FFmpeg: libavcodec/mlpdec.c Source File

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libavcodec

mlpdec.c

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1 /*

2 * MLP decoder

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 */

22 /**

23 * @file

24 * MLP decoder

25 */

27 #include <stdint.h>

29 #include "avcodec.h"

30 #include "libavutil/internal.h"

31 #include "libavutil/intreadwrite.h"

32 #include "libavutil/channel_layout.h"

33 #include "get_bits.h"

34 #include "internal.h"

35 #include "libavutil/crc.h"

36 #include "parser.h"

37 #include "mlp_parser.h"

38 #include "mlpdsp.h"

39 #include "mlp.h"

40 #include "config.h"

42 /** number of bits used for VLC lookup - longest Huffman code is 9 */

43 #if ARCH_ARM

44 #define VLC_BITS 5

45 #define VLC_STATIC_SIZE 64

46 #else

47 #define VLC_BITS 9

48 #define VLC_STATIC_SIZE 512

49 #endif

51 typedef struct SubStream {

52 /// Set if a valid restart header has been read. Otherwise the substream cannot be decoded.

53 uint8_t restart_seen;

55 //@{

56 /** restart header data */

57 /// The type of noise to be used in the rematrix stage.

58 uint16_t noise_type;

60 /// The index of the first channel coded in this substream.

61 uint8_t min_channel;

62 /// The index of the last channel coded in this substream.

63 uint8_t max_channel;

64 /// The number of channels input into the rematrix stage.

65 uint8_t max_matrix_channel;

66 /// For each channel output by the matrix, the output channel to map it to

67 uint8_t ch_assign[MAX_CHANNELS];

68 /// The channel layout for this substream

69 uint64_t ch_layout;

70 /// The matrix encoding mode for this substream

71 enum AVMatrixEncoding matrix_encoding;

73 /// Channel coding parameters for channels in the substream

74 ChannelParams channel_params[MAX_CHANNELS];

76 /// The left shift applied to random noise in 0x31ea substreams.

77 uint8_t noise_shift;

78 /// The current seed value for the pseudorandom noise generator(s).

79 uint32_t noisegen_seed;

81 /// Set if the substream contains extra info to check the size of VLC blocks.

82 uint8_t data_check_present;

84 /// Bitmask of which parameter sets are conveyed in a decoding parameter block.

85 uint8_t param_presence_flags;

86 #define PARAM_BLOCKSIZE (1 << 7)

87 #define PARAM_MATRIX (1 << 6)

88 #define PARAM_OUTSHIFT (1 << 5)

89 #define PARAM_QUANTSTEP (1 << 4)

90 #define PARAM_FIR (1 << 3)

91 #define PARAM_IIR (1 << 2)

92 #define PARAM_HUFFOFFSET (1 << 1)

93 #define PARAM_PRESENCE (1 << 0)

94 //@}

96 //@{

97 /** matrix data */

99 /// Number of matrices to be applied.

100 uint8_t num_primitive_matrices;

101

102 /// matrix output channel

103 uint8_t matrix_out_ch[MAX_MATRICES];

104

105 /// Whether the LSBs of the matrix output are encoded in the bitstream.

106 uint8_t lsb_bypass[MAX_MATRICES];

107 /// Matrix coefficients, stored as 2.14 fixed point.

108 int32_t matrix_coeff[MAX_MATRICES][MAX_CHANNELS];

109 /// Left shift to apply to noise values in 0x31eb substreams.

110 uint8_t matrix_noise_shift[MAX_MATRICES];

111 //@}

112

113 /// Left shift to apply to Huffman-decoded residuals.

114 uint8_t quant_step_size[MAX_CHANNELS];

115

116 /// number of PCM samples in current audio block

117 uint16_t blocksize;

118 /// Number of PCM samples decoded so far in this frame.

119 uint16_t blockpos;

120

121 /// Left shift to apply to decoded PCM values to get final 24-bit output.

122 int8_t output_shift[MAX_CHANNELS];

123

124 /// Running XOR of all output samples.

125 int32_t lossless_check_data;

126

127 } SubStream;

128

129 typedef struct MLPDecodeContext {

130 AVCodecContext *avctx;

131

132 /// Current access unit being read has a major sync.

133 int is_major_sync_unit;

134

135 /// Set if a valid major sync block has been read. Otherwise no decoding is possible.

136 uint8_t params_valid;

137

138 /// Number of substreams contained within this stream.

139 uint8_t num_substreams;

140

141 /// Index of the last substream to decode - further substreams are skipped.

142 uint8_t max_decoded_substream;

143

144 /// Stream needs channel reordering to comply with FFmpeg's channel order

145 uint8_t needs_reordering;

146

147 /// number of PCM samples contained in each frame

148 int access_unit_size;

149 /// next power of two above the number of samples in each frame

150 int access_unit_size_pow2;

151

152 SubStream substream[MAX_SUBSTREAMS];

153

154 int matrix_changed;

155 int filter_changed[MAX_CHANNELS][NUM_FILTERS];

156

157 int8_t noise_buffer[MAX_BLOCKSIZE_POW2];

158 int8_t bypassed_lsbs[MAX_BLOCKSIZE][MAX_CHANNELS];

159 int32_t sample_buffer[MAX_BLOCKSIZE][MAX_CHANNELS];

160

161 MLPDSPContext dsp;

162 } MLPDecodeContext;

163

164 static const uint64_t thd_channel_order[] = {

165 AV_CH_FRONT_LEFT, AV_CH_FRONT_RIGHT, // LR

166 AV_CH_FRONT_CENTER, // C

167 AV_CH_LOW_FREQUENCY, // LFE

168 AV_CH_SIDE_LEFT, AV_CH_SIDE_RIGHT, // LRs

169 AV_CH_TOP_FRONT_LEFT, AV_CH_TOP_FRONT_RIGHT, // LRvh

170 AV_CH_FRONT_LEFT_OF_CENTER, AV_CH_FRONT_RIGHT_OF_CENTER, // LRc

171 AV_CH_BACK_LEFT, AV_CH_BACK_RIGHT, // LRrs

172 AV_CH_BACK_CENTER, // Cs

173 AV_CH_TOP_CENTER, // Ts

174 AV_CH_SURROUND_DIRECT_LEFT, AV_CH_SURROUND_DIRECT_RIGHT, // LRsd

175 AV_CH_WIDE_LEFT, AV_CH_WIDE_RIGHT, // LRw

176 AV_CH_TOP_FRONT_CENTER, // Cvh

177 AV_CH_LOW_FREQUENCY_2, // LFE2

178 };

179

180 static uint64_t thd_channel_layout_extract_channel(uint64_t channel_layout,

181 int index)

182 {

183 int i;

184

185 if (av_get_channel_layout_nb_channels(channel_layout) <= index)

186 return 0;

187

188 for (i = 0; i < FF_ARRAY_ELEMS(thd_channel_order); i++)

189 if (channel_layout & thd_channel_order[i] && !index--)

190 return thd_channel_order[i];

191 return 0;

192 }

193

194 static VLC huff_vlc[3];

195

196 /** Initialize static data, constant between all invocations of the codec. */

197

198 static av_cold void init_static(void)

199 {

200 if (!huff_vlc[0].bits) {

201 INIT_VLC_STATIC(&huff_vlc[0], VLC_BITS, 18,

202 &ff_mlp_huffman_tables[0][0][1], 2, 1,

203 &ff_mlp_huffman_tables[0][0][0], 2, 1, VLC_STATIC_SIZE);

204 INIT_VLC_STATIC(&huff_vlc[1], VLC_BITS, 16,

205 &ff_mlp_huffman_tables[1][0][1], 2, 1,

206 &ff_mlp_huffman_tables[1][0][0], 2, 1, VLC_STATIC_SIZE);

207 INIT_VLC_STATIC(&huff_vlc[2], VLC_BITS, 15,

208 &ff_mlp_huffman_tables[2][0][1], 2, 1,

209 &ff_mlp_huffman_tables[2][0][0], 2, 1, VLC_STATIC_SIZE);

210 }

211

212 ff_mlp_init_crc();

213 }

214

215 static inline int32_t calculate_sign_huff(MLPDecodeContext *m,

216 unsigned int substr, unsigned int ch)

217 {

218 SubStream *s = &m->substream[substr];

219 ChannelParams *cp = &s->channel_params[ch];

220 int lsb_bits = cp->huff_lsbs - s->quant_step_size[ch];

221 int sign_shift = lsb_bits + (cp->codebook ? 2 - cp->codebook : -1);

222 int32_t sign_huff_offset = cp->huff_offset;

223

224 if (cp->codebook > 0)

225 sign_huff_offset -= 7 << lsb_bits;

226

227 if (sign_shift >= 0)

228 sign_huff_offset -= 1 << sign_shift;

229

230 return sign_huff_offset;

231 }

232

233 /** Read a sample, consisting of either, both or neither of entropy-coded MSBs

234 * and plain LSBs. */

235

236 static inline int read_huff_channels(MLPDecodeContext *m, GetBitContext *gbp,

237 unsigned int substr, unsigned int pos)

238 {

239 SubStream *s = &m->substream[substr];

240 unsigned int mat, channel;

241

242 for (mat = 0; mat < s->num_primitive_matrices; mat++)

243 if (s->lsb_bypass[mat])

244 m->bypassed_lsbs[pos + s->blockpos][mat] = get_bits1(gbp);

245

246 for (channel = s->min_channel; channel <= s->max_channel; channel++) {

247 ChannelParams *cp = &s->channel_params[channel];

248 int codebook = cp->codebook;

249 int quant_step_size = s->quant_step_size[channel];

250 int lsb_bits = cp->huff_lsbs - quant_step_size;

251 int result = 0;

252

253 if (codebook > 0)

254 result = get_vlc2(gbp, huff_vlc[codebook-1].table,

255 VLC_BITS, (9 + VLC_BITS - 1) / VLC_BITS);

256

257 if (result < 0)

258 return AVERROR_INVALIDDATA;

259

260 if (lsb_bits > 0)

261 result = (result << lsb_bits) + get_bits(gbp, lsb_bits);

262

263 result += cp->sign_huff_offset;

264 result <<= quant_step_size;

265

266 m->sample_buffer[pos + s->blockpos][channel] = result;

267 }

268

269 return 0;

270 }

271

272 static av_cold int mlp_decode_init(AVCodecContext *avctx)

273 {

274 MLPDecodeContext *m = avctx->priv_data;

275 int substr;

276

277 init_static();

278 m->avctx = avctx;

279 for (substr = 0; substr < MAX_SUBSTREAMS; substr++)

280 m->substream[substr].lossless_check_data = 0xffffffff;

281 ff_mlpdsp_init(&m->dsp);

282

283 return 0;

284 }

285

286 /** Read a major sync info header - contains high level information about

287 * the stream - sample rate, channel arrangement etc. Most of this

288 * information is not actually necessary for decoding, only for playback.

289 */

290

291 static int read_major_sync(MLPDecodeContext *m, GetBitContext *gb)

292 {

293 MLPHeaderInfo mh;

294 int substr, ret;

295

296 if ((ret = ff_mlp_read_major_sync(m->avctx, &mh, gb)) != 0)

297 return ret;

298

299 if (mh.group1_bits == 0) {

300 av_log(m->avctx, AV_LOG_ERROR, "invalid/unknown bits per sample\n");

301 return AVERROR_INVALIDDATA;

302 }

303 if (mh.group2_bits > mh.group1_bits) {

304 av_log(m->avctx, AV_LOG_ERROR,

305 "Channel group 2 cannot have more bits per sample than group 1.\n");

306 return AVERROR_INVALIDDATA;

307 }

308

309 if (mh.group2_samplerate && mh.group2_samplerate != mh.group1_samplerate) {

310 av_log(m->avctx, AV_LOG_ERROR,

311 "Channel groups with differing sample rates are not currently supported.\n");

312 return AVERROR_INVALIDDATA;

313 }

314

315 if (mh.group1_samplerate == 0) {

316 av_log(m->avctx, AV_LOG_ERROR, "invalid/unknown sampling rate\n");

317 return AVERROR_INVALIDDATA;

318 }

319 if (mh.group1_samplerate > MAX_SAMPLERATE) {

320 av_log(m->avctx, AV_LOG_ERROR,

321 "Sampling rate %d is greater than the supported maximum (%d).\n",

322 mh.group1_samplerate, MAX_SAMPLERATE);

323 return AVERROR_INVALIDDATA;

324 }

325 if (mh.access_unit_size > MAX_BLOCKSIZE) {

326 av_log(m->avctx, AV_LOG_ERROR,

327 "Block size %d is greater than the supported maximum (%d).\n",

328 mh.access_unit_size, MAX_BLOCKSIZE);

329 return AVERROR_INVALIDDATA;

330 }

331 if (mh.access_unit_size_pow2 > MAX_BLOCKSIZE_POW2) {

332 av_log(m->avctx, AV_LOG_ERROR,

333 "Block size pow2 %d is greater than the supported maximum (%d).\n",

334 mh.access_unit_size_pow2, MAX_BLOCKSIZE_POW2);

335 return AVERROR_INVALIDDATA;

336 }

337

338 if (mh.num_substreams == 0)

339 return AVERROR_INVALIDDATA;

340 if (m->avctx->codec_id == AV_CODEC_ID_MLP && mh.num_substreams > 2) {

341 av_log(m->avctx, AV_LOG_ERROR, "MLP only supports up to 2 substreams.\n");

342 return AVERROR_INVALIDDATA;

343 }

344 if (mh.num_substreams > MAX_SUBSTREAMS) {

345 avpriv_request_sample(m->avctx,

346 "%d substreams (more than the "

347 "maximum supported by the decoder)",

348 mh.num_substreams);

349 return AVERROR_PATCHWELCOME;

350 }

351

352 m->access_unit_size = mh.access_unit_size;

353 m->access_unit_size_pow2 = mh.access_unit_size_pow2;

354

355 m->num_substreams = mh.num_substreams;

356 m->max_decoded_substream = m->num_substreams - 1;

357

358 m->avctx->sample_rate = mh.group1_samplerate;

359 m->avctx->frame_size = mh.access_unit_size;

360

361 m->avctx->bits_per_raw_sample = mh.group1_bits;

362 if (mh.group1_bits > 16)

363 m->avctx->sample_fmt = AV_SAMPLE_FMT_S32;

364 else

365 m->avctx->sample_fmt = AV_SAMPLE_FMT_S16;

366 m->dsp.mlp_pack_output = m->dsp.mlp_select_pack_output(m->substream[m->max_decoded_substream].ch_assign,

367 m->substream[m->max_decoded_substream].output_shift,

368 m->substream[m->max_decoded_substream].max_matrix_channel,

369 m->avctx->sample_fmt == AV_SAMPLE_FMT_S32);

370

371 m->params_valid = 1;

372 for (substr = 0; substr < MAX_SUBSTREAMS; substr++)

373 m->substream[substr].restart_seen = 0;

374

375 /* Set the layout for each substream. When there's more than one, the first

376 * substream is Stereo. Subsequent substreams' layouts are indicated in the

377 * major sync. */

378 if (m->avctx->codec_id == AV_CODEC_ID_MLP) {

379 if (mh.stream_type != 0xbb) {

380 avpriv_request_sample(m->avctx,

381 "unexpected stream_type %X in MLP",

382 mh.stream_type);

383 return AVERROR_PATCHWELCOME;

384 }

385 if ((substr = (mh.num_substreams > 1)))

386 m->substream[0].ch_layout = AV_CH_LAYOUT_STEREO;

387 m->substream[substr].ch_layout = mh.channel_layout_mlp;

388 } else {

389 if (mh.stream_type != 0xba) {

390 avpriv_request_sample(m->avctx,

391 "unexpected stream_type %X in !MLP",

392 mh.stream_type);

393 return AVERROR_PATCHWELCOME;

394 }

395 if ((substr = (mh.num_substreams > 1)))

396 m->substream[0].ch_layout = AV_CH_LAYOUT_STEREO;

397 if (mh.num_substreams > 2)

398 if (mh.channel_layout_thd_stream2)

399 m->substream[2].ch_layout = mh.channel_layout_thd_stream2;

400 else

401 m->substream[2].ch_layout = mh.channel_layout_thd_stream1;

402 m->substream[substr].ch_layout = mh.channel_layout_thd_stream1;

403

404 if (m->avctx->channels<=2 && m->substream[substr].ch_layout == AV_CH_LAYOUT_MONO && m->max_decoded_substream == 1) {

405 av_log(m->avctx, AV_LOG_DEBUG, "Mono stream with 2 substreams, ignoring 2nd\n");

406 m->max_decoded_substream = 0;

407 if (m->avctx->channels==2)

408 m->avctx->channel_layout = AV_CH_LAYOUT_STEREO;

409 }

410 }

411

412 m->needs_reordering = mh.channel_arrangement >= 18 && mh.channel_arrangement <= 20;

413

414 /* Parse the TrueHD decoder channel modifiers and set each substream's

415 * AVMatrixEncoding accordingly.

416 *

417 * The meaning of the modifiers depends on the channel layout:

418 *

419 * - THD_CH_MODIFIER_LTRT, THD_CH_MODIFIER_LBINRBIN only apply to 2-channel

420 *

421 * - THD_CH_MODIFIER_MONO applies to 1-channel or 2-channel (dual mono)

422 *

423 * - THD_CH_MODIFIER_SURROUNDEX, THD_CH_MODIFIER_NOTSURROUNDEX only apply to

424 * layouts with an Ls/Rs channel pair

425 */

426 for (substr = 0; substr < MAX_SUBSTREAMS; substr++)

427 m->substream[substr].matrix_encoding = AV_MATRIX_ENCODING_NONE;

428 if (m->avctx->codec_id == AV_CODEC_ID_TRUEHD) {

429 if (mh.num_substreams > 2 &&

430 mh.channel_layout_thd_stream2 & AV_CH_SIDE_LEFT &&

431 mh.channel_layout_thd_stream2 & AV_CH_SIDE_RIGHT &&

432 mh.channel_modifier_thd_stream2 == THD_CH_MODIFIER_SURROUNDEX)

433 m->substream[2].matrix_encoding = AV_MATRIX_ENCODING_DOLBYEX;

434

435 if (mh.num_substreams > 1 &&

436 mh.channel_layout_thd_stream1 & AV_CH_SIDE_LEFT &&

437 mh.channel_layout_thd_stream1 & AV_CH_SIDE_RIGHT &&

438 mh.channel_modifier_thd_stream1 == THD_CH_MODIFIER_SURROUNDEX)

439 m->substream[1].matrix_encoding = AV_MATRIX_ENCODING_DOLBYEX;

440

441 if (mh.num_substreams > 0)

442 switch (mh.channel_modifier_thd_stream0) {

443 case THD_CH_MODIFIER_LTRT:

444 m->substream[0].matrix_encoding = AV_MATRIX_ENCODING_DOLBY;

445 break;

446 case THD_CH_MODIFIER_LBINRBIN:

447 m->substream[0].matrix_encoding = AV_MATRIX_ENCODING_DOLBYHEADPHONE;

448 break;

449 default:

450 break;

451 }

452 }

453

454 return 0;

455 }

456

457 /** Read a restart header from a block in a substream. This contains parameters

458 * required to decode the audio that do not change very often. Generally

459 * (always) present only in blocks following a major sync. */

460

461 static int read_restart_header(MLPDecodeContext *m, GetBitContext *gbp,

462 const uint8_t *buf, unsigned int substr)

463 {

464 SubStream *s = &m->substream[substr];

465 unsigned int ch;

466 int sync_word, tmp;

467 uint8_t checksum;

468 uint8_t lossless_check;

469 int start_count = get_bits_count(gbp);

470 int min_channel, max_channel, max_matrix_channel;

471 const int std_max_matrix_channel = m->avctx->codec_id == AV_CODEC_ID_MLP

472 ? MAX_MATRIX_CHANNEL_MLP

473 : MAX_MATRIX_CHANNEL_TRUEHD;

474

475 sync_word = get_bits(gbp, 13);

476

477 if (sync_word != 0x31ea >> 1) {

478 av_log(m->avctx, AV_LOG_ERROR,

479 "restart header sync incorrect (got 0x%04x)\n", sync_word);

480 return AVERROR_INVALIDDATA;

481 }

482

483 s->noise_type = get_bits1(gbp);

484

485 if (m->avctx->codec_id == AV_CODEC_ID_MLP && s->noise_type) {

486 av_log(m->avctx, AV_LOG_ERROR, "MLP must have 0x31ea sync word.\n");

487 return AVERROR_INVALIDDATA;

488 }

489

490 skip_bits(gbp, 16); /* Output timestamp */

491

492 min_channel = get_bits(gbp, 4);

493 max_channel = get_bits(gbp, 4);

494 max_matrix_channel = get_bits(gbp, 4);

495

496 if (max_matrix_channel > std_max_matrix_channel) {

497 av_log(m->avctx, AV_LOG_ERROR,

498 "Max matrix channel cannot be greater than %d.\n",

499 std_max_matrix_channel);

500 return AVERROR_INVALIDDATA;

501 }

502

503 if (max_channel != max_matrix_channel) {

504 av_log(m->avctx, AV_LOG_ERROR,

505 "Max channel must be equal max matrix channel.\n");

506 return AVERROR_INVALIDDATA;

507 }

508

509 /* This should happen for TrueHD streams with >6 channels and MLP's noise

510 * type. It is not yet known if this is allowed. */

511 if (max_channel > MAX_MATRIX_CHANNEL_MLP && !s->noise_type) {

512 avpriv_request_sample(m->avctx,

513 "%d channels (more than the "

514 "maximum supported by the decoder)",

515 max_channel + 2);

516 return AVERROR_PATCHWELCOME;

517 }

518

519 if (min_channel > max_channel) {

520 av_log(m->avctx, AV_LOG_ERROR,

521 "Substream min channel cannot be greater than max channel.\n");

522 return AVERROR_INVALIDDATA;

523 }

524

525 s->min_channel = min_channel;

526 s->max_channel = max_channel;

527 s->max_matrix_channel = max_matrix_channel;

528

529 #if FF_API_REQUEST_CHANNELS

530 FF_DISABLE_DEPRECATION_WARNINGS

531 if (m->avctx->request_channels > 0 &&

532 m->avctx->request_channels <= s->max_channel + 1 &&

533 m->max_decoded_substream > substr) {

534 av_log(m->avctx, AV_LOG_DEBUG,

535 "Extracting %d-channel downmix from substream %d. "

536 "Further substreams will be skipped.\n",

537 s->max_channel + 1, substr);

538 m->max_decoded_substream = substr;

539 FF_ENABLE_DEPRECATION_WARNINGS

540 } else

541 #endif

542 if (m->avctx->request_channel_layout && (s->ch_layout & m->avctx->request_channel_layout) ==

543 m->avctx->request_channel_layout && m->max_decoded_substream > substr) {

544 av_log(m->avctx, AV_LOG_DEBUG,

545 "Extracting %d-channel downmix (0x%"PRIx64") from substream %d. "

546 "Further substreams will be skipped.\n",

547 s->max_channel + 1, s->ch_layout, substr);

548 m->max_decoded_substream = substr;

549 }

550

551 s->noise_shift = get_bits(gbp, 4);

552 s->noisegen_seed = get_bits(gbp, 23);

553

554 skip_bits(gbp, 19);

555

556 s->data_check_present = get_bits1(gbp);

557 lossless_check = get_bits(gbp, 8);

558 if (substr == m->max_decoded_substream

559 && s->lossless_check_data != 0xffffffff) {

560 tmp = xor_32_to_8(s->lossless_check_data);

561 if (tmp != lossless_check)

562 av_log(m->avctx, AV_LOG_WARNING,

563 "Lossless check failed - expected %02x, calculated %02x.\n",

564 lossless_check, tmp);

565 }

566

567 skip_bits(gbp, 16);

568

569 memset(s->ch_assign, 0, sizeof(s->ch_assign));

570

571 for (ch = 0; ch <= s->max_matrix_channel; ch++) {

572 int ch_assign = get_bits(gbp, 6);

573 if (m->avctx->codec_id == AV_CODEC_ID_TRUEHD) {

574 uint64_t channel = thd_channel_layout_extract_channel(s->ch_layout,

575 ch_assign);

576 ch_assign = av_get_channel_layout_channel_index(s->ch_layout,

577 channel);

578 }

579 if ((unsigned)ch_assign > s->max_matrix_channel) {

580 avpriv_request_sample(m->avctx,

581 "Assignment of matrix channel %d to invalid output channel %d",

582 ch, ch_assign);

583 return AVERROR_PATCHWELCOME;

584 }

585 s->ch_assign[ch_assign] = ch;

586 }

587

588 checksum = ff_mlp_restart_checksum(buf, get_bits_count(gbp) - start_count);

589

590 if (checksum != get_bits(gbp, 8))

591 av_log(m->avctx, AV_LOG_ERROR, "restart header checksum error\n");

592

593 /* Set default decoding parameters. */

594 s->param_presence_flags = 0xff;

595 s->num_primitive_matrices = 0;

596 s->blocksize = 8;

597 s->lossless_check_data = 0;

598

599 memset(s->output_shift , 0, sizeof(s->output_shift ));

600 memset(s->quant_step_size, 0, sizeof(s->quant_step_size));

601

602 for (ch = s->min_channel; ch <= s->max_channel; ch++) {

603 ChannelParams *cp = &s->channel_params[ch];

604 cp->filter_params[FIR].order = 0;

605 cp->filter_params[IIR].order = 0;

606 cp->filter_params[FIR].shift = 0;

607 cp->filter_params[IIR].shift = 0;

608

609 /* Default audio coding is 24-bit raw PCM. */

610 cp->huff_offset = 0;

611 cp->sign_huff_offset = (-1) << 23;

612 cp->codebook = 0;

613 cp->huff_lsbs = 24;

614 }

615

616 if (substr == m->max_decoded_substream) {

617 m->avctx->channels = s->max_matrix_channel + 1;

618 m->avctx->channel_layout = s->ch_layout;

619 m->dsp.mlp_pack_output = m->dsp.mlp_select_pack_output(s->ch_assign,

620 s->output_shift,

621 s->max_matrix_channel,

622 m->avctx->sample_fmt == AV_SAMPLE_FMT_S32);

623

624 if (m->avctx->codec_id == AV_CODEC_ID_MLP && m->needs_reordering) {

625 if (m->avctx->channel_layout == (AV_CH_LAYOUT_QUAD|AV_CH_LOW_FREQUENCY) ||

626 m->avctx->channel_layout == AV_CH_LAYOUT_5POINT0_BACK) {

627 int i = s->ch_assign[4];

628 s->ch_assign[4] = s->ch_assign[3];

629 s->ch_assign[3] = s->ch_assign[2];

630 s->ch_assign[2] = i;

631 } else if (m->avctx->channel_layout == AV_CH_LAYOUT_5POINT1_BACK) {

632 FFSWAP(int, s->ch_assign[2], s->ch_assign[4]);

633 FFSWAP(int, s->ch_assign[3], s->ch_assign[5]);

634 }

635 }

636

637 }

638

639 return 0;

640 }

641

642 /** Read parameters for one of the prediction filters. */

643

644 static int read_filter_params(MLPDecodeContext *m, GetBitContext *gbp,

645 unsigned int substr, unsigned int channel,

646 unsigned int filter)

647 {

648 SubStream *s = &m->substream[substr];

649 FilterParams *fp = &s->channel_params[channel].filter_params[filter];

650 const int max_order = filter ? MAX_IIR_ORDER : MAX_FIR_ORDER;

651 const char fchar = filter ? 'I' : 'F';

652 int i, order;

653

654 // Filter is 0 for FIR, 1 for IIR.

655 av_assert0(filter < 2);

656

657 if (m->filter_changed[channel][filter]++ > 1) {

658 av_log(m->avctx, AV_LOG_ERROR, "Filters may change only once per access unit.\n");

659 return AVERROR_INVALIDDATA;

660 }

661

662 order = get_bits(gbp, 4);

663 if (order > max_order) {

664 av_log(m->avctx, AV_LOG_ERROR,

665 "%cIR filter order %d is greater than maximum %d.\n",

666 fchar, order, max_order);

667 return AVERROR_INVALIDDATA;

668 }

669 fp->order = order;

670

671 if (order > 0) {

672 int32_t *fcoeff = s->channel_params[channel].coeff[filter];

673 int coeff_bits, coeff_shift;

674

675 fp->shift = get_bits(gbp, 4);

676

677 coeff_bits = get_bits(gbp, 5);

678 coeff_shift = get_bits(gbp, 3);

679 if (coeff_bits < 1 || coeff_bits > 16) {

680 av_log(m->avctx, AV_LOG_ERROR,

681 "%cIR filter coeff_bits must be between 1 and 16.\n",

682 fchar);

683 return AVERROR_INVALIDDATA;

684 }

685 if (coeff_bits + coeff_shift > 16) {

686 av_log(m->avctx, AV_LOG_ERROR,

687 "Sum of coeff_bits and coeff_shift for %cIR filter must be 16 or less.\n",

688 fchar);

689 return AVERROR_INVALIDDATA;

690 }

691

692 for (i = 0; i < order; i++)

693 fcoeff[i] = get_sbits(gbp, coeff_bits) << coeff_shift;

694

695 if (get_bits1(gbp)) {

696 int state_bits, state_shift;

697

698 if (filter == FIR) {

699 av_log(m->avctx, AV_LOG_ERROR,

700 "FIR filter has state data specified.\n");

701 return AVERROR_INVALIDDATA;

702 }

703

704 state_bits = get_bits(gbp, 4);

705 state_shift = get_bits(gbp, 4);

706

707 /* TODO: Check validity of state data. */

708

709 for (i = 0; i < order; i++)

710 fp->state[i] = state_bits ? get_sbits(gbp, state_bits) << state_shift : 0;

711 }

712 }

713

714 return 0;

715 }

716

717 /** Read parameters for primitive matrices. */

718

719 static int read_matrix_params(MLPDecodeContext *m, unsigned int substr, GetBitContext *gbp)

720 {

721 SubStream *s = &m->substream[substr];

722 unsigned int mat, ch;

723 const int max_primitive_matrices = m->avctx->codec_id == AV_CODEC_ID_MLP

724 ? MAX_MATRICES_MLP

725 : MAX_MATRICES_TRUEHD;

726

727 if (m->matrix_changed++ > 1) {

728 av_log(m->avctx, AV_LOG_ERROR, "Matrices may change only once per access unit.\n");

729 return AVERROR_INVALIDDATA;

730 }

731

732 s->num_primitive_matrices = get_bits(gbp, 4);

733

734 if (s->num_primitive_matrices > max_primitive_matrices) {

735 av_log(m->avctx, AV_LOG_ERROR,

736 "Number of primitive matrices cannot be greater than %d.\n",

737 max_primitive_matrices);

738 return AVERROR_INVALIDDATA;

739 }

740

741 for (mat = 0; mat < s->num_primitive_matrices; mat++) {

742 int frac_bits, max_chan;

743 s->matrix_out_ch[mat] = get_bits(gbp, 4);

744 frac_bits = get_bits(gbp, 4);

745 s->lsb_bypass [mat] = get_bits1(gbp);

746

747 if (s->matrix_out_ch[mat] > s->max_matrix_channel) {

748 av_log(m->avctx, AV_LOG_ERROR,

749 "Invalid channel %d specified as output from matrix.\n",

750 s->matrix_out_ch[mat]);

751 return AVERROR_INVALIDDATA;

752 }

753 if (frac_bits > 14) {

754 av_log(m->avctx, AV_LOG_ERROR,

755 "Too many fractional bits specified.\n");

756 return AVERROR_INVALIDDATA;

757 }

758

759 max_chan = s->max_matrix_channel;

760 if (!s->noise_type)

761 max_chan+=2;

762

763 for (ch = 0; ch <= max_chan; ch++) {

764 int coeff_val = 0;

765 if (get_bits1(gbp))

766 coeff_val = get_sbits(gbp, frac_bits + 2);

767

768 s->matrix_coeff[mat][ch] = coeff_val << (14 - frac_bits);

769 }

770

771 if (s->noise_type)

772 s->matrix_noise_shift[mat] = get_bits(gbp, 4);

773 else

774 s->matrix_noise_shift[mat] = 0;

775 }

776

777 return 0;

778 }

779

780 /** Read channel parameters. */

781

782 static int read_channel_params(MLPDecodeContext *m, unsigned int substr,

783 GetBitContext *gbp, unsigned int ch)

784 {

785 SubStream *s = &m->substream[substr];

786 ChannelParams *cp = &s->channel_params[ch];

787 FilterParams *fir = &cp->filter_params[FIR];

788 FilterParams *iir = &cp->filter_params[IIR];

789 int ret;

790

791 if (s->param_presence_flags & PARAM_FIR)

792 if (get_bits1(gbp))

793 if ((ret = read_filter_params(m, gbp, substr, ch, FIR)) < 0)

794 return ret;

795

796 if (s->param_presence_flags & PARAM_IIR)

797 if (get_bits1(gbp))

798 if ((ret = read_filter_params(m, gbp, substr, ch, IIR)) < 0)

799 return ret;

800

801 if (fir->order + iir->order > 8) {

802 av_log(m->avctx, AV_LOG_ERROR, "Total filter orders too high.\n");

803 return AVERROR_INVALIDDATA;

804 }

805

806 if (fir->order && iir->order &&

807 fir->shift != iir->shift) {

808 av_log(m->avctx, AV_LOG_ERROR,

809 "FIR and IIR filters must use the same precision.\n");

810 return AVERROR_INVALIDDATA;

811 }

812 /* The FIR and IIR filters must have the same precision.

813 * To simplify the filtering code, only the precision of the

814 * FIR filter is considered. If only the IIR filter is employed,

815 * the FIR filter precision is set to that of the IIR filter, so

816 * that the filtering code can use it. */

817 if (!fir->order && iir->order)

818 fir->shift = iir->shift;

819

820 if (s->param_presence_flags & PARAM_HUFFOFFSET)

821 if (get_bits1(gbp))

822 cp->huff_offset = get_sbits(gbp, 15);

823

824 cp->codebook = get_bits(gbp, 2);

825 cp->huff_lsbs = get_bits(gbp, 5);

826

827 if (cp->huff_lsbs > 24) {

828 av_log(m->avctx, AV_LOG_ERROR, "Invalid huff_lsbs.\n");

829 cp->huff_lsbs = 0;

830 return AVERROR_INVALIDDATA;

831 }

832

833 cp->sign_huff_offset = calculate_sign_huff(m, substr, ch);

834

835 return 0;

836 }

837

838 /** Read decoding parameters that change more often than those in the restart

839 * header. */

840

841 static int read_decoding_params(MLPDecodeContext *m, GetBitContext *gbp,

842 unsigned int substr)

843 {

844 SubStream *s = &m->substream[substr];

845 unsigned int ch;

846 int ret;

847

848 if (s->param_presence_flags & PARAM_PRESENCE)

849 if (get_bits1(gbp))

850 s->param_presence_flags = get_bits(gbp, 8);

851

852 if (s->param_presence_flags & PARAM_BLOCKSIZE)

853 if (get_bits1(gbp)) {

854 s->blocksize = get_bits(gbp, 9);

855 if (s->blocksize < 8 || s->blocksize > m->access_unit_size) {

856 av_log(m->avctx, AV_LOG_ERROR, "Invalid blocksize.\n");

857 s->blocksize = 0;

858 return AVERROR_INVALIDDATA;

859 }

860 }

861

862 if (s->param_presence_flags & PARAM_MATRIX)

863 if (get_bits1(gbp))

864 if ((ret = read_matrix_params(m, substr, gbp)) < 0)

865 return ret;

866

867 if (s->param_presence_flags & PARAM_OUTSHIFT)

868 if (get_bits1(gbp)) {

869 for (ch = 0; ch <= s->max_matrix_channel; ch++)

870 s->output_shift[ch] = get_sbits(gbp, 4);

871 if (substr == m->max_decoded_substream)

872 m->dsp.mlp_pack_output = m->dsp.mlp_select_pack_output(s->ch_assign,

873 s->output_shift,

874 s->max_matrix_channel,

875 m->avctx->sample_fmt == AV_SAMPLE_FMT_S32);

876 }

877

878 if (s->param_presence_flags & PARAM_QUANTSTEP)

879 if (get_bits1(gbp))

880 for (ch = 0; ch <= s->max_channel; ch++) {

881 ChannelParams *cp = &s->channel_params[ch];

882

883 s->quant_step_size[ch] = get_bits(gbp, 4);

884

885 cp->sign_huff_offset = calculate_sign_huff(m, substr, ch);

886 }

887

888 for (ch = s->min_channel; ch <= s->max_channel; ch++)

889 if (get_bits1(gbp))

890 if ((ret = read_channel_params(m, substr, gbp, ch)) < 0)

891 return ret;

892

893 return 0;

894 }

895

896 #define MSB_MASK(bits) (-1u << (bits))

897

898 /** Generate PCM samples using the prediction filters and residual values

899 * read from the data stream, and update the filter state. */

900

901 static void filter_channel(MLPDecodeContext *m, unsigned int substr,

902 unsigned int channel)

903 {

904 SubStream *s = &m->substream[substr];

905 const int32_t *fircoeff = s->channel_params[channel].coeff[FIR];

906 int32_t state_buffer[NUM_FILTERS][MAX_BLOCKSIZE + MAX_FIR_ORDER];

907 int32_t *firbuf = state_buffer[FIR] + MAX_BLOCKSIZE;

908 int32_t *iirbuf = state_buffer[IIR] + MAX_BLOCKSIZE;

909 FilterParams *fir = &s->channel_params[channel].filter_params[FIR];

910 FilterParams *iir = &s->channel_params[channel].filter_params[IIR];

911 unsigned int filter_shift = fir->shift;

912 int32_t mask = MSB_MASK(s->quant_step_size[channel]);

913

914 memcpy(firbuf, fir->state, MAX_FIR_ORDER * sizeof(int32_t));

915 memcpy(iirbuf, iir->state, MAX_IIR_ORDER * sizeof(int32_t));

916

917 m->dsp.mlp_filter_channel(firbuf, fircoeff,

918 fir->order, iir->order,

919 filter_shift, mask, s->blocksize,

920 &m->sample_buffer[s->blockpos][channel]);

921

922 memcpy(fir->state, firbuf - s->blocksize, MAX_FIR_ORDER * sizeof(int32_t));

923 memcpy(iir->state, iirbuf - s->blocksize, MAX_IIR_ORDER * sizeof(int32_t));

924 }

925

926 /** Read a block of PCM residual data (or actual if no filtering active). */

927

928 static int read_block_data(MLPDecodeContext *m, GetBitContext *gbp,

929 unsigned int substr)

930 {

931 SubStream *s = &m->substream[substr];

932 unsigned int i, ch, expected_stream_pos = 0;

933 int ret;

934

935 if (s->data_check_present) {

936 expected_stream_pos = get_bits_count(gbp);

937 expected_stream_pos += get_bits(gbp, 16);

938 avpriv_request_sample(m->avctx,

939 "Substreams with VLC block size check info");

940 }

941

942 if (s->blockpos + s->blocksize > m->access_unit_size) {

943 av_log(m->avctx, AV_LOG_ERROR, "too many audio samples in frame\n");

944 return AVERROR_INVALIDDATA;

945 }

946

947 memset(&m->bypassed_lsbs[s->blockpos][0], 0,

948 s->blocksize * sizeof(m->bypassed_lsbs[0]));

949

950 for (i = 0; i < s->blocksize; i++)

951 if ((ret = read_huff_channels(m, gbp, substr, i)) < 0)

952 return ret;

953

954 for (ch = s->min_channel; ch <= s->max_channel; ch++)

955 filter_channel(m, substr, ch);

956

957 s->blockpos += s->blocksize;

958

959 if (s->data_check_present) {

960 if (get_bits_count(gbp) != expected_stream_pos)

961 av_log(m->avctx, AV_LOG_ERROR, "block data length mismatch\n");

962 skip_bits(gbp, 8);

963 }

964

965 return 0;

966 }

967

968 /** Data table used for TrueHD noise generation function. */

969

970 static const int8_t noise_table[256] = {

971 30, 51, 22, 54, 3, 7, -4, 38, 14, 55, 46, 81, 22, 58, -3, 2,

972 52, 31, -7, 51, 15, 44, 74, 30, 85, -17, 10, 33, 18, 80, 28, 62,

973 10, 32, 23, 69, 72, 26, 35, 17, 73, 60, 8, 56, 2, 6, -2, -5,

974 51, 4, 11, 50, 66, 76, 21, 44, 33, 47, 1, 26, 64, 48, 57, 40,

975 38, 16, -10, -28, 92, 22, -18, 29, -10, 5, -13, 49, 19, 24, 70, 34,

976 61, 48, 30, 14, -6, 25, 58, 33, 42, 60, 67, 17, 54, 17, 22, 30,

977 67, 44, -9, 50, -11, 43, 40, 32, 59, 82, 13, 49, -14, 55, 60, 36,

978 48, 49, 31, 47, 15, 12, 4, 65, 1, 23, 29, 39, 45, -2, 84, 69,

979 0, 72, 37, 57, 27, 41, -15, -16, 35, 31, 14, 61, 24, 0, 27, 24,

980 16, 41, 55, 34, 53, 9, 56, 12, 25, 29, 53, 5, 20, -20, -8, 20,

981 13, 28, -3, 78, 38, 16, 11, 62, 46, 29, 21, 24, 46, 65, 43, -23,

982 89, 18, 74, 21, 38, -12, 19, 12, -19, 8, 15, 33, 4, 57, 9, -8,

983 36, 35, 26, 28, 7, 83, 63, 79, 75, 11, 3, 87, 37, 47, 34, 40,

984 39, 19, 20, 42, 27, 34, 39, 77, 13, 42, 59, 64, 45, -1, 32, 37,

985 45, -5, 53, -6, 7, 36, 50, 23, 6, 32, 9, -21, 18, 71, 27, 52,

986 -25, 31, 35, 42, -1, 68, 63, 52, 26, 43, 66, 37, 41, 25, 40, 70,

987 };

988

989 /** Noise generation functions.

990 * I'm not sure what these are for - they seem to be some kind of pseudorandom

991 * sequence generators, used to generate noise data which is used when the

992 * channels are rematrixed. I'm not sure if they provide a practical benefit

993 * to compression, or just obfuscate the decoder. Are they for some kind of

994 * dithering? */

995

996 /** Generate two channels of noise, used in the matrix when

997 * restart sync word == 0x31ea. */

998

999 static void generate_2_noise_channels(MLPDecodeContext *m, unsigned int substr)

1000 {

1001 SubStream *s = &m->substream[substr];

1002 unsigned int i;

1003 uint32_t seed = s->noisegen_seed;

1004 unsigned int maxchan = s->max_matrix_channel;

1005

1006 for (i = 0; i < s->blockpos; i++) {

1007 uint16_t seed_shr7 = seed >> 7;

1008 m->sample_buffer[i][maxchan+1] = ((int8_t)(seed >> 15)) << s->noise_shift;

1009 m->sample_buffer[i][maxchan+2] = ((int8_t) seed_shr7) << s->noise_shift;

1010

1011 seed = (seed << 16) ^ seed_shr7 ^ (seed_shr7 << 5);

1012 }

1013

1014 s->noisegen_seed = seed;

1015 }

1016

1017 /** Generate a block of noise, used when restart sync word == 0x31eb. */

1018

1019 static void fill_noise_buffer(MLPDecodeContext *m, unsigned int substr)

1020 {

1021 SubStream *s = &m->substream[substr];

1022 unsigned int i;

1023 uint32_t seed = s->noisegen_seed;

1024

1025 for (i = 0; i < m->access_unit_size_pow2; i++) {

1026 uint8_t seed_shr15 = seed >> 15;

1027 m->noise_buffer[i] = noise_table[seed_shr15];

1028 seed = (seed << 8) ^ seed_shr15 ^ (seed_shr15 << 5);

1029 }

1030

1031 s->noisegen_seed = seed;

1032 }

1033

1034

1035 /** Apply the channel matrices in turn to reconstruct the original audio

1036 * samples. */

1037

1038 static void rematrix_channels(MLPDecodeContext *m, unsigned int substr)

1039 {

1040 SubStream *s = &m->substream[substr];

1041 unsigned int mat;

1042 unsigned int maxchan;

1043

1044 maxchan = s->max_matrix_channel;

1045 if (!s->noise_type) {

1046 generate_2_noise_channels(m, substr);

1047 maxchan += 2;

1048 } else {

1049 fill_noise_buffer(m, substr);

1050 }

1051

1052 for (mat = 0; mat < s->num_primitive_matrices; mat++) {

1053 unsigned int dest_ch = s->matrix_out_ch[mat];

1054 m->dsp.mlp_rematrix_channel(&m->sample_buffer[0][0],

1055 s->matrix_coeff[mat],

1056 &m->bypassed_lsbs[0][mat],

1057 m->noise_buffer,

1058 s->num_primitive_matrices - mat,

1059 dest_ch,

1060 s->blockpos,

1061 maxchan,

1062 s->matrix_noise_shift[mat],

1063 m->access_unit_size_pow2,

1064 MSB_MASK(s->quant_step_size[dest_ch]));

1065 }

1066 }

1067

1068 /** Write the audio data into the output buffer. */

1069

1070 static int output_data(MLPDecodeContext *m, unsigned int substr,

1071 AVFrame *frame, int *got_frame_ptr)

1072 {

1073 AVCodecContext *avctx = m->avctx;

1074 SubStream *s = &m->substream[substr];

1075 int ret;

1076 int is32 = (m->avctx->sample_fmt == AV_SAMPLE_FMT_S32);

1077

1078 if (m->avctx->channels != s->max_matrix_channel + 1) {

1079 av_log(m->avctx, AV_LOG_ERROR, "channel count mismatch\n");

1080 return AVERROR_INVALIDDATA;

1081 }

1082

1083 if (!s->blockpos) {

1084 av_log(avctx, AV_LOG_ERROR, "No samples to output.\n");

1085 return AVERROR_INVALIDDATA;

1086 }

1087

1088 /* get output buffer */

1089 frame->nb_samples = s->blockpos;

1090 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)

1091 return ret;

1092 s->lossless_check_data = m->dsp.mlp_pack_output(s->lossless_check_data,

1093 s->blockpos,

1094 m->sample_buffer,

1095 frame->data[0],

1096 s->ch_assign,

1097 s->output_shift,

1098 s->max_matrix_channel,

1099 is32);

1100

1101 /* Update matrix encoding side data */

1102 if ((ret = ff_side_data_update_matrix_encoding(frame, s->matrix_encoding)) < 0)

1103 return ret;

1104

1105 *got_frame_ptr = 1;

1106

1107 return 0;

1108 }

1109

1110 /** Read an access unit from the stream.

1111 * @return negative on error, 0 if not enough data is present in the input stream,

1112 * otherwise the number of bytes consumed. */

1113

1114 static int read_access_unit(AVCodecContext *avctx, void* data,

1115 int *got_frame_ptr, AVPacket *avpkt)

1116 {

1117 const uint8_t *buf = avpkt->data;

1118 int buf_size = avpkt->size;

1119 MLPDecodeContext *m = avctx->priv_data;

1120 GetBitContext gb;

1121 unsigned int length, substr;

1122 unsigned int substream_start;

1123 unsigned int header_size = 4;

1124 unsigned int substr_header_size = 0;

1125 uint8_t substream_parity_present[MAX_SUBSTREAMS];

1126 uint16_t substream_data_len[MAX_SUBSTREAMS];

1127 uint8_t parity_bits;

1128 int ret;

1129

1130 if (buf_size < 4)

1131 return AVERROR_INVALIDDATA;

1132

1133 length = (AV_RB16(buf) & 0xfff) * 2;

1134

1135 if (length < 4 || length > buf_size)

1136 return AVERROR_INVALIDDATA;

1137

1138 init_get_bits(&gb, (buf + 4), (length - 4) * 8);

1139

1140 m->is_major_sync_unit = 0;

1141 if (show_bits_long(&gb, 31) == (0xf8726fba >> 1)) {

1142 if (read_major_sync(m, &gb) < 0)

1143 goto error;

1144 m->is_major_sync_unit = 1;

1145 header_size += 28;

1146 }

1147

1148 if (!m->params_valid) {

1149 av_log(m->avctx, AV_LOG_WARNING,

1150 "Stream parameters not seen; skipping frame.\n");

1151 *got_frame_ptr = 0;

1152 return length;

1153 }

1154

1155 substream_start = 0;

1156

1157 for (substr = 0; substr < m->num_substreams; substr++) {

1158 int extraword_present, checkdata_present, end, nonrestart_substr;

1159

1160 extraword_present = get_bits1(&gb);

1161 nonrestart_substr = get_bits1(&gb);

1162 checkdata_present = get_bits1(&gb);

1163 skip_bits1(&gb);

1164

1165 end = get_bits(&gb, 12) * 2;

1166

1167 substr_header_size += 2;

1168

1169 if (extraword_present) {

1170 if (m->avctx->codec_id == AV_CODEC_ID_MLP) {

1171 av_log(m->avctx, AV_LOG_ERROR, "There must be no extraword for MLP.\n");

1172 goto error;

1173 }

1174 skip_bits(&gb, 16);

1175 substr_header_size += 2;

1176 }

1177

1178 if (!(nonrestart_substr ^ m->is_major_sync_unit)) {

1179 av_log(m->avctx, AV_LOG_ERROR, "Invalid nonrestart_substr.\n");

1180 goto error;

1181 }

1182

1183 if (end + header_size + substr_header_size > length) {

1184 av_log(m->avctx, AV_LOG_ERROR,

1185 "Indicated length of substream %d data goes off end of "

1186 "packet.\n", substr);

1187 end = length - header_size - substr_header_size;

1188 }

1189

1190 if (end < substream_start) {

1191 av_log(avctx, AV_LOG_ERROR,

1192 "Indicated end offset of substream %d data "

1193 "is smaller than calculated start offset.\n",

1194 substr);

1195 goto error;

1196 }

1197

1198 if (substr > m->max_decoded_substream)

1199 continue;

1200

1201 substream_parity_present[substr] = checkdata_present;

1202 substream_data_len[substr] = end - substream_start;

1203 substream_start = end;

1204 }

1205

1206 parity_bits = ff_mlp_calculate_parity(buf, 4);

1207 parity_bits ^= ff_mlp_calculate_parity(buf + header_size, substr_header_size);

1208

1209 if ((((parity_bits >> 4) ^ parity_bits) & 0xF) != 0xF) {

1210 av_log(avctx, AV_LOG_ERROR, "Parity check failed.\n");

1211 goto error;

1212 }

1213

1214 buf += header_size + substr_header_size;

1215

1216 for (substr = 0; substr <= m->max_decoded_substream; substr++) {

1217 SubStream *s = &m->substream[substr];

1218 init_get_bits(&gb, buf, substream_data_len[substr] * 8);

1219

1220 m->matrix_changed = 0;

1221 memset(m->filter_changed, 0, sizeof(m->filter_changed));

1222

1223 s->blockpos = 0;

1224 do {

1225 if (get_bits1(&gb)) {

1226 if (get_bits1(&gb)) {

1227 /* A restart header should be present. */

1228 if (read_restart_header(m, &gb, buf, substr) < 0)

1229 goto next_substr;

1230 s->restart_seen = 1;

1231 }

1232

1233 if (!s->restart_seen)

1234 goto next_substr;

1235 if (read_decoding_params(m, &gb, substr) < 0)

1236 goto next_substr;

1237 }

1238

1239 if (!s->restart_seen)

1240 goto next_substr;

1241

1242 if ((ret = read_block_data(m, &gb, substr)) < 0)

1243 return ret;

1244

1245 if (get_bits_count(&gb) >= substream_data_len[substr] * 8)

1246 goto substream_length_mismatch;

1247

1248 } while (!get_bits1(&gb));

1249

1250 skip_bits(&gb, (-get_bits_count(&gb)) & 15);

1251

1252 if (substream_data_len[substr] * 8 - get_bits_count(&gb) >= 32) {

1253 int shorten_by;

1254

1255 if (get_bits(&gb, 16) != 0xD234)

1256 return AVERROR_INVALIDDATA;

1257

1258 shorten_by = get_bits(&gb, 16);

1259 if (m->avctx->codec_id == AV_CODEC_ID_TRUEHD && shorten_by & 0x2000)

1260 s->blockpos -= FFMIN(shorten_by & 0x1FFF, s->blockpos);

1261 else if (m->avctx->codec_id == AV_CODEC_ID_MLP && shorten_by != 0xD234)

1262 return AVERROR_INVALIDDATA;

1263

1264 if (substr == m->max_decoded_substream)

1265 av_log(m->avctx, AV_LOG_INFO, "End of stream indicated.\n");

1266 }

1267

1268 if (substream_parity_present[substr]) {

1269 uint8_t parity, checksum;

1270

1271 if (substream_data_len[substr] * 8 - get_bits_count(&gb) != 16)

1272 goto substream_length_mismatch;

1273

1274 parity = ff_mlp_calculate_parity(buf, substream_data_len[substr] - 2);

1275 checksum = ff_mlp_checksum8 (buf, substream_data_len[substr] - 2);

1276

1277 if ((get_bits(&gb, 8) ^ parity) != 0xa9 )

1278 av_log(m->avctx, AV_LOG_ERROR, "Substream %d parity check failed.\n", substr);

1279 if ( get_bits(&gb, 8) != checksum)

1280 av_log(m->avctx, AV_LOG_ERROR, "Substream %d checksum failed.\n" , substr);

1281 }

1282

1283 if (substream_data_len[substr] * 8 != get_bits_count(&gb))

1284 goto substream_length_mismatch;

1285

1286 next_substr:

1287 if (!s->restart_seen)

1288 av_log(m->avctx, AV_LOG_ERROR,

1289 "No restart header present in substream %d.\n", substr);

1290

1291 buf += substream_data_len[substr];

1292 }

1293

1294 rematrix_channels(m, m->max_decoded_substream);

1295

1296 if ((ret = output_data(m, m->max_decoded_substream, data, got_frame_ptr)) < 0)

1297 return ret;

1298

1299 return length;

1300

1301 substream_length_mismatch:

1302 av_log(m->avctx, AV_LOG_ERROR, "substream %d length mismatch\n", substr);

1303 return AVERROR_INVALIDDATA;

1304

1305 error:

1306 m->params_valid = 0;

1307 return AVERROR_INVALIDDATA;

1308 }

1309

1310 #if CONFIG_MLP_DECODER

1311 AVCodec ff_mlp_decoder = {

1312 .name = "mlp",

1313 .long_name = NULL_IF_CONFIG_SMALL("MLP (Meridian Lossless Packing)"),

1314 .type = AVMEDIA_TYPE_AUDIO,

1315 .id = AV_CODEC_ID_MLP,

1316 .priv_data_size = sizeof(MLPDecodeContext),

1317 .init = mlp_decode_init,

1318 .decode = read_access_unit,

1319 .capabilities = CODEC_CAP_DR1,

1320 };

1321 #endif

1322 #if CONFIG_TRUEHD_DECODER

1323 AVCodec ff_truehd_decoder = {

1324 .name = "truehd",

1325 .long_name = NULL_IF_CONFIG_SMALL("TrueHD"),

1326 .type = AVMEDIA_TYPE_AUDIO,

1327 .id = AV_CODEC_ID_TRUEHD,

1328 .priv_data_size = sizeof(MLPDecodeContext),

1329 .init = mlp_decode_init,

1330 .decode = read_access_unit,

1331 .capabilities = CODEC_CAP_DR1,

1332 };

1333 #endif /* CONFIG_TRUEHD_DECODER */

Generated on Sun Jul 20 2014 23:05:51 for FFmpeg by doxygen 1.8.2