FFmpeg: libavcodec/alsdec.c Source File

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alsdec.c

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1 /*

2 * MPEG-4 ALS 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 * MPEG-4 ALS decoder

25 * @author Thilo Borgmann <thilo.borgmann _at_ mail.de>

26 */

28 #include <inttypes.h>

30 #include "avcodec.h"

31 #include "get_bits.h"

32 #include "unary.h"

33 #include "mpeg4audio.h"

34 #include "bytestream.h"

35 #include "bgmc.h"

36 #include "bswapdsp.h"

37 #include "internal.h"

38 #include "libavutil/samplefmt.h"

39 #include "libavutil/crc.h"

41 #include <stdint.h>

43 /** Rice parameters and corresponding index offsets for decoding the

44 * indices of scaled PARCOR values. The table chosen is set globally

45 * by the encoder and stored in ALSSpecificConfig.

46 */

47 static const int8_t parcor_rice_table[3][20][2] = {

48 { {-52, 4}, {-29, 5}, {-31, 4}, { 19, 4}, {-16, 4},

49 { 12, 3}, { -7, 3}, { 9, 3}, { -5, 3}, { 6, 3},

50 { -4, 3}, { 3, 3}, { -3, 2}, { 3, 2}, { -2, 2},

51 { 3, 2}, { -1, 2}, { 2, 2}, { -1, 2}, { 2, 2} },

52 { {-58, 3}, {-42, 4}, {-46, 4}, { 37, 5}, {-36, 4},

53 { 29, 4}, {-29, 4}, { 25, 4}, {-23, 4}, { 20, 4},

54 {-17, 4}, { 16, 4}, {-12, 4}, { 12, 3}, {-10, 4},

55 { 7, 3}, { -4, 4}, { 3, 3}, { -1, 3}, { 1, 3} },

56 { {-59, 3}, {-45, 5}, {-50, 4}, { 38, 4}, {-39, 4},

57 { 32, 4}, {-30, 4}, { 25, 3}, {-23, 3}, { 20, 3},

58 {-20, 3}, { 16, 3}, {-13, 3}, { 10, 3}, { -7, 3},

59 { 3, 3}, { 0, 3}, { -1, 3}, { 2, 3}, { -1, 2} }

60 };

63 /** Scaled PARCOR values used for the first two PARCOR coefficients.

64 * To be indexed by the Rice coded indices.

65 * Generated by: parcor_scaled_values[i] = 32 + ((i * (i+1)) << 7) - (1 << 20)

66 * Actual values are divided by 32 in order to be stored in 16 bits.

67 */

68 static const int16_t parcor_scaled_values[] = {

69 -1048544 / 32, -1048288 / 32, -1047776 / 32, -1047008 / 32,

70 -1045984 / 32, -1044704 / 32, -1043168 / 32, -1041376 / 32,

71 -1039328 / 32, -1037024 / 32, -1034464 / 32, -1031648 / 32,

72 -1028576 / 32, -1025248 / 32, -1021664 / 32, -1017824 / 32,

73 -1013728 / 32, -1009376 / 32, -1004768 / 32, -999904 / 32,

74 -994784 / 32, -989408 / 32, -983776 / 32, -977888 / 32,

75 -971744 / 32, -965344 / 32, -958688 / 32, -951776 / 32,

76 -944608 / 32, -937184 / 32, -929504 / 32, -921568 / 32,

77 -913376 / 32, -904928 / 32, -896224 / 32, -887264 / 32,

78 -878048 / 32, -868576 / 32, -858848 / 32, -848864 / 32,

79 -838624 / 32, -828128 / 32, -817376 / 32, -806368 / 32,

80 -795104 / 32, -783584 / 32, -771808 / 32, -759776 / 32,

81 -747488 / 32, -734944 / 32, -722144 / 32, -709088 / 32,

82 -695776 / 32, -682208 / 32, -668384 / 32, -654304 / 32,

83 -639968 / 32, -625376 / 32, -610528 / 32, -595424 / 32,

84 -580064 / 32, -564448 / 32, -548576 / 32, -532448 / 32,

85 -516064 / 32, -499424 / 32, -482528 / 32, -465376 / 32,

86 -447968 / 32, -430304 / 32, -412384 / 32, -394208 / 32,

87 -375776 / 32, -357088 / 32, -338144 / 32, -318944 / 32,

88 -299488 / 32, -279776 / 32, -259808 / 32, -239584 / 32,

89 -219104 / 32, -198368 / 32, -177376 / 32, -156128 / 32,

90 -134624 / 32, -112864 / 32, -90848 / 32, -68576 / 32,

91 -46048 / 32, -23264 / 32, -224 / 32, 23072 / 32,

92 46624 / 32, 70432 / 32, 94496 / 32, 118816 / 32,

93 143392 / 32, 168224 / 32, 193312 / 32, 218656 / 32,

94 244256 / 32, 270112 / 32, 296224 / 32, 322592 / 32,

95 349216 / 32, 376096 / 32, 403232 / 32, 430624 / 32,

96 458272 / 32, 486176 / 32, 514336 / 32, 542752 / 32,

97 571424 / 32, 600352 / 32, 629536 / 32, 658976 / 32,

98 688672 / 32, 718624 / 32, 748832 / 32, 779296 / 32,

99 810016 / 32, 840992 / 32, 872224 / 32, 903712 / 32,

100 935456 / 32, 967456 / 32, 999712 / 32, 1032224 / 32

101 };

102

103

104 /** Gain values of p(0) for long-term prediction.

105 * To be indexed by the Rice coded indices.

106 */

107 static const uint8_t ltp_gain_values [4][4] = {

108 { 0, 8, 16, 24},

109 {32, 40, 48, 56},

110 {64, 70, 76, 82},

111 {88, 92, 96, 100}

112 };

113

114

115 /** Inter-channel weighting factors for multi-channel correlation.

116 * To be indexed by the Rice coded indices.

117 */

118 static const int16_t mcc_weightings[] = {

119 204, 192, 179, 166, 153, 140, 128, 115,

120 102, 89, 76, 64, 51, 38, 25, 12,

121 0, -12, -25, -38, -51, -64, -76, -89,

122 -102, -115, -128, -140, -153, -166, -179, -192

123 };

124

125

126 /** Tail codes used in arithmetic coding using block Gilbert-Moore codes.

127 */

128 static const uint8_t tail_code[16][6] = {

129 { 74, 44, 25, 13, 7, 3},

130 { 68, 42, 24, 13, 7, 3},

131 { 58, 39, 23, 13, 7, 3},

132 {126, 70, 37, 19, 10, 5},

133 {132, 70, 37, 20, 10, 5},

134 {124, 70, 38, 20, 10, 5},

135 {120, 69, 37, 20, 11, 5},

136 {116, 67, 37, 20, 11, 5},

137 {108, 66, 36, 20, 10, 5},

138 {102, 62, 36, 20, 10, 5},

139 { 88, 58, 34, 19, 10, 5},

140 {162, 89, 49, 25, 13, 7},

141 {156, 87, 49, 26, 14, 7},

142 {150, 86, 47, 26, 14, 7},

143 {142, 84, 47, 26, 14, 7},

144 {131, 79, 46, 26, 14, 7}

145 };

146

147

148 enum RA_Flag {

149 RA_FLAG_NONE,

150 RA_FLAG_FRAMES,

151 RA_FLAG_HEADER

152 };

153

154

155 typedef struct ALSSpecificConfig {

156 uint32_t samples; ///< number of samples, 0xFFFFFFFF if unknown

157 int resolution; ///< 000 = 8-bit; 001 = 16-bit; 010 = 24-bit; 011 = 32-bit

158 int floating; ///< 1 = IEEE 32-bit floating-point, 0 = integer

159 int msb_first; ///< 1 = original CRC calculated on big-endian system, 0 = little-endian

160 int frame_length; ///< frame length for each frame (last frame may differ)

161 int ra_distance; ///< distance between RA frames (in frames, 0...255)

162 enum RA_Flag ra_flag; ///< indicates where the size of ra units is stored

163 int adapt_order; ///< adaptive order: 1 = on, 0 = off

164 int coef_table; ///< table index of Rice code parameters

165 int long_term_prediction; ///< long term prediction (LTP): 1 = on, 0 = off

166 int max_order; ///< maximum prediction order (0..1023)

167 int block_switching; ///< number of block switching levels

168 int bgmc; ///< "Block Gilbert-Moore Code": 1 = on, 0 = off (Rice coding only)

169 int sb_part; ///< sub-block partition

170 int joint_stereo; ///< joint stereo: 1 = on, 0 = off

171 int mc_coding; ///< extended inter-channel coding (multi channel coding): 1 = on, 0 = off

172 int chan_config; ///< indicates that a chan_config_info field is present

173 int chan_sort; ///< channel rearrangement: 1 = on, 0 = off

174 int rlslms; ///< use "Recursive Least Square-Least Mean Square" predictor: 1 = on, 0 = off

175 int chan_config_info; ///< mapping of channels to loudspeaker locations. Unused until setting channel configuration is implemented.

176 int *chan_pos; ///< original channel positions

177 int crc_enabled; ///< enable Cyclic Redundancy Checksum

178 } ALSSpecificConfig;

179

180

181 typedef struct ALSChannelData {

182 int stop_flag;

183 int master_channel;

184 int time_diff_flag;

185 int time_diff_sign;

186 int time_diff_index;

187 int weighting[6];

188 } ALSChannelData;

189

190

191 typedef struct ALSDecContext {

192 AVCodecContext *avctx;

193 ALSSpecificConfig sconf;

194 GetBitContext gb;

195 BswapDSPContext bdsp;

196 const AVCRC *crc_table;

197 uint32_t crc_org; ///< CRC value of the original input data

198 uint32_t crc; ///< CRC value calculated from decoded data

199 unsigned int cur_frame_length; ///< length of the current frame to decode

200 unsigned int frame_id; ///< the frame ID / number of the current frame

201 unsigned int js_switch; ///< if true, joint-stereo decoding is enforced

202 unsigned int cs_switch; ///< if true, channel rearrangement is done

203 unsigned int num_blocks; ///< number of blocks used in the current frame

204 unsigned int s_max; ///< maximum Rice parameter allowed in entropy coding

205 uint8_t *bgmc_lut; ///< pointer at lookup tables used for BGMC

206 int *bgmc_lut_status; ///< pointer at lookup table status flags used for BGMC

207 int ltp_lag_length; ///< number of bits used for ltp lag value

208 int *const_block; ///< contains const_block flags for all channels

209 unsigned int *shift_lsbs; ///< contains shift_lsbs flags for all channels

210 unsigned int *opt_order; ///< contains opt_order flags for all channels

211 int *store_prev_samples; ///< contains store_prev_samples flags for all channels

212 int *use_ltp; ///< contains use_ltp flags for all channels

213 int *ltp_lag; ///< contains ltp lag values for all channels

214 int **ltp_gain; ///< gain values for ltp 5-tap filter for a channel

215 int *ltp_gain_buffer; ///< contains all gain values for ltp 5-tap filter

216 int32_t **quant_cof; ///< quantized parcor coefficients for a channel

217 int32_t *quant_cof_buffer; ///< contains all quantized parcor coefficients

218 int32_t **lpc_cof; ///< coefficients of the direct form prediction filter for a channel

219 int32_t *lpc_cof_buffer; ///< contains all coefficients of the direct form prediction filter

220 int32_t *lpc_cof_reversed_buffer; ///< temporary buffer to set up a reversed versio of lpc_cof_buffer

221 ALSChannelData **chan_data; ///< channel data for multi-channel correlation

222 ALSChannelData *chan_data_buffer; ///< contains channel data for all channels

223 int *reverted_channels; ///< stores a flag for each reverted channel

224 int32_t *prev_raw_samples; ///< contains unshifted raw samples from the previous block

225 int32_t **raw_samples; ///< decoded raw samples for each channel

226 int32_t *raw_buffer; ///< contains all decoded raw samples including carryover samples

227 uint8_t *crc_buffer; ///< buffer of byte order corrected samples used for CRC check

228 } ALSDecContext;

229

230

231 typedef struct ALSBlockData {

232 unsigned int block_length; ///< number of samples within the block

233 unsigned int ra_block; ///< if true, this is a random access block

234 int *const_block; ///< if true, this is a constant value block

235 int js_blocks; ///< true if this block contains a difference signal

236 unsigned int *shift_lsbs; ///< shift of values for this block

237 unsigned int *opt_order; ///< prediction order of this block

238 int *store_prev_samples;///< if true, carryover samples have to be stored

239 int *use_ltp; ///< if true, long-term prediction is used

240 int *ltp_lag; ///< lag value for long-term prediction

241 int *ltp_gain; ///< gain values for ltp 5-tap filter

242 int32_t *quant_cof; ///< quantized parcor coefficients

243 int32_t *lpc_cof; ///< coefficients of the direct form prediction

244 int32_t *raw_samples; ///< decoded raw samples / residuals for this block

245 int32_t *prev_raw_samples; ///< contains unshifted raw samples from the previous block

246 int32_t *raw_other; ///< decoded raw samples of the other channel of a channel pair

247 } ALSBlockData;

248

249

250 static av_cold void dprint_specific_config(ALSDecContext *ctx)

251 {

252 #ifdef DEBUG

253 AVCodecContext *avctx = ctx->avctx;

254 ALSSpecificConfig *sconf = &ctx->sconf;

255

256 av_dlog(avctx, "resolution = %i\n", sconf->resolution);

257 av_dlog(avctx, "floating = %i\n", sconf->floating);

258 av_dlog(avctx, "frame_length = %i\n", sconf->frame_length);

259 av_dlog(avctx, "ra_distance = %i\n", sconf->ra_distance);

260 av_dlog(avctx, "ra_flag = %i\n", sconf->ra_flag);

261 av_dlog(avctx, "adapt_order = %i\n", sconf->adapt_order);

262 av_dlog(avctx, "coef_table = %i\n", sconf->coef_table);

263 av_dlog(avctx, "long_term_prediction = %i\n", sconf->long_term_prediction);

264 av_dlog(avctx, "max_order = %i\n", sconf->max_order);

265 av_dlog(avctx, "block_switching = %i\n", sconf->block_switching);

266 av_dlog(avctx, "bgmc = %i\n", sconf->bgmc);

267 av_dlog(avctx, "sb_part = %i\n", sconf->sb_part);

268 av_dlog(avctx, "joint_stereo = %i\n", sconf->joint_stereo);

269 av_dlog(avctx, "mc_coding = %i\n", sconf->mc_coding);

270 av_dlog(avctx, "chan_config = %i\n", sconf->chan_config);

271 av_dlog(avctx, "chan_sort = %i\n", sconf->chan_sort);

272 av_dlog(avctx, "RLSLMS = %i\n", sconf->rlslms);

273 av_dlog(avctx, "chan_config_info = %i\n", sconf->chan_config_info);

274 #endif

275 }

276

277

278 /** Read an ALSSpecificConfig from a buffer into the output struct.

279 */

280 static av_cold int read_specific_config(ALSDecContext *ctx)

281 {

282 GetBitContext gb;

283 uint64_t ht_size;

284 int i, config_offset;

285 MPEG4AudioConfig m4ac = {0};

286 ALSSpecificConfig *sconf = &ctx->sconf;

287 AVCodecContext *avctx = ctx->avctx;

288 uint32_t als_id, header_size, trailer_size;

289 int ret;

290

291 if ((ret = init_get_bits8(&gb, avctx->extradata, avctx->extradata_size)) < 0)

292 return ret;

293

294 config_offset = avpriv_mpeg4audio_get_config(&m4ac, avctx->extradata,

295 avctx->extradata_size * 8, 1);

296

297 if (config_offset < 0)

298 return AVERROR_INVALIDDATA;

299

300 skip_bits_long(&gb, config_offset);

301

302 if (get_bits_left(&gb) < (30 << 3))

303 return AVERROR_INVALIDDATA;

304

305 // read the fixed items

306 als_id = get_bits_long(&gb, 32);

307 avctx->sample_rate = m4ac.sample_rate;

308 skip_bits_long(&gb, 32); // sample rate already known

309 sconf->samples = get_bits_long(&gb, 32);

310 avctx->channels = m4ac.channels;

311 skip_bits(&gb, 16); // number of channels already known

312 skip_bits(&gb, 3); // skip file_type

313 sconf->resolution = get_bits(&gb, 3);

314 sconf->floating = get_bits1(&gb);

315 sconf->msb_first = get_bits1(&gb);

316 sconf->frame_length = get_bits(&gb, 16) + 1;

317 sconf->ra_distance = get_bits(&gb, 8);

318 sconf->ra_flag = get_bits(&gb, 2);

319 sconf->adapt_order = get_bits1(&gb);

320 sconf->coef_table = get_bits(&gb, 2);

321 sconf->long_term_prediction = get_bits1(&gb);

322 sconf->max_order = get_bits(&gb, 10);

323 sconf->block_switching = get_bits(&gb, 2);

324 sconf->bgmc = get_bits1(&gb);

325 sconf->sb_part = get_bits1(&gb);

326 sconf->joint_stereo = get_bits1(&gb);

327 sconf->mc_coding = get_bits1(&gb);

328 sconf->chan_config = get_bits1(&gb);

329 sconf->chan_sort = get_bits1(&gb);

330 sconf->crc_enabled = get_bits1(&gb);

331 sconf->rlslms = get_bits1(&gb);

332 skip_bits(&gb, 5); // skip 5 reserved bits

333 skip_bits1(&gb); // skip aux_data_enabled

334

335

336 // check for ALSSpecificConfig struct

337 if (als_id != MKBETAG('A','L','S','0円'))

338 return AVERROR_INVALIDDATA;

339

340 ctx->cur_frame_length = sconf->frame_length;

341

342 // read channel config

343 if (sconf->chan_config)

344 sconf->chan_config_info = get_bits(&gb, 16);

345 // TODO: use this to set avctx->channel_layout

346

347

348 // read channel sorting

349 if (sconf->chan_sort && avctx->channels > 1) {

350 int chan_pos_bits = av_ceil_log2(avctx->channels);

351 int bits_needed = avctx->channels * chan_pos_bits + 7;

352 if (get_bits_left(&gb) < bits_needed)

353 return AVERROR_INVALIDDATA;

354

355 if (!(sconf->chan_pos = av_malloc(avctx->channels * sizeof(*sconf->chan_pos))))

356 return AVERROR(ENOMEM);

357

358 ctx->cs_switch = 1;

359

360 for (i = 0; i < avctx->channels; i++) {

361 int idx;

362

363 idx = get_bits(&gb, chan_pos_bits);

364 if (idx >= avctx->channels) {

365 av_log(avctx, AV_LOG_WARNING, "Invalid channel reordering.\n");

366 ctx->cs_switch = 0;

367 break;

368 }

369 sconf->chan_pos[idx] = i;

370 }

371

372 align_get_bits(&gb);

373 }

374

375

376 // read fixed header and trailer sizes,

377 // if size = 0xFFFFFFFF then there is no data field!

378 if (get_bits_left(&gb) < 64)

379 return AVERROR_INVALIDDATA;

380

381 header_size = get_bits_long(&gb, 32);

382 trailer_size = get_bits_long(&gb, 32);

383 if (header_size == 0xFFFFFFFF)

384 header_size = 0;

385 if (trailer_size == 0xFFFFFFFF)

386 trailer_size = 0;

387

388 ht_size = ((int64_t)(header_size) + (int64_t)(trailer_size)) << 3;

389

390

391 // skip the header and trailer data

392 if (get_bits_left(&gb) < ht_size)

393 return AVERROR_INVALIDDATA;

394

395 if (ht_size > INT32_MAX)

396 return AVERROR_PATCHWELCOME;

397

398 skip_bits_long(&gb, ht_size);

399

400

401 // initialize CRC calculation

402 if (sconf->crc_enabled) {

403 if (get_bits_left(&gb) < 32)

404 return AVERROR_INVALIDDATA;

405

406 if (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL)) {

407 ctx->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);

408 ctx->crc = 0xFFFFFFFF;

409 ctx->crc_org = ~get_bits_long(&gb, 32);

410 } else

411 skip_bits_long(&gb, 32);

412 }

413

414

415 // no need to read the rest of ALSSpecificConfig (ra_unit_size & aux data)

416

417 dprint_specific_config(ctx);

418

419 return 0;

420 }

421

422

423 /** Check the ALSSpecificConfig for unsupported features.

424 */

425 static int check_specific_config(ALSDecContext *ctx)

426 {

427 ALSSpecificConfig *sconf = &ctx->sconf;

428 int error = 0;

429

430 // report unsupported feature and set error value

431 #define MISSING_ERR(cond, str, errval) \

432 { \

433 if (cond) { \

434 avpriv_report_missing_feature(ctx->avctx, \

435 str); \

436 error = errval; \

437 } \

438 }

439

440 MISSING_ERR(sconf->floating, "Floating point decoding", AVERROR_PATCHWELCOME);

441 MISSING_ERR(sconf->rlslms, "Adaptive RLS-LMS prediction", AVERROR_PATCHWELCOME);

442

443 return error;

444 }

445

446

447 /** Parse the bs_info field to extract the block partitioning used in

448 * block switching mode, refer to ISO/IEC 14496-3, section 11.6.2.

449 */

450 static void parse_bs_info(const uint32_t bs_info, unsigned int n,

451 unsigned int div, unsigned int **div_blocks,

452 unsigned int *num_blocks)

453 {

454 if (n < 31 && ((bs_info << n) & 0x40000000)) {

455 // if the level is valid and the investigated bit n is set

456 // then recursively check both children at bits (2n+1) and (2n+2)

457 n *= 2;

458 div += 1;

459 parse_bs_info(bs_info, n + 1, div, div_blocks, num_blocks);

460 parse_bs_info(bs_info, n + 2, div, div_blocks, num_blocks);

461 } else {

462 // else the bit is not set or the last level has been reached

463 // (bit implicitly not set)

464 **div_blocks = div;

465 (*div_blocks)++;

466 (*num_blocks)++;

467 }

468 }

469

470

471 /** Read and decode a Rice codeword.

472 */

473 static int32_t decode_rice(GetBitContext *gb, unsigned int k)

474 {

475 int max = get_bits_left(gb) - k;

476 int q = get_unary(gb, 0, max);

477 int r = k ? get_bits1(gb) : !(q & 1);

478

479 if (k > 1) {

480 q <<= (k - 1);

481 q += get_bits_long(gb, k - 1);

482 } else if (!k) {

483 q >>= 1;

484 }

485 return r ? q : ~q;

486 }

487

488

489 /** Convert PARCOR coefficient k to direct filter coefficient.

490 */

491 static void parcor_to_lpc(unsigned int k, const int32_t *par, int32_t *cof)

492 {

493 int i, j;

494

495 for (i = 0, j = k - 1; i < j; i++, j--) {

496 int tmp1 = ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);

497 cof[j] += ((MUL64(par[k], cof[i]) + (1 << 19)) >> 20);

498 cof[i] += tmp1;

499 }

500 if (i == j)

501 cof[i] += ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);

502

503 cof[k] = par[k];

504 }

505

506

507 /** Read block switching field if necessary and set actual block sizes.

508 * Also assure that the block sizes of the last frame correspond to the

509 * actual number of samples.

510 */

511 static void get_block_sizes(ALSDecContext *ctx, unsigned int *div_blocks,

512 uint32_t *bs_info)

513 {

514 ALSSpecificConfig *sconf = &ctx->sconf;

515 GetBitContext *gb = &ctx->gb;

516 unsigned int *ptr_div_blocks = div_blocks;

517 unsigned int b;

518

519 if (sconf->block_switching) {

520 unsigned int bs_info_len = 1 << (sconf->block_switching + 2);

521 *bs_info = get_bits_long(gb, bs_info_len);

522 *bs_info <<= (32 - bs_info_len);

523 }

524

525 ctx->num_blocks = 0;

526 parse_bs_info(*bs_info, 0, 0, &ptr_div_blocks, &ctx->num_blocks);

527

528 // The last frame may have an overdetermined block structure given in

529 // the bitstream. In that case the defined block structure would need

530 // more samples than available to be consistent.

531 // The block structure is actually used but the block sizes are adapted

532 // to fit the actual number of available samples.

533 // Example: 5 samples, 2nd level block sizes: 2 2 2 2.

534 // This results in the actual block sizes: 2 2 1 0.

535 // This is not specified in 14496-3 but actually done by the reference

536 // codec RM22 revision 2.

537 // This appears to happen in case of an odd number of samples in the last

538 // frame which is actually not allowed by the block length switching part

539 // of 14496-3.

540 // The ALS conformance files feature an odd number of samples in the last

541 // frame.

542

543 for (b = 0; b < ctx->num_blocks; b++)

544 div_blocks[b] = ctx->sconf.frame_length >> div_blocks[b];

545

546 if (ctx->cur_frame_length != ctx->sconf.frame_length) {

547 unsigned int remaining = ctx->cur_frame_length;

548

549 for (b = 0; b < ctx->num_blocks; b++) {

550 if (remaining <= div_blocks[b]) {

551 div_blocks[b] = remaining;

552 ctx->num_blocks = b + 1;

553 break;

554 }

555

556 remaining -= div_blocks[b];

557 }

558 }

559 }

560

561

562 /** Read the block data for a constant block

563 */

564 static int read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)

565 {

566 ALSSpecificConfig *sconf = &ctx->sconf;

567 AVCodecContext *avctx = ctx->avctx;

568 GetBitContext *gb = &ctx->gb;

569

570 if (bd->block_length <= 0)

571 return AVERROR_INVALIDDATA;

572

573 *bd->raw_samples = 0;

574 *bd->const_block = get_bits1(gb); // 1 = constant value, 0 = zero block (silence)

575 bd->js_blocks = get_bits1(gb);

576

577 // skip 5 reserved bits

578 skip_bits(gb, 5);

579

580 if (*bd->const_block) {

581 unsigned int const_val_bits = sconf->floating ? 24 : avctx->bits_per_raw_sample;

582 *bd->raw_samples = get_sbits_long(gb, const_val_bits);

583 }

584

585 // ensure constant block decoding by reusing this field

586 *bd->const_block = 1;

587

588 return 0;

589 }

590

591

592 /** Decode the block data for a constant block

593 */

594 static void decode_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)

595 {

596 int smp = bd->block_length - 1;

597 int32_t val = *bd->raw_samples;

598 int32_t *dst = bd->raw_samples + 1;

599

600 // write raw samples into buffer

601 for (; smp; smp--)

602 *dst++ = val;

603 }

604

605

606 /** Read the block data for a non-constant block

607 */

608 static int read_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)

609 {

610 ALSSpecificConfig *sconf = &ctx->sconf;

611 AVCodecContext *avctx = ctx->avctx;

612 GetBitContext *gb = &ctx->gb;

613 unsigned int k;

614 unsigned int s[8];

615 unsigned int sx[8];

616 unsigned int sub_blocks, log2_sub_blocks, sb_length;

617 unsigned int start = 0;

618 unsigned int opt_order;

619 int sb;

620 int32_t *quant_cof = bd->quant_cof;

621 int32_t *current_res;

622

623

624 // ensure variable block decoding by reusing this field

625 *bd->const_block = 0;

626

627 *bd->opt_order = 1;

628 bd->js_blocks = get_bits1(gb);

629

630 opt_order = *bd->opt_order;

631

632 // determine the number of subblocks for entropy decoding

633 if (!sconf->bgmc && !sconf->sb_part) {

634 log2_sub_blocks = 0;

635 } else {

636 if (sconf->bgmc && sconf->sb_part)

637 log2_sub_blocks = get_bits(gb, 2);

638 else

639 log2_sub_blocks = 2 * get_bits1(gb);

640 }

641

642 sub_blocks = 1 << log2_sub_blocks;

643

644 // do not continue in case of a damaged stream since

645 // block_length must be evenly divisible by sub_blocks

646 if (bd->block_length & (sub_blocks - 1)) {

647 av_log(avctx, AV_LOG_WARNING,

648 "Block length is not evenly divisible by the number of subblocks.\n");

649 return AVERROR_INVALIDDATA;

650 }

651

652 sb_length = bd->block_length >> log2_sub_blocks;

653

654 if (sconf->bgmc) {

655 s[0] = get_bits(gb, 8 + (sconf->resolution > 1));

656 for (k = 1; k < sub_blocks; k++)

657 s[k] = s[k - 1] + decode_rice(gb, 2);

658

659 for (k = 0; k < sub_blocks; k++) {

660 sx[k] = s[k] & 0x0F;

661 s [k] >>= 4;

662 }

663 } else {

664 s[0] = get_bits(gb, 4 + (sconf->resolution > 1));

665 for (k = 1; k < sub_blocks; k++)

666 s[k] = s[k - 1] + decode_rice(gb, 0);

667 }

668 for (k = 1; k < sub_blocks; k++)

669 if (s[k] > 32) {

670 av_log(avctx, AV_LOG_ERROR, "k invalid for rice code.\n");

671 return AVERROR_INVALIDDATA;

672 }

673

674 if (get_bits1(gb))

675 *bd->shift_lsbs = get_bits(gb, 4) + 1;

676

677 *bd->store_prev_samples = (bd->js_blocks && bd->raw_other) || *bd->shift_lsbs;

678

679

680 if (!sconf->rlslms) {

681 if (sconf->adapt_order) {

682 int opt_order_length = av_ceil_log2(av_clip((bd->block_length >> 3) - 1,

683 2, sconf->max_order + 1));

684 *bd->opt_order = get_bits(gb, opt_order_length);

685 if (*bd->opt_order > sconf->max_order) {

686 *bd->opt_order = sconf->max_order;

687 av_log(avctx, AV_LOG_ERROR, "Predictor order too large.\n");

688 return AVERROR_INVALIDDATA;

689 }

690 } else {

691 *bd->opt_order = sconf->max_order;

692 }

693 if (*bd->opt_order > bd->block_length) {

694 *bd->opt_order = bd->block_length;

695 av_log(avctx, AV_LOG_ERROR, "Predictor order too large.\n");

696 return AVERROR_INVALIDDATA;

697 }

698 opt_order = *bd->opt_order;

699

700 if (opt_order) {

701 int add_base;

702

703 if (sconf->coef_table == 3) {

704 add_base = 0x7F;

705

706 // read coefficient 0

707 quant_cof[0] = 32 * parcor_scaled_values[get_bits(gb, 7)];

708

709 // read coefficient 1

710 if (opt_order > 1)

711 quant_cof[1] = -32 * parcor_scaled_values[get_bits(gb, 7)];

712

713 // read coefficients 2 to opt_order

714 for (k = 2; k < opt_order; k++)

715 quant_cof[k] = get_bits(gb, 7);

716 } else {

717 int k_max;

718 add_base = 1;

719

720 // read coefficient 0 to 19

721 k_max = FFMIN(opt_order, 20);

722 for (k = 0; k < k_max; k++) {

723 int rice_param = parcor_rice_table[sconf->coef_table][k][1];

724 int offset = parcor_rice_table[sconf->coef_table][k][0];

725 quant_cof[k] = decode_rice(gb, rice_param) + offset;

726 if (quant_cof[k] < -64 || quant_cof[k] > 63) {

727 av_log(avctx, AV_LOG_ERROR,

728 "quant_cof %"PRIu32" is out of range.\n",

729 quant_cof[k]);

730 return AVERROR_INVALIDDATA;

731 }

732 }

733

734 // read coefficients 20 to 126

735 k_max = FFMIN(opt_order, 127);

736 for (; k < k_max; k++)

737 quant_cof[k] = decode_rice(gb, 2) + (k & 1);

738

739 // read coefficients 127 to opt_order

740 for (; k < opt_order; k++)

741 quant_cof[k] = decode_rice(gb, 1);

742

743 quant_cof[0] = 32 * parcor_scaled_values[quant_cof[0] + 64];

744

745 if (opt_order > 1)

746 quant_cof[1] = -32 * parcor_scaled_values[quant_cof[1] + 64];

747 }

748

749 for (k = 2; k < opt_order; k++)

750 quant_cof[k] = (quant_cof[k] << 14) + (add_base << 13);

751 }

752 }

753

754 // read LTP gain and lag values

755 if (sconf->long_term_prediction) {

756 *bd->use_ltp = get_bits1(gb);

757

758 if (*bd->use_ltp) {

759 int r, c;

760

761 bd->ltp_gain[0] = decode_rice(gb, 1) << 3;

762 bd->ltp_gain[1] = decode_rice(gb, 2) << 3;

763

764 r = get_unary(gb, 0, 3);

765 c = get_bits(gb, 2);

766 bd->ltp_gain[2] = ltp_gain_values[r][c];

767

768 bd->ltp_gain[3] = decode_rice(gb, 2) << 3;

769 bd->ltp_gain[4] = decode_rice(gb, 1) << 3;

770

771 *bd->ltp_lag = get_bits(gb, ctx->ltp_lag_length);

772 *bd->ltp_lag += FFMAX(4, opt_order + 1);

773 }

774 }

775

776 // read first value and residuals in case of a random access block

777 if (bd->ra_block) {

778 if (opt_order)

779 bd->raw_samples[0] = decode_rice(gb, avctx->bits_per_raw_sample - 4);

780 if (opt_order > 1)

781 bd->raw_samples[1] = decode_rice(gb, FFMIN(s[0] + 3, ctx->s_max));

782 if (opt_order > 2)

783 bd->raw_samples[2] = decode_rice(gb, FFMIN(s[0] + 1, ctx->s_max));

784

785 start = FFMIN(opt_order, 3);

786 }

787

788 // read all residuals

789 if (sconf->bgmc) {

790 int delta[8];

791 unsigned int k [8];

792 unsigned int b = av_clip((av_ceil_log2(bd->block_length) - 3) >> 1, 0, 5);

793

794 // read most significant bits

795 unsigned int high;

796 unsigned int low;

797 unsigned int value;

798

799 ff_bgmc_decode_init(gb, &high, &low, &value);

800

801 current_res = bd->raw_samples + start;

802

803 for (sb = 0; sb < sub_blocks; sb++) {

804 unsigned int sb_len = sb_length - (sb ? 0 : start);

805

806 k [sb] = s[sb] > b ? s[sb] - b : 0;

807 delta[sb] = 5 - s[sb] + k[sb];

808

809 ff_bgmc_decode(gb, sb_len, current_res,

810 delta[sb], sx[sb], &high, &low, &value, ctx->bgmc_lut, ctx->bgmc_lut_status);

811

812 current_res += sb_len;

813 }

814

815 ff_bgmc_decode_end(gb);

816

817

818 // read least significant bits and tails

819 current_res = bd->raw_samples + start;

820

821 for (sb = 0; sb < sub_blocks; sb++, start = 0) {

822 unsigned int cur_tail_code = tail_code[sx[sb]][delta[sb]];

823 unsigned int cur_k = k[sb];

824 unsigned int cur_s = s[sb];

825

826 for (; start < sb_length; start++) {

827 int32_t res = *current_res;

828

829 if (res == cur_tail_code) {

830 unsigned int max_msb = (2 + (sx[sb] > 2) + (sx[sb] > 10))

831 << (5 - delta[sb]);

832

833 res = decode_rice(gb, cur_s);

834

835 if (res >= 0) {

836 res += (max_msb ) << cur_k;

837 } else {

838 res -= (max_msb - 1) << cur_k;

839 }

840 } else {

841 if (res > cur_tail_code)

842 res--;

843

844 if (res & 1)

845 res = -res;

846

847 res >>= 1;

848

849 if (cur_k) {

850 res <<= cur_k;

851 res |= get_bits_long(gb, cur_k);

852 }

853 }

854

855 *current_res++ = res;

856 }

857 }

858 } else {

859 current_res = bd->raw_samples + start;

860

861 for (sb = 0; sb < sub_blocks; sb++, start = 0)

862 for (; start < sb_length; start++)

863 *current_res++ = decode_rice(gb, s[sb]);

864 }

865

866 if (!sconf->mc_coding || ctx->js_switch)

867 align_get_bits(gb);

868

869 return 0;

870 }

871

872

873 /** Decode the block data for a non-constant block

874 */

875 static int decode_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)

876 {

877 ALSSpecificConfig *sconf = &ctx->sconf;

878 unsigned int block_length = bd->block_length;

879 unsigned int smp = 0;

880 unsigned int k;

881 int opt_order = *bd->opt_order;

882 int sb;

883 int64_t y;

884 int32_t *quant_cof = bd->quant_cof;

885 int32_t *lpc_cof = bd->lpc_cof;

886 int32_t *raw_samples = bd->raw_samples;

887 int32_t *raw_samples_end = bd->raw_samples + bd->block_length;

888 int32_t *lpc_cof_reversed = ctx->lpc_cof_reversed_buffer;

889

890 // reverse long-term prediction

891 if (*bd->use_ltp) {

892 int ltp_smp;

893

894 for (ltp_smp = FFMAX(*bd->ltp_lag - 2, 0); ltp_smp < block_length; ltp_smp++) {

895 int center = ltp_smp - *bd->ltp_lag;

896 int begin = FFMAX(0, center - 2);

897 int end = center + 3;

898 int tab = 5 - (end - begin);

899 int base;

900

901 y = 1 << 6;

902

903 for (base = begin; base < end; base++, tab++)

904 y += MUL64(bd->ltp_gain[tab], raw_samples[base]);

905

906 raw_samples[ltp_smp] += y >> 7;

907 }

908 }

909

910 // reconstruct all samples from residuals

911 if (bd->ra_block) {

912 for (smp = 0; smp < opt_order; smp++) {

913 y = 1 << 19;

914

915 for (sb = 0; sb < smp; sb++)

916 y += MUL64(lpc_cof[sb], raw_samples[-(sb + 1)]);

917

918 *raw_samples++ -= y >> 20;

919 parcor_to_lpc(smp, quant_cof, lpc_cof);

920 }

921 } else {

922 for (k = 0; k < opt_order; k++)

923 parcor_to_lpc(k, quant_cof, lpc_cof);

924

925 // store previous samples in case that they have to be altered

926 if (*bd->store_prev_samples)

927 memcpy(bd->prev_raw_samples, raw_samples - sconf->max_order,

928 sizeof(*bd->prev_raw_samples) * sconf->max_order);

929

930 // reconstruct difference signal for prediction (joint-stereo)

931 if (bd->js_blocks && bd->raw_other) {

932 int32_t *left, *right;

933

934 if (bd->raw_other > raw_samples) { // D = R - L

935 left = raw_samples;

936 right = bd->raw_other;

937 } else { // D = R - L

938 left = bd->raw_other;

939 right = raw_samples;

940 }

941

942 for (sb = -1; sb >= -sconf->max_order; sb--)

943 raw_samples[sb] = right[sb] - left[sb];

944 }

945

946 // reconstruct shifted signal

947 if (*bd->shift_lsbs)

948 for (sb = -1; sb >= -sconf->max_order; sb--)

949 raw_samples[sb] >>= *bd->shift_lsbs;

950 }

951

952 // reverse linear prediction coefficients for efficiency

953 lpc_cof = lpc_cof + opt_order;

954

955 for (sb = 0; sb < opt_order; sb++)

956 lpc_cof_reversed[sb] = lpc_cof[-(sb + 1)];

957

958 // reconstruct raw samples

959 raw_samples = bd->raw_samples + smp;

960 lpc_cof = lpc_cof_reversed + opt_order;

961

962 for (; raw_samples < raw_samples_end; raw_samples++) {

963 y = 1 << 19;

964

965 for (sb = -opt_order; sb < 0; sb++)

966 y += MUL64(lpc_cof[sb], raw_samples[sb]);

967

968 *raw_samples -= y >> 20;

969 }

970

971 raw_samples = bd->raw_samples;

972

973 // restore previous samples in case that they have been altered

974 if (*bd->store_prev_samples)

975 memcpy(raw_samples - sconf->max_order, bd->prev_raw_samples,

976 sizeof(*raw_samples) * sconf->max_order);

977

978 return 0;

979 }

980

981

982 /** Read the block data.

983 */

984 static int read_block(ALSDecContext *ctx, ALSBlockData *bd)

985 {

986 int ret;

987 GetBitContext *gb = &ctx->gb;

988

989 *bd->shift_lsbs = 0;

990 // read block type flag and read the samples accordingly

991 if (get_bits1(gb)) {

992 ret = read_var_block_data(ctx, bd);

993 } else {

994 ret = read_const_block_data(ctx, bd);

995 }

996

997 return ret;

998 }

999

1000

1001 /** Decode the block data.

1002 */

1003 static int decode_block(ALSDecContext *ctx, ALSBlockData *bd)

1004 {

1005 unsigned int smp;

1006 int ret = 0;

1007

1008 // read block type flag and read the samples accordingly

1009 if (*bd->const_block)

1010 decode_const_block_data(ctx, bd);

1011 else

1012 ret = decode_var_block_data(ctx, bd); // always return 0

1013

1014 if (ret < 0)

1015 return ret;

1016

1017 // TODO: read RLSLMS extension data

1018

1019 if (*bd->shift_lsbs)

1020 for (smp = 0; smp < bd->block_length; smp++)

1021 bd->raw_samples[smp] <<= *bd->shift_lsbs;

1022

1023 return 0;

1024 }

1025

1026

1027 /** Read and decode block data successively.

1028 */

1029 static int read_decode_block(ALSDecContext *ctx, ALSBlockData *bd)

1030 {

1031 int ret;

1032

1033 if ((ret = read_block(ctx, bd)) < 0)

1034 return ret;

1035

1036 return decode_block(ctx, bd);

1037 }

1038

1039

1040 /** Compute the number of samples left to decode for the current frame and

1041 * sets these samples to zero.

1042 */

1043 static void zero_remaining(unsigned int b, unsigned int b_max,

1044 const unsigned int *div_blocks, int32_t *buf)

1045 {

1046 unsigned int count = 0;

1047

1048 while (b < b_max)

1049 count += div_blocks[b++];

1050

1051 if (count)

1052 memset(buf, 0, sizeof(*buf) * count);

1053 }

1054

1055

1056 /** Decode blocks independently.

1057 */

1058 static int decode_blocks_ind(ALSDecContext *ctx, unsigned int ra_frame,

1059 unsigned int c, const unsigned int *div_blocks,

1060 unsigned int *js_blocks)

1061 {

1062 int ret;

1063 unsigned int b;

1064 ALSBlockData bd = { 0 };

1065

1066 bd.ra_block = ra_frame;

1067 bd.const_block = ctx->const_block;

1068 bd.shift_lsbs = ctx->shift_lsbs;

1069 bd.opt_order = ctx->opt_order;

1070 bd.store_prev_samples = ctx->store_prev_samples;

1071 bd.use_ltp = ctx->use_ltp;

1072 bd.ltp_lag = ctx->ltp_lag;

1073 bd.ltp_gain = ctx->ltp_gain[0];

1074 bd.quant_cof = ctx->quant_cof[0];

1075 bd.lpc_cof = ctx->lpc_cof[0];

1076 bd.prev_raw_samples = ctx->prev_raw_samples;

1077 bd.raw_samples = ctx->raw_samples[c];

1078

1079

1080 for (b = 0; b < ctx->num_blocks; b++) {

1081 bd.block_length = div_blocks[b];

1082

1083 if ((ret = read_decode_block(ctx, &bd)) < 0) {

1084 // damaged block, write zero for the rest of the frame

1085 zero_remaining(b, ctx->num_blocks, div_blocks, bd.raw_samples);

1086 return ret;

1087 }

1088 bd.raw_samples += div_blocks[b];

1089 bd.ra_block = 0;

1090 }

1091

1092 return 0;

1093 }

1094

1095

1096 /** Decode blocks dependently.

1097 */

1098 static int decode_blocks(ALSDecContext *ctx, unsigned int ra_frame,

1099 unsigned int c, const unsigned int *div_blocks,

1100 unsigned int *js_blocks)

1101 {

1102 ALSSpecificConfig *sconf = &ctx->sconf;

1103 unsigned int offset = 0;

1104 unsigned int b;

1105 int ret;

1106 ALSBlockData bd[2] = { { 0 } };

1107

1108 bd[0].ra_block = ra_frame;

1109 bd[0].const_block = ctx->const_block;

1110 bd[0].shift_lsbs = ctx->shift_lsbs;

1111 bd[0].opt_order = ctx->opt_order;

1112 bd[0].store_prev_samples = ctx->store_prev_samples;

1113 bd[0].use_ltp = ctx->use_ltp;

1114 bd[0].ltp_lag = ctx->ltp_lag;

1115 bd[0].ltp_gain = ctx->ltp_gain[0];

1116 bd[0].quant_cof = ctx->quant_cof[0];

1117 bd[0].lpc_cof = ctx->lpc_cof[0];

1118 bd[0].prev_raw_samples = ctx->prev_raw_samples;

1119 bd[0].js_blocks = *js_blocks;

1120

1121 bd[1].ra_block = ra_frame;

1122 bd[1].const_block = ctx->const_block;

1123 bd[1].shift_lsbs = ctx->shift_lsbs;

1124 bd[1].opt_order = ctx->opt_order;

1125 bd[1].store_prev_samples = ctx->store_prev_samples;

1126 bd[1].use_ltp = ctx->use_ltp;

1127 bd[1].ltp_lag = ctx->ltp_lag;

1128 bd[1].ltp_gain = ctx->ltp_gain[0];

1129 bd[1].quant_cof = ctx->quant_cof[0];

1130 bd[1].lpc_cof = ctx->lpc_cof[0];

1131 bd[1].prev_raw_samples = ctx->prev_raw_samples;

1132 bd[1].js_blocks = *(js_blocks + 1);

1133

1134 // decode all blocks

1135 for (b = 0; b < ctx->num_blocks; b++) {

1136 unsigned int s;

1137

1138 bd[0].block_length = div_blocks[b];

1139 bd[1].block_length = div_blocks[b];

1140

1141 bd[0].raw_samples = ctx->raw_samples[c ] + offset;

1142 bd[1].raw_samples = ctx->raw_samples[c + 1] + offset;

1143

1144 bd[0].raw_other = bd[1].raw_samples;

1145 bd[1].raw_other = bd[0].raw_samples;

1146

1147 if ((ret = read_decode_block(ctx, &bd[0])) < 0 ||

1148 (ret = read_decode_block(ctx, &bd[1])) < 0)

1149 goto fail;

1150

1151 // reconstruct joint-stereo blocks

1152 if (bd[0].js_blocks) {

1153 if (bd[1].js_blocks)

1154 av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel pair.\n");

1155

1156 for (s = 0; s < div_blocks[b]; s++)

1157 bd[0].raw_samples[s] = bd[1].raw_samples[s] - bd[0].raw_samples[s];

1158 } else if (bd[1].js_blocks) {

1159 for (s = 0; s < div_blocks[b]; s++)

1160 bd[1].raw_samples[s] = bd[1].raw_samples[s] + bd[0].raw_samples[s];

1161 }

1162

1163 offset += div_blocks[b];

1164 bd[0].ra_block = 0;

1165 bd[1].ra_block = 0;

1166 }

1167

1168 // store carryover raw samples,

1169 // the others channel raw samples are stored by the calling function.

1170 memmove(ctx->raw_samples[c] - sconf->max_order,

1171 ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

1172 sizeof(*ctx->raw_samples[c]) * sconf->max_order);

1173

1174 return 0;

1175 fail:

1176 // damaged block, write zero for the rest of the frame

1177 zero_remaining(b, ctx->num_blocks, div_blocks, bd[0].raw_samples);

1178 zero_remaining(b, ctx->num_blocks, div_blocks, bd[1].raw_samples);

1179 return ret;

1180 }

1181

1182 static inline int als_weighting(GetBitContext *gb, int k, int off)

1183 {

1184 int idx = av_clip(decode_rice(gb, k) + off,

1185 0, FF_ARRAY_ELEMS(mcc_weightings) - 1);

1186 return mcc_weightings[idx];

1187 }

1188

1189 /** Read the channel data.

1190 */

1191 static int read_channel_data(ALSDecContext *ctx, ALSChannelData *cd, int c)

1192 {

1193 GetBitContext *gb = &ctx->gb;

1194 ALSChannelData *current = cd;

1195 unsigned int channels = ctx->avctx->channels;

1196 int entries = 0;

1197

1198 while (entries < channels && !(current->stop_flag = get_bits1(gb))) {

1199 current->master_channel = get_bits_long(gb, av_ceil_log2(channels));

1200

1201 if (current->master_channel >= channels) {

1202 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid master channel.\n");

1203 return AVERROR_INVALIDDATA;

1204 }

1205

1206 if (current->master_channel != c) {

1207 current->time_diff_flag = get_bits1(gb);

1208 current->weighting[0] = als_weighting(gb, 1, 16);

1209 current->weighting[1] = als_weighting(gb, 2, 14);

1210 current->weighting[2] = als_weighting(gb, 1, 16);

1211

1212 if (current->time_diff_flag) {

1213 current->weighting[3] = als_weighting(gb, 1, 16);

1214 current->weighting[4] = als_weighting(gb, 1, 16);

1215 current->weighting[5] = als_weighting(gb, 1, 16);

1216

1217 current->time_diff_sign = get_bits1(gb);

1218 current->time_diff_index = get_bits(gb, ctx->ltp_lag_length - 3) + 3;

1219 }

1220 }

1221

1222 current++;

1223 entries++;

1224 }

1225

1226 if (entries == channels) {

1227 av_log(ctx->avctx, AV_LOG_ERROR, "Damaged channel data.\n");

1228 return AVERROR_INVALIDDATA;

1229 }

1230

1231 align_get_bits(gb);

1232 return 0;

1233 }

1234

1235

1236 /** Recursively reverts the inter-channel correlation for a block.

1237 */

1238 static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,

1239 ALSChannelData **cd, int *reverted,

1240 unsigned int offset, int c)

1241 {

1242 ALSChannelData *ch = cd[c];

1243 unsigned int dep = 0;

1244 unsigned int channels = ctx->avctx->channels;

1245

1246 if (reverted[c])

1247 return 0;

1248

1249 reverted[c] = 1;

1250

1251 while (dep < channels && !ch[dep].stop_flag) {

1252 revert_channel_correlation(ctx, bd, cd, reverted, offset,

1253 ch[dep].master_channel);

1254

1255 dep++;

1256 }

1257

1258 if (dep == channels) {

1259 av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation.\n");

1260 return AVERROR_INVALIDDATA;

1261 }

1262

1263 bd->const_block = ctx->const_block + c;

1264 bd->shift_lsbs = ctx->shift_lsbs + c;

1265 bd->opt_order = ctx->opt_order + c;

1266 bd->store_prev_samples = ctx->store_prev_samples + c;

1267 bd->use_ltp = ctx->use_ltp + c;

1268 bd->ltp_lag = ctx->ltp_lag + c;

1269 bd->ltp_gain = ctx->ltp_gain[c];

1270 bd->lpc_cof = ctx->lpc_cof[c];

1271 bd->quant_cof = ctx->quant_cof[c];

1272 bd->raw_samples = ctx->raw_samples[c] + offset;

1273

1274 for (dep = 0; !ch[dep].stop_flag; dep++) {

1275 unsigned int smp;

1276 unsigned int begin = 1;

1277 unsigned int end = bd->block_length - 1;

1278 int64_t y;

1279 int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;

1280

1281 if (ch[dep].master_channel == c)

1282 continue;

1283

1284 if (ch[dep].time_diff_flag) {

1285 int t = ch[dep].time_diff_index;

1286

1287 if (ch[dep].time_diff_sign) {

1288 t = -t;

1289 begin -= t;

1290 } else {

1291 end -= t;

1292 }

1293

1294 for (smp = begin; smp < end; smp++) {

1295 y = (1 << 6) +

1296 MUL64(ch[dep].weighting[0], master[smp - 1 ]) +

1297 MUL64(ch[dep].weighting[1], master[smp ]) +

1298 MUL64(ch[dep].weighting[2], master[smp + 1 ]) +

1299 MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +

1300 MUL64(ch[dep].weighting[4], master[smp + t]) +

1301 MUL64(ch[dep].weighting[5], master[smp + 1 + t]);

1302

1303 bd->raw_samples[smp] += y >> 7;

1304 }

1305 } else {

1306 for (smp = begin; smp < end; smp++) {

1307 y = (1 << 6) +

1308 MUL64(ch[dep].weighting[0], master[smp - 1]) +

1309 MUL64(ch[dep].weighting[1], master[smp ]) +

1310 MUL64(ch[dep].weighting[2], master[smp + 1]);

1311

1312 bd->raw_samples[smp] += y >> 7;

1313 }

1314 }

1315 }

1316

1317 return 0;

1318 }

1319

1320

1321 /** Read the frame data.

1322 */

1323 static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)

1324 {

1325 ALSSpecificConfig *sconf = &ctx->sconf;

1326 AVCodecContext *avctx = ctx->avctx;

1327 GetBitContext *gb = &ctx->gb;

1328 unsigned int div_blocks[32]; ///< block sizes.

1329 unsigned int c;

1330 unsigned int js_blocks[2];

1331 uint32_t bs_info = 0;

1332 int ret;

1333

1334 // skip the size of the ra unit if present in the frame

1335 if (sconf->ra_flag == RA_FLAG_FRAMES && ra_frame)

1336 skip_bits_long(gb, 32);

1337

1338 if (sconf->mc_coding && sconf->joint_stereo) {

1339 ctx->js_switch = get_bits1(gb);

1340 align_get_bits(gb);

1341 }

1342

1343 if (!sconf->mc_coding || ctx->js_switch) {

1344 int independent_bs = !sconf->joint_stereo;

1345

1346 for (c = 0; c < avctx->channels; c++) {

1347 js_blocks[0] = 0;

1348 js_blocks[1] = 0;

1349

1350 get_block_sizes(ctx, div_blocks, &bs_info);

1351

1352 // if joint_stereo and block_switching is set, independent decoding

1353 // is signaled via the first bit of bs_info

1354 if (sconf->joint_stereo && sconf->block_switching)

1355 if (bs_info >> 31)

1356 independent_bs = 2;

1357

1358 // if this is the last channel, it has to be decoded independently

1359 if (c == avctx->channels - 1)

1360 independent_bs = 1;

1361

1362 if (independent_bs) {

1363 ret = decode_blocks_ind(ctx, ra_frame, c,

1364 div_blocks, js_blocks);

1365 if (ret < 0)

1366 return ret;

1367 independent_bs--;

1368 } else {

1369 ret = decode_blocks(ctx, ra_frame, c, div_blocks, js_blocks);

1370 if (ret < 0)

1371 return ret;

1372

1373 c++;

1374 }

1375

1376 // store carryover raw samples

1377 memmove(ctx->raw_samples[c] - sconf->max_order,

1378 ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

1379 sizeof(*ctx->raw_samples[c]) * sconf->max_order);

1380 }

1381 } else { // multi-channel coding

1382 ALSBlockData bd = { 0 };

1383 int b, ret;

1384 int *reverted_channels = ctx->reverted_channels;

1385 unsigned int offset = 0;

1386

1387 for (c = 0; c < avctx->channels; c++)

1388 if (ctx->chan_data[c] < ctx->chan_data_buffer) {

1389 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid channel data.\n");

1390 return AVERROR_INVALIDDATA;

1391 }

1392

1393 memset(reverted_channels, 0, sizeof(*reverted_channels) * avctx->channels);

1394

1395 bd.ra_block = ra_frame;

1396 bd.prev_raw_samples = ctx->prev_raw_samples;

1397

1398 get_block_sizes(ctx, div_blocks, &bs_info);

1399

1400 for (b = 0; b < ctx->num_blocks; b++) {

1401 bd.block_length = div_blocks[b];

1402 if (bd.block_length <= 0) {

1403 av_log(ctx->avctx, AV_LOG_WARNING,

1404 "Invalid block length %u in channel data!\n",

1405 bd.block_length);

1406 continue;

1407 }

1408

1409 for (c = 0; c < avctx->channels; c++) {

1410 bd.const_block = ctx->const_block + c;

1411 bd.shift_lsbs = ctx->shift_lsbs + c;

1412 bd.opt_order = ctx->opt_order + c;

1413 bd.store_prev_samples = ctx->store_prev_samples + c;

1414 bd.use_ltp = ctx->use_ltp + c;

1415 bd.ltp_lag = ctx->ltp_lag + c;

1416 bd.ltp_gain = ctx->ltp_gain[c];

1417 bd.lpc_cof = ctx->lpc_cof[c];

1418 bd.quant_cof = ctx->quant_cof[c];

1419 bd.raw_samples = ctx->raw_samples[c] + offset;

1420 bd.raw_other = NULL;

1421

1422 if ((ret = read_block(ctx, &bd)) < 0)

1423 return ret;

1424 if ((ret = read_channel_data(ctx, ctx->chan_data[c], c)) < 0)

1425 return ret;

1426 }

1427

1428 for (c = 0; c < avctx->channels; c++) {

1429 ret = revert_channel_correlation(ctx, &bd, ctx->chan_data,

1430 reverted_channels, offset, c);

1431 if (ret < 0)

1432 return ret;

1433 }

1434 for (c = 0; c < avctx->channels; c++) {

1435 bd.const_block = ctx->const_block + c;

1436 bd.shift_lsbs = ctx->shift_lsbs + c;

1437 bd.opt_order = ctx->opt_order + c;

1438 bd.store_prev_samples = ctx->store_prev_samples + c;

1439 bd.use_ltp = ctx->use_ltp + c;

1440 bd.ltp_lag = ctx->ltp_lag + c;

1441 bd.ltp_gain = ctx->ltp_gain[c];

1442 bd.lpc_cof = ctx->lpc_cof[c];

1443 bd.quant_cof = ctx->quant_cof[c];

1444 bd.raw_samples = ctx->raw_samples[c] + offset;

1445

1446 if ((ret = decode_block(ctx, &bd)) < 0)

1447 return ret;

1448 }

1449

1450 memset(reverted_channels, 0, avctx->channels * sizeof(*reverted_channels));

1451 offset += div_blocks[b];

1452 bd.ra_block = 0;

1453 }

1454

1455 // store carryover raw samples

1456 for (c = 0; c < avctx->channels; c++)

1457 memmove(ctx->raw_samples[c] - sconf->max_order,

1458 ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

1459 sizeof(*ctx->raw_samples[c]) * sconf->max_order);

1460 }

1461

1462 // TODO: read_diff_float_data

1463

1464 return 0;

1465 }

1466

1467

1468 /** Decode an ALS frame.

1469 */

1470 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,

1471 AVPacket *avpkt)

1472 {

1473 ALSDecContext *ctx = avctx->priv_data;

1474 AVFrame *frame = data;

1475 ALSSpecificConfig *sconf = &ctx->sconf;

1476 const uint8_t *buffer = avpkt->data;

1477 int buffer_size = avpkt->size;

1478 int invalid_frame, ret;

1479 unsigned int c, sample, ra_frame, bytes_read, shift;

1480

1481 if ((ret = init_get_bits8(&ctx->gb, buffer, buffer_size)) < 0)

1482 return ret;

1483

1484 // In the case that the distance between random access frames is set to zero

1485 // (sconf->ra_distance == 0) no frame is treated as a random access frame.

1486 // For the first frame, if prediction is used, all samples used from the

1487 // previous frame are assumed to be zero.

1488 ra_frame = sconf->ra_distance && !(ctx->frame_id % sconf->ra_distance);

1489

1490 // the last frame to decode might have a different length

1491 if (sconf->samples != 0xFFFFFFFF)

1492 ctx->cur_frame_length = FFMIN(sconf->samples - ctx->frame_id * (uint64_t) sconf->frame_length,

1493 sconf->frame_length);

1494 else

1495 ctx->cur_frame_length = sconf->frame_length;

1496

1497 // decode the frame data

1498 if ((invalid_frame = read_frame_data(ctx, ra_frame)) < 0)

1499 av_log(ctx->avctx, AV_LOG_WARNING,

1500 "Reading frame data failed. Skipping RA unit.\n");

1501

1502 ctx->frame_id++;

1503

1504 /* get output buffer */

1505 frame->nb_samples = ctx->cur_frame_length;

1506 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)

1507 return ret;

1508

1509 // transform decoded frame into output format

1510 #define INTERLEAVE_OUTPUT(bps) \

1511 { \

1512 int##bps##_t *dest = (int##bps##_t*)frame->data[0]; \

1513 shift = bps - ctx->avctx->bits_per_raw_sample; \

1514 if (!ctx->cs_switch) { \

1515 for (sample = 0; sample < ctx->cur_frame_length; sample++) \

1516 for (c = 0; c < avctx->channels; c++) \

1517 *dest++ = ctx->raw_samples[c][sample] << shift; \

1518 } else { \

1519 for (sample = 0; sample < ctx->cur_frame_length; sample++) \

1520 for (c = 0; c < avctx->channels; c++) \

1521 *dest++ = ctx->raw_samples[sconf->chan_pos[c]][sample] << shift; \

1522 } \

1523 }

1524

1525 if (ctx->avctx->bits_per_raw_sample <= 16) {

1526 INTERLEAVE_OUTPUT(16)

1527 } else {

1528 INTERLEAVE_OUTPUT(32)

1529 }

1530

1531 // update CRC

1532 if (sconf->crc_enabled && (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {

1533 int swap = HAVE_BIGENDIAN != sconf->msb_first;

1534

1535 if (ctx->avctx->bits_per_raw_sample == 24) {

1536 int32_t *src = (int32_t *)frame->data[0];

1537

1538 for (sample = 0;

1539 sample < ctx->cur_frame_length * avctx->channels;

1540 sample++) {

1541 int32_t v;

1542

1543 if (swap)

1544 v = av_bswap32(src[sample]);

1545 else

1546 v = src[sample];

1547 if (!HAVE_BIGENDIAN)

1548 v >>= 8;

1549

1550 ctx->crc = av_crc(ctx->crc_table, ctx->crc, (uint8_t*)(&v), 3);

1551 }

1552 } else {

1553 uint8_t *crc_source;

1554

1555 if (swap) {

1556 if (ctx->avctx->bits_per_raw_sample <= 16) {

1557 int16_t *src = (int16_t*) frame->data[0];

1558 int16_t *dest = (int16_t*) ctx->crc_buffer;

1559 for (sample = 0;

1560 sample < ctx->cur_frame_length * avctx->channels;

1561 sample++)

1562 *dest++ = av_bswap16(src[sample]);

1563 } else {

1564 ctx->bdsp.bswap_buf((uint32_t *) ctx->crc_buffer,

1565 (uint32_t *) frame->data[0],

1566 ctx->cur_frame_length * avctx->channels);

1567 }

1568 crc_source = ctx->crc_buffer;

1569 } else {

1570 crc_source = frame->data[0];

1571 }

1572

1573 ctx->crc = av_crc(ctx->crc_table, ctx->crc, crc_source,

1574 ctx->cur_frame_length * avctx->channels *

1575 av_get_bytes_per_sample(avctx->sample_fmt));

1576 }

1577

1578

1579 // check CRC sums if this is the last frame

1580 if (ctx->cur_frame_length != sconf->frame_length &&

1581 ctx->crc_org != ctx->crc) {

1582 av_log(avctx, AV_LOG_ERROR, "CRC error.\n");

1583 if (avctx->err_recognition & AV_EF_EXPLODE)

1584 return AVERROR_INVALIDDATA;

1585 }

1586 }

1587

1588 *got_frame_ptr = 1;

1589

1590 bytes_read = invalid_frame ? buffer_size :

1591 (get_bits_count(&ctx->gb) + 7) >> 3;

1592

1593 return bytes_read;

1594 }

1595

1596

1597 /** Uninitialize the ALS decoder.

1598 */

1599 static av_cold int decode_end(AVCodecContext *avctx)

1600 {

1601 ALSDecContext *ctx = avctx->priv_data;

1602

1603 av_freep(&ctx->sconf.chan_pos);

1604

1605 ff_bgmc_end(&ctx->bgmc_lut, &ctx->bgmc_lut_status);

1606

1607 av_freep(&ctx->const_block);

1608 av_freep(&ctx->shift_lsbs);

1609 av_freep(&ctx->opt_order);

1610 av_freep(&ctx->store_prev_samples);

1611 av_freep(&ctx->use_ltp);

1612 av_freep(&ctx->ltp_lag);

1613 av_freep(&ctx->ltp_gain);

1614 av_freep(&ctx->ltp_gain_buffer);

1615 av_freep(&ctx->quant_cof);

1616 av_freep(&ctx->lpc_cof);

1617 av_freep(&ctx->quant_cof_buffer);

1618 av_freep(&ctx->lpc_cof_buffer);

1619 av_freep(&ctx->lpc_cof_reversed_buffer);

1620 av_freep(&ctx->prev_raw_samples);

1621 av_freep(&ctx->raw_samples);

1622 av_freep(&ctx->raw_buffer);

1623 av_freep(&ctx->chan_data);

1624 av_freep(&ctx->chan_data_buffer);

1625 av_freep(&ctx->reverted_channels);

1626 av_freep(&ctx->crc_buffer);

1627

1628 return 0;

1629 }

1630

1631

1632 /** Initialize the ALS decoder.

1633 */

1634 static av_cold int decode_init(AVCodecContext *avctx)

1635 {

1636 unsigned int c;

1637 unsigned int channel_size;

1638 int num_buffers, ret;

1639 ALSDecContext *ctx = avctx->priv_data;

1640 ALSSpecificConfig *sconf = &ctx->sconf;

1641 ctx->avctx = avctx;

1642

1643 if (!avctx->extradata) {

1644 av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n");

1645 return AVERROR_INVALIDDATA;

1646 }

1647

1648 if ((ret = read_specific_config(ctx)) < 0) {

1649 av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n");

1650 goto fail;

1651 }

1652

1653 if ((ret = check_specific_config(ctx)) < 0) {

1654 goto fail;

1655 }

1656

1657 if (sconf->bgmc) {

1658 ret = ff_bgmc_init(avctx, &ctx->bgmc_lut, &ctx->bgmc_lut_status);

1659 if (ret < 0)

1660 goto fail;

1661 }

1662 if (sconf->floating) {

1663 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;

1664 avctx->bits_per_raw_sample = 32;

1665 } else {

1666 avctx->sample_fmt = sconf->resolution > 1

1667 ? AV_SAMPLE_FMT_S32 : AV_SAMPLE_FMT_S16;

1668 avctx->bits_per_raw_sample = (sconf->resolution + 1) * 8;

1669 }

1670

1671 // set maximum Rice parameter for progressive decoding based on resolution

1672 // This is not specified in 14496-3 but actually done by the reference

1673 // codec RM22 revision 2.

1674 ctx->s_max = sconf->resolution > 1 ? 31 : 15;

1675

1676 // set lag value for long-term prediction

1677 ctx->ltp_lag_length = 8 + (avctx->sample_rate >= 96000) +

1678 (avctx->sample_rate >= 192000);

1679

1680 // allocate quantized parcor coefficient buffer

1681 num_buffers = sconf->mc_coding ? avctx->channels : 1;

1682

1683 ctx->quant_cof = av_malloc(sizeof(*ctx->quant_cof) * num_buffers);

1684 ctx->lpc_cof = av_malloc(sizeof(*ctx->lpc_cof) * num_buffers);

1685 ctx->quant_cof_buffer = av_malloc(sizeof(*ctx->quant_cof_buffer) *

1686 num_buffers * sconf->max_order);

1687 ctx->lpc_cof_buffer = av_malloc(sizeof(*ctx->lpc_cof_buffer) *

1688 num_buffers * sconf->max_order);

1689 ctx->lpc_cof_reversed_buffer = av_malloc(sizeof(*ctx->lpc_cof_buffer) *

1690 sconf->max_order);

1691

1692 if (!ctx->quant_cof || !ctx->lpc_cof ||

1693 !ctx->quant_cof_buffer || !ctx->lpc_cof_buffer ||

1694 !ctx->lpc_cof_reversed_buffer) {

1695 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

1696 ret = AVERROR(ENOMEM);

1697 goto fail;

1698 }

1699

1700 // assign quantized parcor coefficient buffers

1701 for (c = 0; c < num_buffers; c++) {

1702 ctx->quant_cof[c] = ctx->quant_cof_buffer + c * sconf->max_order;

1703 ctx->lpc_cof[c] = ctx->lpc_cof_buffer + c * sconf->max_order;

1704 }

1705

1706 // allocate and assign lag and gain data buffer for ltp mode

1707 ctx->const_block = av_malloc (sizeof(*ctx->const_block) * num_buffers);

1708 ctx->shift_lsbs = av_malloc (sizeof(*ctx->shift_lsbs) * num_buffers);

1709 ctx->opt_order = av_malloc (sizeof(*ctx->opt_order) * num_buffers);

1710 ctx->store_prev_samples = av_malloc(sizeof(*ctx->store_prev_samples) * num_buffers);

1711 ctx->use_ltp = av_mallocz(sizeof(*ctx->use_ltp) * num_buffers);

1712 ctx->ltp_lag = av_malloc (sizeof(*ctx->ltp_lag) * num_buffers);

1713 ctx->ltp_gain = av_malloc (sizeof(*ctx->ltp_gain) * num_buffers);

1714 ctx->ltp_gain_buffer = av_malloc (sizeof(*ctx->ltp_gain_buffer) *

1715 num_buffers * 5);

1716

1717 if (!ctx->const_block || !ctx->shift_lsbs ||

1718 !ctx->opt_order || !ctx->store_prev_samples ||

1719 !ctx->use_ltp || !ctx->ltp_lag ||

1720 !ctx->ltp_gain || !ctx->ltp_gain_buffer) {

1721 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

1722 ret = AVERROR(ENOMEM);

1723 goto fail;

1724 }

1725

1726 for (c = 0; c < num_buffers; c++)

1727 ctx->ltp_gain[c] = ctx->ltp_gain_buffer + c * 5;

1728

1729 // allocate and assign channel data buffer for mcc mode

1730 if (sconf->mc_coding) {

1731 ctx->chan_data_buffer = av_malloc(sizeof(*ctx->chan_data_buffer) *

1732 num_buffers * num_buffers);

1733 ctx->chan_data = av_malloc(sizeof(*ctx->chan_data) *

1734 num_buffers);

1735 ctx->reverted_channels = av_malloc(sizeof(*ctx->reverted_channels) *

1736 num_buffers);

1737

1738 if (!ctx->chan_data_buffer || !ctx->chan_data || !ctx->reverted_channels) {

1739 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

1740 ret = AVERROR(ENOMEM);

1741 goto fail;

1742 }

1743

1744 for (c = 0; c < num_buffers; c++)

1745 ctx->chan_data[c] = ctx->chan_data_buffer + c * num_buffers;

1746 } else {

1747 ctx->chan_data = NULL;

1748 ctx->chan_data_buffer = NULL;

1749 ctx->reverted_channels = NULL;

1750 }

1751

1752 channel_size = sconf->frame_length + sconf->max_order;

1753

1754 ctx->prev_raw_samples = av_malloc (sizeof(*ctx->prev_raw_samples) * sconf->max_order);

1755 ctx->raw_buffer = av_mallocz(sizeof(*ctx-> raw_buffer) * avctx->channels * channel_size);

1756 ctx->raw_samples = av_malloc (sizeof(*ctx-> raw_samples) * avctx->channels);

1757

1758 // allocate previous raw sample buffer

1759 if (!ctx->prev_raw_samples || !ctx->raw_buffer|| !ctx->raw_samples) {

1760 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

1761 ret = AVERROR(ENOMEM);

1762 goto fail;

1763 }

1764

1765 // assign raw samples buffers

1766 ctx->raw_samples[0] = ctx->raw_buffer + sconf->max_order;

1767 for (c = 1; c < avctx->channels; c++)

1768 ctx->raw_samples[c] = ctx->raw_samples[c - 1] + channel_size;

1769

1770 // allocate crc buffer

1771 if (HAVE_BIGENDIAN != sconf->msb_first && sconf->crc_enabled &&

1772 (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {

1773 ctx->crc_buffer = av_malloc(sizeof(*ctx->crc_buffer) *

1774 ctx->cur_frame_length *

1775 avctx->channels *

1776 av_get_bytes_per_sample(avctx->sample_fmt));

1777 if (!ctx->crc_buffer) {

1778 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

1779 ret = AVERROR(ENOMEM);

1780 goto fail;

1781 }

1782 }

1783

1784 ff_bswapdsp_init(&ctx->bdsp);

1785

1786 return 0;

1787

1788 fail:

1789 decode_end(avctx);

1790 return ret;

1791 }

1792

1793

1794 /** Flush (reset) the frame ID after seeking.

1795 */

1796 static av_cold void flush(AVCodecContext *avctx)

1797 {

1798 ALSDecContext *ctx = avctx->priv_data;

1799

1800 ctx->frame_id = 0;

1801 }

1802

1803

1804 AVCodec ff_als_decoder = {

1805 .name = "als",

1806 .long_name = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),

1807 .type = AVMEDIA_TYPE_AUDIO,

1808 .id = AV_CODEC_ID_MP4ALS,

1809 .priv_data_size = sizeof(ALSDecContext),

1810 .init = decode_init,

1811 .close = decode_end,

1812 .decode = decode_frame,

1813 .flush = flush,

1814 .capabilities = CODEC_CAP_SUBFRAMES | CODEC_CAP_DR1,

1815 };

Generated on Sun Mar 8 2015 02:34:47 for FFmpeg by doxygen 1.8.2