2 * Core Audio Format demuxer
3 * Copyright (c) 2007 Justin Ruggles
4 * Copyright (c) 2009 Peter Ross
6 * This file is part of Libav.
8 * Libav 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.
13 * Libav 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.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with Libav; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 * Core Audio Format demuxer
34 #include "libavutil/intreadwrite.h"
35 #include "libavutil/intfloat.h"
36 #include "libavutil/dict.h"
40 int bytes_per_packet; ///< bytes in a packet, or 0 if variable
41 int frames_per_packet; ///< frames in a packet, or 0 if variable
42 int64_t num_bytes; ///< total number of bytes in stream
44 int64_t packet_cnt; ///< packet counter
45 int64_t frame_cnt; ///< frame counter
47 int64_t data_start; ///< data start position, in bytes
48 int64_t data_size; ///< raw data size, in bytes
51 static int probe(AVProbeData *p)
53 if (AV_RB32(p->buf) == MKBETAG('c','a','f','f') && AV_RB16(&p->buf[4]) == 1)
54 return AVPROBE_SCORE_MAX;
58 /** Read audio description chunk */
59 static int read_desc_chunk(AVFormatContext *s)
61 AVIOContext *pb = s->pb;
62 CaffContext *caf = s->priv_data;
66 /* new audio stream */
67 st = avformat_new_stream(s, NULL);
69 return AVERROR(ENOMEM);
71 /* parse format description */
72 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
73 st->codec->sample_rate = av_int2double(avio_rb64(pb));
74 st->codec->codec_tag = avio_rb32(pb);
75 flags = avio_rb32(pb);
76 caf->bytes_per_packet = avio_rb32(pb);
77 st->codec->block_align = caf->bytes_per_packet;
78 caf->frames_per_packet = avio_rb32(pb);
79 st->codec->channels = avio_rb32(pb);
80 st->codec->bits_per_coded_sample = avio_rb32(pb);
82 /* calculate bit rate for constant size packets */
83 if (caf->frames_per_packet > 0 && caf->bytes_per_packet > 0) {
84 st->codec->bit_rate = (uint64_t)st->codec->sample_rate * (uint64_t)caf->bytes_per_packet * 8
85 / (uint64_t)caf->frames_per_packet;
87 st->codec->bit_rate = 0;
91 if (st->codec->codec_tag == MKBETAG('l','p','c','m'))
92 st->codec->codec_id = ff_mov_get_lpcm_codec_id(st->codec->bits_per_coded_sample, (flags ^ 0x2) | 0x4);
94 st->codec->codec_id = ff_codec_get_id(ff_codec_caf_tags, st->codec->codec_tag);
98 /** Read magic cookie chunk */
99 static int read_kuki_chunk(AVFormatContext *s, int64_t size)
101 AVIOContext *pb = s->pb;
102 AVStream *st = s->streams[0];
104 if (size < 0 || size > INT_MAX - FF_INPUT_BUFFER_PADDING_SIZE)
107 if (st->codec->codec_id == AV_CODEC_ID_AAC) {
108 /* The magic cookie format for AAC is an mp4 esds atom.
109 The lavc AAC decoder requires the data from the codec specific
110 description as extradata input. */
114 strt = avio_tell(pb);
115 ff_mov_read_esds(s, pb, atom);
116 skip = size - (avio_tell(pb) - strt);
117 if (skip < 0 || !st->codec->extradata ||
118 st->codec->codec_id != AV_CODEC_ID_AAC) {
119 av_log(s, AV_LOG_ERROR, "invalid AAC magic cookie\n");
120 return AVERROR_INVALIDDATA;
123 } else if (st->codec->codec_id == AV_CODEC_ID_ALAC) {
124 #define ALAC_PREAMBLE 12
125 #define ALAC_HEADER 36
126 #define ALAC_NEW_KUKI 24
127 uint8_t preamble[12];
128 if (size < ALAC_NEW_KUKI) {
129 av_log(s, AV_LOG_ERROR, "invalid ALAC magic cookie\n");
131 return AVERROR_INVALIDDATA;
133 avio_read(pb, preamble, ALAC_PREAMBLE);
135 st->codec->extradata = av_mallocz(ALAC_HEADER + FF_INPUT_BUFFER_PADDING_SIZE);
136 if (!st->codec->extradata)
137 return AVERROR(ENOMEM);
139 /* For the old style cookie, we skip 12 bytes, then read 36 bytes.
140 * The new style cookie only contains the last 24 bytes of what was
141 * 36 bytes in the old style cookie, so we fabricate the first 12 bytes
142 * in that case to maintain compatibility. */
143 if (!memcmp(&preamble[4], "frmaalac", 8)) {
144 if (size < ALAC_PREAMBLE + ALAC_HEADER) {
145 av_log(s, AV_LOG_ERROR, "invalid ALAC magic cookie\n");
146 av_freep(&st->codec->extradata);
147 return AVERROR_INVALIDDATA;
149 avio_read(pb, st->codec->extradata, ALAC_HEADER);
150 avio_skip(pb, size - ALAC_PREAMBLE - ALAC_HEADER);
152 AV_WB32(st->codec->extradata, 36);
153 memcpy(&st->codec->extradata[4], "alac", 4);
154 AV_WB32(&st->codec->extradata[8], 0);
155 memcpy(&st->codec->extradata[12], preamble, 12);
156 avio_read(pb, &st->codec->extradata[24], ALAC_NEW_KUKI - 12);
157 avio_skip(pb, size - ALAC_NEW_KUKI);
159 st->codec->extradata_size = ALAC_HEADER;
161 st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
162 if (!st->codec->extradata)
163 return AVERROR(ENOMEM);
164 avio_read(pb, st->codec->extradata, size);
165 st->codec->extradata_size = size;
171 /** Read packet table chunk */
172 static int read_pakt_chunk(AVFormatContext *s, int64_t size)
174 AVIOContext *pb = s->pb;
175 AVStream *st = s->streams[0];
176 CaffContext *caf = s->priv_data;
177 int64_t pos = 0, ccount, num_packets;
180 ccount = avio_tell(pb);
182 num_packets = avio_rb64(pb);
183 if (num_packets < 0 || INT32_MAX / sizeof(AVIndexEntry) < num_packets)
184 return AVERROR_INVALIDDATA;
186 st->nb_frames = avio_rb64(pb); /* valid frames */
187 st->nb_frames += avio_rb32(pb); /* priming frames */
188 st->nb_frames += avio_rb32(pb); /* remainder frames */
191 for (i = 0; i < num_packets; i++) {
192 av_add_index_entry(s->streams[0], pos, st->duration, 0, 0, AVINDEX_KEYFRAME);
193 pos += caf->bytes_per_packet ? caf->bytes_per_packet : ff_mp4_read_descr_len(pb);
194 st->duration += caf->frames_per_packet ? caf->frames_per_packet : ff_mp4_read_descr_len(pb);
197 if (avio_tell(pb) - ccount > size) {
198 av_log(s, AV_LOG_ERROR, "error reading packet table\n");
199 return AVERROR_INVALIDDATA;
201 avio_skip(pb, ccount + size - avio_tell(pb));
203 caf->num_bytes = pos;
207 /** Read information chunk */
208 static void read_info_chunk(AVFormatContext *s, int64_t size)
210 AVIOContext *pb = s->pb;
212 unsigned int nb_entries = avio_rb32(pb);
213 for (i = 0; i < nb_entries; i++) {
216 avio_get_str(pb, INT_MAX, key, sizeof(key));
217 avio_get_str(pb, INT_MAX, value, sizeof(value));
218 av_dict_set(&s->metadata, key, value, 0);
222 static int read_header(AVFormatContext *s)
224 AVIOContext *pb = s->pb;
225 CaffContext *caf = s->priv_data;
231 avio_skip(pb, 8); /* magic, version, file flags */
233 /* audio description chunk */
234 if (avio_rb32(pb) != MKBETAG('d','e','s','c')) {
235 av_log(s, AV_LOG_ERROR, "desc chunk not present\n");
236 return AVERROR_INVALIDDATA;
238 size = avio_rb64(pb);
240 return AVERROR_INVALIDDATA;
242 ret = read_desc_chunk(s);
247 /* parse each chunk */
249 while (!pb->eof_reached) {
251 /* stop at data chunk if seeking is not supported or
252 data chunk size is unknown */
253 if (found_data && (caf->data_size < 0 || !pb->seekable))
257 size = avio_rb64(pb);
262 case MKBETAG('d','a','t','a'):
263 avio_skip(pb, 4); /* edit count */
264 caf->data_start = avio_tell(pb);
265 caf->data_size = size < 0 ? -1 : size - 4;
266 if (caf->data_size > 0 && pb->seekable)
267 avio_skip(pb, caf->data_size);
271 case MKBETAG('c','h','a','n'):
272 if ((ret = ff_mov_read_chan(s, s->pb, st, size)) < 0)
276 /* magic cookie chunk */
277 case MKBETAG('k','u','k','i'):
278 if (read_kuki_chunk(s, size))
279 return AVERROR_INVALIDDATA;
282 /* packet table chunk */
283 case MKBETAG('p','a','k','t'):
284 if (read_pakt_chunk(s, size))
285 return AVERROR_INVALIDDATA;
288 case MKBETAG('i','n','f','o'):
289 read_info_chunk(s, size);
293 #define _(x) ((x) >= ' ' ? (x) : ' ')
294 av_log(s, AV_LOG_WARNING,
295 "skipping CAF chunk: %08"PRIX32" (%"PRIu8"%"PRIu8"%"PRIu8"%"PRIu8")\n",
296 tag, _(tag>>24), _((tag>>16)&0xFF), _((tag>>8)&0xFF), _(tag&0xFF));
298 case MKBETAG('f','r','e','e'):
300 return AVERROR_INVALIDDATA;
307 return AVERROR_INVALIDDATA;
309 if (caf->bytes_per_packet > 0 && caf->frames_per_packet > 0) {
310 if (caf->data_size > 0)
311 st->nb_frames = (caf->data_size / caf->bytes_per_packet) * caf->frames_per_packet;
312 } else if (st->nb_index_entries) {
313 st->codec->bit_rate = st->codec->sample_rate * caf->data_size * 8 /
316 av_log(s, AV_LOG_ERROR, "Missing packet table. It is required when "
317 "block size or frame size are variable.\n");
318 return AVERROR_INVALIDDATA;
321 avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
324 /* position the stream at the start of data */
325 if (caf->data_size >= 0)
326 avio_seek(pb, caf->data_start, SEEK_SET);
331 #define CAF_MAX_PKT_SIZE 4096
333 static int read_packet(AVFormatContext *s, AVPacket *pkt)
335 AVIOContext *pb = s->pb;
336 AVStream *st = s->streams[0];
337 CaffContext *caf = s->priv_data;
338 int res, pkt_size = 0, pkt_frames = 0;
339 int64_t left = CAF_MAX_PKT_SIZE;
344 /* don't read past end of data chunk */
345 if (caf->data_size > 0) {
346 left = (caf->data_start + caf->data_size) - avio_tell(pb);
351 pkt_frames = caf->frames_per_packet;
352 pkt_size = caf->bytes_per_packet;
354 if (pkt_size > 0 && pkt_frames == 1) {
355 pkt_size = (CAF_MAX_PKT_SIZE / pkt_size) * pkt_size;
356 pkt_size = FFMIN(pkt_size, left);
357 pkt_frames = pkt_size / caf->bytes_per_packet;
358 } else if (st->nb_index_entries) {
359 if (caf->packet_cnt < st->nb_index_entries - 1) {
360 pkt_size = st->index_entries[caf->packet_cnt + 1].pos - st->index_entries[caf->packet_cnt].pos;
361 pkt_frames = st->index_entries[caf->packet_cnt + 1].timestamp - st->index_entries[caf->packet_cnt].timestamp;
362 } else if (caf->packet_cnt == st->nb_index_entries - 1) {
363 pkt_size = caf->num_bytes - st->index_entries[caf->packet_cnt].pos;
364 pkt_frames = st->duration - st->index_entries[caf->packet_cnt].timestamp;
370 if (pkt_size == 0 || pkt_frames == 0 || pkt_size > left)
373 res = av_get_packet(pb, pkt, pkt_size);
378 pkt->stream_index = 0;
379 pkt->dts = pkt->pts = caf->frame_cnt;
382 caf->frame_cnt += pkt_frames;
387 static int read_seek(AVFormatContext *s, int stream_index,
388 int64_t timestamp, int flags)
390 AVStream *st = s->streams[0];
391 CaffContext *caf = s->priv_data;
392 int64_t pos, packet_cnt, frame_cnt;
394 timestamp = FFMAX(timestamp, 0);
396 if (caf->frames_per_packet > 0 && caf->bytes_per_packet > 0) {
397 /* calculate new byte position based on target frame position */
398 pos = caf->bytes_per_packet * timestamp / caf->frames_per_packet;
399 if (caf->data_size > 0)
400 pos = FFMIN(pos, caf->data_size);
401 packet_cnt = pos / caf->bytes_per_packet;
402 frame_cnt = caf->frames_per_packet * packet_cnt;
403 } else if (st->nb_index_entries) {
404 packet_cnt = av_index_search_timestamp(st, timestamp, flags);
405 frame_cnt = st->index_entries[packet_cnt].timestamp;
406 pos = st->index_entries[packet_cnt].pos;
411 if (avio_seek(s->pb, pos + caf->data_start, SEEK_SET) < 0)
414 caf->packet_cnt = packet_cnt;
415 caf->frame_cnt = frame_cnt;
420 AVInputFormat ff_caf_demuxer = {
422 .long_name = NULL_IF_CONFIG_SMALL("Apple CAF (Core Audio Format)"),
423 .priv_data_size = sizeof(CaffContext),
425 .read_header = read_header,
426 .read_packet = read_packet,
427 .read_seek = read_seek,
428 .codec_tag = (const AVCodecTag* const []){ ff_codec_caf_tags, 0 },