Libav
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00001 /* 00002 * IMC compatible decoder 00003 * Copyright (c) 2002-2004 Maxim Poliakovski 00004 * Copyright (c) 2006 Benjamin Larsson 00005 * Copyright (c) 2006 Konstantin Shishkov 00006 * 00007 * This file is part of FFmpeg. 00008 * 00009 * FFmpeg is free software; you can redistribute it and/or 00010 * modify it under the terms of the GNU Lesser General Public 00011 * License as published by the Free Software Foundation; either 00012 * version 2.1 of the License, or (at your option) any later version. 00013 * 00014 * FFmpeg is distributed in the hope that it will be useful, 00015 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00017 * Lesser General Public License for more details. 00018 * 00019 * You should have received a copy of the GNU Lesser General Public 00020 * License along with FFmpeg; if not, write to the Free Software 00021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00022 */ 00023 00034 #include <math.h> 00035 #include <stddef.h> 00036 #include <stdio.h> 00037 00038 #define ALT_BITSTREAM_READER 00039 #include "avcodec.h" 00040 #include "get_bits.h" 00041 #include "dsputil.h" 00042 #include "fft.h" 00043 00044 #include "imcdata.h" 00045 00046 #define IMC_BLOCK_SIZE 64 00047 #define IMC_FRAME_ID 0x21 00048 #define BANDS 32 00049 #define COEFFS 256 00050 00051 typedef struct { 00052 float old_floor[BANDS]; 00053 float flcoeffs1[BANDS]; 00054 float flcoeffs2[BANDS]; 00055 float flcoeffs3[BANDS]; 00056 float flcoeffs4[BANDS]; 00057 float flcoeffs5[BANDS]; 00058 float flcoeffs6[BANDS]; 00059 float CWdecoded[COEFFS]; 00060 00063 float mdct_sine_window[COEFFS]; 00064 float post_cos[COEFFS]; 00065 float post_sin[COEFFS]; 00066 float pre_coef1[COEFFS]; 00067 float pre_coef2[COEFFS]; 00068 float last_fft_im[COEFFS]; 00070 00071 int bandWidthT[BANDS]; 00072 int bitsBandT[BANDS]; 00073 int CWlengthT[COEFFS]; 00074 int levlCoeffBuf[BANDS]; 00075 int bandFlagsBuf[BANDS]; 00076 int sumLenArr[BANDS]; 00077 int skipFlagRaw[BANDS]; 00078 int skipFlagBits[BANDS]; 00079 int skipFlagCount[BANDS]; 00080 int skipFlags[COEFFS]; 00081 int codewords[COEFFS]; 00082 float sqrt_tab[30]; 00083 GetBitContext gb; 00084 int decoder_reset; 00085 float one_div_log2; 00086 00087 DSPContext dsp; 00088 FFTContext fft; 00089 DECLARE_ALIGNED(16, FFTComplex, samples)[COEFFS/2]; 00090 DECLARE_ALIGNED(16, float, out_samples)[COEFFS]; 00091 } IMCContext; 00092 00093 static VLC huffman_vlc[4][4]; 00094 00095 #define VLC_TABLES_SIZE 9512 00096 00097 static const int vlc_offsets[17] = { 00098 0, 640, 1156, 1732, 2308, 2852, 3396, 3924, 00099 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE}; 00100 00101 static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2]; 00102 00103 static av_cold int imc_decode_init(AVCodecContext * avctx) 00104 { 00105 int i, j; 00106 IMCContext *q = avctx->priv_data; 00107 double r1, r2; 00108 00109 q->decoder_reset = 1; 00110 00111 for(i = 0; i < BANDS; i++) 00112 q->old_floor[i] = 1.0; 00113 00114 /* Build mdct window, a simple sine window normalized with sqrt(2) */ 00115 ff_sine_window_init(q->mdct_sine_window, COEFFS); 00116 for(i = 0; i < COEFFS; i++) 00117 q->mdct_sine_window[i] *= sqrt(2.0); 00118 for(i = 0; i < COEFFS/2; i++){ 00119 q->post_cos[i] = cos(i / 256.0 * M_PI); 00120 q->post_sin[i] = sin(i / 256.0 * M_PI); 00121 00122 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI); 00123 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI); 00124 00125 if (i & 0x1) 00126 { 00127 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0); 00128 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0); 00129 } 00130 else 00131 { 00132 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0); 00133 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0); 00134 } 00135 00136 q->last_fft_im[i] = 0; 00137 } 00138 00139 /* Generate a square root table */ 00140 00141 for(i = 0; i < 30; i++) { 00142 q->sqrt_tab[i] = sqrt(i); 00143 } 00144 00145 /* initialize the VLC tables */ 00146 for(i = 0; i < 4 ; i++) { 00147 for(j = 0; j < 4; j++) { 00148 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]]; 00149 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j]; 00150 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i], 00151 imc_huffman_lens[i][j], 1, 1, 00152 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC); 00153 } 00154 } 00155 q->one_div_log2 = 1/log(2); 00156 00157 ff_fft_init(&q->fft, 7, 1); 00158 dsputil_init(&q->dsp, avctx); 00159 avctx->sample_fmt = SAMPLE_FMT_S16; 00160 avctx->channel_layout = (avctx->channels==2) ? CH_LAYOUT_STEREO : CH_LAYOUT_MONO; 00161 return 0; 00162 } 00163 00164 static void imc_calculate_coeffs(IMCContext* q, float* flcoeffs1, float* flcoeffs2, int* bandWidthT, 00165 float* flcoeffs3, float* flcoeffs5) 00166 { 00167 float workT1[BANDS]; 00168 float workT2[BANDS]; 00169 float workT3[BANDS]; 00170 float snr_limit = 1.e-30; 00171 float accum = 0.0; 00172 int i, cnt2; 00173 00174 for(i = 0; i < BANDS; i++) { 00175 flcoeffs5[i] = workT2[i] = 0.0; 00176 if (bandWidthT[i]){ 00177 workT1[i] = flcoeffs1[i] * flcoeffs1[i]; 00178 flcoeffs3[i] = 2.0 * flcoeffs2[i]; 00179 } else { 00180 workT1[i] = 0.0; 00181 flcoeffs3[i] = -30000.0; 00182 } 00183 workT3[i] = bandWidthT[i] * workT1[i] * 0.01; 00184 if (workT3[i] <= snr_limit) 00185 workT3[i] = 0.0; 00186 } 00187 00188 for(i = 0; i < BANDS; i++) { 00189 for(cnt2 = i; cnt2 < cyclTab[i]; cnt2++) 00190 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i]; 00191 workT2[cnt2-1] = workT2[cnt2-1] + workT3[i]; 00192 } 00193 00194 for(i = 1; i < BANDS; i++) { 00195 accum = (workT2[i-1] + accum) * imc_weights1[i-1]; 00196 flcoeffs5[i] += accum; 00197 } 00198 00199 for(i = 0; i < BANDS; i++) 00200 workT2[i] = 0.0; 00201 00202 for(i = 0; i < BANDS; i++) { 00203 for(cnt2 = i-1; cnt2 > cyclTab2[i]; cnt2--) 00204 flcoeffs5[cnt2] += workT3[i]; 00205 workT2[cnt2+1] += workT3[i]; 00206 } 00207 00208 accum = 0.0; 00209 00210 for(i = BANDS-2; i >= 0; i--) { 00211 accum = (workT2[i+1] + accum) * imc_weights2[i]; 00212 flcoeffs5[i] += accum; 00213 //there is missing code here, but it seems to never be triggered 00214 } 00215 } 00216 00217 00218 static void imc_read_level_coeffs(IMCContext* q, int stream_format_code, int* levlCoeffs) 00219 { 00220 int i; 00221 VLC *hufftab[4]; 00222 int start = 0; 00223 const uint8_t *cb_sel; 00224 int s; 00225 00226 s = stream_format_code >> 1; 00227 hufftab[0] = &huffman_vlc[s][0]; 00228 hufftab[1] = &huffman_vlc[s][1]; 00229 hufftab[2] = &huffman_vlc[s][2]; 00230 hufftab[3] = &huffman_vlc[s][3]; 00231 cb_sel = imc_cb_select[s]; 00232 00233 if(stream_format_code & 4) 00234 start = 1; 00235 if(start) 00236 levlCoeffs[0] = get_bits(&q->gb, 7); 00237 for(i = start; i < BANDS; i++){ 00238 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table, hufftab[cb_sel[i]]->bits, 2); 00239 if(levlCoeffs[i] == 17) 00240 levlCoeffs[i] += get_bits(&q->gb, 4); 00241 } 00242 } 00243 00244 static void imc_decode_level_coefficients(IMCContext* q, int* levlCoeffBuf, float* flcoeffs1, 00245 float* flcoeffs2) 00246 { 00247 int i, level; 00248 float tmp, tmp2; 00249 //maybe some frequency division thingy 00250 00251 flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125 00252 flcoeffs2[0] = log(flcoeffs1[0])/log(2); 00253 tmp = flcoeffs1[0]; 00254 tmp2 = flcoeffs2[0]; 00255 00256 for(i = 1; i < BANDS; i++) { 00257 level = levlCoeffBuf[i]; 00258 if (level == 16) { 00259 flcoeffs1[i] = 1.0; 00260 flcoeffs2[i] = 0.0; 00261 } else { 00262 if (level < 17) 00263 level -=7; 00264 else if (level <= 24) 00265 level -=32; 00266 else 00267 level -=16; 00268 00269 tmp *= imc_exp_tab[15 + level]; 00270 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25 00271 flcoeffs1[i] = tmp; 00272 flcoeffs2[i] = tmp2; 00273 } 00274 } 00275 } 00276 00277 00278 static void imc_decode_level_coefficients2(IMCContext* q, int* levlCoeffBuf, float* old_floor, float* flcoeffs1, 00279 float* flcoeffs2) { 00280 int i; 00281 //FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors 00282 // and flcoeffs2 old scale factors 00283 // might be incomplete due to a missing table that is in the binary code 00284 for(i = 0; i < BANDS; i++) { 00285 flcoeffs1[i] = 0; 00286 if(levlCoeffBuf[i] < 16) { 00287 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i]; 00288 flcoeffs2[i] = (levlCoeffBuf[i]-7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25 00289 } else { 00290 flcoeffs1[i] = old_floor[i]; 00291 } 00292 } 00293 } 00294 00298 static int bit_allocation (IMCContext* q, int stream_format_code, int freebits, int flag) { 00299 int i, j; 00300 const float limit = -1.e20; 00301 float highest = 0.0; 00302 int indx; 00303 int t1 = 0; 00304 int t2 = 1; 00305 float summa = 0.0; 00306 int iacc = 0; 00307 int summer = 0; 00308 int rres, cwlen; 00309 float lowest = 1.e10; 00310 int low_indx = 0; 00311 float workT[32]; 00312 int flg; 00313 int found_indx = 0; 00314 00315 for(i = 0; i < BANDS; i++) 00316 highest = FFMAX(highest, q->flcoeffs1[i]); 00317 00318 for(i = 0; i < BANDS-1; i++) { 00319 q->flcoeffs4[i] = q->flcoeffs3[i] - log(q->flcoeffs5[i])/log(2); 00320 } 00321 q->flcoeffs4[BANDS - 1] = limit; 00322 00323 highest = highest * 0.25; 00324 00325 for(i = 0; i < BANDS; i++) { 00326 indx = -1; 00327 if ((band_tab[i+1] - band_tab[i]) == q->bandWidthT[i]) 00328 indx = 0; 00329 00330 if ((band_tab[i+1] - band_tab[i]) > q->bandWidthT[i]) 00331 indx = 1; 00332 00333 if (((band_tab[i+1] - band_tab[i])/2) >= q->bandWidthT[i]) 00334 indx = 2; 00335 00336 if (indx == -1) 00337 return -1; 00338 00339 q->flcoeffs4[i] = q->flcoeffs4[i] + xTab[(indx*2 + (q->flcoeffs1[i] < highest)) * 2 + flag]; 00340 } 00341 00342 if (stream_format_code & 0x2) { 00343 q->flcoeffs4[0] = limit; 00344 q->flcoeffs4[1] = limit; 00345 q->flcoeffs4[2] = limit; 00346 q->flcoeffs4[3] = limit; 00347 } 00348 00349 for(i = (stream_format_code & 0x2)?4:0; i < BANDS-1; i++) { 00350 iacc += q->bandWidthT[i]; 00351 summa += q->bandWidthT[i] * q->flcoeffs4[i]; 00352 } 00353 q->bandWidthT[BANDS-1] = 0; 00354 summa = (summa * 0.5 - freebits) / iacc; 00355 00356 00357 for(i = 0; i < BANDS/2; i++) { 00358 rres = summer - freebits; 00359 if((rres >= -8) && (rres <= 8)) break; 00360 00361 summer = 0; 00362 iacc = 0; 00363 00364 for(j = (stream_format_code & 0x2)?4:0; j < BANDS; j++) { 00365 cwlen = av_clip((int)((q->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6); 00366 00367 q->bitsBandT[j] = cwlen; 00368 summer += q->bandWidthT[j] * cwlen; 00369 00370 if (cwlen > 0) 00371 iacc += q->bandWidthT[j]; 00372 } 00373 00374 flg = t2; 00375 t2 = 1; 00376 if (freebits < summer) 00377 t2 = -1; 00378 if (i == 0) 00379 flg = t2; 00380 if(flg != t2) 00381 t1++; 00382 00383 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa; 00384 } 00385 00386 for(i = (stream_format_code & 0x2)?4:0; i < BANDS; i++) { 00387 for(j = band_tab[i]; j < band_tab[i+1]; j++) 00388 q->CWlengthT[j] = q->bitsBandT[i]; 00389 } 00390 00391 if (freebits > summer) { 00392 for(i = 0; i < BANDS; i++) { 00393 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415); 00394 } 00395 00396 highest = 0.0; 00397 00398 do{ 00399 if (highest <= -1.e20) 00400 break; 00401 00402 found_indx = 0; 00403 highest = -1.e20; 00404 00405 for(i = 0; i < BANDS; i++) { 00406 if (workT[i] > highest) { 00407 highest = workT[i]; 00408 found_indx = i; 00409 } 00410 } 00411 00412 if (highest > -1.e20) { 00413 workT[found_indx] -= 2.0; 00414 if (++(q->bitsBandT[found_indx]) == 6) 00415 workT[found_indx] = -1.e20; 00416 00417 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (freebits > summer); j++){ 00418 q->CWlengthT[j]++; 00419 summer++; 00420 } 00421 } 00422 }while (freebits > summer); 00423 } 00424 if (freebits < summer) { 00425 for(i = 0; i < BANDS; i++) { 00426 workT[i] = q->bitsBandT[i] ? (q->bitsBandT[i] * -2 + q->flcoeffs4[i] + 1.585) : 1.e20; 00427 } 00428 if (stream_format_code & 0x2) { 00429 workT[0] = 1.e20; 00430 workT[1] = 1.e20; 00431 workT[2] = 1.e20; 00432 workT[3] = 1.e20; 00433 } 00434 while (freebits < summer){ 00435 lowest = 1.e10; 00436 low_indx = 0; 00437 for(i = 0; i < BANDS; i++) { 00438 if (workT[i] < lowest) { 00439 lowest = workT[i]; 00440 low_indx = i; 00441 } 00442 } 00443 //if(lowest >= 1.e10) break; 00444 workT[low_indx] = lowest + 2.0; 00445 00446 if (!(--q->bitsBandT[low_indx])) 00447 workT[low_indx] = 1.e20; 00448 00449 for(j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++){ 00450 if(q->CWlengthT[j] > 0){ 00451 q->CWlengthT[j]--; 00452 summer--; 00453 } 00454 } 00455 } 00456 } 00457 return 0; 00458 } 00459 00460 static void imc_get_skip_coeff(IMCContext* q) { 00461 int i, j; 00462 00463 memset(q->skipFlagBits, 0, sizeof(q->skipFlagBits)); 00464 memset(q->skipFlagCount, 0, sizeof(q->skipFlagCount)); 00465 for(i = 0; i < BANDS; i++) { 00466 if (!q->bandFlagsBuf[i] || !q->bandWidthT[i]) 00467 continue; 00468 00469 if (!q->skipFlagRaw[i]) { 00470 q->skipFlagBits[i] = band_tab[i+1] - band_tab[i]; 00471 00472 for(j = band_tab[i]; j < band_tab[i+1]; j++) { 00473 if ((q->skipFlags[j] = get_bits1(&q->gb))) 00474 q->skipFlagCount[i]++; 00475 } 00476 } else { 00477 for(j = band_tab[i]; j < (band_tab[i+1]-1); j += 2) { 00478 if(!get_bits1(&q->gb)){//0 00479 q->skipFlagBits[i]++; 00480 q->skipFlags[j]=1; 00481 q->skipFlags[j+1]=1; 00482 q->skipFlagCount[i] += 2; 00483 }else{ 00484 if(get_bits1(&q->gb)){//11 00485 q->skipFlagBits[i] +=2; 00486 q->skipFlags[j]=0; 00487 q->skipFlags[j+1]=1; 00488 q->skipFlagCount[i]++; 00489 }else{ 00490 q->skipFlagBits[i] +=3; 00491 q->skipFlags[j+1]=0; 00492 if(!get_bits1(&q->gb)){//100 00493 q->skipFlags[j]=1; 00494 q->skipFlagCount[i]++; 00495 }else{//101 00496 q->skipFlags[j]=0; 00497 } 00498 } 00499 } 00500 } 00501 00502 if (j < band_tab[i+1]) { 00503 q->skipFlagBits[i]++; 00504 if ((q->skipFlags[j] = get_bits1(&q->gb))) 00505 q->skipFlagCount[i]++; 00506 } 00507 } 00508 } 00509 } 00510 00514 static void imc_adjust_bit_allocation (IMCContext* q, int summer) { 00515 float workT[32]; 00516 int corrected = 0; 00517 int i, j; 00518 float highest = 0; 00519 int found_indx=0; 00520 00521 for(i = 0; i < BANDS; i++) { 00522 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415); 00523 } 00524 00525 while (corrected < summer) { 00526 if(highest <= -1.e20) 00527 break; 00528 00529 highest = -1.e20; 00530 00531 for(i = 0; i < BANDS; i++) { 00532 if (workT[i] > highest) { 00533 highest = workT[i]; 00534 found_indx = i; 00535 } 00536 } 00537 00538 if (highest > -1.e20) { 00539 workT[found_indx] -= 2.0; 00540 if (++(q->bitsBandT[found_indx]) == 6) 00541 workT[found_indx] = -1.e20; 00542 00543 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) { 00544 if (!q->skipFlags[j] && (q->CWlengthT[j] < 6)) { 00545 q->CWlengthT[j]++; 00546 corrected++; 00547 } 00548 } 00549 } 00550 } 00551 } 00552 00553 static void imc_imdct256(IMCContext *q) { 00554 int i; 00555 float re, im; 00556 00557 /* prerotation */ 00558 for(i=0; i < COEFFS/2; i++){ 00559 q->samples[i].re = -(q->pre_coef1[i] * q->CWdecoded[COEFFS-1-i*2]) - 00560 (q->pre_coef2[i] * q->CWdecoded[i*2]); 00561 q->samples[i].im = (q->pre_coef2[i] * q->CWdecoded[COEFFS-1-i*2]) - 00562 (q->pre_coef1[i] * q->CWdecoded[i*2]); 00563 } 00564 00565 /* FFT */ 00566 ff_fft_permute(&q->fft, q->samples); 00567 ff_fft_calc (&q->fft, q->samples); 00568 00569 /* postrotation, window and reorder */ 00570 for(i = 0; i < COEFFS/2; i++){ 00571 re = (q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]); 00572 im = (-q->samples[i].im * q->post_cos[i]) - (q->samples[i].re * q->post_sin[i]); 00573 q->out_samples[i*2] = (q->mdct_sine_window[COEFFS-1-i*2] * q->last_fft_im[i]) + (q->mdct_sine_window[i*2] * re); 00574 q->out_samples[COEFFS-1-i*2] = (q->mdct_sine_window[i*2] * q->last_fft_im[i]) - (q->mdct_sine_window[COEFFS-1-i*2] * re); 00575 q->last_fft_im[i] = im; 00576 } 00577 } 00578 00579 static int inverse_quant_coeff (IMCContext* q, int stream_format_code) { 00580 int i, j; 00581 int middle_value, cw_len, max_size; 00582 const float* quantizer; 00583 00584 for(i = 0; i < BANDS; i++) { 00585 for(j = band_tab[i]; j < band_tab[i+1]; j++) { 00586 q->CWdecoded[j] = 0; 00587 cw_len = q->CWlengthT[j]; 00588 00589 if (cw_len <= 0 || q->skipFlags[j]) 00590 continue; 00591 00592 max_size = 1 << cw_len; 00593 middle_value = max_size >> 1; 00594 00595 if (q->codewords[j] >= max_size || q->codewords[j] < 0) 00596 return -1; 00597 00598 if (cw_len >= 4){ 00599 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1]; 00600 if (q->codewords[j] >= middle_value) 00601 q->CWdecoded[j] = quantizer[q->codewords[j] - 8] * q->flcoeffs6[i]; 00602 else 00603 q->CWdecoded[j] = -quantizer[max_size - q->codewords[j] - 8 - 1] * q->flcoeffs6[i]; 00604 }else{ 00605 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (q->bandFlagsBuf[i] << 1)]; 00606 if (q->codewords[j] >= middle_value) 00607 q->CWdecoded[j] = quantizer[q->codewords[j] - 1] * q->flcoeffs6[i]; 00608 else 00609 q->CWdecoded[j] = -quantizer[max_size - 2 - q->codewords[j]] * q->flcoeffs6[i]; 00610 } 00611 } 00612 } 00613 return 0; 00614 } 00615 00616 00617 static int imc_get_coeffs (IMCContext* q) { 00618 int i, j, cw_len, cw; 00619 00620 for(i = 0; i < BANDS; i++) { 00621 if(!q->sumLenArr[i]) continue; 00622 if (q->bandFlagsBuf[i] || q->bandWidthT[i]) { 00623 for(j = band_tab[i]; j < band_tab[i+1]; j++) { 00624 cw_len = q->CWlengthT[j]; 00625 cw = 0; 00626 00627 if (get_bits_count(&q->gb) + cw_len > 512){ 00628 //av_log(NULL,0,"Band %i coeff %i cw_len %i\n",i,j,cw_len); 00629 return -1; 00630 } 00631 00632 if(cw_len && (!q->bandFlagsBuf[i] || !q->skipFlags[j])) 00633 cw = get_bits(&q->gb, cw_len); 00634 00635 q->codewords[j] = cw; 00636 } 00637 } 00638 } 00639 return 0; 00640 } 00641 00642 static int imc_decode_frame(AVCodecContext * avctx, 00643 void *data, int *data_size, 00644 AVPacket *avpkt) 00645 { 00646 const uint8_t *buf = avpkt->data; 00647 int buf_size = avpkt->size; 00648 00649 IMCContext *q = avctx->priv_data; 00650 00651 int stream_format_code; 00652 int imc_hdr, i, j; 00653 int flag; 00654 int bits, summer; 00655 int counter, bitscount; 00656 uint16_t buf16[IMC_BLOCK_SIZE / 2]; 00657 00658 if (buf_size < IMC_BLOCK_SIZE) { 00659 av_log(avctx, AV_LOG_ERROR, "imc frame too small!\n"); 00660 return -1; 00661 } 00662 for(i = 0; i < IMC_BLOCK_SIZE / 2; i++) 00663 buf16[i] = bswap_16(((const uint16_t*)buf)[i]); 00664 00665 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8); 00666 00667 /* Check the frame header */ 00668 imc_hdr = get_bits(&q->gb, 9); 00669 if (imc_hdr != IMC_FRAME_ID) { 00670 av_log(avctx, AV_LOG_ERROR, "imc frame header check failed!\n"); 00671 av_log(avctx, AV_LOG_ERROR, "got %x instead of 0x21.\n", imc_hdr); 00672 return -1; 00673 } 00674 stream_format_code = get_bits(&q->gb, 3); 00675 00676 if(stream_format_code & 1){ 00677 av_log(avctx, AV_LOG_ERROR, "Stream code format %X is not supported\n", stream_format_code); 00678 return -1; 00679 } 00680 00681 // av_log(avctx, AV_LOG_DEBUG, "stream_format_code = %d\n", stream_format_code); 00682 00683 if (stream_format_code & 0x04) 00684 q->decoder_reset = 1; 00685 00686 if(q->decoder_reset) { 00687 memset(q->out_samples, 0, sizeof(q->out_samples)); 00688 for(i = 0; i < BANDS; i++)q->old_floor[i] = 1.0; 00689 for(i = 0; i < COEFFS; i++)q->CWdecoded[i] = 0; 00690 q->decoder_reset = 0; 00691 } 00692 00693 flag = get_bits1(&q->gb); 00694 imc_read_level_coeffs(q, stream_format_code, q->levlCoeffBuf); 00695 00696 if (stream_format_code & 0x4) 00697 imc_decode_level_coefficients(q, q->levlCoeffBuf, q->flcoeffs1, q->flcoeffs2); 00698 else 00699 imc_decode_level_coefficients2(q, q->levlCoeffBuf, q->old_floor, q->flcoeffs1, q->flcoeffs2); 00700 00701 memcpy(q->old_floor, q->flcoeffs1, 32 * sizeof(float)); 00702 00703 counter = 0; 00704 for (i=0 ; i<BANDS ; i++) { 00705 if (q->levlCoeffBuf[i] == 16) { 00706 q->bandWidthT[i] = 0; 00707 counter++; 00708 } else 00709 q->bandWidthT[i] = band_tab[i+1] - band_tab[i]; 00710 } 00711 memset(q->bandFlagsBuf, 0, BANDS * sizeof(int)); 00712 for(i = 0; i < BANDS-1; i++) { 00713 if (q->bandWidthT[i]) 00714 q->bandFlagsBuf[i] = get_bits1(&q->gb); 00715 } 00716 00717 imc_calculate_coeffs(q, q->flcoeffs1, q->flcoeffs2, q->bandWidthT, q->flcoeffs3, q->flcoeffs5); 00718 00719 bitscount = 0; 00720 /* first 4 bands will be assigned 5 bits per coefficient */ 00721 if (stream_format_code & 0x2) { 00722 bitscount += 15; 00723 00724 q->bitsBandT[0] = 5; 00725 q->CWlengthT[0] = 5; 00726 q->CWlengthT[1] = 5; 00727 q->CWlengthT[2] = 5; 00728 for(i = 1; i < 4; i++){ 00729 bits = (q->levlCoeffBuf[i] == 16) ? 0 : 5; 00730 q->bitsBandT[i] = bits; 00731 for(j = band_tab[i]; j < band_tab[i+1]; j++) { 00732 q->CWlengthT[j] = bits; 00733 bitscount += bits; 00734 } 00735 } 00736 } 00737 00738 if(bit_allocation (q, stream_format_code, 512 - bitscount - get_bits_count(&q->gb), flag) < 0) { 00739 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n"); 00740 q->decoder_reset = 1; 00741 return -1; 00742 } 00743 00744 for(i = 0; i < BANDS; i++) { 00745 q->sumLenArr[i] = 0; 00746 q->skipFlagRaw[i] = 0; 00747 for(j = band_tab[i]; j < band_tab[i+1]; j++) 00748 q->sumLenArr[i] += q->CWlengthT[j]; 00749 if (q->bandFlagsBuf[i]) 00750 if( (((band_tab[i+1] - band_tab[i]) * 1.5) > q->sumLenArr[i]) && (q->sumLenArr[i] > 0)) 00751 q->skipFlagRaw[i] = 1; 00752 } 00753 00754 imc_get_skip_coeff(q); 00755 00756 for(i = 0; i < BANDS; i++) { 00757 q->flcoeffs6[i] = q->flcoeffs1[i]; 00758 /* band has flag set and at least one coded coefficient */ 00759 if (q->bandFlagsBuf[i] && (band_tab[i+1] - band_tab[i]) != q->skipFlagCount[i]){ 00760 q->flcoeffs6[i] *= q->sqrt_tab[band_tab[i+1] - band_tab[i]] / 00761 q->sqrt_tab[(band_tab[i+1] - band_tab[i] - q->skipFlagCount[i])]; 00762 } 00763 } 00764 00765 /* calculate bits left, bits needed and adjust bit allocation */ 00766 bits = summer = 0; 00767 00768 for(i = 0; i < BANDS; i++) { 00769 if (q->bandFlagsBuf[i]) { 00770 for(j = band_tab[i]; j < band_tab[i+1]; j++) { 00771 if(q->skipFlags[j]) { 00772 summer += q->CWlengthT[j]; 00773 q->CWlengthT[j] = 0; 00774 } 00775 } 00776 bits += q->skipFlagBits[i]; 00777 summer -= q->skipFlagBits[i]; 00778 } 00779 } 00780 imc_adjust_bit_allocation(q, summer); 00781 00782 for(i = 0; i < BANDS; i++) { 00783 q->sumLenArr[i] = 0; 00784 00785 for(j = band_tab[i]; j < band_tab[i+1]; j++) 00786 if (!q->skipFlags[j]) 00787 q->sumLenArr[i] += q->CWlengthT[j]; 00788 } 00789 00790 memset(q->codewords, 0, sizeof(q->codewords)); 00791 00792 if(imc_get_coeffs(q) < 0) { 00793 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n"); 00794 q->decoder_reset = 1; 00795 return 0; 00796 } 00797 00798 if(inverse_quant_coeff(q, stream_format_code) < 0) { 00799 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n"); 00800 q->decoder_reset = 1; 00801 return 0; 00802 } 00803 00804 memset(q->skipFlags, 0, sizeof(q->skipFlags)); 00805 00806 imc_imdct256(q); 00807 00808 q->dsp.float_to_int16(data, q->out_samples, COEFFS); 00809 00810 *data_size = COEFFS * sizeof(int16_t); 00811 00812 return IMC_BLOCK_SIZE; 00813 } 00814 00815 00816 static av_cold int imc_decode_close(AVCodecContext * avctx) 00817 { 00818 IMCContext *q = avctx->priv_data; 00819 00820 ff_fft_end(&q->fft); 00821 return 0; 00822 } 00823 00824 00825 AVCodec imc_decoder = { 00826 .name = "imc", 00827 .type = AVMEDIA_TYPE_AUDIO, 00828 .id = CODEC_ID_IMC, 00829 .priv_data_size = sizeof(IMCContext), 00830 .init = imc_decode_init, 00831 .close = imc_decode_close, 00832 .decode = imc_decode_frame, 00833 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"), 00834 };