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 "avcodec.h"

29 #include "get_bits.h"

30 #include "unary.h"

31 #include "mpeg4audio.h"

32 #include "bytestream.h"

33 #include "bgmc.h"

34 #include "dsputil.h"

35 #include "internal.h"

36 #include "libavutil/samplefmt.h"

37 #include "libavutil/crc.h"

39 #include <stdint.h>

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

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

43 * by the encoder and stored in ALSSpecificConfig.

44 */

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

46 { {-52, 4}, {-29, 5}, {-31, 4}, { 19, 4}, {-16, 4},

47 { 12, 3}, { -7, 3}, { 9, 3}, { -5, 3}, { 6, 3},

48 { -4, 3}, { 3, 3}, { -3, 2}, { 3, 2}, { -2, 2},

49 { 3, 2}, { -1, 2}, { 2, 2}, { -1, 2}, { 2, 2} },

50 { {-58, 3}, {-42, 4}, {-46, 4}, { 37, 5}, {-36, 4},

51 { 29, 4}, {-29, 4}, { 25, 4}, {-23, 4}, { 20, 4},

52 {-17, 4}, { 16, 4}, {-12, 4}, { 12, 3}, {-10, 4},

53 { 7, 3}, { -4, 4}, { 3, 3}, { -1, 3}, { 1, 3} },

54 { {-59, 3}, {-45, 5}, {-50, 4}, { 38, 4}, {-39, 4},

55 { 32, 4}, {-30, 4}, { 25, 3}, {-23, 3}, { 20, 3},

56 {-20, 3}, { 16, 3}, {-13, 3}, { 10, 3}, { -7, 3},

57 { 3, 3}, { 0, 3}, { -1, 3}, { 2, 3}, { -1, 2} }

58 };

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

62 * To be indexed by the Rice coded indices.

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

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

65 */

66 static const int16_t parcor_scaled_values[] = {

67 -1048544 / 32, -1048288 / 32, -1047776 / 32, -1047008 / 32,

68 -1045984 / 32, -1044704 / 32, -1043168 / 32, -1041376 / 32,

69 -1039328 / 32, -1037024 / 32, -1034464 / 32, -1031648 / 32,

70 -1028576 / 32, -1025248 / 32, -1021664 / 32, -1017824 / 32,

71 -1013728 / 32, -1009376 / 32, -1004768 / 32, -999904 / 32,

72 -994784 / 32, -989408 / 32, -983776 / 32, -977888 / 32,

73 -971744 / 32, -965344 / 32, -958688 / 32, -951776 / 32,

74 -944608 / 32, -937184 / 32, -929504 / 32, -921568 / 32,

75 -913376 / 32, -904928 / 32, -896224 / 32, -887264 / 32,

76 -878048 / 32, -868576 / 32, -858848 / 32, -848864 / 32,

77 -838624 / 32, -828128 / 32, -817376 / 32, -806368 / 32,

78 -795104 / 32, -783584 / 32, -771808 / 32, -759776 / 32,

79 -747488 / 32, -734944 / 32, -722144 / 32, -709088 / 32,

80 -695776 / 32, -682208 / 32, -668384 / 32, -654304 / 32,

81 -639968 / 32, -625376 / 32, -610528 / 32, -595424 / 32,

82 -580064 / 32, -564448 / 32, -548576 / 32, -532448 / 32,

83 -516064 / 32, -499424 / 32, -482528 / 32, -465376 / 32,

84 -447968 / 32, -430304 / 32, -412384 / 32, -394208 / 32,

85 -375776 / 32, -357088 / 32, -338144 / 32, -318944 / 32,

86 -299488 / 32, -279776 / 32, -259808 / 32, -239584 / 32,

87 -219104 / 32, -198368 / 32, -177376 / 32, -156128 / 32,

88 -134624 / 32, -112864 / 32, -90848 / 32, -68576 / 32,

89 -46048 / 32, -23264 / 32, -224 / 32, 23072 / 32,

90 46624 / 32, 70432 / 32, 94496 / 32, 118816 / 32,

91 143392 / 32, 168224 / 32, 193312 / 32, 218656 / 32,

92 244256 / 32, 270112 / 32, 296224 / 32, 322592 / 32,

93 349216 / 32, 376096 / 32, 403232 / 32, 430624 / 32,

94 458272 / 32, 486176 / 32, 514336 / 32, 542752 / 32,

95 571424 / 32, 600352 / 32, 629536 / 32, 658976 / 32,

96 688672 / 32, 718624 / 32, 748832 / 32, 779296 / 32,

97 810016 / 32, 840992 / 32, 872224 / 32, 903712 / 32,

98 935456 / 32, 967456 / 32, 999712 / 32, 1032224 / 32

99 };

100

101

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

103 * To be indexed by the Rice coded indices.

104 */

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

106 { 0, 8, 16, 24},

107 {32, 40, 48, 56},

108 {64, 70, 76, 82},

109 {88, 92, 96, 100}

110 };

111

112

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

114 * To be indexed by the Rice coded indices.

115 */

116 static const int16_t mcc_weightings[] = {

117 204, 192, 179, 166, 153, 140, 128, 115,

118 102, 89, 76, 64, 51, 38, 25, 12,

119 0, -12, -25, -38, -51, -64, -76, -89,

120 -102, -115, -128, -140, -153, -166, -179, -192

121 };

122

123

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

125 */

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

127 { 74, 44, 25, 13, 7, 3},

128 { 68, 42, 24, 13, 7, 3},

129 { 58, 39, 23, 13, 7, 3},

130 {126, 70, 37, 19, 10, 5},

131 {132, 70, 37, 20, 10, 5},

132 {124, 70, 38, 20, 10, 5},

133 {120, 69, 37, 20, 11, 5},

134 {116, 67, 37, 20, 11, 5},

135 {108, 66, 36, 20, 10, 5},

136 {102, 62, 36, 20, 10, 5},

137 { 88, 58, 34, 19, 10, 5},

138 {162, 89, 49, 25, 13, 7},

139 {156, 87, 49, 26, 14, 7},

140 {150, 86, 47, 26, 14, 7},

141 {142, 84, 47, 26, 14, 7},

142 {131, 79, 46, 26, 14, 7}

143 };

144

145

146 enum RA_Flag {

147 RA_FLAG_NONE,

148 RA_FLAG_FRAMES,

149 RA_FLAG_HEADER

150 };

151

152

153 typedef struct {

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

176 } ALSSpecificConfig;

177

178

179 typedef struct {

180 int stop_flag;

181 int master_channel;

182 int time_diff_flag;

183 int time_diff_sign;

184 int time_diff_index;

185 int weighting[6];

186 } ALSChannelData;

187

188

189 typedef struct {

190 AVCodecContext *avctx;

191 ALSSpecificConfig sconf;

192 GetBitContext gb;

193 DSPContext dsp;

194 const AVCRC *crc_table;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

226 } ALSDecContext;

227

228

229 typedef struct {

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

245 } ALSBlockData;

246

247

248 static av_cold void dprint_specific_config(ALSDecContext *ctx)

249 {

250 #ifdef DEBUG

251 AVCodecContext *avctx = ctx->avctx;

252 ALSSpecificConfig *sconf = &ctx->sconf;

253

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

272 #endif

273 }

274

275

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

277 */

278 static av_cold int read_specific_config(ALSDecContext *ctx)

279 {

280 GetBitContext gb;

281 uint64_t ht_size;

282 int i, config_offset;

283 MPEG4AudioConfig m4ac;

284 ALSSpecificConfig *sconf = &ctx->sconf;

285 AVCodecContext *avctx = ctx->avctx;

286 uint32_t als_id, header_size, trailer_size;

287 int ret;

288

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

290 return ret;

291

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

293 avctx->extradata_size * 8, 1);

294

295 if (config_offset < 0)

296 return AVERROR_INVALIDDATA;

297

298 skip_bits_long(&gb, config_offset);

299

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

301 return AVERROR_INVALIDDATA;

302

303 // read the fixed items

304 als_id = get_bits_long(&gb, 32);

305 avctx->sample_rate = m4ac.sample_rate;

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

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

308 avctx->channels = m4ac.channels;

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

331 skip_bits1(&gb); // skip aux_data_enabled

332

333

334 // check for ALSSpecificConfig struct

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

336 return AVERROR_INVALIDDATA;

337

338 ctx->cur_frame_length = sconf->frame_length;

339

340 // read channel config

341 if (sconf->chan_config)

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

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

344

345

346 // read channel sorting

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

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

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

350 if (get_bits_left(&gb) < bits_needed)

351 return AVERROR_INVALIDDATA;

352

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

354 return AVERROR(ENOMEM);

355

356 ctx->cs_switch = 1;

357

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

359 int idx;

360

361 idx = get_bits(&gb, chan_pos_bits);

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

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

364 ctx->cs_switch = 0;

365 break;

366 }

367 sconf->chan_pos[idx] = i;

368 }

369

370 align_get_bits(&gb);

371 }

372

373

374 // read fixed header and trailer sizes,

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

376 if (get_bits_left(&gb) < 64)

377 return AVERROR_INVALIDDATA;

378

379 header_size = get_bits_long(&gb, 32);

380 trailer_size = get_bits_long(&gb, 32);

381 if (header_size == 0xFFFFFFFF)

382 header_size = 0;

383 if (trailer_size == 0xFFFFFFFF)

384 trailer_size = 0;

385

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

387

388

389 // skip the header and trailer data

390 if (get_bits_left(&gb) < ht_size)

391 return AVERROR_INVALIDDATA;

392

393 if (ht_size > INT32_MAX)

394 return AVERROR_PATCHWELCOME;

395

396 skip_bits_long(&gb, ht_size);

397

398

399 // initialize CRC calculation

400 if (sconf->crc_enabled) {

401 if (get_bits_left(&gb) < 32)

402 return AVERROR_INVALIDDATA;

403

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

405 ctx->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);

406 ctx->crc = 0xFFFFFFFF;

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

408 } else

409 skip_bits_long(&gb, 32);

410 }

411

412

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

414

415 dprint_specific_config(ctx);

416

417 return 0;

418 }

419

420

421 /** Check the ALSSpecificConfig for unsupported features.

422 */

423 static int check_specific_config(ALSDecContext *ctx)

424 {

425 ALSSpecificConfig *sconf = &ctx->sconf;

426 int error = 0;

427

428 // report unsupported feature and set error value

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

430 { \

431 if (cond) { \

432 avpriv_report_missing_feature(ctx->avctx, \

433 str); \

434 error = errval; \

435 } \

436 }

437

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

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

440

441 return error;

442 }

443

444

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

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

447 */

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

449 unsigned int div, unsigned int **div_blocks,

450 unsigned int *num_blocks)

451 {

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

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

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

455 n *= 2;

456 div += 1;

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

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

459 } else {

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

461 // (bit implicitly not set)

462 **div_blocks = div;

463 (*div_blocks)++;

464 (*num_blocks)++;

465 }

466 }

467

468

469 /** Read and decode a Rice codeword.

470 */

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

472 {

473 int max = get_bits_left(gb) - k;

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

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

476

477 if (k > 1) {

478 q <<= (k - 1);

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

480 } else if (!k) {

481 q >>= 1;

482 }

483 return r ? q : ~q;

484 }

485

486

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

488 */

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

490 {

491 int i, j;

492

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

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

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

496 cof[i] += tmp1;

497 }

498 if (i == j)

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

500

501 cof[k] = par[k];

502 }

503

504

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

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

507 * actual number of samples.

508 */

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

510 uint32_t *bs_info)

511 {

512 ALSSpecificConfig *sconf = &ctx->sconf;

513 GetBitContext *gb = &ctx->gb;

514 unsigned int *ptr_div_blocks = div_blocks;

515 unsigned int b;

516

517 if (sconf->block_switching) {

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

519 *bs_info = get_bits_long(gb, bs_info_len);

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

521 }

522

523 ctx->num_blocks = 0;

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

525

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

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

528 // more samples than available to be consistent.

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

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

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

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

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

534 // codec RM22 revision 2.

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

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

537 // of 14496-3.

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

539 // frame.

540

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

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

543

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

545 unsigned int remaining = ctx->cur_frame_length;

546

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

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

549 div_blocks[b] = remaining;

550 ctx->num_blocks = b + 1;

551 break;

552 }

553

554 remaining -= div_blocks[b];

555 }

556 }

557 }

558

559

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

561 */

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

563 {

564 ALSSpecificConfig *sconf = &ctx->sconf;

565 AVCodecContext *avctx = ctx->avctx;

566 GetBitContext *gb = &ctx->gb;

567

568 if (bd->block_length <= 0)

569 return AVERROR_INVALIDDATA;

570

571 *bd->raw_samples = 0;

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

573 bd->js_blocks = get_bits1(gb);

574

575 // skip 5 reserved bits

576 skip_bits(gb, 5);

577

578 if (*bd->const_block) {

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

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

581 }

582

583 // ensure constant block decoding by reusing this field

584 *bd->const_block = 1;

585

586 return 0;

587 }

588

589

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

591 */

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

593 {

594 int smp = bd->block_length - 1;

595 int32_t val = *bd->raw_samples;

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

597

598 // write raw samples into buffer

599 for (; smp; smp--)

600 *dst++ = val;

601 }

602

603

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

605 */

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

607 {

608 ALSSpecificConfig *sconf = &ctx->sconf;

609 AVCodecContext *avctx = ctx->avctx;

610 GetBitContext *gb = &ctx->gb;

611 unsigned int k;

612 unsigned int s[8];

613 unsigned int sx[8];

614 unsigned int sub_blocks, log2_sub_blocks, sb_length;

615 unsigned int start = 0;

616 unsigned int opt_order;

617 int sb;

618 int32_t *quant_cof = bd->quant_cof;

619 int32_t *current_res;

620

621

622 // ensure variable block decoding by reusing this field

623 *bd->const_block = 0;

624

625 *bd->opt_order = 1;

626 bd->js_blocks = get_bits1(gb);

627

628 opt_order = *bd->opt_order;

629

630 // determine the number of subblocks for entropy decoding

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

632 log2_sub_blocks = 0;

633 } else {

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

635 log2_sub_blocks = get_bits(gb, 2);

636 else

637 log2_sub_blocks = 2 * get_bits1(gb);

638 }

639

640 sub_blocks = 1 << log2_sub_blocks;

641

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

643 // block_length must be evenly divisible by sub_blocks

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

645 av_log(avctx, AV_LOG_WARNING,

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

647 return AVERROR_INVALIDDATA;

648 }

649

650 sb_length = bd->block_length >> log2_sub_blocks;

651

652 if (sconf->bgmc) {

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

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

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

656

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

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

659 s [k] >>= 4;

660 }

661 } else {

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

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

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

665 }

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

667 if (s[k] > 32) {

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

669 return AVERROR_INVALIDDATA;

670 }

671

672 if (get_bits1(gb))

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

674

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

676

677

678 if (!sconf->rlslms) {

679 if (sconf->adapt_order) {

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

681 2, sconf->max_order + 1));

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

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

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

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

686 return AVERROR_INVALIDDATA;

687 }

688 } else {

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

690 }

691

692 opt_order = *bd->opt_order;

693

694 if (opt_order) {

695 int add_base;

696

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

698 add_base = 0x7F;

699

700 // read coefficient 0

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

702

703 // read coefficient 1

704 if (opt_order > 1)

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

706

707 // read coefficients 2 to opt_order

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

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

710 } else {

711 int k_max;

712 add_base = 1;

713

714 // read coefficient 0 to 19

715 k_max = FFMIN(opt_order, 20);

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

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

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

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

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

721 av_log(avctx, AV_LOG_ERROR, "quant_cof %d is out of range.\n", quant_cof[k]);

722 return AVERROR_INVALIDDATA;

723 }

724 }

725

726 // read coefficients 20 to 126

727 k_max = FFMIN(opt_order, 127);

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

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

730

731 // read coefficients 127 to opt_order

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

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

734

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

736

737 if (opt_order > 1)

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

739 }

740

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

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

743 }

744 }

745

746 // read LTP gain and lag values

747 if (sconf->long_term_prediction) {

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

749

750 if (*bd->use_ltp) {

751 int r, c;

752

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

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

755

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

757 c = get_bits(gb, 2);

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

759

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

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

762

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

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

765 }

766 }

767

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

769 if (bd->ra_block) {

770 if (opt_order)

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

772 if (opt_order > 1)

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

774 if (opt_order > 2)

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

776

777 start = FFMIN(opt_order, 3);

778 }

779

780 // read all residuals

781 if (sconf->bgmc) {

782 int delta[8];

783 unsigned int k [8];

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

785

786 // read most significant bits

787 unsigned int high;

788 unsigned int low;

789 unsigned int value;

790

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

792

793 current_res = bd->raw_samples + start;

794

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

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

797

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

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

800

801 ff_bgmc_decode(gb, sb_len, current_res,

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

803

804 current_res += sb_len;

805 }

806

807 ff_bgmc_decode_end(gb);

808

809

810 // read least significant bits and tails

811 current_res = bd->raw_samples + start;

812

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

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

815 unsigned int cur_k = k[sb];

816 unsigned int cur_s = s[sb];

817

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

819 int32_t res = *current_res;

820

821 if (res == cur_tail_code) {

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

823 << (5 - delta[sb]);

824

825 res = decode_rice(gb, cur_s);

826

827 if (res >= 0) {

828 res += (max_msb ) << cur_k;

829 } else {

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

831 }

832 } else {

833 if (res > cur_tail_code)

834 res--;

835

836 if (res & 1)

837 res = -res;

838

839 res >>= 1;

840

841 if (cur_k) {

842 res <<= cur_k;

843 res |= get_bits_long(gb, cur_k);

844 }

845 }

846

847 *current_res++ = res;

848 }

849 }

850 } else {

851 current_res = bd->raw_samples + start;

852

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

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

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

856 }

857

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

859 align_get_bits(gb);

860

861 return 0;

862 }

863

864

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

866 */

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

868 {

869 ALSSpecificConfig *sconf = &ctx->sconf;

870 unsigned int block_length = bd->block_length;

871 unsigned int smp = 0;

872 unsigned int k;

873 int opt_order = *bd->opt_order;

874 int sb;

875 int64_t y;

876 int32_t *quant_cof = bd->quant_cof;

877 int32_t *lpc_cof = bd->lpc_cof;

878 int32_t *raw_samples = bd->raw_samples;

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

880 int32_t *lpc_cof_reversed = ctx->lpc_cof_reversed_buffer;

881

882 // reverse long-term prediction

883 if (*bd->use_ltp) {

884 int ltp_smp;

885

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

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

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

889 int end = center + 3;

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

891 int base;

892

893 y = 1 << 6;

894

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

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

897

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

899 }

900 }

901

902 // reconstruct all samples from residuals

903 if (bd->ra_block) {

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

905 y = 1 << 19;

906

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

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

909

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

911 parcor_to_lpc(smp, quant_cof, lpc_cof);

912 }

913 } else {

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

915 parcor_to_lpc(k, quant_cof, lpc_cof);

916

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

918 if (*bd->store_prev_samples)

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

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

921

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

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

924 int32_t *left, *right;

925

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

927 left = raw_samples;

928 right = bd->raw_other;

929 } else { // D = R - L

930 left = bd->raw_other;

931 right = raw_samples;

932 }

933

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

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

936 }

937

938 // reconstruct shifted signal

939 if (*bd->shift_lsbs)

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

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

942 }

943

944 // reverse linear prediction coefficients for efficiency

945 lpc_cof = lpc_cof + opt_order;

946

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

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

949

950 // reconstruct raw samples

951 raw_samples = bd->raw_samples + smp;

952 lpc_cof = lpc_cof_reversed + opt_order;

953

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

955 y = 1 << 19;

956

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

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

959

960 *raw_samples -= y >> 20;

961 }

962

963 raw_samples = bd->raw_samples;

964

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

966 if (*bd->store_prev_samples)

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

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

969

970 return 0;

971 }

972

973

974 /** Read the block data.

975 */

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

977 {

978 int ret;

979 GetBitContext *gb = &ctx->gb;

980

981 *bd->shift_lsbs = 0;

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

983 if (get_bits1(gb)) {

984 ret = read_var_block_data(ctx, bd);

985 } else {

986 ret = read_const_block_data(ctx, bd);

987 }

988

989 return ret;

990 }

991

992

993 /** Decode the block data.

994 */

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

996 {

997 unsigned int smp;

998 int ret = 0;

999

1000 // read block type flag and read the samples accordingly

1001 if (*bd->const_block)

1002 decode_const_block_data(ctx, bd);

1003 else

1004 ret = decode_var_block_data(ctx, bd); // always return 0

1005

1006 if (ret < 0)

1007 return ret;

1008

1009 // TODO: read RLSLMS extension data

1010

1011 if (*bd->shift_lsbs)

1012 for (smp = 0; smp < bd->block_length; smp++)

1013 bd->raw_samples[smp] <<= *bd->shift_lsbs;

1014

1015 return 0;

1016 }

1017

1018

1019 /** Read and decode block data successively.

1020 */

1021 static int read_decode_block(ALSDecContext *ctx, ALSBlockData *bd)

1022 {

1023 int ret;

1024

1025 if ((ret = read_block(ctx, bd)) < 0)

1026 return ret;

1027

1028 return decode_block(ctx, bd);

1029 }

1030

1031

1032 /** Compute the number of samples left to decode for the current frame and

1033 * sets these samples to zero.

1034 */

1035 static void zero_remaining(unsigned int b, unsigned int b_max,

1036 const unsigned int *div_blocks, int32_t *buf)

1037 {

1038 unsigned int count = 0;

1039

1040 while (b < b_max)

1041 count += div_blocks[b++];

1042

1043 if (count)

1044 memset(buf, 0, sizeof(*buf) * count);

1045 }

1046

1047

1048 /** Decode blocks independently.

1049 */

1050 static int decode_blocks_ind(ALSDecContext *ctx, unsigned int ra_frame,

1051 unsigned int c, const unsigned int *div_blocks,

1052 unsigned int *js_blocks)

1053 {

1054 int ret;

1055 unsigned int b;

1056 ALSBlockData bd = { 0 };

1057

1058 bd.ra_block = ra_frame;

1059 bd.const_block = ctx->const_block;

1060 bd.shift_lsbs = ctx->shift_lsbs;

1061 bd.opt_order = ctx->opt_order;

1062 bd.store_prev_samples = ctx->store_prev_samples;

1063 bd.use_ltp = ctx->use_ltp;

1064 bd.ltp_lag = ctx->ltp_lag;

1065 bd.ltp_gain = ctx->ltp_gain[0];

1066 bd.quant_cof = ctx->quant_cof[0];

1067 bd.lpc_cof = ctx->lpc_cof[0];

1068 bd.prev_raw_samples = ctx->prev_raw_samples;

1069 bd.raw_samples = ctx->raw_samples[c];

1070

1071

1072 for (b = 0; b < ctx->num_blocks; b++) {

1073 bd.block_length = div_blocks[b];

1074

1075 if ((ret = read_decode_block(ctx, &bd)) < 0) {

1076 // damaged block, write zero for the rest of the frame

1077 zero_remaining(b, ctx->num_blocks, div_blocks, bd.raw_samples);

1078 return ret;

1079 }

1080 bd.raw_samples += div_blocks[b];

1081 bd.ra_block = 0;

1082 }

1083

1084 return 0;

1085 }

1086

1087

1088 /** Decode blocks dependently.

1089 */

1090 static int decode_blocks(ALSDecContext *ctx, unsigned int ra_frame,

1091 unsigned int c, const unsigned int *div_blocks,

1092 unsigned int *js_blocks)

1093 {

1094 ALSSpecificConfig *sconf = &ctx->sconf;

1095 unsigned int offset = 0;

1096 unsigned int b;

1097 int ret;

1098 ALSBlockData bd[2] = { { 0 } };

1099

1100 bd[0].ra_block = ra_frame;

1101 bd[0].const_block = ctx->const_block;

1102 bd[0].shift_lsbs = ctx->shift_lsbs;

1103 bd[0].opt_order = ctx->opt_order;

1104 bd[0].store_prev_samples = ctx->store_prev_samples;

1105 bd[0].use_ltp = ctx->use_ltp;

1106 bd[0].ltp_lag = ctx->ltp_lag;

1107 bd[0].ltp_gain = ctx->ltp_gain[0];

1108 bd[0].quant_cof = ctx->quant_cof[0];

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

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

1111 bd[0].js_blocks = *js_blocks;

1112

1113 bd[1].ra_block = ra_frame;

1114 bd[1].const_block = ctx->const_block;

1115 bd[1].shift_lsbs = ctx->shift_lsbs;

1116 bd[1].opt_order = ctx->opt_order;

1117 bd[1].store_prev_samples = ctx->store_prev_samples;

1118 bd[1].use_ltp = ctx->use_ltp;

1119 bd[1].ltp_lag = ctx->ltp_lag;

1120 bd[1].ltp_gain = ctx->ltp_gain[0];

1121 bd[1].quant_cof = ctx->quant_cof[0];

1122 bd[1].lpc_cof = ctx->lpc_cof[0];

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

1124 bd[1].js_blocks = *(js_blocks + 1);

1125

1126 // decode all blocks

1127 for (b = 0; b < ctx->num_blocks; b++) {

1128 unsigned int s;

1129

1130 bd[0].block_length = div_blocks[b];

1131 bd[1].block_length = div_blocks[b];

1132

1133 bd[0].raw_samples = ctx->raw_samples[c ] + offset;

1134 bd[1].raw_samples = ctx->raw_samples[c + 1] + offset;

1135

1136 bd[0].raw_other = bd[1].raw_samples;

1137 bd[1].raw_other = bd[0].raw_samples;

1138

1139 if ((ret = read_decode_block(ctx, &bd[0])) < 0 ||

1140 (ret = read_decode_block(ctx, &bd[1])) < 0)

1141 goto fail;

1142

1143 // reconstruct joint-stereo blocks

1144 if (bd[0].js_blocks) {

1145 if (bd[1].js_blocks)

1146 av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel pair.\n");

1147

1148 for (s = 0; s < div_blocks[b]; s++)

1149 bd[0].raw_samples[s] = bd[1].raw_samples[s] - bd[0].raw_samples[s];

1150 } else if (bd[1].js_blocks) {

1151 for (s = 0; s < div_blocks[b]; s++)

1152 bd[1].raw_samples[s] = bd[1].raw_samples[s] + bd[0].raw_samples[s];

1153 }

1154

1155 offset += div_blocks[b];

1156 bd[0].ra_block = 0;

1157 bd[1].ra_block = 0;

1158 }

1159

1160 // store carryover raw samples,

1161 // the others channel raw samples are stored by the calling function.

1162 memmove(ctx->raw_samples[c] - sconf->max_order,

1163 ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

1164 sizeof(*ctx->raw_samples[c]) * sconf->max_order);

1165

1166 return 0;

1167 fail:

1168 // damaged block, write zero for the rest of the frame

1169 zero_remaining(b, ctx->num_blocks, div_blocks, bd[0].raw_samples);

1170 zero_remaining(b, ctx->num_blocks, div_blocks, bd[1].raw_samples);

1171 return ret;

1172 }

1173

1174 static inline int als_weighting(GetBitContext *gb, int k, int off)

1175 {

1176 int idx = av_clip(decode_rice(gb, k) + off,

1177 0, FF_ARRAY_ELEMS(mcc_weightings) - 1);

1178 return mcc_weightings[idx];

1179 }

1180

1181 /** Read the channel data.

1182 */

1183 static int read_channel_data(ALSDecContext *ctx, ALSChannelData *cd, int c)

1184 {

1185 GetBitContext *gb = &ctx->gb;

1186 ALSChannelData *current = cd;

1187 unsigned int channels = ctx->avctx->channels;

1188 int entries = 0;

1189

1190 while (entries < channels && !(current->stop_flag = get_bits1(gb))) {

1191 current->master_channel = get_bits_long(gb, av_ceil_log2(channels));

1192

1193 if (current->master_channel >= channels) {

1194 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid master channel.\n");

1195 return AVERROR_INVALIDDATA;

1196 }

1197

1198 if (current->master_channel != c) {

1199 current->time_diff_flag = get_bits1(gb);

1200 current->weighting[0] = als_weighting(gb, 1, 16);

1201 current->weighting[1] = als_weighting(gb, 2, 14);

1202 current->weighting[2] = als_weighting(gb, 1, 16);

1203

1204 if (current->time_diff_flag) {

1205 current->weighting[3] = als_weighting(gb, 1, 16);

1206 current->weighting[4] = als_weighting(gb, 1, 16);

1207 current->weighting[5] = als_weighting(gb, 1, 16);

1208

1209 current->time_diff_sign = get_bits1(gb);

1210 current->time_diff_index = get_bits(gb, ctx->ltp_lag_length - 3) + 3;

1211 }

1212 }

1213

1214 current++;

1215 entries++;

1216 }

1217

1218 if (entries == channels) {

1219 av_log(ctx->avctx, AV_LOG_ERROR, "Damaged channel data.\n");

1220 return AVERROR_INVALIDDATA;

1221 }

1222

1223 align_get_bits(gb);

1224 return 0;

1225 }

1226

1227

1228 /** Recursively reverts the inter-channel correlation for a block.

1229 */

1230 static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,

1231 ALSChannelData **cd, int *reverted,

1232 unsigned int offset, int c)

1233 {

1234 ALSChannelData *ch = cd[c];

1235 unsigned int dep = 0;

1236 unsigned int channels = ctx->avctx->channels;

1237

1238 if (reverted[c])

1239 return 0;

1240

1241 reverted[c] = 1;

1242

1243 while (dep < channels && !ch[dep].stop_flag) {

1244 revert_channel_correlation(ctx, bd, cd, reverted, offset,

1245 ch[dep].master_channel);

1246

1247 dep++;

1248 }

1249

1250 if (dep == channels) {

1251 av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation.\n");

1252 return AVERROR_INVALIDDATA;

1253 }

1254

1255 bd->const_block = ctx->const_block + c;

1256 bd->shift_lsbs = ctx->shift_lsbs + c;

1257 bd->opt_order = ctx->opt_order + c;

1258 bd->store_prev_samples = ctx->store_prev_samples + c;

1259 bd->use_ltp = ctx->use_ltp + c;

1260 bd->ltp_lag = ctx->ltp_lag + c;

1261 bd->ltp_gain = ctx->ltp_gain[c];

1262 bd->lpc_cof = ctx->lpc_cof[c];

1263 bd->quant_cof = ctx->quant_cof[c];

1264 bd->raw_samples = ctx->raw_samples[c] + offset;

1265

1266 dep = 0;

1267 while (!ch[dep].stop_flag) {

1268 unsigned int smp;

1269 unsigned int begin = 1;

1270 unsigned int end = bd->block_length - 1;

1271 int64_t y;

1272 int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;

1273

1274 if (ch[dep].time_diff_flag) {

1275 int t = ch[dep].time_diff_index;

1276

1277 if (ch[dep].time_diff_sign) {

1278 t = -t;

1279 begin -= t;

1280 } else {

1281 end -= t;

1282 }

1283

1284 for (smp = begin; smp < end; smp++) {

1285 y = (1 << 6) +

1286 MUL64(ch[dep].weighting[0], master[smp - 1 ]) +

1287 MUL64(ch[dep].weighting[1], master[smp ]) +

1288 MUL64(ch[dep].weighting[2], master[smp + 1 ]) +

1289 MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +

1290 MUL64(ch[dep].weighting[4], master[smp + t]) +

1291 MUL64(ch[dep].weighting[5], master[smp + 1 + t]);

1292

1293 bd->raw_samples[smp] += y >> 7;

1294 }

1295 } else {

1296 for (smp = begin; smp < end; smp++) {

1297 y = (1 << 6) +

1298 MUL64(ch[dep].weighting[0], master[smp - 1]) +

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

1300 MUL64(ch[dep].weighting[2], master[smp + 1]);

1301

1302 bd->raw_samples[smp] += y >> 7;

1303 }

1304 }

1305

1306 dep++;

1307 }

1308

1309 return 0;

1310 }

1311

1312

1313 /** Read the frame data.

1314 */

1315 static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)

1316 {

1317 ALSSpecificConfig *sconf = &ctx->sconf;

1318 AVCodecContext *avctx = ctx->avctx;

1319 GetBitContext *gb = &ctx->gb;

1320 unsigned int div_blocks[32]; ///< block sizes.

1321 unsigned int c;

1322 unsigned int js_blocks[2];

1323 uint32_t bs_info = 0;

1324 int ret;

1325

1326 // skip the size of the ra unit if present in the frame

1327 if (sconf->ra_flag == RA_FLAG_FRAMES && ra_frame)

1328 skip_bits_long(gb, 32);

1329

1330 if (sconf->mc_coding && sconf->joint_stereo) {

1331 ctx->js_switch = get_bits1(gb);

1332 align_get_bits(gb);

1333 }

1334

1335 if (!sconf->mc_coding || ctx->js_switch) {

1336 int independent_bs = !sconf->joint_stereo;

1337

1338 for (c = 0; c < avctx->channels; c++) {

1339 js_blocks[0] = 0;

1340 js_blocks[1] = 0;

1341

1342 get_block_sizes(ctx, div_blocks, &bs_info);

1343

1344 // if joint_stereo and block_switching is set, independent decoding

1345 // is signaled via the first bit of bs_info

1346 if (sconf->joint_stereo && sconf->block_switching)

1347 if (bs_info >> 31)

1348 independent_bs = 2;

1349

1350 // if this is the last channel, it has to be decoded independently

1351 if (c == avctx->channels - 1)

1352 independent_bs = 1;

1353

1354 if (independent_bs) {

1355 ret = decode_blocks_ind(ctx, ra_frame, c,

1356 div_blocks, js_blocks);

1357 if (ret < 0)

1358 return ret;

1359 independent_bs--;

1360 } else {

1361 ret = decode_blocks(ctx, ra_frame, c, div_blocks, js_blocks);

1362 if (ret < 0)

1363 return ret;

1364

1365 c++;

1366 }

1367

1368 // store carryover raw samples

1369 memmove(ctx->raw_samples[c] - sconf->max_order,

1370 ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

1371 sizeof(*ctx->raw_samples[c]) * sconf->max_order);

1372 }

1373 } else { // multi-channel coding

1374 ALSBlockData bd = { 0 };

1375 int b, ret;

1376 int *reverted_channels = ctx->reverted_channels;

1377 unsigned int offset = 0;

1378

1379 for (c = 0; c < avctx->channels; c++)

1380 if (ctx->chan_data[c] < ctx->chan_data_buffer) {

1381 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid channel data.\n");

1382 return AVERROR_INVALIDDATA;

1383 }

1384

1385 memset(reverted_channels, 0, sizeof(*reverted_channels) * avctx->channels);

1386

1387 bd.ra_block = ra_frame;

1388 bd.prev_raw_samples = ctx->prev_raw_samples;

1389

1390 get_block_sizes(ctx, div_blocks, &bs_info);

1391

1392 for (b = 0; b < ctx->num_blocks; b++) {

1393 bd.block_length = div_blocks[b];

1394

1395 for (c = 0; c < avctx->channels; c++) {

1396 bd.const_block = ctx->const_block + c;

1397 bd.shift_lsbs = ctx->shift_lsbs + c;

1398 bd.opt_order = ctx->opt_order + c;

1399 bd.store_prev_samples = ctx->store_prev_samples + c;

1400 bd.use_ltp = ctx->use_ltp + c;

1401 bd.ltp_lag = ctx->ltp_lag + c;

1402 bd.ltp_gain = ctx->ltp_gain[c];

1403 bd.lpc_cof = ctx->lpc_cof[c];

1404 bd.quant_cof = ctx->quant_cof[c];

1405 bd.raw_samples = ctx->raw_samples[c] + offset;

1406 bd.raw_other = NULL;

1407

1408 if ((ret = read_block(ctx, &bd)) < 0)

1409 return ret;

1410 if ((ret = read_channel_data(ctx, ctx->chan_data[c], c)) < 0)

1411 return ret;

1412 }

1413

1414 for (c = 0; c < avctx->channels; c++) {

1415 ret = revert_channel_correlation(ctx, &bd, ctx->chan_data,

1416 reverted_channels, offset, c);

1417 if (ret < 0)

1418 return ret;

1419 }

1420 for (c = 0; c < avctx->channels; c++) {

1421 bd.const_block = ctx->const_block + c;

1422 bd.shift_lsbs = ctx->shift_lsbs + c;

1423 bd.opt_order = ctx->opt_order + c;

1424 bd.store_prev_samples = ctx->store_prev_samples + c;

1425 bd.use_ltp = ctx->use_ltp + c;

1426 bd.ltp_lag = ctx->ltp_lag + c;

1427 bd.ltp_gain = ctx->ltp_gain[c];

1428 bd.lpc_cof = ctx->lpc_cof[c];

1429 bd.quant_cof = ctx->quant_cof[c];

1430 bd.raw_samples = ctx->raw_samples[c] + offset;

1431

1432 if ((ret = decode_block(ctx, &bd)) < 0)

1433 return ret;

1434 }

1435

1436 memset(reverted_channels, 0, avctx->channels * sizeof(*reverted_channels));

1437 offset += div_blocks[b];

1438 bd.ra_block = 0;

1439 }

1440

1441 // store carryover raw samples

1442 for (c = 0; c < avctx->channels; c++)

1443 memmove(ctx->raw_samples[c] - sconf->max_order,

1444 ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,

1445 sizeof(*ctx->raw_samples[c]) * sconf->max_order);

1446 }

1447

1448 // TODO: read_diff_float_data

1449

1450 return 0;

1451 }

1452

1453

1454 /** Decode an ALS frame.

1455 */

1456 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,

1457 AVPacket *avpkt)

1458 {

1459 ALSDecContext *ctx = avctx->priv_data;

1460 AVFrame *frame = data;

1461 ALSSpecificConfig *sconf = &ctx->sconf;

1462 const uint8_t *buffer = avpkt->data;

1463 int buffer_size = avpkt->size;

1464 int invalid_frame, ret;

1465 unsigned int c, sample, ra_frame, bytes_read, shift;

1466

1467 init_get_bits(&ctx->gb, buffer, buffer_size * 8);

1468

1469 // In the case that the distance between random access frames is set to zero

1470 // (sconf->ra_distance == 0) no frame is treated as a random access frame.

1471 // For the first frame, if prediction is used, all samples used from the

1472 // previous frame are assumed to be zero.

1473 ra_frame = sconf->ra_distance && !(ctx->frame_id % sconf->ra_distance);

1474

1475 // the last frame to decode might have a different length

1476 if (sconf->samples != 0xFFFFFFFF)

1477 ctx->cur_frame_length = FFMIN(sconf->samples - ctx->frame_id * (uint64_t) sconf->frame_length,

1478 sconf->frame_length);

1479 else

1480 ctx->cur_frame_length = sconf->frame_length;

1481

1482 // decode the frame data

1483 if ((invalid_frame = read_frame_data(ctx, ra_frame)) < 0)

1484 av_log(ctx->avctx, AV_LOG_WARNING,

1485 "Reading frame data failed. Skipping RA unit.\n");

1486

1487 ctx->frame_id++;

1488

1489 /* get output buffer */

1490 frame->nb_samples = ctx->cur_frame_length;

1491 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)

1492 return ret;

1493

1494 // transform decoded frame into output format

1495 #define INTERLEAVE_OUTPUT(bps) \

1496 { \

1497 int##bps##_t *dest = (int##bps##_t*)frame->data[0]; \

1498 shift = bps - ctx->avctx->bits_per_raw_sample; \

1499 if (!ctx->cs_switch) { \

1500 for (sample = 0; sample < ctx->cur_frame_length; sample++) \

1501 for (c = 0; c < avctx->channels; c++) \

1502 *dest++ = ctx->raw_samples[c][sample] << shift; \

1503 } else { \

1504 for (sample = 0; sample < ctx->cur_frame_length; sample++) \

1505 for (c = 0; c < avctx->channels; c++) \

1506 *dest++ = ctx->raw_samples[sconf->chan_pos[c]][sample] << shift; \

1507 } \

1508 }

1509

1510 if (ctx->avctx->bits_per_raw_sample <= 16) {

1511 INTERLEAVE_OUTPUT(16)

1512 } else {

1513 INTERLEAVE_OUTPUT(32)

1514 }

1515

1516 // update CRC

1517 if (sconf->crc_enabled && (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {

1518 int swap = HAVE_BIGENDIAN != sconf->msb_first;

1519

1520 if (ctx->avctx->bits_per_raw_sample == 24) {

1521 int32_t *src = (int32_t *)frame->data[0];

1522

1523 for (sample = 0;

1524 sample < ctx->cur_frame_length * avctx->channels;

1525 sample++) {

1526 int32_t v;

1527

1528 if (swap)

1529 v = av_bswap32(src[sample]);

1530 else

1531 v = src[sample];

1532 if (!HAVE_BIGENDIAN)

1533 v >>= 8;

1534

1535 ctx->crc = av_crc(ctx->crc_table, ctx->crc, (uint8_t*)(&v), 3);

1536 }

1537 } else {

1538 uint8_t *crc_source;

1539

1540 if (swap) {

1541 if (ctx->avctx->bits_per_raw_sample <= 16) {

1542 int16_t *src = (int16_t*) frame->data[0];

1543 int16_t *dest = (int16_t*) ctx->crc_buffer;

1544 for (sample = 0;

1545 sample < ctx->cur_frame_length * avctx->channels;

1546 sample++)

1547 *dest++ = av_bswap16(src[sample]);

1548 } else {

1549 ctx->dsp.bswap_buf((uint32_t*)ctx->crc_buffer,

1550 (uint32_t *)frame->data[0],

1551 ctx->cur_frame_length * avctx->channels);

1552 }

1553 crc_source = ctx->crc_buffer;

1554 } else {

1555 crc_source = frame->data[0];

1556 }

1557

1558 ctx->crc = av_crc(ctx->crc_table, ctx->crc, crc_source,

1559 ctx->cur_frame_length * avctx->channels *

1560 av_get_bytes_per_sample(avctx->sample_fmt));

1561 }

1562

1563

1564 // check CRC sums if this is the last frame

1565 if (ctx->cur_frame_length != sconf->frame_length &&

1566 ctx->crc_org != ctx->crc) {

1567 av_log(avctx, AV_LOG_ERROR, "CRC error.\n");

1568 }

1569 }

1570

1571 *got_frame_ptr = 1;

1572

1573 bytes_read = invalid_frame ? buffer_size :

1574 (get_bits_count(&ctx->gb) + 7) >> 3;

1575

1576 return bytes_read;

1577 }

1578

1579

1580 /** Uninitialize the ALS decoder.

1581 */

1582 static av_cold int decode_end(AVCodecContext *avctx)

1583 {

1584 ALSDecContext *ctx = avctx->priv_data;

1585

1586 av_freep(&ctx->sconf.chan_pos);

1587

1588 ff_bgmc_end(&ctx->bgmc_lut, &ctx->bgmc_lut_status);

1589

1590 av_freep(&ctx->const_block);

1591 av_freep(&ctx->shift_lsbs);

1592 av_freep(&ctx->opt_order);

1593 av_freep(&ctx->store_prev_samples);

1594 av_freep(&ctx->use_ltp);

1595 av_freep(&ctx->ltp_lag);

1596 av_freep(&ctx->ltp_gain);

1597 av_freep(&ctx->ltp_gain_buffer);

1598 av_freep(&ctx->quant_cof);

1599 av_freep(&ctx->lpc_cof);

1600 av_freep(&ctx->quant_cof_buffer);

1601 av_freep(&ctx->lpc_cof_buffer);

1602 av_freep(&ctx->lpc_cof_reversed_buffer);

1603 av_freep(&ctx->prev_raw_samples);

1604 av_freep(&ctx->raw_samples);

1605 av_freep(&ctx->raw_buffer);

1606 av_freep(&ctx->chan_data);

1607 av_freep(&ctx->chan_data_buffer);

1608 av_freep(&ctx->reverted_channels);

1609 av_freep(&ctx->crc_buffer);

1610

1611 return 0;

1612 }

1613

1614

1615 /** Initialize the ALS decoder.

1616 */

1617 static av_cold int decode_init(AVCodecContext *avctx)

1618 {

1619 unsigned int c;

1620 unsigned int channel_size;

1621 int num_buffers, ret;

1622 ALSDecContext *ctx = avctx->priv_data;

1623 ALSSpecificConfig *sconf = &ctx->sconf;

1624 ctx->avctx = avctx;

1625

1626 if (!avctx->extradata) {

1627 av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n");

1628 return AVERROR_INVALIDDATA;

1629 }

1630

1631 if ((ret = read_specific_config(ctx)) < 0) {

1632 av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n");

1633 goto fail;

1634 }

1635

1636 if ((ret = check_specific_config(ctx)) < 0) {

1637 goto fail;

1638 }

1639

1640 if (sconf->bgmc) {

1641 ret = ff_bgmc_init(avctx, &ctx->bgmc_lut, &ctx->bgmc_lut_status);

1642 if (ret < 0)

1643 goto fail;

1644 }

1645 if (sconf->floating) {

1646 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;

1647 avctx->bits_per_raw_sample = 32;

1648 } else {

1649 avctx->sample_fmt = sconf->resolution > 1

1650 ? AV_SAMPLE_FMT_S32 : AV_SAMPLE_FMT_S16;

1651 avctx->bits_per_raw_sample = (sconf->resolution + 1) * 8;

1652 }

1653

1654 // set maximum Rice parameter for progressive decoding based on resolution

1655 // This is not specified in 14496-3 but actually done by the reference

1656 // codec RM22 revision 2.

1657 ctx->s_max = sconf->resolution > 1 ? 31 : 15;

1658

1659 // set lag value for long-term prediction

1660 ctx->ltp_lag_length = 8 + (avctx->sample_rate >= 96000) +

1661 (avctx->sample_rate >= 192000);

1662

1663 // allocate quantized parcor coefficient buffer

1664 num_buffers = sconf->mc_coding ? avctx->channels : 1;

1665

1666 ctx->quant_cof = av_malloc(sizeof(*ctx->quant_cof) * num_buffers);

1667 ctx->lpc_cof = av_malloc(sizeof(*ctx->lpc_cof) * num_buffers);

1668 ctx->quant_cof_buffer = av_malloc(sizeof(*ctx->quant_cof_buffer) *

1669 num_buffers * sconf->max_order);

1670 ctx->lpc_cof_buffer = av_malloc(sizeof(*ctx->lpc_cof_buffer) *

1671 num_buffers * sconf->max_order);

1672 ctx->lpc_cof_reversed_buffer = av_malloc(sizeof(*ctx->lpc_cof_buffer) *

1673 sconf->max_order);

1674

1675 if (!ctx->quant_cof || !ctx->lpc_cof ||

1676 !ctx->quant_cof_buffer || !ctx->lpc_cof_buffer ||

1677 !ctx->lpc_cof_reversed_buffer) {

1678 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

1679 ret = AVERROR(ENOMEM);

1680 goto fail;

1681 }

1682

1683 // assign quantized parcor coefficient buffers

1684 for (c = 0; c < num_buffers; c++) {

1685 ctx->quant_cof[c] = ctx->quant_cof_buffer + c * sconf->max_order;

1686 ctx->lpc_cof[c] = ctx->lpc_cof_buffer + c * sconf->max_order;

1687 }

1688

1689 // allocate and assign lag and gain data buffer for ltp mode

1690 ctx->const_block = av_malloc (sizeof(*ctx->const_block) * num_buffers);

1691 ctx->shift_lsbs = av_malloc (sizeof(*ctx->shift_lsbs) * num_buffers);

1692 ctx->opt_order = av_malloc (sizeof(*ctx->opt_order) * num_buffers);

1693 ctx->store_prev_samples = av_malloc(sizeof(*ctx->store_prev_samples) * num_buffers);

1694 ctx->use_ltp = av_mallocz(sizeof(*ctx->use_ltp) * num_buffers);

1695 ctx->ltp_lag = av_malloc (sizeof(*ctx->ltp_lag) * num_buffers);

1696 ctx->ltp_gain = av_malloc (sizeof(*ctx->ltp_gain) * num_buffers);

1697 ctx->ltp_gain_buffer = av_malloc (sizeof(*ctx->ltp_gain_buffer) *

1698 num_buffers * 5);

1699

1700 if (!ctx->const_block || !ctx->shift_lsbs ||

1701 !ctx->opt_order || !ctx->store_prev_samples ||

1702 !ctx->use_ltp || !ctx->ltp_lag ||

1703 !ctx->ltp_gain || !ctx->ltp_gain_buffer) {

1704 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

1705 ret = AVERROR(ENOMEM);

1706 goto fail;

1707 }

1708

1709 for (c = 0; c < num_buffers; c++)

1710 ctx->ltp_gain[c] = ctx->ltp_gain_buffer + c * 5;

1711

1712 // allocate and assign channel data buffer for mcc mode

1713 if (sconf->mc_coding) {

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

1715 num_buffers * num_buffers);

1716 ctx->chan_data = av_malloc(sizeof(*ctx->chan_data) *

1717 num_buffers);

1718 ctx->reverted_channels = av_malloc(sizeof(*ctx->reverted_channels) *

1719 num_buffers);

1720

1721 if (!ctx->chan_data_buffer || !ctx->chan_data || !ctx->reverted_channels) {

1722 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

1723 ret = AVERROR(ENOMEM);

1724 goto fail;

1725 }

1726

1727 for (c = 0; c < num_buffers; c++)

1728 ctx->chan_data[c] = ctx->chan_data_buffer + c * num_buffers;

1729 } else {

1730 ctx->chan_data = NULL;

1731 ctx->chan_data_buffer = NULL;

1732 ctx->reverted_channels = NULL;

1733 }

1734

1735 channel_size = sconf->frame_length + sconf->max_order;

1736

1737 ctx->prev_raw_samples = av_malloc (sizeof(*ctx->prev_raw_samples) * sconf->max_order);

1738 ctx->raw_buffer = av_mallocz(sizeof(*ctx-> raw_buffer) * avctx->channels * channel_size);

1739 ctx->raw_samples = av_malloc (sizeof(*ctx-> raw_samples) * avctx->channels);

1740

1741 // allocate previous raw sample buffer

1742 if (!ctx->prev_raw_samples || !ctx->raw_buffer|| !ctx->raw_samples) {

1743 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

1744 ret = AVERROR(ENOMEM);

1745 goto fail;

1746 }

1747

1748 // assign raw samples buffers

1749 ctx->raw_samples[0] = ctx->raw_buffer + sconf->max_order;

1750 for (c = 1; c < avctx->channels; c++)

1751 ctx->raw_samples[c] = ctx->raw_samples[c - 1] + channel_size;

1752

1753 // allocate crc buffer

1754 if (HAVE_BIGENDIAN != sconf->msb_first && sconf->crc_enabled &&

1755 (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {

1756 ctx->crc_buffer = av_malloc(sizeof(*ctx->crc_buffer) *

1757 ctx->cur_frame_length *

1758 avctx->channels *

1759 av_get_bytes_per_sample(avctx->sample_fmt));

1760 if (!ctx->crc_buffer) {

1761 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");

1762 ret = AVERROR(ENOMEM);

1763 goto fail;

1764 }

1765 }

1766

1767 ff_dsputil_init(&ctx->dsp, avctx);

1768

1769 return 0;

1770

1771 fail:

1772 decode_end(avctx);

1773 return ret;

1774 }

1775

1776

1777 /** Flush (reset) the frame ID after seeking.

1778 */

1779 static av_cold void flush(AVCodecContext *avctx)

1780 {

1781 ALSDecContext *ctx = avctx->priv_data;

1782

1783 ctx->frame_id = 0;

1784 }

1785

1786

1787 AVCodec ff_als_decoder = {

1788 .name = "als",

1789 .long_name = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),

1790 .type = AVMEDIA_TYPE_AUDIO,

1791 .id = AV_CODEC_ID_MP4ALS,

1792 .priv_data_size = sizeof(ALSDecContext),

1793 .init = decode_init,

1794 .close = decode_end,

1795 .decode = decode_frame,

1796 .flush = flush,

1797 .capabilities = CODEC_CAP_SUBFRAMES | CODEC_CAP_DR1,

1798 };

Generated on Sat Jan 25 2014 19:51:44 for FFmpeg by doxygen 1.8.2