) < 0) return AV_NOPTS_VALUE; av_init_packet(&pkt); parser = av_parser_init(st->codec->codec_id); if (!parser){ return AV_NOPTS_VALUE; } parser->flags |= PARSER_FLAG_USE_CODEC_TS; for (;;){ ret = ff_raw_read_partial_packet(s, &pkt); if (ret < 0){ if (ret == AVERROR(EAGAIN)) continue; else break; } av_init_packet(&out_pkt); ret = av_parser_parse2(parser, st->codec, &out_pkt.data, &out_pkt.size, pkt.data, pkt.size, pkt.pts, pkt.dts, *ppos); av_free_packet(&pkt); if (out_pkt.size){ int size = out_pkt.size; if (parser->pts != AV_NOPTS_VALUE){ // seeking may not have started from beginning of a frame // calculate frame start position from next frame backwards *ppos = parser->next_frame_offset - size; pts = parser->pts; break; } } } av_parser_close(parser); return pts; } AVInputFormat ff_flac_demuxer = { .name = "flac", .long_name = NULL_IF_CONFIG_SMALL("raw FLAC"), .read_probe = flac_probe, .read_header = flac_read_header, .read_packet = ff_raw_read_partial_packet, .read_timestamp = flac_read_timestamp, .flags = AVFMT_GENERIC_INDEX, .extensions = "flac", .raw_codec_id = AV_CODEC_ID_FLAC, };