1/* 2 * Core Audio Format demuxer 3 * Copyright (c) 2007 Justin Ruggles 4 * Copyright (c) 2009 Peter Ross 5 * 6 * This file is part of FFmpeg. 7 * 8 * FFmpeg is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Lesser General Public 10 * License as published by the Free Software Foundation; either 11 * version 2.1 of the License, or (at your option) any later version. 12 * 13 * FFmpeg is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with FFmpeg; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 21 */ 22 23/** 24 * @file 25 * Core Audio Format demuxer 26 */ 27 28#include "avformat.h" 29#include "riff.h" 30#include "isom.h" 31#include "libavutil/intreadwrite.h" 32#include "caf.h" 33 34typedef struct { 35 int bytes_per_packet; ///< bytes in a packet, or 0 if variable 36 int frames_per_packet; ///< frames in a packet, or 0 if variable 37 int64_t num_bytes; ///< total number of bytes in stream 38 39 int64_t packet_cnt; ///< packet counter 40 int64_t frame_cnt; ///< frame counter 41 42 int64_t data_start; ///< data start position, in bytes 43 int64_t data_size; ///< raw data size, in bytes 44} CaffContext; 45 46static int probe(AVProbeData *p) 47{ 48 if (AV_RB32(p->buf) == MKBETAG('c','a','f','f') && AV_RB16(&p->buf[4]) == 1) 49 return AVPROBE_SCORE_MAX; 50 return 0; 51} 52 53/** Read audio description chunk */ 54static int read_desc_chunk(AVFormatContext *s) 55{ 56 ByteIOContext *pb = s->pb; 57 CaffContext *caf = s->priv_data; 58 AVStream *st; 59 int flags; 60 61 /* new audio stream */ 62 st = av_new_stream(s, 0); 63 if (!st) 64 return AVERROR(ENOMEM); 65 66 /* parse format description */ 67 st->codec->codec_type = AVMEDIA_TYPE_AUDIO; 68 st->codec->sample_rate = av_int2dbl(get_be64(pb)); 69 st->codec->codec_tag = get_be32(pb); 70 flags = get_be32(pb); 71 caf->bytes_per_packet = get_be32(pb); 72 st->codec->block_align = caf->bytes_per_packet; 73 caf->frames_per_packet = get_be32(pb); 74 st->codec->channels = get_be32(pb); 75 st->codec->bits_per_coded_sample = get_be32(pb); 76 77 /* calculate bit rate for constant size packets */ 78 if (caf->frames_per_packet > 0 && caf->bytes_per_packet > 0) { 79 st->codec->bit_rate = (uint64_t)st->codec->sample_rate * (uint64_t)caf->bytes_per_packet * 8 80 / (uint64_t)caf->frames_per_packet; 81 } else { 82 st->codec->bit_rate = 0; 83 } 84 85 /* determine codec */ 86 if (st->codec->codec_tag == MKBETAG('l','p','c','m')) 87 st->codec->codec_id = ff_mov_get_lpcm_codec_id(st->codec->bits_per_coded_sample, (flags ^ 0x2) | 0x4); 88 else 89 st->codec->codec_id = ff_codec_get_id(ff_codec_caf_tags, st->codec->codec_tag); 90 return 0; 91} 92 93/** Read magic cookie chunk */ 94static int read_kuki_chunk(AVFormatContext *s, int64_t size) 95{ 96 ByteIOContext *pb = s->pb; 97 AVStream *st = s->streams[0]; 98 99 if (size < 0 || size > INT_MAX - FF_INPUT_BUFFER_PADDING_SIZE) 100 return -1; 101 102 if (st->codec->codec_id == CODEC_ID_AAC) { 103 /* The magic cookie format for AAC is an mp4 esds atom. 104 The lavc AAC decoder requires the data from the codec specific 105 description as extradata input. */ 106 int strt, skip; 107 MOVAtom atom; 108 109 strt = url_ftell(pb); 110 ff_mov_read_esds(s, pb, atom); 111 skip = size - (url_ftell(pb) - strt); 112 if (skip < 0 || !st->codec->extradata || 113 st->codec->codec_id != CODEC_ID_AAC) { 114 av_log(s, AV_LOG_ERROR, "invalid AAC magic cookie\n"); 115 return AVERROR_INVALIDDATA; 116 } 117 url_fskip(pb, skip); 118 } else { 119 st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE); 120 if (!st->codec->extradata) 121 return AVERROR(ENOMEM); 122 get_buffer(pb, st->codec->extradata, size); 123 st->codec->extradata_size = size; 124 } 125 126 return 0; 127} 128 129/** Read packet table chunk */ 130static int read_pakt_chunk(AVFormatContext *s, int64_t size) 131{ 132 ByteIOContext *pb = s->pb; 133 AVStream *st = s->streams[0]; 134 CaffContext *caf = s->priv_data; 135 int64_t pos = 0, ccount; 136 int num_packets, i; 137 138 ccount = url_ftell(pb); 139 140 num_packets = get_be64(pb); 141 if (num_packets < 0 || INT32_MAX / sizeof(AVIndexEntry) < num_packets) 142 return AVERROR_INVALIDDATA; 143 144 st->nb_frames = get_be64(pb); /* valid frames */ 145 st->nb_frames += get_be32(pb); /* priming frames */ 146 st->nb_frames += get_be32(pb); /* remainder frames */ 147 148 st->duration = 0; 149 for (i = 0; i < num_packets; i++) { 150 av_add_index_entry(s->streams[0], pos, st->duration, 0, 0, AVINDEX_KEYFRAME); 151 pos += caf->bytes_per_packet ? caf->bytes_per_packet : ff_mp4_read_descr_len(pb); 152 st->duration += caf->frames_per_packet ? caf->frames_per_packet : ff_mp4_read_descr_len(pb); 153 } 154 155 if (url_ftell(pb) - ccount != size) { 156 av_log(s, AV_LOG_ERROR, "error reading packet table\n"); 157 return -1; 158 } 159 160 caf->num_bytes = pos; 161 return 0; 162} 163 164/** Read information chunk */ 165static void read_info_chunk(AVFormatContext *s, int64_t size) 166{ 167 ByteIOContext *pb = s->pb; 168 unsigned int i; 169 unsigned int nb_entries = get_be32(pb); 170 for (i = 0; i < nb_entries; i++) { 171 char key[32]; 172 char value[1024]; 173 get_strz(pb, key, sizeof(key)); 174 get_strz(pb, value, sizeof(value)); 175 av_metadata_set2(&s->metadata, key, value, 0); 176 } 177} 178 179static int read_header(AVFormatContext *s, 180 AVFormatParameters *ap) 181{ 182 ByteIOContext *pb = s->pb; 183 CaffContext *caf = s->priv_data; 184 AVStream *st; 185 uint32_t tag = 0; 186 int found_data, ret; 187 int64_t size; 188 189 url_fskip(pb, 8); /* magic, version, file flags */ 190 191 /* audio description chunk */ 192 if (get_be32(pb) != MKBETAG('d','e','s','c')) { 193 av_log(s, AV_LOG_ERROR, "desc chunk not present\n"); 194 return AVERROR_INVALIDDATA; 195 } 196 size = get_be64(pb); 197 if (size != 32) 198 return AVERROR_INVALIDDATA; 199 200 ret = read_desc_chunk(s); 201 if (ret) 202 return ret; 203 st = s->streams[0]; 204 205 /* parse each chunk */ 206 found_data = 0; 207 while (!url_feof(pb)) { 208 209 /* stop at data chunk if seeking is not supported or 210 data chunk size is unknown */ 211 if (found_data && (caf->data_size < 0 || url_is_streamed(pb))) 212 break; 213 214 tag = get_be32(pb); 215 size = get_be64(pb); 216 if (url_feof(pb)) 217 break; 218 219 switch (tag) { 220 case MKBETAG('d','a','t','a'): 221 url_fskip(pb, 4); /* edit count */ 222 caf->data_start = url_ftell(pb); 223 caf->data_size = size < 0 ? -1 : size - 4; 224 if (caf->data_size > 0 && !url_is_streamed(pb)) 225 url_fskip(pb, caf->data_size); 226 found_data = 1; 227 break; 228 229 /* magic cookie chunk */ 230 case MKBETAG('k','u','k','i'): 231 if (read_kuki_chunk(s, size)) 232 return AVERROR_INVALIDDATA; 233 break; 234 235 /* packet table chunk */ 236 case MKBETAG('p','a','k','t'): 237 if (read_pakt_chunk(s, size)) 238 return AVERROR_INVALIDDATA; 239 break; 240 241 case MKBETAG('i','n','f','o'): 242 read_info_chunk(s, size); 243 break; 244 245 default: 246#define _(x) ((x) >= ' ' ? (x) : ' ') 247 av_log(s, AV_LOG_WARNING, "skipping CAF chunk: %08X (%c%c%c%c)\n", 248 tag, _(tag>>24), _((tag>>16)&0xFF), _((tag>>8)&0xFF), _(tag&0xFF)); 249#undef _ 250 case MKBETAG('f','r','e','e'): 251 if (size < 0) 252 return AVERROR_INVALIDDATA; 253 url_fskip(pb, size); 254 break; 255 } 256 } 257 258 if (!found_data) 259 return AVERROR_INVALIDDATA; 260 261 if (caf->bytes_per_packet > 0 && caf->frames_per_packet > 0) { 262 if (caf->data_size > 0) 263 st->nb_frames = (caf->data_size / caf->bytes_per_packet) * caf->frames_per_packet; 264 } else if (st->nb_index_entries) { 265 st->codec->bit_rate = st->codec->sample_rate * caf->data_size * 8 / 266 st->duration; 267 } else { 268 av_log(s, AV_LOG_ERROR, "Missing packet table. It is required when " 269 "block size or frame size are variable.\n"); 270 return AVERROR_INVALIDDATA; 271 } 272 s->file_size = url_fsize(pb); 273 s->file_size = FFMAX(0, s->file_size); 274 275 av_set_pts_info(st, 64, 1, st->codec->sample_rate); 276 st->start_time = 0; 277 278 /* position the stream at the start of data */ 279 if (caf->data_size >= 0) 280 url_fseek(pb, caf->data_start, SEEK_SET); 281 282 return 0; 283} 284 285#define CAF_MAX_PKT_SIZE 4096 286 287static int read_packet(AVFormatContext *s, AVPacket *pkt) 288{ 289 ByteIOContext *pb = s->pb; 290 AVStream *st = s->streams[0]; 291 CaffContext *caf = s->priv_data; 292 int res, pkt_size = 0, pkt_frames = 0; 293 int64_t left = CAF_MAX_PKT_SIZE; 294 295 if (url_feof(pb)) 296 return AVERROR(EIO); 297 298 /* don't read past end of data chunk */ 299 if (caf->data_size > 0) { 300 left = (caf->data_start + caf->data_size) - url_ftell(pb); 301 if (left <= 0) 302 return AVERROR(EIO); 303 } 304 305 pkt_frames = caf->frames_per_packet; 306 pkt_size = caf->bytes_per_packet; 307 308 if (pkt_size > 0 && pkt_frames == 1) { 309 pkt_size = (CAF_MAX_PKT_SIZE / pkt_size) * pkt_size; 310 pkt_size = FFMIN(pkt_size, left); 311 pkt_frames = pkt_size / caf->bytes_per_packet; 312 } else if (st->nb_index_entries) { 313 if (caf->packet_cnt < st->nb_index_entries - 1) { 314 pkt_size = st->index_entries[caf->packet_cnt + 1].pos - st->index_entries[caf->packet_cnt].pos; 315 pkt_frames = st->index_entries[caf->packet_cnt + 1].timestamp - st->index_entries[caf->packet_cnt].timestamp; 316 } else if (caf->packet_cnt == st->nb_index_entries - 1) { 317 pkt_size = caf->num_bytes - st->index_entries[caf->packet_cnt].pos; 318 pkt_frames = st->duration - st->index_entries[caf->packet_cnt].timestamp; 319 } else { 320 return AVERROR(EIO); 321 } 322 } 323 324 if (pkt_size == 0 || pkt_frames == 0 || pkt_size > left) 325 return AVERROR(EIO); 326 327 res = av_get_packet(pb, pkt, pkt_size); 328 if (res < 0) 329 return res; 330 331 pkt->size = res; 332 pkt->stream_index = 0; 333 pkt->dts = pkt->pts = caf->frame_cnt; 334 335 caf->packet_cnt++; 336 caf->frame_cnt += pkt_frames; 337 338 return 0; 339} 340 341static int read_seek(AVFormatContext *s, int stream_index, 342 int64_t timestamp, int flags) 343{ 344 AVStream *st = s->streams[0]; 345 CaffContext *caf = s->priv_data; 346 int64_t pos; 347 348 timestamp = FFMAX(timestamp, 0); 349 350 if (caf->frames_per_packet > 0 && caf->bytes_per_packet > 0) { 351 /* calculate new byte position based on target frame position */ 352 pos = caf->bytes_per_packet * timestamp / caf->frames_per_packet; 353 if (caf->data_size > 0) 354 pos = FFMIN(pos, caf->data_size); 355 caf->packet_cnt = pos / caf->bytes_per_packet; 356 caf->frame_cnt = caf->frames_per_packet * caf->packet_cnt; 357 } else if (st->nb_index_entries) { 358 caf->packet_cnt = av_index_search_timestamp(st, timestamp, flags); 359 caf->frame_cnt = st->index_entries[caf->packet_cnt].timestamp; 360 pos = st->index_entries[caf->packet_cnt].pos; 361 } else { 362 return -1; 363 } 364 365 url_fseek(s->pb, pos + caf->data_start, SEEK_SET); 366 return 0; 367} 368 369AVInputFormat caf_demuxer = { 370 "caf", 371 NULL_IF_CONFIG_SMALL("Apple Core Audio Format"), 372 sizeof(CaffContext), 373 probe, 374 read_header, 375 read_packet, 376 NULL, 377 read_seek, 378 .codec_tag = (const AVCodecTag*[]){ff_codec_caf_tags, 0}, 379}; 380