1/* 2 * QCELP decoder 3 * Copyright (c) 2007 Reynaldo H. Verdejo Pinochet 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 */ 21 22/** 23 * @file libavcodec/qcelpdec.c 24 * QCELP decoder 25 * @author Reynaldo H. Verdejo Pinochet 26 * @remark FFmpeg merging spearheaded by Kenan Gillet 27 * @remark Development mentored by Benjamin Larson 28 */ 29 30#include <stddef.h> 31 32#include "avcodec.h" 33#include "internal.h" 34#include "bitstream.h" 35 36#include "qcelpdata.h" 37 38#include "celp_math.h" 39#include "celp_filters.h" 40 41#undef NDEBUG 42#include <assert.h> 43 44typedef enum 45{ 46 I_F_Q = -1, /*!< insufficient frame quality */ 47 SILENCE, 48 RATE_OCTAVE, 49 RATE_QUARTER, 50 RATE_HALF, 51 RATE_FULL 52} qcelp_packet_rate; 53 54typedef struct 55{ 56 GetBitContext gb; 57 qcelp_packet_rate bitrate; 58 QCELPFrame frame; /*!< unpacked data frame */ 59 60 uint8_t erasure_count; 61 uint8_t octave_count; /*!< count the consecutive RATE_OCTAVE frames */ 62 float prev_lspf[10]; 63 float predictor_lspf[10];/*!< LSP predictor for RATE_OCTAVE and I_F_Q */ 64 float pitch_synthesis_filter_mem[303]; 65 float pitch_pre_filter_mem[303]; 66 float rnd_fir_filter_mem[180]; 67 float formant_mem[170]; 68 float last_codebook_gain; 69 int prev_g1[2]; 70 int prev_bitrate; 71 float pitch_gain[4]; 72 uint8_t pitch_lag[4]; 73 uint16_t first16bits; 74 uint8_t warned_buf_mismatch_bitrate; 75} QCELPContext; 76 77/** 78 * Reconstructs LPC coefficients from the line spectral pair frequencies. 79 * 80 * TIA/EIA/IS-733 2.4.3.3.5 81 */ 82void ff_qcelp_lspf2lpc(const float *lspf, float *lpc); 83 84static void weighted_vector_sumf(float *out, const float *in_a, 85 const float *in_b, float weight_coeff_a, 86 float weight_coeff_b, int length) 87{ 88 int i; 89 90 for(i=0; i<length; i++) 91 out[i] = weight_coeff_a * in_a[i] 92 + weight_coeff_b * in_b[i]; 93} 94 95/** 96 * Initialize the speech codec according to the specification. 97 * 98 * TIA/EIA/IS-733 2.4.9 99 */ 100static av_cold int qcelp_decode_init(AVCodecContext *avctx) 101{ 102 QCELPContext *q = avctx->priv_data; 103 int i; 104 105 avctx->sample_fmt = SAMPLE_FMT_FLT; 106 107 for(i=0; i<10; i++) 108 q->prev_lspf[i] = (i+1)/11.; 109 110 return 0; 111} 112 113/** 114 * Decodes the 10 quantized LSP frequencies from the LSPV/LSP 115 * transmission codes of any bitrate and checks for badly received packets. 116 * 117 * @param q the context 118 * @param lspf line spectral pair frequencies 119 * 120 * @return 0 on success, -1 if the packet is badly received 121 * 122 * TIA/EIA/IS-733 2.4.3.2.6.2-2, 2.4.8.7.3 123 */ 124static int decode_lspf(QCELPContext *q, float *lspf) 125{ 126 int i; 127 float tmp_lspf, smooth, erasure_coeff; 128 const float *predictors; 129 130 if(q->bitrate == RATE_OCTAVE || q->bitrate == I_F_Q) 131 { 132 predictors = (q->prev_bitrate != RATE_OCTAVE && 133 q->prev_bitrate != I_F_Q ? 134 q->prev_lspf : q->predictor_lspf); 135 136 if(q->bitrate == RATE_OCTAVE) 137 { 138 q->octave_count++; 139 140 for(i=0; i<10; i++) 141 { 142 q->predictor_lspf[i] = 143 lspf[i] = (q->frame.lspv[i] ? QCELP_LSP_SPREAD_FACTOR 144 : -QCELP_LSP_SPREAD_FACTOR) 145 + predictors[i] * QCELP_LSP_OCTAVE_PREDICTOR 146 + (i + 1) * ((1 - QCELP_LSP_OCTAVE_PREDICTOR)/11); 147 } 148 smooth = (q->octave_count < 10 ? .875 : 0.1); 149 }else 150 { 151 erasure_coeff = QCELP_LSP_OCTAVE_PREDICTOR; 152 153 assert(q->bitrate == I_F_Q); 154 155 if(q->erasure_count > 1) 156 erasure_coeff *= (q->erasure_count < 4 ? 0.9 : 0.7); 157 158 for(i=0; i<10; i++) 159 { 160 q->predictor_lspf[i] = 161 lspf[i] = (i + 1) * ( 1 - erasure_coeff)/11 162 + erasure_coeff * predictors[i]; 163 } 164 smooth = 0.125; 165 } 166 167 // Check the stability of the LSP frequencies. 168 lspf[0] = FFMAX(lspf[0], QCELP_LSP_SPREAD_FACTOR); 169 for(i=1; i<10; i++) 170 lspf[i] = FFMAX(lspf[i], (lspf[i-1] + QCELP_LSP_SPREAD_FACTOR)); 171 172 lspf[9] = FFMIN(lspf[9], (1.0 - QCELP_LSP_SPREAD_FACTOR)); 173 for(i=9; i>0; i--) 174 lspf[i-1] = FFMIN(lspf[i-1], (lspf[i] - QCELP_LSP_SPREAD_FACTOR)); 175 176 // Low-pass filter the LSP frequencies. 177 weighted_vector_sumf(lspf, lspf, q->prev_lspf, smooth, 1.0-smooth, 10); 178 }else 179 { 180 q->octave_count = 0; 181 182 tmp_lspf = 0.; 183 for(i=0; i<5 ; i++) 184 { 185 lspf[2*i+0] = tmp_lspf += qcelp_lspvq[i][q->frame.lspv[i]][0] * 0.0001; 186 lspf[2*i+1] = tmp_lspf += qcelp_lspvq[i][q->frame.lspv[i]][1] * 0.0001; 187 } 188 189 // Check for badly received packets. 190 if(q->bitrate == RATE_QUARTER) 191 { 192 if(lspf[9] <= .70 || lspf[9] >= .97) 193 return -1; 194 for(i=3; i<10; i++) 195 if(fabs(lspf[i] - lspf[i-2]) < .08) 196 return -1; 197 }else 198 { 199 if(lspf[9] <= .66 || lspf[9] >= .985) 200 return -1; 201 for(i=4; i<10; i++) 202 if (fabs(lspf[i] - lspf[i-4]) < .0931) 203 return -1; 204 } 205 } 206 return 0; 207} 208 209/** 210 * Converts codebook transmission codes to GAIN and INDEX. 211 * 212 * @param q the context 213 * @param gain array holding the decoded gain 214 * 215 * TIA/EIA/IS-733 2.4.6.2 216 */ 217static void decode_gain_and_index(QCELPContext *q, 218 float *gain) { 219 int i, subframes_count, g1[16]; 220 float slope; 221 222 if(q->bitrate >= RATE_QUARTER) 223 { 224 switch(q->bitrate) 225 { 226 case RATE_FULL: subframes_count = 16; break; 227 case RATE_HALF: subframes_count = 4; break; 228 default: subframes_count = 5; 229 } 230 for(i=0; i<subframes_count; i++) 231 { 232 g1[i] = 4 * q->frame.cbgain[i]; 233 if(q->bitrate == RATE_FULL && !((i+1) & 3)) 234 { 235 g1[i] += av_clip((g1[i-1] + g1[i-2] + g1[i-3]) / 3 - 6, 0, 32); 236 } 237 238 gain[i] = qcelp_g12ga[g1[i]]; 239 240 if(q->frame.cbsign[i]) 241 { 242 gain[i] = -gain[i]; 243 q->frame.cindex[i] = (q->frame.cindex[i]-89) & 127; 244 } 245 } 246 247 q->prev_g1[0] = g1[i-2]; 248 q->prev_g1[1] = g1[i-1]; 249 q->last_codebook_gain = qcelp_g12ga[g1[i-1]]; 250 251 if(q->bitrate == RATE_QUARTER) 252 { 253 // Provide smoothing of the unvoiced excitation energy. 254 gain[7] = gain[4]; 255 gain[6] = 0.4*gain[3] + 0.6*gain[4]; 256 gain[5] = gain[3]; 257 gain[4] = 0.8*gain[2] + 0.2*gain[3]; 258 gain[3] = 0.2*gain[1] + 0.8*gain[2]; 259 gain[2] = gain[1]; 260 gain[1] = 0.6*gain[0] + 0.4*gain[1]; 261 } 262 }else 263 { 264 if(q->bitrate == RATE_OCTAVE) 265 { 266 g1[0] = 2 * q->frame.cbgain[0] 267 + av_clip((q->prev_g1[0] + q->prev_g1[1]) / 2 - 5, 0, 54); 268 subframes_count = 8; 269 }else 270 { 271 assert(q->bitrate == I_F_Q); 272 273 g1[0] = q->prev_g1[1]; 274 switch(q->erasure_count) 275 { 276 case 1 : break; 277 case 2 : g1[0] -= 1; break; 278 case 3 : g1[0] -= 2; break; 279 default: g1[0] -= 6; 280 } 281 if(g1[0] < 0) 282 g1[0] = 0; 283 subframes_count = 4; 284 } 285 // This interpolation is done to produce smoother background noise. 286 slope = 0.5*(qcelp_g12ga[g1[0]] - q->last_codebook_gain) / subframes_count; 287 for(i=1; i<=subframes_count; i++) 288 gain[i-1] = q->last_codebook_gain + slope * i; 289 290 q->last_codebook_gain = gain[i-2]; 291 q->prev_g1[0] = q->prev_g1[1]; 292 q->prev_g1[1] = g1[0]; 293 } 294} 295 296/** 297 * If the received packet is Rate 1/4 a further sanity check is made of the 298 * codebook gain. 299 * 300 * @param cbgain the unpacked cbgain array 301 * @return -1 if the sanity check fails, 0 otherwise 302 * 303 * TIA/EIA/IS-733 2.4.8.7.3 304 */ 305static int codebook_sanity_check_for_rate_quarter(const uint8_t *cbgain) 306{ 307 int i, diff, prev_diff=0; 308 309 for(i=1; i<5; i++) 310 { 311 diff = cbgain[i] - cbgain[i-1]; 312 if(FFABS(diff) > 10) 313 return -1; 314 else if(FFABS(diff - prev_diff) > 12) 315 return -1; 316 prev_diff = diff; 317 } 318 return 0; 319} 320 321/** 322 * Computes the scaled codebook vector Cdn From INDEX and GAIN 323 * for all rates. 324 * 325 * The specification lacks some information here. 326 * 327 * TIA/EIA/IS-733 has an omission on the codebook index determination 328 * formula for RATE_FULL and RATE_HALF frames at section 2.4.8.1.1. It says 329 * you have to subtract the decoded index parameter from the given scaled 330 * codebook vector index 'n' to get the desired circular codebook index, but 331 * it does not mention that you have to clamp 'n' to [0-9] in order to get 332 * RI-compliant results. 333 * 334 * The reason for this mistake seems to be the fact they forgot to mention you 335 * have to do these calculations per codebook subframe and adjust given 336 * equation values accordingly. 337 * 338 * @param q the context 339 * @param gain array holding the 4 pitch subframe gain values 340 * @param cdn_vector array for the generated scaled codebook vector 341 */ 342static void compute_svector(QCELPContext *q, const float *gain, 343 float *cdn_vector) 344{ 345 int i, j, k; 346 uint16_t cbseed, cindex; 347 float *rnd, tmp_gain, fir_filter_value; 348 349 switch(q->bitrate) 350 { 351 case RATE_FULL: 352 for(i=0; i<16; i++) 353 { 354 tmp_gain = gain[i] * QCELP_RATE_FULL_CODEBOOK_RATIO; 355 cindex = -q->frame.cindex[i]; 356 for(j=0; j<10; j++) 357 *cdn_vector++ = tmp_gain * qcelp_rate_full_codebook[cindex++ & 127]; 358 } 359 break; 360 case RATE_HALF: 361 for(i=0; i<4; i++) 362 { 363 tmp_gain = gain[i] * QCELP_RATE_HALF_CODEBOOK_RATIO; 364 cindex = -q->frame.cindex[i]; 365 for (j = 0; j < 40; j++) 366 *cdn_vector++ = tmp_gain * qcelp_rate_half_codebook[cindex++ & 127]; 367 } 368 break; 369 case RATE_QUARTER: 370 cbseed = (0x0003 & q->frame.lspv[4])<<14 | 371 (0x003F & q->frame.lspv[3])<< 8 | 372 (0x0060 & q->frame.lspv[2])<< 1 | 373 (0x0007 & q->frame.lspv[1])<< 3 | 374 (0x0038 & q->frame.lspv[0])>> 3 ; 375 rnd = q->rnd_fir_filter_mem + 20; 376 for(i=0; i<8; i++) 377 { 378 tmp_gain = gain[i] * (QCELP_SQRT1887 / 32768.0); 379 for(k=0; k<20; k++) 380 { 381 cbseed = 521 * cbseed + 259; 382 *rnd = (int16_t)cbseed; 383 384 // FIR filter 385 fir_filter_value = 0.0; 386 for(j=0; j<10; j++) 387 fir_filter_value += qcelp_rnd_fir_coefs[j ] 388 * (rnd[-j ] + rnd[-20+j]); 389 390 fir_filter_value += qcelp_rnd_fir_coefs[10] * rnd[-10]; 391 *cdn_vector++ = tmp_gain * fir_filter_value; 392 rnd++; 393 } 394 } 395 memcpy(q->rnd_fir_filter_mem, q->rnd_fir_filter_mem + 160, 20 * sizeof(float)); 396 break; 397 case RATE_OCTAVE: 398 cbseed = q->first16bits; 399 for(i=0; i<8; i++) 400 { 401 tmp_gain = gain[i] * (QCELP_SQRT1887 / 32768.0); 402 for(j=0; j<20; j++) 403 { 404 cbseed = 521 * cbseed + 259; 405 *cdn_vector++ = tmp_gain * (int16_t)cbseed; 406 } 407 } 408 break; 409 case I_F_Q: 410 cbseed = -44; // random codebook index 411 for(i=0; i<4; i++) 412 { 413 tmp_gain = gain[i] * QCELP_RATE_FULL_CODEBOOK_RATIO; 414 for(j=0; j<40; j++) 415 *cdn_vector++ = tmp_gain * qcelp_rate_full_codebook[cbseed++ & 127]; 416 } 417 break; 418 case SILENCE: 419 memset(cdn_vector, 0, 160 * sizeof(float)); 420 break; 421 } 422} 423 424/** 425 * Apply generic gain control. 426 * 427 * @param v_out output vector 428 * @param v_in gain-controlled vector 429 * @param v_ref vector to control gain of 430 * 431 * FIXME: If v_ref is a zero vector, it energy is zero 432 * and the behavior of the gain control is 433 * undefined in the specs. 434 * 435 * TIA/EIA/IS-733 2.4.8.3-2/3/4/5, 2.4.8.6 436 */ 437static void apply_gain_ctrl(float *v_out, const float *v_ref, 438 const float *v_in) 439{ 440 int i, j, len; 441 float scalefactor; 442 443 for(i=0, j=0; i<4; i++) 444 { 445 scalefactor = ff_dot_productf(v_in + j, v_in + j, 40); 446 if(scalefactor) 447 scalefactor = sqrt(ff_dot_productf(v_ref + j, v_ref + j, 40) 448 / scalefactor); 449 else 450 ff_log_missing_feature(NULL, "Zero energy for gain control", 1); 451 for(len=j+40; j<len; j++) 452 v_out[j] = scalefactor * v_in[j]; 453 } 454} 455 456/** 457 * Apply filter in pitch-subframe steps. 458 * 459 * @param memory buffer for the previous state of the filter 460 * - must be able to contain 303 elements 461 * - the 143 first elements are from the previous state 462 * - the next 160 are for output 463 * @param v_in input filter vector 464 * @param gain per-subframe gain array, each element is between 0.0 and 2.0 465 * @param lag per-subframe lag array, each element is 466 * - between 16 and 143 if its corresponding pfrac is 0, 467 * - between 16 and 139 otherwise 468 * @param pfrac per-subframe boolean array, 1 if the lag is fractional, 0 469 * otherwise 470 * 471 * @return filter output vector 472 */ 473static const float *do_pitchfilter(float memory[303], const float v_in[160], 474 const float gain[4], const uint8_t *lag, 475 const uint8_t pfrac[4]) 476{ 477 int i, j; 478 float *v_lag, *v_out; 479 const float *v_len; 480 481 v_out = memory + 143; // Output vector starts at memory[143]. 482 483 for(i=0; i<4; i++) 484 { 485 if(gain[i]) 486 { 487 v_lag = memory + 143 + 40 * i - lag[i]; 488 for(v_len=v_in+40; v_in<v_len; v_in++) 489 { 490 if(pfrac[i]) // If it is a fractional lag... 491 { 492 for(j=0, *v_out=0.; j<4; j++) 493 *v_out += qcelp_hammsinc_table[j] * (v_lag[j-4] + v_lag[3-j]); 494 }else 495 *v_out = *v_lag; 496 497 *v_out = *v_in + gain[i] * *v_out; 498 499 v_lag++; 500 v_out++; 501 } 502 }else 503 { 504 memcpy(v_out, v_in, 40 * sizeof(float)); 505 v_in += 40; 506 v_out += 40; 507 } 508 } 509 510 memmove(memory, memory + 160, 143 * sizeof(float)); 511 return memory + 143; 512} 513 514/** 515 * Apply pitch synthesis filter and pitch prefilter to the scaled codebook vector. 516 * TIA/EIA/IS-733 2.4.5.2, 2.4.8.7.2 517 * 518 * @param q the context 519 * @param cdn_vector the scaled codebook vector 520 */ 521static void apply_pitch_filters(QCELPContext *q, float *cdn_vector) 522{ 523 int i; 524 const float *v_synthesis_filtered, *v_pre_filtered; 525 526 if(q->bitrate >= RATE_HALF || 527 q->bitrate == SILENCE || 528 (q->bitrate == I_F_Q && (q->prev_bitrate >= RATE_HALF))) 529 { 530 531 if(q->bitrate >= RATE_HALF) 532 { 533 534 // Compute gain & lag for the whole frame. 535 for(i=0; i<4; i++) 536 { 537 q->pitch_gain[i] = q->frame.plag[i] ? (q->frame.pgain[i] + 1) * 0.25 : 0.0; 538 539 q->pitch_lag[i] = q->frame.plag[i] + 16; 540 } 541 }else 542 { 543 float max_pitch_gain; 544 545 if (q->bitrate == I_F_Q) 546 { 547 if (q->erasure_count < 3) 548 max_pitch_gain = 0.9 - 0.3 * (q->erasure_count - 1); 549 else 550 max_pitch_gain = 0.0; 551 }else 552 { 553 assert(q->bitrate == SILENCE); 554 max_pitch_gain = 1.0; 555 } 556 for(i=0; i<4; i++) 557 q->pitch_gain[i] = FFMIN(q->pitch_gain[i], max_pitch_gain); 558 559 memset(q->frame.pfrac, 0, sizeof(q->frame.pfrac)); 560 } 561 562 // pitch synthesis filter 563 v_synthesis_filtered = do_pitchfilter(q->pitch_synthesis_filter_mem, 564 cdn_vector, q->pitch_gain, 565 q->pitch_lag, q->frame.pfrac); 566 567 // pitch prefilter update 568 for(i=0; i<4; i++) 569 q->pitch_gain[i] = 0.5 * FFMIN(q->pitch_gain[i], 1.0); 570 571 v_pre_filtered = do_pitchfilter(q->pitch_pre_filter_mem, 572 v_synthesis_filtered, 573 q->pitch_gain, q->pitch_lag, 574 q->frame.pfrac); 575 576 apply_gain_ctrl(cdn_vector, v_synthesis_filtered, v_pre_filtered); 577 }else 578 { 579 memcpy(q->pitch_synthesis_filter_mem, cdn_vector + 17, 580 143 * sizeof(float)); 581 memcpy(q->pitch_pre_filter_mem, cdn_vector + 17, 143 * sizeof(float)); 582 memset(q->pitch_gain, 0, sizeof(q->pitch_gain)); 583 memset(q->pitch_lag, 0, sizeof(q->pitch_lag)); 584 } 585} 586 587/** 588 * Interpolates LSP frequencies and computes LPC coefficients 589 * for a given bitrate & pitch subframe. 590 * 591 * TIA/EIA/IS-733 2.4.3.3.4, 2.4.8.7.2 592 * 593 * @param q the context 594 * @param curr_lspf LSP frequencies vector of the current frame 595 * @param lpc float vector for the resulting LPC 596 * @param subframe_num frame number in decoded stream 597 */ 598void interpolate_lpc(QCELPContext *q, const float *curr_lspf, float *lpc, 599 const int subframe_num) 600{ 601 float interpolated_lspf[10]; 602 float weight; 603 604 if(q->bitrate >= RATE_QUARTER) 605 weight = 0.25 * (subframe_num + 1); 606 else if(q->bitrate == RATE_OCTAVE && !subframe_num) 607 weight = 0.625; 608 else 609 weight = 1.0; 610 611 if(weight != 1.0) 612 { 613 weighted_vector_sumf(interpolated_lspf, curr_lspf, q->prev_lspf, 614 weight, 1.0 - weight, 10); 615 ff_qcelp_lspf2lpc(interpolated_lspf, lpc); 616 }else if(q->bitrate >= RATE_QUARTER || 617 (q->bitrate == I_F_Q && !subframe_num)) 618 ff_qcelp_lspf2lpc(curr_lspf, lpc); 619 else if(q->bitrate == SILENCE && !subframe_num) 620 ff_qcelp_lspf2lpc(q->prev_lspf, lpc); 621} 622 623static qcelp_packet_rate buf_size2bitrate(const int buf_size) 624{ 625 switch(buf_size) 626 { 627 case 35: return RATE_FULL; 628 case 17: return RATE_HALF; 629 case 8: return RATE_QUARTER; 630 case 4: return RATE_OCTAVE; 631 case 1: return SILENCE; 632 } 633 634 return I_F_Q; 635} 636 637/** 638 * Determine the bitrate from the frame size and/or the first byte of the frame. 639 * 640 * @param avctx the AV codec context 641 * @param buf_size length of the buffer 642 * @param buf the bufffer 643 * 644 * @return the bitrate on success, 645 * I_F_Q if the bitrate cannot be satisfactorily determined 646 * 647 * TIA/EIA/IS-733 2.4.8.7.1 648 */ 649static qcelp_packet_rate determine_bitrate(AVCodecContext *avctx, const int buf_size, 650 const uint8_t **buf) 651{ 652 qcelp_packet_rate bitrate; 653 654 if((bitrate = buf_size2bitrate(buf_size)) >= 0) 655 { 656 if(bitrate > **buf) 657 { 658 QCELPContext *q = avctx->priv_data; 659 if (!q->warned_buf_mismatch_bitrate) 660 { 661 av_log(avctx, AV_LOG_WARNING, 662 "Claimed bitrate and buffer size mismatch.\n"); 663 q->warned_buf_mismatch_bitrate = 1; 664 } 665 bitrate = **buf; 666 }else if(bitrate < **buf) 667 { 668 av_log(avctx, AV_LOG_ERROR, 669 "Buffer is too small for the claimed bitrate.\n"); 670 return I_F_Q; 671 } 672 (*buf)++; 673 }else if((bitrate = buf_size2bitrate(buf_size + 1)) >= 0) 674 { 675 av_log(avctx, AV_LOG_WARNING, 676 "Bitrate byte is missing, guessing the bitrate from packet size.\n"); 677 }else 678 return I_F_Q; 679 680 if(bitrate == SILENCE) 681 { 682 //FIXME: Remove experimental warning when tested with samples. 683 ff_log_ask_for_sample(avctx, "'Blank frame handling is experimental."); 684 } 685 return bitrate; 686} 687 688static void warn_insufficient_frame_quality(AVCodecContext *avctx, 689 const char *message) 690{ 691 av_log(avctx, AV_LOG_WARNING, "Frame #%d, IFQ: %s\n", avctx->frame_number, 692 message); 693} 694 695static int qcelp_decode_frame(AVCodecContext *avctx, void *data, int *data_size, 696 const uint8_t *buf, int buf_size) 697{ 698 QCELPContext *q = avctx->priv_data; 699 float *outbuffer = data; 700 int i; 701 float quantized_lspf[10], lpc[10]; 702 float gain[16]; 703 float *formant_mem; 704 705 if((q->bitrate = determine_bitrate(avctx, buf_size, &buf)) == I_F_Q) 706 { 707 warn_insufficient_frame_quality(avctx, "bitrate cannot be determined."); 708 goto erasure; 709 } 710 711 if(q->bitrate == RATE_OCTAVE && 712 (q->first16bits = AV_RB16(buf)) == 0xFFFF) 713 { 714 warn_insufficient_frame_quality(avctx, "Bitrate is 1/8 and first 16 bits are on."); 715 goto erasure; 716 } 717 718 if(q->bitrate > SILENCE) 719 { 720 const QCELPBitmap *bitmaps = qcelp_unpacking_bitmaps_per_rate[q->bitrate]; 721 const QCELPBitmap *bitmaps_end = qcelp_unpacking_bitmaps_per_rate[q->bitrate] 722 + qcelp_unpacking_bitmaps_lengths[q->bitrate]; 723 uint8_t *unpacked_data = (uint8_t *)&q->frame; 724 725 init_get_bits(&q->gb, buf, 8*buf_size); 726 727 memset(&q->frame, 0, sizeof(QCELPFrame)); 728 729 for(; bitmaps < bitmaps_end; bitmaps++) 730 unpacked_data[bitmaps->index] |= get_bits(&q->gb, bitmaps->bitlen) << bitmaps->bitpos; 731 732 // Check for erasures/blanks on rates 1, 1/4 and 1/8. 733 if(q->frame.reserved) 734 { 735 warn_insufficient_frame_quality(avctx, "Wrong data in reserved frame area."); 736 goto erasure; 737 } 738 if(q->bitrate == RATE_QUARTER && 739 codebook_sanity_check_for_rate_quarter(q->frame.cbgain)) 740 { 741 warn_insufficient_frame_quality(avctx, "Codebook gain sanity check failed."); 742 goto erasure; 743 } 744 745 if(q->bitrate >= RATE_HALF) 746 { 747 for(i=0; i<4; i++) 748 { 749 if(q->frame.pfrac[i] && q->frame.plag[i] >= 124) 750 { 751 warn_insufficient_frame_quality(avctx, "Cannot initialize pitch filter."); 752 goto erasure; 753 } 754 } 755 } 756 } 757 758 decode_gain_and_index(q, gain); 759 compute_svector(q, gain, outbuffer); 760 761 if(decode_lspf(q, quantized_lspf) < 0) 762 { 763 warn_insufficient_frame_quality(avctx, "Badly received packets in frame."); 764 goto erasure; 765 } 766 767 768 apply_pitch_filters(q, outbuffer); 769 770 if(q->bitrate == I_F_Q) 771 { 772erasure: 773 q->bitrate = I_F_Q; 774 q->erasure_count++; 775 decode_gain_and_index(q, gain); 776 compute_svector(q, gain, outbuffer); 777 decode_lspf(q, quantized_lspf); 778 apply_pitch_filters(q, outbuffer); 779 }else 780 q->erasure_count = 0; 781 782 formant_mem = q->formant_mem + 10; 783 for(i=0; i<4; i++) 784 { 785 interpolate_lpc(q, quantized_lspf, lpc, i); 786 ff_celp_lp_synthesis_filterf(formant_mem, lpc, outbuffer + i * 40, 40, 787 10); 788 formant_mem += 40; 789 } 790 memcpy(q->formant_mem, q->formant_mem + 160, 10 * sizeof(float)); 791 792 // FIXME: postfilter and final gain control should be here. 793 // TIA/EIA/IS-733 2.4.8.6 794 795 formant_mem = q->formant_mem + 10; 796 for(i=0; i<160; i++) 797 *outbuffer++ = av_clipf(*formant_mem++, QCELP_CLIP_LOWER_BOUND, 798 QCELP_CLIP_UPPER_BOUND); 799 800 memcpy(q->prev_lspf, quantized_lspf, sizeof(q->prev_lspf)); 801 q->prev_bitrate = q->bitrate; 802 803 *data_size = 160 * sizeof(*outbuffer); 804 805 return *data_size; 806} 807 808AVCodec qcelp_decoder = 809{ 810 .name = "qcelp", 811 .type = CODEC_TYPE_AUDIO, 812 .id = CODEC_ID_QCELP, 813 .init = qcelp_decode_init, 814 .decode = qcelp_decode_frame, 815 .priv_data_size = sizeof(QCELPContext), 816 .long_name = NULL_IF_CONFIG_SMALL("QCELP / PureVoice"), 817}; 818