1/* 2 * Raw FLAC demuxer 3 * Copyright (c) 2001 Fabrice Bellard 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22#include "libavcodec/flac.h" 23#include "avformat.h" 24#include "flac_picture.h" 25#include "internal.h" 26#include "rawdec.h" 27#include "oggdec.h" 28#include "vorbiscomment.h" 29#include "replaygain.h" 30#include "libavcodec/bytestream.h" 31 32static int flac_read_header(AVFormatContext *s) 33{ 34 int ret, metadata_last=0, metadata_type, metadata_size, found_streaminfo=0; 35 uint8_t header[4]; 36 uint8_t *buffer=NULL; 37 AVStream *st = avformat_new_stream(s, NULL); 38 if (!st) 39 return AVERROR(ENOMEM); 40 st->codec->codec_type = AVMEDIA_TYPE_AUDIO; 41 st->codec->codec_id = AV_CODEC_ID_FLAC; 42 st->need_parsing = AVSTREAM_PARSE_FULL_RAW; 43 /* the parameters will be extracted from the compressed bitstream */ 44 45 /* if fLaC marker is not found, assume there is no header */ 46 if (avio_rl32(s->pb) != MKTAG('f','L','a','C')) { 47 avio_seek(s->pb, -4, SEEK_CUR); 48 return 0; 49 } 50 51 /* process metadata blocks */ 52 while (!url_feof(s->pb) && !metadata_last) { 53 avio_read(s->pb, header, 4); 54 flac_parse_block_header(header, &metadata_last, &metadata_type, 55 &metadata_size); 56 switch (metadata_type) { 57 /* allocate and read metadata block for supported types */ 58 case FLAC_METADATA_TYPE_STREAMINFO: 59 case FLAC_METADATA_TYPE_CUESHEET: 60 case FLAC_METADATA_TYPE_PICTURE: 61 case FLAC_METADATA_TYPE_VORBIS_COMMENT: 62 buffer = av_mallocz(metadata_size + FF_INPUT_BUFFER_PADDING_SIZE); 63 if (!buffer) { 64 return AVERROR(ENOMEM); 65 } 66 if (avio_read(s->pb, buffer, metadata_size) != metadata_size) { 67 RETURN_ERROR(AVERROR(EIO)); 68 } 69 break; 70 /* skip metadata block for unsupported types */ 71 default: 72 ret = avio_skip(s->pb, metadata_size); 73 if (ret < 0) 74 return ret; 75 } 76 77 if (metadata_type == FLAC_METADATA_TYPE_STREAMINFO) { 78 FLACStreaminfo si; 79 /* STREAMINFO can only occur once */ 80 if (found_streaminfo) { 81 RETURN_ERROR(AVERROR_INVALIDDATA); 82 } 83 if (metadata_size != FLAC_STREAMINFO_SIZE) { 84 RETURN_ERROR(AVERROR_INVALIDDATA); 85 } 86 found_streaminfo = 1; 87 st->codec->extradata = buffer; 88 st->codec->extradata_size = metadata_size; 89 buffer = NULL; 90 91 /* get codec params from STREAMINFO header */ 92 avpriv_flac_parse_streaminfo(st->codec, &si, st->codec->extradata); 93 94 /* set time base and duration */ 95 if (si.samplerate > 0) { 96 avpriv_set_pts_info(st, 64, 1, si.samplerate); 97 if (si.samples > 0) 98 st->duration = si.samples; 99 } 100 } else if (metadata_type == FLAC_METADATA_TYPE_CUESHEET) { 101 uint8_t isrc[13]; 102 uint64_t start; 103 const uint8_t *offset; 104 int i, chapters, track, ti; 105 if (metadata_size < 431) 106 RETURN_ERROR(AVERROR_INVALIDDATA); 107 offset = buffer + 395; 108 chapters = bytestream_get_byte(&offset) - 1; 109 if (chapters <= 0) 110 RETURN_ERROR(AVERROR_INVALIDDATA); 111 for (i = 0; i < chapters; i++) { 112 if (offset + 36 - buffer > metadata_size) 113 RETURN_ERROR(AVERROR_INVALIDDATA); 114 start = bytestream_get_be64(&offset); 115 track = bytestream_get_byte(&offset); 116 bytestream_get_buffer(&offset, isrc, 12); 117 isrc[12] = 0; 118 offset += 14; 119 ti = bytestream_get_byte(&offset); 120 if (ti <= 0) RETURN_ERROR(AVERROR_INVALIDDATA); 121 offset += ti * 12; 122 avpriv_new_chapter(s, track, st->time_base, start, AV_NOPTS_VALUE, isrc); 123 } 124 av_freep(&buffer); 125 } else if (metadata_type == FLAC_METADATA_TYPE_PICTURE) { 126 ret = ff_flac_parse_picture(s, buffer, metadata_size); 127 av_freep(&buffer); 128 if (ret < 0) { 129 av_log(s, AV_LOG_ERROR, "Error parsing attached picture.\n"); 130 return ret; 131 } 132 } else { 133 /* STREAMINFO must be the first block */ 134 if (!found_streaminfo) { 135 RETURN_ERROR(AVERROR_INVALIDDATA); 136 } 137 /* process supported blocks other than STREAMINFO */ 138 if (metadata_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) { 139 AVDictionaryEntry *chmask; 140 141 if (ff_vorbis_comment(s, &s->metadata, buffer, metadata_size, 1)) { 142 av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n"); 143 } 144 145 /* parse the channels mask if present */ 146 chmask = av_dict_get(s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0); 147 if (chmask) { 148 uint64_t mask = strtol(chmask->value, NULL, 0); 149 if (!mask || mask & ~0x3ffffULL) { 150 av_log(s, AV_LOG_WARNING, 151 "Invalid value of WAVEFORMATEXTENSIBLE_CHANNEL_MASK\n"); 152 } else { 153 st->codec->channel_layout = mask; 154 av_dict_set(&s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", NULL, 0); 155 } 156 } 157 } 158 av_freep(&buffer); 159 } 160 } 161 162 ret = ff_replaygain_export(st, s->metadata); 163 if (ret < 0) 164 return ret; 165 166 return 0; 167 168fail: 169 av_free(buffer); 170 return ret; 171} 172 173static int flac_probe(AVProbeData *p) 174{ 175 if (p->buf_size < 4 || memcmp(p->buf, "fLaC", 4)) 176 return 0; 177 return AVPROBE_SCORE_EXTENSION; 178} 179 180static av_unused int64_t flac_read_timestamp(AVFormatContext *s, int stream_index, 181 int64_t *ppos, int64_t pos_limit) 182{ 183 AVPacket pkt, out_pkt; 184 AVStream *st = s->streams[stream_index]; 185 AVCodecParserContext *parser; 186 int ret; 187 int64_t pts = AV_NOPTS_VALUE; 188 189 if (avio_seek(s->pb, *ppos, SEEK_SET) < 0) 190 return AV_NOPTS_VALUE; 191 192 av_init_packet(&pkt); 193 parser = av_parser_init(st->codec->codec_id); 194 if (!parser){ 195 return AV_NOPTS_VALUE; 196 } 197 parser->flags |= PARSER_FLAG_USE_CODEC_TS; 198 199 for (;;){ 200 ret = ff_raw_read_partial_packet(s, &pkt); 201 if (ret < 0){ 202 if (ret == AVERROR(EAGAIN)) 203 continue; 204 else 205 break; 206 } 207 av_init_packet(&out_pkt); 208 ret = av_parser_parse2(parser, st->codec, 209 &out_pkt.data, &out_pkt.size, pkt.data, pkt.size, 210 pkt.pts, pkt.dts, *ppos); 211 212 av_free_packet(&pkt); 213 if (out_pkt.size){ 214 int size = out_pkt.size; 215 if (parser->pts != AV_NOPTS_VALUE){ 216 // seeking may not have started from beginning of a frame 217 // calculate frame start position from next frame backwards 218 *ppos = parser->next_frame_offset - size; 219 pts = parser->pts; 220 break; 221 } 222 } 223 } 224 av_parser_close(parser); 225 return pts; 226} 227 228AVInputFormat ff_flac_demuxer = { 229 .name = "flac", 230 .long_name = NULL_IF_CONFIG_SMALL("raw FLAC"), 231 .read_probe = flac_probe, 232 .read_header = flac_read_header, 233 .read_packet = ff_raw_read_partial_packet, 234 .read_timestamp = flac_read_timestamp, 235 .flags = AVFMT_GENERIC_INDEX, 236 .extensions = "flac", 237 .raw_codec_id = AV_CODEC_ID_FLAC, 238}; 239