FFmpeg: libavformat/omadec.c Source File

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libavformat

omadec.c

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1 /*

2 * Sony OpenMG (OMA) demuxer

3 *

5 * 2008 Benjamin Larsson

6 * 2011 David Goldwich

7 *

8 * This file is part of FFmpeg.

9 *

10 * FFmpeg is free software; you can redistribute it and/or

11 * modify it under the terms of the GNU Lesser General Public

12 * License as published by the Free Software Foundation; either

13 * version 2.1 of the License, or (at your option) any later version.

14 *

15 * FFmpeg is distributed in the hope that it will be useful,

16 * but WITHOUT ANY WARRANTY; without even the implied warranty of

17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

18 * Lesser General Public License for more details.

19 *

20 * You should have received a copy of the GNU Lesser General Public

21 * License along with FFmpeg; if not, write to the Free Software

22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

23 */

25 /**

26 * @file

27 * This is a demuxer for Sony OpenMG Music files

28 *

29 * Known file extensions: ".oma", "aa3"

30 * The format of such files consists of three parts:

31 * - "ea3" header carrying overall info and metadata. Except for starting with

32 * "ea" instead of "ID", it's an ID3v2 header.

33 * - "EA3" header is a Sony-specific header containing information about

34 * the OpenMG file: codec type (usually ATRAC, can also be MP3 or WMA),

35 * codec specific info (packet size, sample rate, channels and so on)

36 * and DRM related info (file encryption, content id).

37 * - Sound data organized in packets follow the EA3 header

38 * (can be encrypted using the Sony DRM!).

39 *

40 */

42 #include "libavutil/channel_layout.h"

43 #include "avformat.h"

44 #include "internal.h"

45 #include "libavutil/intreadwrite.h"

46 #include "libavutil/des.h"

47 #include "oma.h"

48 #include "pcm.h"

49 #include "id3v2.h"

52 static const uint64_t leaf_table[] = {

53 0xd79e8283acea4620, 0x7a9762f445afd0d8,

54 0x354d60a60b8c79f1, 0x584e1cde00b07aee,

55 0x1573cd93da7df623, 0x47f98d79620dd535

56 };

58 typedef struct OMAContext {

59 uint64_t content_start;

60 int encrypted;

61 uint16_t k_size;

62 uint16_t e_size;

63 uint16_t i_size;

64 uint16_t s_size;

65 uint32_t rid;

66 uint8_t r_val[24];

67 uint8_t n_val[24];

68 uint8_t m_val[8];

69 uint8_t s_val[8];

70 uint8_t sm_val[8];

71 uint8_t e_val[8];

72 uint8_t iv[8];

73 struct AVDES av_des;

74 } OMAContext;

76 static void hex_log(AVFormatContext *s, int level, const char *name, const uint8_t *value, int len)

77 {

78 char buf[33];

79 len = FFMIN(len, 16);

80 if (av_log_get_level() < level)

81 return;

82 ff_data_to_hex(buf, value, len, 1);

83 buf[len<<1] = '0円';

84 av_log(s, level, "%s: %s\n", name, buf);

85 }

87 static int kset(AVFormatContext *s, const uint8_t *r_val, const uint8_t *n_val, int len)

88 {

89 OMAContext *oc = s->priv_data;

91 if (!r_val && !n_val)

92 return -1;

94 len = FFMIN(len, 16);

96 /* use first 64 bits in the third round again */

97 if (r_val) {

98 if (r_val != oc->r_val) {

99 memset(oc->r_val, 0, 24);

100 memcpy(oc->r_val, r_val, len);

101 }

102 memcpy(&oc->r_val[16], r_val, 8);

103 }

104 if (n_val) {

105 if (n_val != oc->n_val) {

106 memset(oc->n_val, 0, 24);

107 memcpy(oc->n_val, n_val, len);

108 }

109 memcpy(&oc->n_val[16], n_val, 8);

110 }

111

112 return 0;

113 }

114

115 static int rprobe(AVFormatContext *s, uint8_t *enc_header, const uint8_t *r_val)

116 {

117 OMAContext *oc = s->priv_data;

118 unsigned int pos;

119 struct AVDES av_des;

120

121 if (!enc_header || !r_val)

122 return -1;

123

124 /* m_val */

125 av_des_init(&av_des, r_val, 192, 1);

126 av_des_crypt(&av_des, oc->m_val, &enc_header[48], 1, NULL, 1);

127

128 /* s_val */

129 av_des_init(&av_des, oc->m_val, 64, 0);

130 av_des_crypt(&av_des, oc->s_val, NULL, 1, NULL, 0);

131

132 /* sm_val */

133 pos = OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size;

134 av_des_init(&av_des, oc->s_val, 64, 0);

135 av_des_mac(&av_des, oc->sm_val, &enc_header[pos], (oc->i_size >> 3));

136

137 pos += oc->i_size;

138

139 return memcmp(&enc_header[pos], oc->sm_val, 8) ? -1 : 0;

140 }

141

142 static int nprobe(AVFormatContext *s, uint8_t *enc_header, int size, const uint8_t *n_val)

143 {

144 OMAContext *oc = s->priv_data;

145 uint32_t pos, taglen, datalen;

146 struct AVDES av_des;

147

148 if (!enc_header || !n_val)

149 return -1;

150

151 pos = OMA_ENC_HEADER_SIZE + oc->k_size;

152 if (!memcmp(&enc_header[pos], "EKB ", 4))

153 pos += 32;

154

155 if (AV_RB32(&enc_header[pos]) != oc->rid)

156 av_log(s, AV_LOG_DEBUG, "Mismatching RID\n");

157

158 taglen = AV_RB32(&enc_header[pos+32]);

159 datalen = AV_RB32(&enc_header[pos+36]) >> 4;

160

161 if(pos + (uint64_t)taglen + (((uint64_t)datalen)<<4) + 44 > size)

162 return -1;

163

164 pos += 44 + taglen;

165

166 av_des_init(&av_des, n_val, 192, 1);

167 while (datalen-- > 0) {

168 av_des_crypt(&av_des, oc->r_val, &enc_header[pos], 2, NULL, 1);

169 kset(s, oc->r_val, NULL, 16);

170 if (!rprobe(s, enc_header, oc->r_val))

171 return 0;

172 pos += 16;

173 }

174

175 return -1;

176 }

177

178 static int decrypt_init(AVFormatContext *s, ID3v2ExtraMeta *em, uint8_t *header)

179 {

180 OMAContext *oc = s->priv_data;

181 ID3v2ExtraMetaGEOB *geob = NULL;

182 uint8_t *gdata;

183

184 oc->encrypted = 1;

185 av_log(s, AV_LOG_INFO, "File is encrypted\n");

186

187 /* find GEOB metadata */

188 while (em) {

189 if (!strcmp(em->tag, "GEOB") &&

190 (geob = em->data) &&

191 (!strcmp(geob->description, "OMG_LSI") ||

192 !strcmp(geob->description, "OMG_BKLSI"))) {

193 break;

194 }

195 em = em->next;

196 }

197 if (!em) {

198 av_log(s, AV_LOG_ERROR, "No encryption header found\n");

199 return -1;

200 }

201

202 if (geob->datasize < 64) {

203 av_log(s, AV_LOG_ERROR, "Invalid GEOB data size: %u\n", geob->datasize);

204 return -1;

205 }

206

207 gdata = geob->data;

208

209 if (AV_RB16(gdata) != 1)

210 av_log(s, AV_LOG_WARNING, "Unknown version in encryption header\n");

211

212 oc->k_size = AV_RB16(&gdata[2]);

213 oc->e_size = AV_RB16(&gdata[4]);

214 oc->i_size = AV_RB16(&gdata[6]);

215 oc->s_size = AV_RB16(&gdata[8]);

216

217 if (memcmp(&gdata[OMA_ENC_HEADER_SIZE], "KEYRING ", 12)) {

218 av_log(s, AV_LOG_ERROR, "Invalid encryption header\n");

219 return -1;

220 }

221 if ( OMA_ENC_HEADER_SIZE + oc->k_size + oc->e_size + oc->i_size + 8 > geob->datasize

222 || OMA_ENC_HEADER_SIZE + 48 > geob->datasize

223 ) {

224 av_log(s, AV_LOG_ERROR, "Too little GEOB data\n");

225 return AVERROR_INVALIDDATA;

226 }

227 oc->rid = AV_RB32(&gdata[OMA_ENC_HEADER_SIZE + 28]);

228 av_log(s, AV_LOG_DEBUG, "RID: %.8x\n", oc->rid);

229

230 memcpy(oc->iv, &header[0x58], 8);

231 hex_log(s, AV_LOG_DEBUG, "IV", oc->iv, 8);

232

233 hex_log(s, AV_LOG_DEBUG, "CBC-MAC", &gdata[OMA_ENC_HEADER_SIZE+oc->k_size+oc->e_size+oc->i_size], 8);

234

235 if (s->keylen > 0) {

236 kset(s, s->key, s->key, s->keylen);

237 }

238 if (!memcmp(oc->r_val, (const uint8_t[8]){0}, 8) ||

239 rprobe(s, gdata, oc->r_val) < 0 &&

240 nprobe(s, gdata, geob->datasize, oc->n_val) < 0) {

241 int i;

242 for (i = 0; i < FF_ARRAY_ELEMS(leaf_table); i += 2) {

243 uint8_t buf[16];

244 AV_WL64(buf, leaf_table[i]);

245 AV_WL64(&buf[8], leaf_table[i+1]);

246 kset(s, buf, buf, 16);

247 if (!rprobe(s, gdata, oc->r_val) || !nprobe(s, gdata, geob->datasize, oc->n_val))

248 break;

249 }

250 if (i >= FF_ARRAY_ELEMS(leaf_table)) {

251 av_log(s, AV_LOG_ERROR, "Invalid key\n");

252 return -1;

253 }

254 }

255

256 /* e_val */

257 av_des_init(&oc->av_des, oc->m_val, 64, 0);

258 av_des_crypt(&oc->av_des, oc->e_val, &gdata[OMA_ENC_HEADER_SIZE + 40], 1, NULL, 0);

259 hex_log(s, AV_LOG_DEBUG, "EK", oc->e_val, 8);

260

261 /* init e_val */

262 av_des_init(&oc->av_des, oc->e_val, 64, 1);

263

264 return 0;

265 }

266

267 static int oma_read_header(AVFormatContext *s)

268 {

269 int ret, framesize, jsflag, samplerate;

270 uint32_t codec_params;

271 int16_t eid;

272 uint8_t buf[EA3_HEADER_SIZE];

273 uint8_t *edata;

274 AVStream *st;

275 ID3v2ExtraMeta *extra_meta = NULL;

276 OMAContext *oc = s->priv_data;

277

278 ff_id3v2_read(s, ID3v2_EA3_MAGIC, &extra_meta);

279 ret = avio_read(s->pb, buf, EA3_HEADER_SIZE);

280 if (ret < EA3_HEADER_SIZE)

281 return -1;

282

283 if (memcmp(buf, ((const uint8_t[]){'E', 'A', '3'}),3) || buf[4] != 0 || buf[5] != EA3_HEADER_SIZE) {

284 av_log(s, AV_LOG_ERROR, "Couldn't find the EA3 header !\n");

285 return -1;

286 }

287

288 oc->content_start = avio_tell(s->pb);

289

290 /* encrypted file */

291 eid = AV_RB16(&buf[6]);

292 if (eid != -1 && eid != -128 && decrypt_init(s, extra_meta, buf) < 0) {

293 ff_id3v2_free_extra_meta(&extra_meta);

294 return -1;

295 }

296

297 ff_id3v2_free_extra_meta(&extra_meta);

298

299 codec_params = AV_RB24(&buf[33]);

300

301 st = avformat_new_stream(s, NULL);

302 if (!st)

303 return AVERROR(ENOMEM);

304

305 st->start_time = 0;

306 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

307 st->codec->codec_tag = buf[32];

308 st->codec->codec_id = ff_codec_get_id(ff_oma_codec_tags, st->codec->codec_tag);

309

310 switch (buf[32]) {

311 case OMA_CODECID_ATRAC3:

312 samplerate = ff_oma_srate_tab[(codec_params >> 13) & 7]*100;

313 if (samplerate != 44100)

314 av_log_ask_for_sample(s, "Unsupported sample rate: %d\n",

315 samplerate);

316

317 framesize = (codec_params & 0x3FF) * 8;

318 jsflag = (codec_params >> 17) & 1; /* get stereo coding mode, 1 for joint-stereo */

319 st->codec->channels = 2;

320 st->codec->channel_layout = AV_CH_LAYOUT_STEREO;

321 st->codec->sample_rate = samplerate;

322 st->codec->bit_rate = st->codec->sample_rate * framesize * 8 / 1024;

323

324 /* fake the atrac3 extradata (wav format, makes stream copy to wav work) */

325 st->codec->extradata_size = 14;

326 edata = av_mallocz(14 + FF_INPUT_BUFFER_PADDING_SIZE);

327 if (!edata)

328 return AVERROR(ENOMEM);

329

330 st->codec->extradata = edata;

331 AV_WL16(&edata[0], 1); // always 1

332 AV_WL32(&edata[2], samplerate); // samples rate

333 AV_WL16(&edata[6], jsflag); // coding mode

334 AV_WL16(&edata[8], jsflag); // coding mode

335 AV_WL16(&edata[10], 1); // always 1

336 // AV_WL16(&edata[12], 0); // always 0

337

338 avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);

339 break;

340 case OMA_CODECID_ATRAC3P:

341 st->codec->channels = (codec_params >> 10) & 7;

342 framesize = ((codec_params & 0x3FF) * 8) + 8;

343 st->codec->sample_rate = ff_oma_srate_tab[(codec_params >> 13) & 7]*100;

344 st->codec->bit_rate = st->codec->sample_rate * framesize * 8 / 1024;

345 avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);

346 av_log(s, AV_LOG_ERROR, "Unsupported codec ATRAC3+!\n");

347 break;

348 case OMA_CODECID_MP3:

349 st->need_parsing = AVSTREAM_PARSE_FULL_RAW;

350 framesize = 1024;

351 break;

352 case OMA_CODECID_LPCM:

353 /* PCM 44.1 kHz 16 bit stereo big-endian */

354 st->codec->channels = 2;

355 st->codec->channel_layout = AV_CH_LAYOUT_STEREO;

356 st->codec->sample_rate = 44100;

357 framesize = 1024;

358 /* bit rate = sample rate x PCM block align (= 4) x 8 */

359 st->codec->bit_rate = st->codec->sample_rate * 32;

360 st->codec->bits_per_coded_sample = av_get_bits_per_sample(st->codec->codec_id);

361 avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);

362 break;

363 default:

364 av_log(s, AV_LOG_ERROR, "Unsupported codec %d!\n",buf[32]);

365 return -1;

366 }

367

368 st->codec->block_align = framesize;

369

370 return 0;

371 }

372

373

374 static int oma_read_packet(AVFormatContext *s, AVPacket *pkt)

375 {

376 OMAContext *oc = s->priv_data;

377 int packet_size = s->streams[0]->codec->block_align;

378 int ret = av_get_packet(s->pb, pkt, packet_size);

379

380 if (ret <= 0)

381 return AVERROR(EIO);

382

383 pkt->stream_index = 0;

384

385 if (oc->encrypted) {

386 /* previous unencrypted block saved in IV for the next packet (CBC mode) */

387 av_des_crypt(&oc->av_des, pkt->data, pkt->data, (ret >> 3), oc->iv, 1);

388 }

389

390 return ret;

391 }

392

393 static int oma_read_probe(AVProbeData *p)

394 {

395 const uint8_t *buf;

396 unsigned tag_len = 0;

397

398 buf = p->buf;

399

400 if (p->buf_size < ID3v2_HEADER_SIZE ||

401 !ff_id3v2_match(buf, ID3v2_EA3_MAGIC) ||

402 buf[3] != 3 || // version must be 3

403 buf[4]) // flags byte zero

404 return 0;

405

406 tag_len = ff_id3v2_tag_len(buf);

407

408 /* This check cannot overflow as tag_len has at most 28 bits */

409 if (p->buf_size < tag_len + 5)

410 /* EA3 header comes late, might be outside of the probe buffer */

411 return AVPROBE_SCORE_MAX / 2;

412

413 buf += tag_len;

414

415 if (!memcmp(buf, "EA3", 3) && !buf[4] && buf[5] == EA3_HEADER_SIZE)

416 return AVPROBE_SCORE_MAX;

417 else

418 return 0;

419 }

420

421 static int oma_read_seek(struct AVFormatContext *s, int stream_index, int64_t timestamp, int flags)

422 {

423 OMAContext *oc = s->priv_data;

424

425 ff_pcm_read_seek(s, stream_index, timestamp, flags);

426

427 if (oc->encrypted) {

428 /* readjust IV for CBC */

429 int64_t pos = avio_tell(s->pb);

430 if (pos < oc->content_start)

431 memset(oc->iv, 0, 8);

432 else {

433 if (avio_seek(s->pb, -8, SEEK_CUR) < 0 || avio_read(s->pb, oc->iv, 8) < 8) {

434 memset(oc->iv, 0, 8);

435 return -1;

436 }

437 }

438 }

439

440 return 0;

441 }

442

443 AVInputFormat ff_oma_demuxer = {

444 .name = "oma",

445 .long_name = NULL_IF_CONFIG_SMALL("Sony OpenMG audio"),

446 .priv_data_size = sizeof(OMAContext),

447 .read_probe = oma_read_probe,

448 .read_header = oma_read_header,

449 .read_packet = oma_read_packet,

450 .read_seek = oma_read_seek,

451 .flags = AVFMT_GENERIC_INDEX,

452 .extensions = "oma,omg,aa3",

453 .codec_tag = (const AVCodecTag* const []){ff_oma_codec_tags, 0},

454 };

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