35702f9b72a16b39b98166f2e176065dd424f202
[libav.git] / libavcodec / imc.c
1 /*
2 * IMC compatible decoder
3 * Copyright (c) 2002-2004 Maxim Poliakovski
4 * Copyright (c) 2006 Benjamin Larsson
5 * Copyright (c) 2006 Konstantin Shishkov
6 *
7 * This file is part of FFmpeg.
8 *
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24 /**
25 * @file imc.c IMC - Intel Music Coder
26 * A mdct based codec using a 256 points large transform
27 * divied into 32 bands with some mix of scale factors.
28 * Only mono is supported.
29 *
30 */
31
32
33 #include <math.h>
34 #include <stddef.h>
35 #include <stdio.h>
36
37 #define ALT_BITSTREAM_READER
38 #include "avcodec.h"
39 #include "bitstream.h"
40 #include "dsputil.h"
41
42 #include "imcdata.h"
43
44 #define IMC_BLOCK_SIZE 64
45 #define IMC_FRAME_ID 0x21
46 #define BANDS 32
47 #define COEFFS 256
48
49 typedef struct {
50 float old_floor[BANDS];
51 float flcoeffs1[BANDS];
52 float flcoeffs2[BANDS];
53 float flcoeffs3[BANDS];
54 float flcoeffs4[BANDS];
55 float flcoeffs5[BANDS];
56 float flcoeffs6[BANDS];
57 float CWdecoded[COEFFS];
58
59 /** MDCT tables */
60 //@{
61 float mdct_sine_window[COEFFS];
62 float post_cos[COEFFS];
63 float post_sin[COEFFS];
64 float pre_coef1[COEFFS];
65 float pre_coef2[COEFFS];
66 float last_fft_im[COEFFS];
67 //@}
68
69 int bandWidthT[BANDS]; ///< codewords per band
70 int bitsBandT[BANDS]; ///< how many bits per codeword in band
71 int CWlengthT[COEFFS]; ///< how many bits in each codeword
72 int levlCoeffBuf[BANDS];
73 int bandFlagsBuf[BANDS]; ///< flags for each band
74 int sumLenArr[BANDS]; ///< bits for all coeffs in band
75 int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not
76 int skipFlagBits[BANDS]; ///< bits used to code skip flags
77 int skipFlagCount[BANDS]; ///< skipped coeffients per band
78 int skipFlags[COEFFS]; ///< skip coefficient decoding or not
79 int codewords[COEFFS]; ///< raw codewords read from bitstream
80 float sqrt_tab[30];
81 GetBitContext gb;
82 VLC huffman_vlc[4][4];
83 int decoder_reset;
84 float one_div_log2;
85
86 DSPContext dsp;
87 FFTContext fft;
88 DECLARE_ALIGNED_16(FFTComplex, samples[COEFFS/2]);
89 DECLARE_ALIGNED_16(float, out_samples[COEFFS]);
90 } IMCContext;
91
92
93 static int imc_decode_init(AVCodecContext * avctx)
94 {
95 int i, j;
96 IMCContext *q = avctx->priv_data;
97 double r1, r2;
98
99 q->decoder_reset = 1;
100
101 for(i = 0; i < BANDS; i++)
102 q->old_floor[i] = 1.0;
103
104 /* Build mdct window, a simple sine window normalized with sqrt(2) */
105 for(i = 0; i < COEFFS; i++)
106 q->mdct_sine_window[i] = sin((i + 0.5) / 512.0 * M_PI) * sqrt(2.0);
107 for(i = 0; i < COEFFS/2; i++){
108 q->post_cos[i] = cos(i / 256.0 * M_PI);
109 q->post_sin[i] = sin(i / 256.0 * M_PI);
110
111 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
112 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
113
114 if (i & 0x1)
115 {
116 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
117 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
118 }
119 else
120 {
121 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
122 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
123 }
124
125 q->last_fft_im[i] = 0;
126 }
127
128 /* Generate a square root table */
129
130 for(i = 0; i < 30; i++) {
131 q->sqrt_tab[i] = sqrt(i);
132 }
133
134 /* initialize the VLC tables */
135 for(i = 0; i < 4 ; i++) {
136 for(j = 0; j < 4; j++) {
137 init_vlc (&q->huffman_vlc[i][j], 9, imc_huffman_sizes[i],
138 imc_huffman_lens[i][j], 1, 1,
139 imc_huffman_bits[i][j], 2, 2, 1);
140 }
141 }
142 q->one_div_log2 = 1/log(2);
143
144 ff_fft_init(&q->fft, 7, 1);
145 dsputil_init(&q->dsp, avctx);
146 return 0;
147 }
148
149 static void imc_calculate_coeffs(IMCContext* q, float* flcoeffs1, float* flcoeffs2, int* bandWidthT,
150 float* flcoeffs3, float* flcoeffs5)
151 {
152 float workT1[BANDS];
153 float workT2[BANDS];
154 float workT3[BANDS];
155 float snr_limit = 1.e-30;
156 float accum = 0.0;
157 int i, cnt2;
158
159 for(i = 0; i < BANDS; i++) {
160 flcoeffs5[i] = workT2[i] = 0.0;
161 if (bandWidthT[i]){
162 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
163 flcoeffs3[i] = 2.0 * flcoeffs2[i];
164 } else {
165 workT1[i] = 0.0;
166 flcoeffs3[i] = -30000.0;
167 }
168 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
169 if (workT3[i] <= snr_limit)
170 workT3[i] = 0.0;
171 }
172
173 for(i = 0; i < BANDS; i++) {
174 for(cnt2 = i; cnt2 < cyclTab[i]; cnt2++)
175 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
176 workT2[cnt2-1] = workT2[cnt2-1] + workT3[i];
177 }
178
179 for(i = 1; i < BANDS; i++) {
180 accum = (workT2[i-1] + accum) * imc_weights1[i-1];
181 flcoeffs5[i] += accum;
182 }
183
184 for(i = 0; i < BANDS; i++)
185 workT2[i] = 0.0;
186
187 for(i = 0; i < BANDS; i++) {
188 for(cnt2 = i-1; cnt2 > cyclTab2[i]; cnt2--)
189 flcoeffs5[cnt2] += workT3[i];
190 workT2[cnt2+1] += workT3[i];
191 }
192
193 accum = 0.0;
194
195 for(i = BANDS-2; i >= 0; i--) {
196 accum = (workT2[i+1] + accum) * imc_weights2[i];
197 flcoeffs5[i] += accum;
198 //there is missing code here, but it seems to never be triggered
199 }
200 }
201
202
203 static void imc_read_level_coeffs(IMCContext* q, int stream_format_code, int* levlCoeffs)
204 {
205 int i;
206 VLC *hufftab[4];
207 int start = 0;
208 const uint8_t *cb_sel;
209 int s;
210
211 s = stream_format_code >> 1;
212 hufftab[0] = &q->huffman_vlc[s][0];
213 hufftab[1] = &q->huffman_vlc[s][1];
214 hufftab[2] = &q->huffman_vlc[s][2];
215 hufftab[3] = &q->huffman_vlc[s][3];
216 cb_sel = imc_cb_select[s];
217
218 if(stream_format_code & 4)
219 start = 1;
220 if(start)
221 levlCoeffs[0] = get_bits(&q->gb, 7);
222 for(i = start; i < BANDS; i++){
223 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table, hufftab[cb_sel[i]]->bits, 2);
224 if(levlCoeffs[i] == 17)
225 levlCoeffs[i] += get_bits(&q->gb, 4);
226 }
227 }
228
229 static void imc_decode_level_coefficients(IMCContext* q, int* levlCoeffBuf, float* flcoeffs1,
230 float* flcoeffs2)
231 {
232 int i, level;
233 float tmp, tmp2;
234 //maybe some frequency division thingy
235
236 flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
237 flcoeffs2[0] = log(flcoeffs1[0])/log(2);
238 tmp = flcoeffs1[0];
239 tmp2 = flcoeffs2[0];
240
241 for(i = 1; i < BANDS; i++) {
242 level = levlCoeffBuf[i];
243 if (level == 16) {
244 flcoeffs1[i] = 1.0;
245 flcoeffs2[i] = 0.0;
246 } else {
247 if (level < 17)
248 level -=7;
249 else if (level <= 24)
250 level -=32;
251 else
252 level -=16;
253
254 tmp *= imc_exp_tab[15 + level];
255 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
256 flcoeffs1[i] = tmp;
257 flcoeffs2[i] = tmp2;
258 }
259 }
260 }
261
262
263 static void imc_decode_level_coefficients2(IMCContext* q, int* levlCoeffBuf, float* old_floor, float* flcoeffs1,
264 float* flcoeffs2) {
265 int i;
266 //FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
267 // and flcoeffs2 old scale factors
268 // might be incomplete due to a missing table that is in the binary code
269 for(i = 0; i < BANDS; i++) {
270 flcoeffs1[i] = 0;
271 if(levlCoeffBuf[i] < 16) {
272 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
273 flcoeffs2[i] = (levlCoeffBuf[i]-7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
274 } else {
275 flcoeffs1[i] = old_floor[i];
276 }
277 }
278 }
279
280 /**
281 * Perform bit allocation depending on bits available
282 */
283 static int bit_allocation (IMCContext* q, int stream_format_code, int freebits, int flag) {
284 int i, j;
285 const float limit = -1.e20;
286 float highest = 0.0;
287 int indx;
288 int t1 = 0;
289 int t2 = 1;
290 float summa = 0.0;
291 int iacc = 0;
292 int summer = 0;
293 int rres, cwlen;
294 float lowest = 1.e10;
295 int low_indx = 0;
296 float workT[32];
297 int flg;
298 int found_indx = 0;
299
300 for(i = 0; i < BANDS; i++)
301 highest = FFMAX(highest, q->flcoeffs1[i]);
302
303 for(i = 0; i < BANDS-1; i++) {
304 q->flcoeffs4[i] = q->flcoeffs3[i] - log(q->flcoeffs5[i])/log(2);
305 }
306 q->flcoeffs4[BANDS - 1] = limit;
307
308 highest = highest * 0.25;
309
310 for(i = 0; i < BANDS; i++) {
311 indx = -1;
312 if ((band_tab[i+1] - band_tab[i]) == q->bandWidthT[i])
313 indx = 0;
314
315 if ((band_tab[i+1] - band_tab[i]) > q->bandWidthT[i])
316 indx = 1;
317
318 if (((band_tab[i+1] - band_tab[i])/2) >= q->bandWidthT[i])
319 indx = 2;
320
321 if (indx == -1)
322 return -1;
323
324 q->flcoeffs4[i] = q->flcoeffs4[i] + xTab[(indx*2 + (q->flcoeffs1[i] < highest)) * 2 + flag];
325 }
326
327 if (stream_format_code & 0x2) {
328 q->flcoeffs4[0] = limit;
329 q->flcoeffs4[1] = limit;
330 q->flcoeffs4[2] = limit;
331 q->flcoeffs4[3] = limit;
332 }
333
334 for(i = (stream_format_code & 0x2)?4:0; i < BANDS-1; i++) {
335 iacc += q->bandWidthT[i];
336 summa += q->bandWidthT[i] * q->flcoeffs4[i];
337 }
338 q->bandWidthT[BANDS-1] = 0;
339 summa = (summa * 0.5 - freebits) / iacc;
340
341
342 for(i = 0; i < BANDS/2; i++) {
343 rres = summer - freebits;
344 if((rres >= -8) && (rres <= 8)) break;
345
346 summer = 0;
347 iacc = 0;
348
349 for(j = (stream_format_code & 0x2)?4:0; j < BANDS; j++) {
350 cwlen = av_clip((int)((q->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
351
352 q->bitsBandT[j] = cwlen;
353 summer += q->bandWidthT[j] * cwlen;
354
355 if (cwlen > 0)
356 iacc += q->bandWidthT[j];
357 }
358
359 flg = t2;
360 t2 = 1;
361 if (freebits < summer)
362 t2 = -1;
363 if (i == 0)
364 flg = t2;
365 if(flg != t2)
366 t1++;
367
368 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
369 }
370
371 for(i = (stream_format_code & 0x2)?4:0; i < BANDS; i++) {
372 for(j = band_tab[i]; j < band_tab[i+1]; j++)
373 q->CWlengthT[j] = q->bitsBandT[i];
374 }
375
376 if (freebits > summer) {
377 for(i = 0; i < BANDS; i++) {
378 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
379 }
380
381 highest = 0.0;
382
383 do{
384 if (highest <= -1.e20)
385 break;
386
387 found_indx = 0;
388 highest = -1.e20;
389
390 for(i = 0; i < BANDS; i++) {
391 if (workT[i] > highest) {
392 highest = workT[i];
393 found_indx = i;
394 }
395 }
396
397 if (highest > -1.e20) {
398 workT[found_indx] -= 2.0;
399 if (++(q->bitsBandT[found_indx]) == 6)
400 workT[found_indx] = -1.e20;
401
402 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (freebits > summer); j++){
403 q->CWlengthT[j]++;
404 summer++;
405 }
406 }
407 }while (freebits > summer);
408 }
409 if (freebits < summer) {
410 for(i = 0; i < BANDS; i++) {
411 workT[i] = q->bitsBandT[i] ? (q->bitsBandT[i] * -2 + q->flcoeffs4[i] + 1.585) : 1.e20;
412 }
413 if (stream_format_code & 0x2) {
414 workT[0] = 1.e20;
415 workT[1] = 1.e20;
416 workT[2] = 1.e20;
417 workT[3] = 1.e20;
418 }
419 while (freebits < summer){
420 lowest = 1.e10;
421 low_indx = 0;
422 for(i = 0; i < BANDS; i++) {
423 if (workT[i] < lowest) {
424 lowest = workT[i];
425 low_indx = i;
426 }
427 }
428 //if(lowest >= 1.e10) break;
429 workT[low_indx] = lowest + 2.0;
430
431 if (!(--q->bitsBandT[low_indx]))
432 workT[low_indx] = 1.e20;
433
434 for(j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++){
435 if(q->CWlengthT[j] > 0){
436 q->CWlengthT[j]--;
437 summer--;
438 }
439 }
440 }
441 }
442 return 0;
443 }
444
445 static void imc_get_skip_coeff(IMCContext* q) {
446 int i, j;
447
448 memset(q->skipFlagBits, 0, sizeof(q->skipFlagBits));
449 memset(q->skipFlagCount, 0, sizeof(q->skipFlagCount));
450 for(i = 0; i < BANDS; i++) {
451 if (!q->bandFlagsBuf[i] || !q->bandWidthT[i])
452 continue;
453
454 if (!q->skipFlagRaw[i]) {
455 q->skipFlagBits[i] = band_tab[i+1] - band_tab[i];
456
457 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
458 if ((q->skipFlags[j] = get_bits1(&q->gb)))
459 q->skipFlagCount[i]++;
460 }
461 } else {
462 for(j = band_tab[i]; j < (band_tab[i+1]-1); j += 2) {
463 if(!get_bits1(&q->gb)){//0
464 q->skipFlagBits[i]++;
465 q->skipFlags[j]=1;
466 q->skipFlags[j+1]=1;
467 q->skipFlagCount[i] += 2;
468 }else{
469 if(get_bits1(&q->gb)){//11
470 q->skipFlagBits[i] +=2;
471 q->skipFlags[j]=0;
472 q->skipFlags[j+1]=1;
473 q->skipFlagCount[i]++;
474 }else{
475 q->skipFlagBits[i] +=3;
476 q->skipFlags[j+1]=0;
477 if(!get_bits1(&q->gb)){//100
478 q->skipFlags[j]=1;
479 q->skipFlagCount[i]++;
480 }else{//101
481 q->skipFlags[j]=0;
482 }
483 }
484 }
485 }
486
487 if (j < band_tab[i+1]) {
488 q->skipFlagBits[i]++;
489 if ((q->skipFlags[j] = get_bits1(&q->gb)))
490 q->skipFlagCount[i]++;
491 }
492 }
493 }
494 }
495
496 /**
497 * Increase highest' band coefficient sizes as some bits won't be used
498 */
499 static void imc_adjust_bit_allocation (IMCContext* q, int summer) {
500 float workT[32];
501 int corrected = 0;
502 int i, j;
503 float highest = 0;
504 int found_indx=0;
505
506 for(i = 0; i < BANDS; i++) {
507 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
508 }
509
510 while (corrected < summer) {
511 if(highest <= -1.e20)
512 break;
513
514 highest = -1.e20;
515
516 for(i = 0; i < BANDS; i++) {
517 if (workT[i] > highest) {
518 highest = workT[i];
519 found_indx = i;
520 }
521 }
522
523 if (highest > -1.e20) {
524 workT[found_indx] -= 2.0;
525 if (++(q->bitsBandT[found_indx]) == 6)
526 workT[found_indx] = -1.e20;
527
528 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
529 if (!q->skipFlags[j] && (q->CWlengthT[j] < 6)) {
530 q->CWlengthT[j]++;
531 corrected++;
532 }
533 }
534 }
535 }
536 }
537
538 static void imc_imdct256(IMCContext *q) {
539 int i;
540 float re, im;
541
542 /* prerotation */
543 for(i=0; i < COEFFS/2; i++){
544 q->samples[i].re = -(q->pre_coef1[i] * q->CWdecoded[COEFFS-1-i*2]) -
545 (q->pre_coef2[i] * q->CWdecoded[i*2]);
546 q->samples[i].im = (q->pre_coef2[i] * q->CWdecoded[COEFFS-1-i*2]) -
547 (q->pre_coef1[i] * q->CWdecoded[i*2]);
548 }
549
550 /* FFT */
551 ff_fft_permute(&q->fft, q->samples);
552 ff_fft_calc (&q->fft, q->samples);
553
554 /* postrotation, window and reorder */
555 for(i = 0; i < COEFFS/2; i++){
556 re = (q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
557 im = (-q->samples[i].im * q->post_cos[i]) - (q->samples[i].re * q->post_sin[i]);
558 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);
559 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);
560 q->last_fft_im[i] = im;
561 }
562 }
563
564 static int inverse_quant_coeff (IMCContext* q, int stream_format_code) {
565 int i, j;
566 int middle_value, cw_len, max_size;
567 const float* quantizer;
568
569 for(i = 0; i < BANDS; i++) {
570 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
571 q->CWdecoded[j] = 0;
572 cw_len = q->CWlengthT[j];
573
574 if (cw_len <= 0 || q->skipFlags[j])
575 continue;
576
577 max_size = 1 << cw_len;
578 middle_value = max_size >> 1;
579
580 if (q->codewords[j] >= max_size || q->codewords[j] < 0)
581 return -1;
582
583 if (cw_len >= 4){
584 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
585 if (q->codewords[j] >= middle_value)
586 q->CWdecoded[j] = quantizer[q->codewords[j] - 8] * q->flcoeffs6[i];
587 else
588 q->CWdecoded[j] = -quantizer[max_size - q->codewords[j] - 8 - 1] * q->flcoeffs6[i];
589 }else{
590 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (q->bandFlagsBuf[i] << 1)];
591 if (q->codewords[j] >= middle_value)
592 q->CWdecoded[j] = quantizer[q->codewords[j] - 1] * q->flcoeffs6[i];
593 else
594 q->CWdecoded[j] = -quantizer[max_size - 2 - q->codewords[j]] * q->flcoeffs6[i];
595 }
596 }
597 }
598 return 0;
599 }
600
601
602 static int imc_get_coeffs (IMCContext* q) {
603 int i, j, cw_len, cw;
604
605 for(i = 0; i < BANDS; i++) {
606 if(!q->sumLenArr[i]) continue;
607 if (q->bandFlagsBuf[i] || q->bandWidthT[i]) {
608 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
609 cw_len = q->CWlengthT[j];
610 cw = 0;
611
612 if (get_bits_count(&q->gb) + cw_len > 512){
613 //av_log(NULL,0,"Band %i coeff %i cw_len %i\n",i,j,cw_len);
614 return -1;
615 }
616
617 if(cw_len && (!q->bandFlagsBuf[i] || !q->skipFlags[j]))
618 cw = get_bits(&q->gb, cw_len);
619
620 q->codewords[j] = cw;
621 }
622 }
623 }
624 return 0;
625 }
626
627 static int imc_decode_frame(AVCodecContext * avctx,
628 void *data, int *data_size,
629 const uint8_t * buf, int buf_size)
630 {
631
632 IMCContext *q = avctx->priv_data;
633
634 int stream_format_code;
635 int imc_hdr, i, j;
636 int flag;
637 int bits, summer;
638 int counter, bitscount;
639 uint16_t buf16[IMC_BLOCK_SIZE / 2];
640
641 for(i = 0; i < IMC_BLOCK_SIZE / 2; i++)
642 buf16[i] = bswap_16(((const uint16_t*)buf)[i]);
643
644 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
645
646 /* Check the frame header */
647 imc_hdr = get_bits(&q->gb, 9);
648 if (imc_hdr != IMC_FRAME_ID) {
649 av_log(avctx, AV_LOG_ERROR, "imc frame header check failed!\n");
650 av_log(avctx, AV_LOG_ERROR, "got %x instead of 0x21.\n", imc_hdr);
651 return -1;
652 }
653 stream_format_code = get_bits(&q->gb, 3);
654
655 if(stream_format_code & 1){
656 av_log(avctx, AV_LOG_ERROR, "Stream code format %X is not supported\n", stream_format_code);
657 return -1;
658 }
659
660 // av_log(avctx, AV_LOG_DEBUG, "stream_format_code = %d\n", stream_format_code);
661
662 if (stream_format_code & 0x04)
663 q->decoder_reset = 1;
664
665 if(q->decoder_reset) {
666 memset(q->out_samples, 0, sizeof(q->out_samples));
667 for(i = 0; i < BANDS; i++)q->old_floor[i] = 1.0;
668 for(i = 0; i < COEFFS; i++)q->CWdecoded[i] = 0;
669 q->decoder_reset = 0;
670 }
671
672 flag = get_bits1(&q->gb);
673 imc_read_level_coeffs(q, stream_format_code, q->levlCoeffBuf);
674
675 if (stream_format_code & 0x4)
676 imc_decode_level_coefficients(q, q->levlCoeffBuf, q->flcoeffs1, q->flcoeffs2);
677 else
678 imc_decode_level_coefficients2(q, q->levlCoeffBuf, q->old_floor, q->flcoeffs1, q->flcoeffs2);
679
680 memcpy(q->old_floor, q->flcoeffs1, 32 * sizeof(float));
681
682 counter = 0;
683 for (i=0 ; i<BANDS ; i++) {
684 if (q->levlCoeffBuf[i] == 16) {
685 q->bandWidthT[i] = 0;
686 counter++;
687 } else
688 q->bandWidthT[i] = band_tab[i+1] - band_tab[i];
689 }
690 memset(q->bandFlagsBuf, 0, BANDS * sizeof(int));
691 for(i = 0; i < BANDS-1; i++) {
692 if (q->bandWidthT[i])
693 q->bandFlagsBuf[i] = get_bits1(&q->gb);
694 }
695
696 imc_calculate_coeffs(q, q->flcoeffs1, q->flcoeffs2, q->bandWidthT, q->flcoeffs3, q->flcoeffs5);
697
698 bitscount = 0;
699 /* first 4 bands will be assigned 5 bits per coefficient */
700 if (stream_format_code & 0x2) {
701 bitscount += 15;
702
703 q->bitsBandT[0] = 5;
704 q->CWlengthT[0] = 5;
705 q->CWlengthT[1] = 5;
706 q->CWlengthT[2] = 5;
707 for(i = 1; i < 4; i++){
708 bits = (q->levlCoeffBuf[i] == 16) ? 0 : 5;
709 q->bitsBandT[i] = bits;
710 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
711 q->CWlengthT[j] = bits;
712 bitscount += bits;
713 }
714 }
715 }
716
717 if(bit_allocation (q, stream_format_code, 512 - bitscount - get_bits_count(&q->gb), flag) < 0) {
718 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
719 q->decoder_reset = 1;
720 return -1;
721 }
722
723 for(i = 0; i < BANDS; i++) {
724 q->sumLenArr[i] = 0;
725 q->skipFlagRaw[i] = 0;
726 for(j = band_tab[i]; j < band_tab[i+1]; j++)
727 q->sumLenArr[i] += q->CWlengthT[j];
728 if (q->bandFlagsBuf[i])
729 if( (((band_tab[i+1] - band_tab[i]) * 1.5) > q->sumLenArr[i]) && (q->sumLenArr[i] > 0))
730 q->skipFlagRaw[i] = 1;
731 }
732
733 imc_get_skip_coeff(q);
734
735 for(i = 0; i < BANDS; i++) {
736 q->flcoeffs6[i] = q->flcoeffs1[i];
737 /* band has flag set and at least one coded coefficient */
738 if (q->bandFlagsBuf[i] && (band_tab[i+1] - band_tab[i]) != q->skipFlagCount[i]){
739 q->flcoeffs6[i] *= q->sqrt_tab[band_tab[i+1] - band_tab[i]] /
740 q->sqrt_tab[(band_tab[i+1] - band_tab[i] - q->skipFlagCount[i])];
741 }
742 }
743
744 /* calculate bits left, bits needed and adjust bit allocation */
745 bits = summer = 0;
746
747 for(i = 0; i < BANDS; i++) {
748 if (q->bandFlagsBuf[i]) {
749 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
750 if(q->skipFlags[j]) {
751 summer += q->CWlengthT[j];
752 q->CWlengthT[j] = 0;
753 }
754 }
755 bits += q->skipFlagBits[i];
756 summer -= q->skipFlagBits[i];
757 }
758 }
759 imc_adjust_bit_allocation(q, summer);
760
761 for(i = 0; i < BANDS; i++) {
762 q->sumLenArr[i] = 0;
763
764 for(j = band_tab[i]; j < band_tab[i+1]; j++)
765 if (!q->skipFlags[j])
766 q->sumLenArr[i] += q->CWlengthT[j];
767 }
768
769 memset(q->codewords, 0, sizeof(q->codewords));
770
771 if(imc_get_coeffs(q) < 0) {
772 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");
773 q->decoder_reset = 1;
774 return 0;
775 }
776
777 if(inverse_quant_coeff(q, stream_format_code) < 0) {
778 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
779 q->decoder_reset = 1;
780 return 0;
781 }
782
783 memset(q->skipFlags, 0, sizeof(q->skipFlags));
784
785 imc_imdct256(q);
786
787 q->dsp.float_to_int16(data, q->out_samples, COEFFS);
788
789 *data_size = COEFFS * sizeof(int16_t);
790
791 return IMC_BLOCK_SIZE;
792 }
793
794
795 static int imc_decode_close(AVCodecContext * avctx)
796 {
797 IMCContext *q = avctx->priv_data;
798
799 ff_fft_end(&q->fft);
800 return 0;
801 }
802
803
804 AVCodec imc_decoder = {
805 .name = "imc",
806 .type = CODEC_TYPE_AUDIO,
807 .id = CODEC_ID_IMC,
808 .priv_data_size = sizeof(IMCContext),
809 .init = imc_decode_init,
810 .close = imc_decode_close,
811 .decode = imc_decode_frame,
812 };