FFmpeg: libavcodec/evrcdec.c Source File

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evrcdec.c

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1 /*

2 * Enhanced Variable Rate Codec, Service Option 3 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 * Enhanced Variable Rate Codec, Service Option 3 decoder

25 * @author Paul B Mahol

26 */

28 #include "libavutil/mathematics.h"

29 #include "libavutil/opt.h"

30 #include "avcodec.h"

31 #include "internal.h"

32 #include "get_bits.h"

33 #include "evrcdata.h"

34 #include "acelp_vectors.h"

35 #include "lsp.h"

37 #define MIN_LSP_SEP (0.05 / (2.0 * M_PI))

38 #define MIN_DELAY 20

39 #define MAX_DELAY 120

40 #define NB_SUBFRAMES 3

41 #define SUBFRAME_SIZE 54

42 #define FILTER_ORDER 10

43 #define ACB_SIZE 128

45 typedef enum {

46 RATE_ERRS = -1,

47 SILENCE,

48 RATE_QUANT,

49 RATE_QUARTER,

50 RATE_HALF,

51 RATE_FULL,

52 } evrc_packet_rate;

54 /**

55 * EVRC-A unpacked data frame

56 */

57 typedef struct EVRCAFrame {

58 uint8_t lpc_flag; ///< spectral change indicator

59 uint16_t lsp[4]; ///< index into LSP codebook

60 uint8_t pitch_delay; ///< pitch delay for entire frame

61 uint8_t delay_diff; ///< delay difference for entire frame

62 uint8_t acb_gain[3]; ///< adaptive codebook gain

63 uint16_t fcb_shape[3][4]; ///< fixed codebook shape

64 uint8_t fcb_gain[3]; ///< fixed codebook gain index

65 uint8_t energy_gain; ///< frame energy gain index

66 uint8_t tty; ///< tty baud rate bit

67 } EVRCAFrame;

69 typedef struct EVRCContext {

70 AVClass *class;

72 int postfilter;

74 GetBitContext gb;

75 evrc_packet_rate bitrate;

76 evrc_packet_rate last_valid_bitrate;

77 EVRCAFrame frame;

79 float lspf[FILTER_ORDER];

80 float prev_lspf[FILTER_ORDER];

81 float synthesis[FILTER_ORDER];

82 float postfilter_fir[FILTER_ORDER];

83 float postfilter_iir[FILTER_ORDER];

84 float postfilter_residual[ACB_SIZE + SUBFRAME_SIZE];

85 float pitch_delay;

86 float prev_pitch_delay;

87 float avg_acb_gain; ///< average adaptive codebook gain

88 float avg_fcb_gain; ///< average fixed codebook gain

89 float pitch[ACB_SIZE + FILTER_ORDER + SUBFRAME_SIZE];

90 float pitch_back[ACB_SIZE];

91 float interpolation_coeffs[136];

92 float energy_vector[NB_SUBFRAMES];

93 float fade_scale;

94 float last;

96 uint8_t prev_energy_gain;

97 uint8_t prev_error_flag;

98 uint8_t warned_buf_mismatch_bitrate;

99 } EVRCContext;

100

101 /**

102 * Frame unpacking for RATE_FULL, RATE_HALF and RATE_QUANT

103 *

104 * @param e the context

105 *

106 * TIA/IS-127 Table 4.21-1

107 */

108 static void unpack_frame(EVRCContext *e)

109 {

110 EVRCAFrame *frame = &e->frame;

111 GetBitContext *gb = &e->gb;

112

113 switch (e->bitrate) {

114 case RATE_FULL:

115 frame->lpc_flag = get_bits1(gb);

116 frame->lsp[0] = get_bits(gb, 6);

117 frame->lsp[1] = get_bits(gb, 6);

118 frame->lsp[2] = get_bits(gb, 9);

119 frame->lsp[3] = get_bits(gb, 7);

120 frame->pitch_delay = get_bits(gb, 7);

121 frame->delay_diff = get_bits(gb, 5);

122 frame->acb_gain[0] = get_bits(gb, 3);

123 frame->fcb_shape[0][0] = get_bits(gb, 8);

124 frame->fcb_shape[0][1] = get_bits(gb, 8);

125 frame->fcb_shape[0][2] = get_bits(gb, 8);

126 frame->fcb_shape[0][3] = get_bits(gb, 11);

127 frame->fcb_gain[0] = get_bits(gb, 5);

128 frame->acb_gain[1] = get_bits(gb, 3);

129 frame->fcb_shape[1][0] = get_bits(gb, 8);

130 frame->fcb_shape[1][1] = get_bits(gb, 8);

131 frame->fcb_shape[1][2] = get_bits(gb, 8);

132 frame->fcb_shape[1][3] = get_bits(gb, 11);

133 frame->fcb_gain [1] = get_bits(gb, 5);

134 frame->acb_gain [2] = get_bits(gb, 3);

135 frame->fcb_shape[2][0] = get_bits(gb, 8);

136 frame->fcb_shape[2][1] = get_bits(gb, 8);

137 frame->fcb_shape[2][2] = get_bits(gb, 8);

138 frame->fcb_shape[2][3] = get_bits(gb, 11);

139 frame->fcb_gain [2] = get_bits(gb, 5);

140 frame->tty = get_bits1(gb);

141 break;

142 case RATE_HALF:

143 frame->lsp [0] = get_bits(gb, 7);

144 frame->lsp [1] = get_bits(gb, 7);

145 frame->lsp [2] = get_bits(gb, 8);

146 frame->pitch_delay = get_bits(gb, 7);

147 frame->acb_gain [0] = get_bits(gb, 3);

148 frame->fcb_shape[0][0] = get_bits(gb, 10);

149 frame->fcb_gain [0] = get_bits(gb, 4);

150 frame->acb_gain [1] = get_bits(gb, 3);

151 frame->fcb_shape[1][0] = get_bits(gb, 10);

152 frame->fcb_gain [1] = get_bits(gb, 4);

153 frame->acb_gain [2] = get_bits(gb, 3);

154 frame->fcb_shape[2][0] = get_bits(gb, 10);

155 frame->fcb_gain [2] = get_bits(gb, 4);

156 break;

157 case RATE_QUANT:

158 frame->lsp [0] = get_bits(gb, 4);

159 frame->lsp [1] = get_bits(gb, 4);

160 frame->energy_gain = get_bits(gb, 8);

161 break;

162 }

163 }

164

165 static evrc_packet_rate buf_size2bitrate(const int buf_size)

166 {

167 switch (buf_size) {

168 case 23: return RATE_FULL;

169 case 11: return RATE_HALF;

170 case 6: return RATE_QUARTER;

171 case 3: return RATE_QUANT;

172 case 1: return SILENCE;

173 }

174

175 return RATE_ERRS;

176 }

177

178 /**

179 * Determine the bitrate from the frame size and/or the first byte of the frame.

180 *

181 * @param avctx the AV codec context

182 * @param buf_size length of the buffer

183 * @param buf the bufffer

184 *

185 * @return the bitrate on success,

186 * RATE_ERRS if the bitrate cannot be satisfactorily determined

187 */

188 static evrc_packet_rate determine_bitrate(AVCodecContext *avctx,

189 int *buf_size,

190 const uint8_t **buf)

191 {

192 evrc_packet_rate bitrate;

193

194 if ((bitrate = buf_size2bitrate(*buf_size)) >= 0) {

195 if (bitrate > **buf) {

196 EVRCContext *e = avctx->priv_data;

197 if (!e->warned_buf_mismatch_bitrate) {

198 av_log(avctx, AV_LOG_WARNING,

199 "Claimed bitrate and buffer size mismatch.\n");

200 e->warned_buf_mismatch_bitrate = 1;

201 }

202 bitrate = **buf;

203 } else if (bitrate < **buf) {

204 av_log(avctx, AV_LOG_ERROR,

205 "Buffer is too small for the claimed bitrate.\n");

206 return RATE_ERRS;

207 }

208 (*buf)++;

209 *buf_size -= 1;

210 } else if ((bitrate = buf_size2bitrate(*buf_size + 1)) >= 0) {

211 av_log(avctx, AV_LOG_DEBUG,

212 "Bitrate byte is missing, guessing the bitrate from packet size.\n");

213 } else

214 return RATE_ERRS;

215

216 return bitrate;

217 }

218

219 static void warn_insufficient_frame_quality(AVCodecContext *avctx,

220 const char *message)

221 {

222 av_log(avctx, AV_LOG_WARNING, "Frame #%d, %s\n",

223 avctx->frame_number, message);

224 }

225

226 /**

227 * Initialize the speech codec according to the specification.

228 *

229 * TIA/IS-127 5.2

230 */

231 static av_cold int evrc_decode_init(AVCodecContext *avctx)

232 {

233 EVRCContext *e = avctx->priv_data;

234 int i, n, idx = 0;

235 float denom = 2.0 / (2.0 * 8.0 + 1.0);

236

237 avctx->channels = 1;

238 avctx->channel_layout = AV_CH_LAYOUT_MONO;

239 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;

240

241 for (i = 0; i < FILTER_ORDER; i++) {

242 e->prev_lspf[i] = (i + 1) * 0.048;

243 e->synthesis[i] = 0.0;

244 }

245

246 for (i = 0; i < ACB_SIZE; i++)

247 e->pitch[i] = e->pitch_back[i] = 0.0;

248

249 e->last_valid_bitrate = RATE_QUANT;

250 e->prev_pitch_delay = 40.0;

251 e->fade_scale = 1.0;

252 e->prev_error_flag = 0;

253 e->avg_acb_gain = e->avg_fcb_gain = 0.0;

254

255 for (i = 0; i < 8; i++) {

256 float tt = ((float)i - 8.0 / 2.0) / 8.0;

257

258 for (n = -8; n <= 8; n++, idx++) {

259 float arg1 = M_PI * 0.9 * (tt - n);

260 float arg2 = M_PI * (tt - n);

261

262 e->interpolation_coeffs[idx] = 0.9;

263 if (arg1)

264 e->interpolation_coeffs[idx] *= (0.54 + 0.46 * cos(arg2 * denom)) *

265 sin(arg1) / arg1;

266 }

267 }

268

269 return 0;

270 }

271

272 /**

273 * Decode the 10 vector quantized line spectral pair frequencies from the LSP

274 * transmission codes of any bitrate and check for badly received packets.

275 *

276 * @param e the context

277 *

278 * @return 0 on success, -1 if the packet is badly received

279 *

280 * TIA/IS-127 5.2.1, 5.7.1

281 */

282 static int decode_lspf(EVRCContext *e)

283 {

284 const float * const *codebooks = evrc_lspq_codebooks[e->bitrate];

285 int i, j, k = 0;

286

287 for (i = 0; i < evrc_lspq_nb_codebooks[e->bitrate]; i++) {

288 int row_size = evrc_lspq_codebooks_row_sizes[e->bitrate][i];

289 const float *codebook = codebooks[i];

290

291 for (j = 0; j < row_size; j++)

292 e->lspf[k++] = codebook[e->frame.lsp[i] * row_size + j];

293 }

294

295 // check for monotonic LSPs

296 for (i = 1; i < FILTER_ORDER; i++)

297 if (e->lspf[i] <= e->lspf[i - 1])

298 return -1;

299

300 // check for minimum separation of LSPs at the splits

301 for (i = 0, k = 0; i < evrc_lspq_nb_codebooks[e->bitrate] - 1; i++) {

302 k += evrc_lspq_codebooks_row_sizes[e->bitrate][i];

303 if (e->lspf[k] - e->lspf[k - 1] <= MIN_LSP_SEP)

304 return -1;

305 }

306

307 return 0;

308 }

309

310 /*

311 * Interpolation of LSP parameters.

312 *

313 * TIA/IS-127 5.2.3.1, 5.7.3.2

314 */

315 static void interpolate_lsp(float *ilsp, const float *lsp,

316 const float *prev, int index)

317 {

318 static const float lsp_interpolation_factors[] = { 0.1667, 0.5, 0.8333 };

319 ff_weighted_vector_sumf(ilsp, prev, lsp,

320 1.0 - lsp_interpolation_factors[index],

321 lsp_interpolation_factors[index], FILTER_ORDER);

322 }

323

324 /*

325 * Reconstruction of the delay contour.

326 *

327 * TIA/IS-127 5.2.2.3.2

328 */

329 static void interpolate_delay(float *dst, float current, float prev, int index)

330 {

331 static const float d_interpolation_factors[] = { 0, 0.3313, 0.6625, 1, 1 };

332 dst[0] = (1.0 - d_interpolation_factors[index ]) * prev

333 + d_interpolation_factors[index ] * current;

334 dst[1] = (1.0 - d_interpolation_factors[index + 1]) * prev

335 + d_interpolation_factors[index + 1] * current;

336 dst[2] = (1.0 - d_interpolation_factors[index + 2]) * prev

337 + d_interpolation_factors[index + 2] * current;

338 }

339

340 /*

341 * Convert the quantized, interpolated line spectral frequencies,

342 * to prediction coefficients.

343 *

344 * TIA/IS-127 5.2.3.2, 4.7.2.2

345 */

346 static void decode_predictor_coeffs(const float *ilspf, float *ilpc)

347 {

348 double lsp[FILTER_ORDER];

349 float a[FILTER_ORDER / 2 + 1], b[FILTER_ORDER / 2 + 1];

350 float a1[FILTER_ORDER / 2] = { 0 };

351 float a2[FILTER_ORDER / 2] = { 0 };

352 float b1[FILTER_ORDER / 2] = { 0 };

353 float b2[FILTER_ORDER / 2] = { 0 };

354 int i, k;

355

356 ff_acelp_lsf2lspd(lsp, ilspf, FILTER_ORDER);

357

358 for (k = 0; k <= FILTER_ORDER; k++) {

359 a[0] = k < 2 ? 0.25 : 0;

360 b[0] = k < 2 ? k < 1 ? 0.25 : -0.25 : 0;

361

362 for (i = 0; i < FILTER_ORDER / 2; i++) {

363 a[i + 1] = a[i] - 2 * lsp[i * 2 ] * a1[i] + a2[i];

364 b[i + 1] = b[i] - 2 * lsp[i * 2 + 1] * b1[i] + b2[i];

365 a2[i] = a1[i];

366 a1[i] = a[i];

367 b2[i] = b1[i];

368 b1[i] = b[i];

369 }

370

371 if (k)

372 ilpc[k - 1] = 2.0 * (a[FILTER_ORDER / 2] + b[FILTER_ORDER / 2]);

373 }

374 }

375

376 static void bl_intrp(EVRCContext *e, float *ex, float delay)

377 {

378 float *f;

379 int offset, i, coef_idx;

380 int16_t t;

381

382 offset = lrintf(delay);

383

384 t = (offset - delay + 0.5) * 8.0 + 0.5;

385 if (t == 8) {

386 t = 0;

387 offset--;

388 }

389

390 f = ex - offset - 8;

391

392 coef_idx = t * (2 * 8 + 1);

393

394 ex[0] = 0.0;

395 for (i = 0; i < 2 * 8 + 1; i++)

396 ex[0] += e->interpolation_coeffs[coef_idx + i] * f[i];

397 }

398

399 /*

400 * Adaptive codebook excitation.

401 *

402 * TIA/IS-127 5.2.2.3.3, 4.12.5.2

403 */

404 static void acb_excitation(EVRCContext *e, float *excitation, float gain,

405 const float delay[3], int length)

406 {

407 float denom, locdelay, dpr, invl;

408 int i;

409

410 invl = 1.0 / ((float) length);

411 dpr = length;

412

413 /* first at-most extra samples */

414 denom = (delay[1] - delay[0]) * invl;

415 for (i = 0; i < dpr; i++) {

416 locdelay = delay[0] + i * denom;

417 bl_intrp(e, excitation + i, locdelay);

418 }

419

420 denom = (delay[2] - delay[1]) * invl;

421 /* interpolation */

422 for (i = dpr; i < dpr + 10; i++) {

423 locdelay = delay[1] + (i - dpr) * denom;

424 bl_intrp(e, excitation + i, locdelay);

425 }

426

427 for (i = 0; i < length; i++)

428 excitation[i] *= gain;

429 }

430

431 static void decode_8_pulses_35bits(const uint16_t *fixed_index, float *cod)

432 {

433 int i, pos1, pos2, offset;

434

435 offset = (fixed_index[3] >> 9) & 3;

436

437 for (i = 0; i < 3; i++) {

438 pos1 = ((fixed_index[i] & 0x7f) / 11) * 5 + ((i + offset) % 5);

439 pos2 = ((fixed_index[i] & 0x7f) % 11) * 5 + ((i + offset) % 5);

440

441 cod[pos1] = (fixed_index[i] & 0x80) ? -1.0 : 1.0;

442

443 if (pos2 < pos1)

444 cod[pos2] = -cod[pos1];

445 else

446 cod[pos2] += cod[pos1];

447 }

448

449 pos1 = ((fixed_index[3] & 0x7f) / 11) * 5 + ((3 + offset) % 5);

450 pos2 = ((fixed_index[3] & 0x7f) % 11) * 5 + ((4 + offset) % 5);

451

452 cod[pos1] = (fixed_index[3] & 0x100) ? -1.0 : 1.0;

453 cod[pos2] = (fixed_index[3] & 0x80 ) ? -1.0 : 1.0;

454 }

455

456 static void decode_3_pulses_10bits(uint16_t fixed_index, float *cod)

457 {

458 float sign;

459 int pos;

460

461 sign = (fixed_index & 0x200) ? -1.0 : 1.0;

462

463 pos = ((fixed_index & 0x7) * 7) + 4;

464 cod[pos] += sign;

465 pos = (((fixed_index >> 3) & 0x7) * 7) + 2;

466 cod[pos] -= sign;

467 pos = (((fixed_index >> 6) & 0x7) * 7);

468 cod[pos] += sign;

469 }

470

471 /*

472 * Reconstruction of ACELP fixed codebook excitation for full and half rate.

473 *

474 * TIA/IS-127 5.2.3.7

475 */

476 static void fcb_excitation(EVRCContext *e, const uint16_t *codebook,

477 float *excitation, float pitch_gain,

478 int pitch_lag, int subframe_size)

479 {

480 int i;

481

482 if (e->bitrate == RATE_FULL)

483 decode_8_pulses_35bits(codebook, excitation);

484 else

485 decode_3_pulses_10bits(*codebook, excitation);

486

487 pitch_gain = av_clipf(pitch_gain, 0.2, 0.9);

488

489 for (i = pitch_lag; i < subframe_size; i++)

490 excitation[i] += pitch_gain * excitation[i - pitch_lag];

491 }

492

493 /**

494 * Synthesis of the decoder output signal.

495 *

496 * param[in] in input signal

497 * param[in] filter_coeffs LPC coefficients

498 * param[in/out] memory synthesis filter memory

499 * param buffer_length amount of data to process

500 * param[out] samples output samples

501 *

502 * TIA/IS-127 5.2.3.15, 5.7.3.4

503 */

504 static void synthesis_filter(const float *in, const float *filter_coeffs,

505 float *memory, int buffer_length, float *samples)

506 {

507 int i, j;

508

509 for (i = 0; i < buffer_length; i++) {

510 samples[i] = in[i];

511 for (j = FILTER_ORDER - 1; j > 0; j--) {

512 samples[i] -= filter_coeffs[j] * memory[j];

513 memory[j] = memory[j - 1];

514 }

515 samples[i] -= filter_coeffs[0] * memory[0];

516 memory[0] = samples[i];

517 }

518 }

519

520 static void bandwidth_expansion(float *coeff, const float *inbuf, float gamma)

521 {

522 double fac = gamma;

523 int i;

524

525 for (i = 0; i < FILTER_ORDER; i++) {

526 coeff[i] = inbuf[i] * fac;

527 fac *= gamma;

528 }

529 }

530

531 static void residual_filter(float *output, const float *input,

532 const float *coef, float *memory, int length)

533 {

534 float sum;

535 int i, j;

536

537 for (i = 0; i < length; i++) {

538 sum = input[i];

539

540 for (j = FILTER_ORDER - 1; j > 0; j--) {

541 sum += coef[j] * memory[j];

542 memory[j] = memory[j - 1];

543 }

544 sum += coef[0] * memory[0];

545 memory[0] = input[i];

546 output[i] = sum;

547 }

548 }

549

550 /*

551 * TIA/IS-127 Table 5.9.1-1.

552 */

553 static const struct PfCoeff {

554 float tilt;

555 float ltgain;

556 float p1;

557 float p2;

558 } postfilter_coeffs[5] = {

559 { 0.0 , 0.0 , 0.0 , 0.0 },

560 { 0.0 , 0.0 , 0.57, 0.57 },

561 { 0.0 , 0.0 , 0.0 , 0.0 },

562 { 0.35, 0.50, 0.50, 0.75 },

563 { 0.20, 0.50, 0.57, 0.75 },

564 };

565

566 /*

567 * Adaptive postfilter.

568 *

569 * TIA/IS-127 5.9

570 */

571 static void postfilter(EVRCContext *e, float *in, const float *coeff,

572 float *out, int idx, const struct PfCoeff *pfc,

573 int length)

574 {

575 float wcoef1[FILTER_ORDER], wcoef2[FILTER_ORDER],

576 scratch[SUBFRAME_SIZE], temp[SUBFRAME_SIZE],

577 mem[SUBFRAME_SIZE];

578 float sum1 = 0.0, sum2 = 0.0, gamma, gain;

579 float tilt = pfc->tilt;

580 int i, n, best;

581

582 bandwidth_expansion(wcoef1, coeff, pfc->p1);

583 bandwidth_expansion(wcoef2, coeff, pfc->p2);

584

585 /* Tilt compensation filter, TIA/IS-127 5.9.1 */

586 for (i = 0; i < length - 1; i++)

587 sum2 += in[i] * in[i + 1];

588 if (sum2 < 0.0)

589 tilt = 0.0;

590

591 for (i = 0; i < length; i++) {

592 scratch[i] = in[i] - tilt * e->last;

593 e->last = in[i];

594 }

595

596 /* Short term residual filter, TIA/IS-127 5.9.2 */

597 residual_filter(&e->postfilter_residual[ACB_SIZE], scratch, wcoef1, e->postfilter_fir, length);

598

599 /* Long term postfilter */

600 best = idx;

601 for (i = FFMIN(MIN_DELAY, idx - 3); i <= FFMAX(MAX_DELAY, idx + 3); i++) {

602 for (n = ACB_SIZE, sum2 = 0; n < ACB_SIZE + length; n++)

603 sum2 += e->postfilter_residual[n] * e->postfilter_residual[n - i];

604 if (sum2 > sum1) {

605 sum1 = sum2;

606 best = i;

607 }

608 }

609

610 for (i = ACB_SIZE, sum1 = 0; i < ACB_SIZE + length; i++)

611 sum1 += e->postfilter_residual[i - best] * e->postfilter_residual[i - best];

612 for (i = ACB_SIZE, sum2 = 0; i < ACB_SIZE + length; i++)

613 sum2 += e->postfilter_residual[i] * e->postfilter_residual[i - best];

614

615 if (sum2 * sum1 == 0 || e->bitrate == RATE_QUANT) {

616 memcpy(temp, e->postfilter_residual + ACB_SIZE, length * sizeof(float));

617 } else {

618 gamma = sum2 / sum1;

619 if (gamma < 0.5)

620 memcpy(temp, e->postfilter_residual + ACB_SIZE, length * sizeof(float));

621 else {

622 gamma = FFMIN(gamma, 1.0);

623

624 for (i = 0; i < length; i++) {

625 temp[i] = e->postfilter_residual[ACB_SIZE + i] + gamma *

626 pfc->ltgain * e->postfilter_residual[ACB_SIZE + i - best];

627 }

628 }

629 }

630

631 memcpy(scratch, temp, length * sizeof(float));

632 memcpy(mem, e->postfilter_iir, FILTER_ORDER * sizeof(float));

633 synthesis_filter(scratch, wcoef2, mem, length, scratch);

634

635 /* Gain computation, TIA/IS-127 5.9.4-2 */

636 for (i = 0, sum1 = 0, sum2 = 0; i < length; i++) {

637 sum1 += in[i] * in[i];

638 sum2 += scratch[i] * scratch[i];

639 }

640 gain = sum2 ? sqrt(sum1 / sum2) : 1.0;

641

642 for (i = 0; i < length; i++)

643 temp[i] *= gain;

644

645 /* Short term postfilter */

646 synthesis_filter(temp, wcoef2, e->postfilter_iir, length, out);

647

648 memmove(e->postfilter_residual,

649 e->postfilter_residual + length, ACB_SIZE * sizeof(float));

650 }

651

652 static void frame_erasure(EVRCContext *e, float *samples)

653 {

654 float ilspf[FILTER_ORDER], ilpc[FILTER_ORDER], idelay[NB_SUBFRAMES],

655 tmp[SUBFRAME_SIZE + 6], f;

656 int i, j;

657

658 for (i = 0; i < FILTER_ORDER; i++) {

659 if (e->bitrate != RATE_QUANT)

660 e->lspf[i] = e->prev_lspf[i] * 0.875 + 0.125 * (i + 1) * 0.048;

661 else

662 e->lspf[i] = e->prev_lspf[i];

663 }

664

665 if (e->prev_error_flag)

666 e->avg_acb_gain *= 0.75;

667 if (e->bitrate == RATE_FULL)

668 memcpy(e->pitch_back, e->pitch, ACB_SIZE * sizeof(float));

669 if (e->last_valid_bitrate == RATE_QUANT)

670 e->bitrate = RATE_QUANT;

671 else

672 e->bitrate = RATE_FULL;

673

674 if (e->bitrate == RATE_FULL || e->bitrate == RATE_HALF) {

675 e->pitch_delay = e->prev_pitch_delay;

676 } else {

677 float sum = 0;

678

679 idelay[0] = idelay[1] = idelay[2] = MIN_DELAY;

680

681 for (i = 0; i < NB_SUBFRAMES; i++)

682 sum += evrc_energy_quant[e->prev_energy_gain][i];

683 sum /= (float) NB_SUBFRAMES;

684 sum = pow(10, sum);

685 for (i = 0; i < NB_SUBFRAMES; i++)

686 e->energy_vector[i] = sum;

687 }

688

689 if (fabs(e->pitch_delay - e->prev_pitch_delay) > 15)

690 e->prev_pitch_delay = e->pitch_delay;

691

692 for (i = 0; i < NB_SUBFRAMES; i++) {

693 int subframe_size = subframe_sizes[i];

694 int pitch_lag;

695

696 interpolate_lsp(ilspf, e->lspf, e->prev_lspf, i);

697

698 if (e->bitrate != RATE_QUANT) {

699 if (e->avg_acb_gain < 0.3) {

700 idelay[0] = estimation_delay[i];

701 idelay[1] = estimation_delay[i + 1];

702 idelay[2] = estimation_delay[i + 2];

703 } else {

704 interpolate_delay(idelay, e->pitch_delay, e->prev_pitch_delay, i);

705 }

706 }

707

708 pitch_lag = lrintf((idelay[1] + idelay[0]) / 2.0);

709 decode_predictor_coeffs(ilspf, ilpc);

710

711 if (e->bitrate != RATE_QUANT) {

712 acb_excitation(e, e->pitch + ACB_SIZE,

713 e->avg_acb_gain, idelay, subframe_size);

714 for (j = 0; j < subframe_size; j++)

715 e->pitch[ACB_SIZE + j] *= e->fade_scale;

716 e->fade_scale = FFMAX(e->fade_scale - 0.05, 0.0);

717 } else {

718 for (j = 0; j < subframe_size; j++)

719 e->pitch[ACB_SIZE + j] = e->energy_vector[i];

720 }

721

722 memmove(e->pitch, e->pitch + subframe_size, ACB_SIZE * sizeof(float));

723

724 if (e->bitrate != RATE_QUANT && e->avg_acb_gain < 0.4) {

725 f = 0.1 * e->avg_fcb_gain;

726 for (j = 0; j < subframe_size; j++)

727 e->pitch[ACB_SIZE + j] += f;

728 } else if (e->bitrate == RATE_QUANT) {

729 for (j = 0; j < subframe_size; j++)

730 e->pitch[ACB_SIZE + j] = e->energy_vector[i];

731 }

732

733 synthesis_filter(e->pitch + ACB_SIZE, ilpc,

734 e->synthesis, subframe_size, tmp);

735 postfilter(e, tmp, ilpc, samples, pitch_lag,

736 &postfilter_coeffs[e->bitrate], subframe_size);

737

738 samples += subframe_size;

739 }

740 }

741

742 static int evrc_decode_frame(AVCodecContext *avctx, void *data,

743 int *got_frame_ptr, AVPacket *avpkt)

744 {

745 const uint8_t *buf = avpkt->data;

746 AVFrame *frame = data;

747 EVRCContext *e = avctx->priv_data;

748 int buf_size = avpkt->size;

749 float ilspf[FILTER_ORDER], ilpc[FILTER_ORDER], idelay[NB_SUBFRAMES];

750 float *samples;

751 int i, j, ret, error_flag = 0;

752

753 frame->nb_samples = 160;

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

755 return ret;

756 samples = (float *)frame->data[0];

757

758 if ((e->bitrate = determine_bitrate(avctx, &buf_size, &buf)) == RATE_ERRS) {

759 warn_insufficient_frame_quality(avctx, "bitrate cannot be determined.");

760 goto erasure;

761 }

762 if (e->bitrate <= SILENCE || e->bitrate == RATE_QUARTER)

763 goto erasure;

764 if (e->bitrate == RATE_QUANT && e->last_valid_bitrate == RATE_FULL

765 && !e->prev_error_flag)

766 goto erasure;

767

768 if ((ret = init_get_bits8(&e->gb, buf, buf_size)) < 0)

769 return ret;

770 memset(&e->frame, 0, sizeof(EVRCAFrame));

771

772 unpack_frame(e);

773

774 if (e->bitrate != RATE_QUANT) {

775 uint8_t *p = (uint8_t *) &e->frame;

776 for (i = 0; i < sizeof(EVRCAFrame); i++) {

777 if (p[i])

778 break;

779 }

780 if (i == sizeof(EVRCAFrame))

781 goto erasure;

782 } else if (e->frame.lsp[0] == 0xf &&

783 e->frame.lsp[1] == 0xf &&

784 e->frame.energy_gain == 0xff) {

785 goto erasure;

786 }

787

788 if (decode_lspf(e) < 0)

789 goto erasure;

790

791 if (e->bitrate == RATE_FULL || e->bitrate == RATE_HALF) {

792 /* Pitch delay parameter checking as per TIA/IS-127 5.1.5.1 */

793 if (e->frame.pitch_delay > MAX_DELAY - MIN_DELAY)

794 goto erasure;

795

796 e->pitch_delay = e->frame.pitch_delay + MIN_DELAY;

797

798 /* Delay diff parameter checking as per TIA/IS-127 5.1.5.2 */

799 if (e->frame.delay_diff) {

800 int p = e->pitch_delay - e->frame.delay_diff + 16;

801 if (p < MIN_DELAY || p > MAX_DELAY)

802 goto erasure;

803 }

804

805 /* Delay contour reconstruction as per TIA/IS-127 5.2.2.2 */

806 if (e->frame.delay_diff &&

807 e->bitrate == RATE_FULL && e->prev_error_flag) {

808 float delay;

809

810 memcpy(e->pitch, e->pitch_back, ACB_SIZE * sizeof(float));

811

812 delay = e->prev_pitch_delay;

813 e->prev_pitch_delay = delay - e->frame.delay_diff + 16.0;

814

815 if (fabs(e->pitch_delay - delay) > 15)

816 delay = e->pitch_delay;

817

818 for (i = 0; i < NB_SUBFRAMES; i++) {

819 int subframe_size = subframe_sizes[i];

820

821 interpolate_delay(idelay, delay, e->prev_pitch_delay, i);

822 acb_excitation(e, e->pitch + ACB_SIZE, e->avg_acb_gain, idelay, subframe_size);

823 memmove(e->pitch, e->pitch + subframe_size, ACB_SIZE * sizeof(float));

824 }

825 }

826

827 /* Smoothing of the decoded delay as per TIA/IS-127 5.2.2.5 */

828 if (fabs(e->pitch_delay - e->prev_pitch_delay) > 15)

829 e->prev_pitch_delay = e->pitch_delay;

830

831 e->avg_acb_gain = e->avg_fcb_gain = 0.0;

832 } else {

833 idelay[0] = idelay[1] = idelay[2] = MIN_DELAY;

834

835 /* Decode frame energy vectors as per TIA/IS-127 5.7.2 */

836 for (i = 0; i < NB_SUBFRAMES; i++)

837 e->energy_vector[i] = pow(10, evrc_energy_quant[e->frame.energy_gain][i]);

838 e->prev_energy_gain = e->frame.energy_gain;

839 }

840

841 for (i = 0; i < NB_SUBFRAMES; i++) {

842 float tmp[SUBFRAME_SIZE + 6] = { 0 };

843 int subframe_size = subframe_sizes[i];

844 int pitch_lag;

845

846 interpolate_lsp(ilspf, e->lspf, e->prev_lspf, i);

847

848 if (e->bitrate != RATE_QUANT)

849 interpolate_delay(idelay, e->pitch_delay, e->prev_pitch_delay, i);

850

851 pitch_lag = lrintf((idelay[1] + idelay[0]) / 2.0);

852 decode_predictor_coeffs(ilspf, ilpc);

853

854 /* Bandwidth expansion as per TIA/IS-127 5.2.3.3 */

855 if (e->frame.lpc_flag && e->prev_error_flag)

856 bandwidth_expansion(ilpc, ilpc, 0.75);

857

858 if (e->bitrate != RATE_QUANT) {

859 float acb_sum, f;

860

861 f = exp((e->bitrate == RATE_HALF ? 0.5 : 0.25)

862 * (e->frame.fcb_gain[i] + 1));

863 acb_sum = pitch_gain_vq[e->frame.acb_gain[i]];

864 e->avg_acb_gain += acb_sum / NB_SUBFRAMES;

865 e->avg_fcb_gain += f / NB_SUBFRAMES;

866

867 acb_excitation(e, e->pitch + ACB_SIZE,

868 acb_sum, idelay, subframe_size);

869 fcb_excitation(e, e->frame.fcb_shape[i], tmp,

870 acb_sum, pitch_lag, subframe_size);

871

872 /* Total excitation generation as per TIA/IS-127 5.2.3.9 */

873 for (j = 0; j < subframe_size; j++)

874 e->pitch[ACB_SIZE + j] += f * tmp[j];

875 e->fade_scale = FFMIN(e->fade_scale + 0.2, 1.0);

876 } else {

877 for (j = 0; j < subframe_size; j++)

878 e->pitch[ACB_SIZE + j] = e->energy_vector[i];

879 }

880

881 memmove(e->pitch, e->pitch + subframe_size, ACB_SIZE * sizeof(float));

882

883 synthesis_filter(e->pitch + ACB_SIZE, ilpc,

884 e->synthesis, subframe_size,

885 e->postfilter ? tmp : samples);

886 if (e->postfilter)

887 postfilter(e, tmp, ilpc, samples, pitch_lag,

888 &postfilter_coeffs[e->bitrate], subframe_size);

889

890 samples += subframe_size;

891 }

892

893 if (error_flag) {

894 erasure:

895 error_flag = 1;

896 av_log(avctx, AV_LOG_WARNING, "frame erasure\n");

897 frame_erasure(e, samples);

898 }

899

900 memcpy(e->prev_lspf, e->lspf, sizeof(e->prev_lspf));

901 e->prev_error_flag = error_flag;

902 e->last_valid_bitrate = e->bitrate;

903

904 if (e->bitrate != RATE_QUANT)

905 e->prev_pitch_delay = e->pitch_delay;

906

907 samples = (float *)frame->data[0];

908 for (i = 0; i < 160; i++)

909 samples[i] /= 32768;

910

911 *got_frame_ptr = 1;

912

913 return avpkt->size;

914 }

915

916 #define OFFSET(x) offsetof(EVRCContext, x)

917 #define AD AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM

918

919 static const AVOption options[] = {

920 { "postfilter", "enable postfilter", OFFSET(postfilter), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, AD },

921 { NULL }

922 };

923

924 static const AVClass evrcdec_class = {

925 .class_name = "evrc",

926 .item_name = av_default_item_name,

927 .option = options,

928 .version = LIBAVUTIL_VERSION_INT,

929 };

930

931 AVCodec ff_evrc_decoder = {

932 .name = "evrc",

933 .long_name = NULL_IF_CONFIG_SMALL("EVRC (Enhanced Variable Rate Codec)"),

934 .type = AVMEDIA_TYPE_AUDIO,

935 .id = AV_CODEC_ID_EVRC,

936 .init = evrc_decode_init,

937 .decode = evrc_decode_frame,

938 .capabilities = AV_CODEC_CAP_DR1,

939 .priv_data_size = sizeof(EVRCContext),

940 .priv_class = &evrcdec_class,

941 };

NULL

#define NULL

Definition: coverity.c:32

evrcdata.h

Data tables for the EVRC decoder.

AVFrame

This structure describes decoded (raw) audio or video data.

Definition: frame.h:184

row_size

BYTE int const BYTE int int row_size

Definition: avisynth_c.h:813

message

Definition: api-threadmessage-test.c:46

evrcdec_class

static const AVClass evrcdec_class

Definition: evrcdec.c:924

EVRCAFrame::fcb_gain

uint8_t fcb_gain[3]

fixed codebook gain index

Definition: evrcdec.c:64

EVRCAFrame::lsp

uint16_t lsp[4]

index into LSP codebook

Definition: evrcdec.c:59

AVOption

AVOption.

Definition: opt.h:245

data

ptrdiff_t const GLvoid * data

Definition: opengl_enc.c:101

get_bits

static unsigned int get_bits(GetBitContext *s, int n)

Read 1-25 bits.

Definition: get_bits.h:247

AV_LOG_WARNING

#define AV_LOG_WARNING

Something somehow does not look correct.

Definition: log.h:182

FILTER_ORDER

#define FILTER_ORDER

Definition: evrcdec.c:42

LIBAVUTIL_VERSION_INT

#define LIBAVUTIL_VERSION_INT

Definition: version.h:85

EVRCContext::prev_energy_gain

uint8_t prev_energy_gain

Definition: evrcdec.c:96

determine_bitrate

static evrc_packet_rate determine_bitrate(AVCodecContext *avctx, int *buf_size, const uint8_t **buf)

Determine the bitrate from the frame size and/or the first byte of the frame.

Definition: evrcdec.c:188

temp

else temp

Definition: vf_mcdeint.c:259

MIN_LSP_SEP

#define MIN_LSP_SEP

Definition: evrcdec.c:37

ff_weighted_vector_sumf

void ff_weighted_vector_sumf(float *out, const float *in_a, const float *in_b, float weight_coeff_a, float weight_coeff_b, int length)

float implementation of weighted sum of two vectors.

Definition: acelp_vectors.c:193

RATE_HALF

Definition: evrcdec.c:50

evrc_lspq_codebooks

static const float *const *const evrc_lspq_codebooks[]

Definition: evrcdata.h:1454

AVPacket::size

int size

Definition: avcodec.h:1602

const char * b

Definition: vf_curves.c:113

fcb_excitation

static void fcb_excitation(EVRCContext *e, const uint16_t *codebook, float *excitation, float pitch_gain, int pitch_lag, int subframe_size)

Definition: evrcdec.c:476

#define a1

Definition: regdef.h:47

EVRCContext::pitch_delay

float pitch_delay

Definition: evrcdec.c:85

EVRCContext::energy_vector

float energy_vector[NB_SUBFRAMES]

Definition: evrcdec.c:92

evrc_decode_init

static av_cold int evrc_decode_init(AVCodecContext *avctx)

Initialize the speech codec according to the specification.

Definition: evrcdec.c:231

EVRCContext::avg_fcb_gain

float avg_fcb_gain

average fixed codebook gain

Definition: evrcdec.c:88

AV_SAMPLE_FMT_FLT

float

Definition: samplefmt.h:63

AVCodec

AVCodec.

Definition: avcodec.h:3600

EVRCContext::warned_buf_mismatch_bitrate

uint8_t warned_buf_mismatch_bitrate

Definition: evrcdec.c:98

EVRCContext::lspf

float lspf[FILTER_ORDER]

Definition: evrcdec.c:79

EVRCAFrame::tty

uint8_t tty

tty baud rate bit

Definition: evrcdec.c:66

mathematics.h

AVClass::class_name

const char * class_name

The name of the class; usually it is the same name as the context structure type to which the AVClass...

Definition: log.h:72

buf_size2bitrate

static evrc_packet_rate buf_size2bitrate(const int buf_size)

Definition: evrcdec.c:165

AVCodecContext::sample_fmt

enum AVSampleFormat sample_fmt

audio sample format

Definition: avcodec.h:2446

mem

int mem

Definition: avisynth_c.h:821

interpolate_lsp

static void interpolate_lsp(float *ilsp, const float *lsp, const float *prev, int index)

Definition: evrcdec.c:315

uint8_t

Definition: audio_convert.c:194

av_cold

#define av_cold

Definition: attributes.h:82

opt.h

AVOptions.

EVRCAFrame::lpc_flag

uint8_t lpc_flag

spectral change indicator

Definition: evrcdec.c:58

bl_intrp

static void bl_intrp(EVRCContext *e, float *ex, float delay)

Definition: evrcdec.c:376

EVRCAFrame::fcb_shape

uint16_t fcb_shape[3][4]

fixed codebook shape

Definition: evrcdec.c:63

frame

static AVFrame * frame

Definition: demuxing_decoding.c:53

evrc_lspq_codebooks_row_sizes

static const uint8_t *const evrc_lspq_codebooks_row_sizes[]

Definition: evrcdata.h:1488

AVPacket::data

uint8_t * data

Definition: avcodec.h:1601

evrc_energy_quant

static const float evrc_energy_quant[][3]

Rate 1/8 frame energy quantization.

Definition: evrcdata.h:38

PfCoeff::p1

float p1

Definition: evrcdec.c:556

get_bits.h

bitstream reader API header.

lrintf

#define lrintf(x)

Definition: libm_mips.h:70

subframe_sizes

static const uint8_t subframe_sizes[]

Definition: evrcdata.h:1498

RATE_QUARTER

Definition: evrcdec.c:49

EVRCContext::last

float last

Definition: evrcdec.c:94

av_log

#define av_log(a,...)

Definition: tableprint_vlc.h:28

EVRCContext::pitch

float pitch[ACB_SIZE+FILTER_ORDER+SUBFRAME_SIZE]

Definition: evrcdec.c:89

AV_LOG_ERROR

#define AV_LOG_ERROR

Something went wrong and cannot losslessly be recovered.

Definition: log.h:176

EVRCContext::prev_error_flag

uint8_t prev_error_flag

Definition: evrcdec.c:97

ACB_SIZE

#define ACB_SIZE

Definition: evrcdec.c:43

evrc_lspq_nb_codebooks

static const uint8_t evrc_lspq_nb_codebooks[]

Definition: evrcdata.h:1462

acb_excitation

static void acb_excitation(EVRCContext *e, float *excitation, float gain, const float delay[3], int length)

Definition: evrcdec.c:404

EVRCContext::interpolation_coeffs

float interpolation_coeffs[136]

Definition: evrcdec.c:91

av_default_item_name

Definition: libopenh264enc.c:78

EVRCContext::postfilter_residual

float postfilter_residual[ACB_SIZE+SUBFRAME_SIZE]

Definition: evrcdec.c:84

NULL_IF_CONFIG_SMALL

#define NULL_IF_CONFIG_SMALL(x)

Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...

Definition: internal.h:176

ff_evrc_decoder

AVCodec ff_evrc_decoder

Definition: evrcdec.c:931

AV_LOG_DEBUG

#define AV_LOG_DEBUG

Stuff which is only useful for libav* developers.

Definition: log.h:197

unpack_frame

static void unpack_frame(EVRCContext *e)

Frame unpacking for RATE_FULL, RATE_HALF and RATE_QUANT.

Definition: evrcdec.c:108

AVMEDIA_TYPE_AUDIO

Definition: avutil.h:196

PfCoeff

Definition: evrcdec.c:553

EVRCContext

Definition: evrcdec.c:69

length

GLsizei GLsizei * length

Definition: opengl_enc.c:115

AVCodec::name

const char * name

Name of the codec implementation.

Definition: avcodec.h:3607

evrc_decode_frame

static int evrc_decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)

Definition: evrcdec.c:742

offset

static const uint8_t offset[127][2]

Definition: vf_spp.c:92

FFMAX

#define FFMAX(a, b)

Definition: common.h:94

EVRCAFrame::acb_gain

uint8_t acb_gain[3]

adaptive codebook gain

Definition: evrcdec.c:62

MAX_DELAY

#define MAX_DELAY

Definition: evrcdec.c:39

exp

int8_t exp

Definition: eval.c:64

pitch_gain_vq

static const float pitch_gain_vq[]

Definition: evrcdata.h:1496

AVCodecContext::channel_layout

uint64_t channel_layout

Audio channel layout.

Definition: avcodec.h:2489

OFFSET

#define OFFSET(x)

Definition: evrcdec.c:916

EVRCContext::prev_pitch_delay

float prev_pitch_delay

Definition: evrcdec.c:86

EVRCContext::avg_acb_gain

float avg_acb_gain

average adaptive codebook gain

Definition: evrcdec.c:87

FFMIN

#define FFMIN(a, b)

Definition: common.h:96

evrc_packet_rate

Definition: evrcdec.c:45

#define AD

Definition: evrcdec.c:917

EVRCContext::gb

GetBitContext gb

Definition: evrcdec.c:74

NB_SUBFRAMES

#define NB_SUBFRAMES

Definition: evrcdec.c:40

#define a2

Definition: regdef.h:48

AV_OPT_TYPE_BOOL

Definition: opt.h:239

EVRCContext::pitch_back

float pitch_back[ACB_SIZE]

Definition: evrcdec.c:90

int n

Definition: avisynth_c.h:684

EVRCContext::prev_lspf

float prev_lspf[FILTER_ORDER]

Definition: evrcdec.c:80

postfilter

static void postfilter(EVRCContext *e, float *in, const float *coeff, float *out, int idx, const struct PfCoeff *pfc, int length)

Definition: evrcdec.c:571

EVRCContext::postfilter_fir

float postfilter_fir[FILTER_ORDER]

Definition: evrcdec.c:82

bandwidth_expansion

static void bandwidth_expansion(float *coeff, const float *inbuf, float gamma)

Definition: evrcdec.c:520

EVRCAFrame::pitch_delay

uint8_t pitch_delay

pitch delay for entire frame

Definition: evrcdec.c:60

decode_8_pulses_35bits

static void decode_8_pulses_35bits(const uint16_t *fixed_index, float *cod)

Definition: evrcdec.c:431

EVRCAFrame::delay_diff

uint8_t delay_diff

delay difference for entire frame

Definition: evrcdec.c:61

RATE_ERRS

Definition: evrcdec.c:46

acelp_vectors.h

RATE_FULL

Definition: evrcdec.c:51

avcodec.h

Libavcodec external API header.

estimation_delay

static const float estimation_delay[]

Definition: evrcdata.h:1497

PfCoeff::p2

float p2

Definition: evrcdec.c:557

init_get_bits8

static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)

Initialize GetBitContext.

Definition: get_bits.h:437

postfilter_coeffs

static const struct PfCoeff postfilter_coeffs[5]

AVCodecContext

main external API structure.

Definition: avcodec.h:1676

decode_3_pulses_10bits

static void decode_3_pulses_10bits(uint16_t fixed_index, float *cod)

Definition: evrcdec.c:456

ff_get_buffer

int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)

Get a buffer for a frame.

Definition: utils.c:947

uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(constuint8_t *) pi-0x80)*(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(constuint8_t *) pi-0x80)*(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(constint16_t *) pi >>8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t,*(constint16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t,*(constint16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(constint32_t *) pi >>24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t,*(constint32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t,*(constint32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(constfloat *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(constfloat *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(constfloat *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(constdouble *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(constdouble *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(constdouble *) pi *(1U<< 31))))#defineSET_CONV_FUNC_GROUP(ofmt, ifmt) staticvoidset_generic_function(AudioConvert *ac){}voidff_audio_convert_free(AudioConvert **ac){if(!*ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);}AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enumAVSampleFormatout_fmt, enumAVSampleFormatin_fmt, intchannels, intsample_rate, intapply_map){AudioConvert *ac;intin_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) returnNULL;ac->avr=avr;ac->out_fmt=out_fmt;ac->in_fmt=in_fmt;ac->channels=channels;ac->apply_map=apply_map;if(avr->dither_method!=AV_RESAMPLE_DITHER_NONE &&av_get_packed_sample_fmt(out_fmt)==AV_SAMPLE_FMT_S16 &&av_get_bytes_per_sample(in_fmt)>2){ac->dc=ff_dither_alloc(avr, out_fmt, in_fmt, channels, sample_rate, apply_map);if(!ac->dc){av_free(ac);returnNULL;}returnac;}in_planar=ff_sample_fmt_is_planar(in_fmt, channels);out_planar=ff_sample_fmt_is_planar(out_fmt, channels);if(in_planar==out_planar){ac->func_type=CONV_FUNC_TYPE_FLAT;ac->planes=in_planar?ac->channels:1;}elseif(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;elseac->func_type=CONV_FUNC_TYPE_DEINTERLEAVE;set_generic_function(ac);if(ARCH_AARCH64) ff_audio_convert_init_aarch64(ac);if(ARCH_ARM) ff_audio_convert_init_arm(ac);if(ARCH_X86) ff_audio_convert_init_x86(ac);returnac;}intff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in){intuse_generic=1;intlen=in->nb_samples;intp;if(ac->dc){av_log(ac->avr, AV_LOG_TRACE,"%dsamples-audio_convert:%sto%s(dithered)\n", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));returnff_convert_dither(ac-> in

Definition: audio_convert.c:194

buf

void * buf

Definition: avisynth_c.h:690

SILENCE

Definition: evrcdec.c:47

get_bits1

static unsigned int get_bits1(GetBitContext *s)

Definition: get_bits.h:299

AVClass

Describe the class of an AVClass context structure.

Definition: log.h:67