/* * 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" #define SEEKPOINT_SIZE 18 typedef struct FLACDecContext { int found_seektable; } FLACDecContext; static void reset_index_position(int64_t metadata_head_size, AVStream *st) { /* the real seek index offset should be the size of metadata blocks with the offset in the frame blocks */ int i; for(i=0; i<st->nb_index_entries; i++) { st->index_entries[i].pos += metadata_head_size; } } 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; } static int raw_flac_probe(AVProbeData *p) { if ((p->buf[2] & 0xF0) == 0) // blocksize code invalid return 0; if ((p->buf[2] & 0x0F) == 0x0F) // sample rate code invalid return 0; if ((p->buf[3] & 0xF0) >= FLAC_MAX_CHANNELS + FLAC_CHMODE_MID_SIDE << 4) // channel mode invalid return 0; if ((p->buf[3] & 0x06) == 0x06) // bits per sample code invalid return 0; if ((p->buf[3] & 0x01) == 0x01) // reserved bit set return 0; return AVPROBE_SCORE_EXTENSION / 4 + 1; } static int flac_probe(AVProbeData *p) { if ((AV_RB16(p->buf) & 0xFFFE) == 0xFFF8) return raw_flac_probe(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->codecpar->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 { av_packet_unref(&pkt); av_assert1(!pkt.size); } } av_init_packet(&out_pkt); av_parser_parse2(parser, st->internal->avctx, &out_pkt.data, &out_pkt.size, pkt.data, pkt.size, pkt.pts, pkt.dts, *ppos); av_packet_unref(&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; } } else if (ret < 0) break; } av_parser_close(parser); return pts; } static int flac_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags) { int index; int64_t pos; AVIndexEntry e; FLACDecContext *flac = s->priv_data; if (!flac->found_seektable || !(s->flags&AVFMT_FLAG_FAST_SEEK)) { return -1; } index = av_index_search_timestamp(s->streams[0], timestamp, flags); if(index<0 || index >= s->streams[0]->nb_index_entries) return -1; e = s->streams[0]->index_entries[index]; pos = avio_seek(s->pb, e.pos, SEEK_SET); if (pos >= 0) { return 0; } return -1; } 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_seek = flac_seek, .read_timestamp = flac_read_timestamp, .flags = AVFMT_GENERIC_INDEX, .extensions = "flac", .raw_codec_id = AV_CODEC_ID_FLAC, .priv_data_size = sizeof(FLACDecContext), };