c8bf3367ac93882257453c49a7685ce3f7abcde4
[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 libavcodec/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 "get_bits.h"
40 #include "dsputil.h"
41 #include "fft.h"
42
43 #include "imcdata.h"
44
45 #define IMC_BLOCK_SIZE 64
46 #define IMC_FRAME_ID 0x21
47 #define BANDS 32
48 #define COEFFS 256
49
50 typedef struct {
51 float old_floor[BANDS];
52 float flcoeffs1[BANDS];
53 float flcoeffs2[BANDS];
54 float flcoeffs3[BANDS];
55 float flcoeffs4[BANDS];
56 float flcoeffs5[BANDS];
57 float flcoeffs6[BANDS];
58 float CWdecoded[COEFFS];
59
60 /** MDCT tables */
61 //@{
62 float mdct_sine_window[COEFFS];
63 float post_cos[COEFFS];
64 float post_sin[COEFFS];
65 float pre_coef1[COEFFS];
66 float pre_coef2[COEFFS];
67 float last_fft_im[COEFFS];
68 //@}
69
70 int bandWidthT[BANDS]; ///< codewords per band
71 int bitsBandT[BANDS]; ///< how many bits per codeword in band
72 int CWlengthT[COEFFS]; ///< how many bits in each codeword
73 int levlCoeffBuf[BANDS];
74 int bandFlagsBuf[BANDS]; ///< flags for each band
75 int sumLenArr[BANDS]; ///< bits for all coeffs in band
76 int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not
77 int skipFlagBits[BANDS]; ///< bits used to code skip flags
78 int skipFlagCount[BANDS]; ///< skipped coeffients per band
79 int skipFlags[COEFFS]; ///< skip coefficient decoding or not
80 int codewords[COEFFS]; ///< raw codewords read from bitstream
81 float sqrt_tab[30];
82 GetBitContext gb;
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 static VLC huffman_vlc[4][4];
93
94 #define VLC_TABLES_SIZE 9512
95
96 static const int vlc_offsets[17] = {
97 0, 640, 1156, 1732, 2308, 2852, 3396, 3924,
98 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE};
99
100 static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];
101
102 static av_cold int imc_decode_init(AVCodecContext * avctx)
103 {
104 int i, j;
105 IMCContext *q = avctx->priv_data;
106 double r1, r2;
107
108 q->decoder_reset = 1;
109
110 for(i = 0; i < BANDS; i++)
111 q->old_floor[i] = 1.0;
112
113 /* Build mdct window, a simple sine window normalized with sqrt(2) */
114 ff_sine_window_init(q->mdct_sine_window, COEFFS);
115 for(i = 0; i < COEFFS; i++)
116 q->mdct_sine_window[i] *= sqrt(2.0);
117 for(i = 0; i < COEFFS/2; i++){
118 q->post_cos[i] = cos(i / 256.0 * M_PI);
119 q->post_sin[i] = sin(i / 256.0 * M_PI);
120
121 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
122 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
123
124 if (i & 0x1)
125 {
126 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
127 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
128 }
129 else
130 {
131 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
132 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
133 }
134
135 q->last_fft_im[i] = 0;
136 }
137
138 /* Generate a square root table */
139
140 for(i = 0; i < 30; i++) {
141 q->sqrt_tab[i] = sqrt(i);
142 }
143
144 /* initialize the VLC tables */
145 for(i = 0; i < 4 ; i++) {
146 for(j = 0; j < 4; j++) {
147 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]];
148 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];
149 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i],
150 imc_huffman_lens[i][j], 1, 1,
151 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC);
152 }
153 }
154 q->one_div_log2 = 1/log(2);
155
156 ff_fft_init(&q->fft, 7, 1);
157 dsputil_init(&q->dsp, avctx);
158 avctx->sample_fmt = SAMPLE_FMT_S16;
159 avctx->channel_layout = (avctx->channels==2) ? CH_LAYOUT_STEREO : CH_LAYOUT_MONO;
160 return 0;
161 }
162
163 static void imc_calculate_coeffs(IMCContext* q, float* flcoeffs1, float* flcoeffs2, int* bandWidthT,
164 float* flcoeffs3, float* flcoeffs5)
165 {
166 float workT1[BANDS];
167 float workT2[BANDS];
168 float workT3[BANDS];
169 float snr_limit = 1.e-30;
170 float accum = 0.0;
171 int i, cnt2;
172
173 for(i = 0; i < BANDS; i++) {
174 flcoeffs5[i] = workT2[i] = 0.0;
175 if (bandWidthT[i]){
176 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
177 flcoeffs3[i] = 2.0 * flcoeffs2[i];
178 } else {
179 workT1[i] = 0.0;
180 flcoeffs3[i] = -30000.0;
181 }
182 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
183 if (workT3[i] <= snr_limit)
184 workT3[i] = 0.0;
185 }
186
187 for(i = 0; i < BANDS; i++) {
188 for(cnt2 = i; cnt2 < cyclTab[i]; cnt2++)
189 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
190 workT2[cnt2-1] = workT2[cnt2-1] + workT3[i];
191 }
192
193 for(i = 1; i < BANDS; i++) {
194 accum = (workT2[i-1] + accum) * imc_weights1[i-1];
195 flcoeffs5[i] += accum;
196 }
197
198 for(i = 0; i < BANDS; i++)
199 workT2[i] = 0.0;
200
201 for(i = 0; i < BANDS; i++) {
202 for(cnt2 = i-1; cnt2 > cyclTab2[i]; cnt2--)
203 flcoeffs5[cnt2] += workT3[i];
204 workT2[cnt2+1] += workT3[i];
205 }
206
207 accum = 0.0;
208
209 for(i = BANDS-2; i >= 0; i--) {
210 accum = (workT2[i+1] + accum) * imc_weights2[i];
211 flcoeffs5[i] += accum;
212 //there is missing code here, but it seems to never be triggered
213 }
214 }
215
216
217 static void imc_read_level_coeffs(IMCContext* q, int stream_format_code, int* levlCoeffs)
218 {
219 int i;
220 VLC *hufftab[4];
221 int start = 0;
222 const uint8_t *cb_sel;
223 int s;
224
225 s = stream_format_code >> 1;
226 hufftab[0] = &huffman_vlc[s][0];
227 hufftab[1] = &huffman_vlc[s][1];
228 hufftab[2] = &huffman_vlc[s][2];
229 hufftab[3] = &huffman_vlc[s][3];
230 cb_sel = imc_cb_select[s];
231
232 if(stream_format_code & 4)
233 start = 1;
234 if(start)
235 levlCoeffs[0] = get_bits(&q->gb, 7);
236 for(i = start; i < BANDS; i++){
237 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table, hufftab[cb_sel[i]]->bits, 2);
238 if(levlCoeffs[i] == 17)
239 levlCoeffs[i] += get_bits(&q->gb, 4);
240 }
241 }
242
243 static void imc_decode_level_coefficients(IMCContext* q, int* levlCoeffBuf, float* flcoeffs1,
244 float* flcoeffs2)
245 {
246 int i, level;
247 float tmp, tmp2;
248 //maybe some frequency division thingy
249
250 flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
251 flcoeffs2[0] = log(flcoeffs1[0])/log(2);
252 tmp = flcoeffs1[0];
253 tmp2 = flcoeffs2[0];
254
255 for(i = 1; i < BANDS; i++) {
256 level = levlCoeffBuf[i];
257 if (level == 16) {
258 flcoeffs1[i] = 1.0;
259 flcoeffs2[i] = 0.0;
260 } else {
261 if (level < 17)
262 level -=7;
263 else if (level <= 24)
264 level -=32;
265 else
266 level -=16;
267
268 tmp *= imc_exp_tab[15 + level];
269 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
270 flcoeffs1[i] = tmp;
271 flcoeffs2[i] = tmp2;
272 }
273 }
274 }
275
276
277 static void imc_decode_level_coefficients2(IMCContext* q, int* levlCoeffBuf, float* old_floor, float* flcoeffs1,
278 float* flcoeffs2) {
279 int i;
280 //FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
281 // and flcoeffs2 old scale factors
282 // might be incomplete due to a missing table that is in the binary code
283 for(i = 0; i < BANDS; i++) {
284 flcoeffs1[i] = 0;
285 if(levlCoeffBuf[i] < 16) {
286 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
287 flcoeffs2[i] = (levlCoeffBuf[i]-7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
288 } else {
289 flcoeffs1[i] = old_floor[i];
290 }
291 }
292 }
293
294 /**
295 * Perform bit allocation depending on bits available
296 */
297 static int bit_allocation (IMCContext* q, int stream_format_code, int freebits, int flag) {
298 int i, j;
299 const float limit = -1.e20;
300 float highest = 0.0;
301 int indx;
302 int t1 = 0;
303 int t2 = 1;
304 float summa = 0.0;
305 int iacc = 0;
306 int summer = 0;
307 int rres, cwlen;
308 float lowest = 1.e10;
309 int low_indx = 0;
310 float workT[32];
311 int flg;
312 int found_indx = 0;
313
314 for(i = 0; i < BANDS; i++)
315 highest = FFMAX(highest, q->flcoeffs1[i]);
316
317 for(i = 0; i < BANDS-1; i++) {
318 q->flcoeffs4[i] = q->flcoeffs3[i] - log(q->flcoeffs5[i])/log(2);
319 }
320 q->flcoeffs4[BANDS - 1] = limit;
321
322 highest = highest * 0.25;
323
324 for(i = 0; i < BANDS; i++) {
325 indx = -1;
326 if ((band_tab[i+1] - band_tab[i]) == q->bandWidthT[i])
327 indx = 0;
328
329 if ((band_tab[i+1] - band_tab[i]) > q->bandWidthT[i])
330 indx = 1;
331
332 if (((band_tab[i+1] - band_tab[i])/2) >= q->bandWidthT[i])
333 indx = 2;
334
335 if (indx == -1)
336 return -1;
337
338 q->flcoeffs4[i] = q->flcoeffs4[i] + xTab[(indx*2 + (q->flcoeffs1[i] < highest)) * 2 + flag];
339 }
340
341 if (stream_format_code & 0x2) {
342 q->flcoeffs4[0] = limit;
343 q->flcoeffs4[1] = limit;
344 q->flcoeffs4[2] = limit;
345 q->flcoeffs4[3] = limit;
346 }
347
348 for(i = (stream_format_code & 0x2)?4:0; i < BANDS-1; i++) {
349 iacc += q->bandWidthT[i];
350 summa += q->bandWidthT[i] * q->flcoeffs4[i];
351 }
352 q->bandWidthT[BANDS-1] = 0;
353 summa = (summa * 0.5 - freebits) / iacc;
354
355
356 for(i = 0; i < BANDS/2; i++) {
357 rres = summer - freebits;
358 if((rres >= -8) && (rres <= 8)) break;
359
360 summer = 0;
361 iacc = 0;
362
363 for(j = (stream_format_code & 0x2)?4:0; j < BANDS; j++) {
364 cwlen = av_clip((int)((q->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
365
366 q->bitsBandT[j] = cwlen;
367 summer += q->bandWidthT[j] * cwlen;
368
369 if (cwlen > 0)
370 iacc += q->bandWidthT[j];
371 }
372
373 flg = t2;
374 t2 = 1;
375 if (freebits < summer)
376 t2 = -1;
377 if (i == 0)
378 flg = t2;
379 if(flg != t2)
380 t1++;
381
382 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
383 }
384
385 for(i = (stream_format_code & 0x2)?4:0; i < BANDS; i++) {
386 for(j = band_tab[i]; j < band_tab[i+1]; j++)
387 q->CWlengthT[j] = q->bitsBandT[i];
388 }
389
390 if (freebits > summer) {
391 for(i = 0; i < BANDS; i++) {
392 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
393 }
394
395 highest = 0.0;
396
397 do{
398 if (highest <= -1.e20)
399 break;
400
401 found_indx = 0;
402 highest = -1.e20;
403
404 for(i = 0; i < BANDS; i++) {
405 if (workT[i] > highest) {
406 highest = workT[i];
407 found_indx = i;
408 }
409 }
410
411 if (highest > -1.e20) {
412 workT[found_indx] -= 2.0;
413 if (++(q->bitsBandT[found_indx]) == 6)
414 workT[found_indx] = -1.e20;
415
416 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (freebits > summer); j++){
417 q->CWlengthT[j]++;
418 summer++;
419 }
420 }
421 }while (freebits > summer);
422 }
423 if (freebits < summer) {
424 for(i = 0; i < BANDS; i++) {
425 workT[i] = q->bitsBandT[i] ? (q->bitsBandT[i] * -2 + q->flcoeffs4[i] + 1.585) : 1.e20;
426 }
427 if (stream_format_code & 0x2) {
428 workT[0] = 1.e20;
429 workT[1] = 1.e20;
430 workT[2] = 1.e20;
431 workT[3] = 1.e20;
432 }
433 while (freebits < summer){
434 lowest = 1.e10;
435 low_indx = 0;
436 for(i = 0; i < BANDS; i++) {
437 if (workT[i] < lowest) {
438 lowest = workT[i];
439 low_indx = i;
440 }
441 }
442 //if(lowest >= 1.e10) break;
443 workT[low_indx] = lowest + 2.0;
444
445 if (!(--q->bitsBandT[low_indx]))
446 workT[low_indx] = 1.e20;
447
448 for(j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++){
449 if(q->CWlengthT[j] > 0){
450 q->CWlengthT[j]--;
451 summer--;
452 }
453 }
454 }
455 }
456 return 0;
457 }
458
459 static void imc_get_skip_coeff(IMCContext* q) {
460 int i, j;
461
462 memset(q->skipFlagBits, 0, sizeof(q->skipFlagBits));
463 memset(q->skipFlagCount, 0, sizeof(q->skipFlagCount));
464 for(i = 0; i < BANDS; i++) {
465 if (!q->bandFlagsBuf[i] || !q->bandWidthT[i])
466 continue;
467
468 if (!q->skipFlagRaw[i]) {
469 q->skipFlagBits[i] = band_tab[i+1] - band_tab[i];
470
471 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
472 if ((q->skipFlags[j] = get_bits1(&q->gb)))
473 q->skipFlagCount[i]++;
474 }
475 } else {
476 for(j = band_tab[i]; j < (band_tab[i+1]-1); j += 2) {
477 if(!get_bits1(&q->gb)){//0
478 q->skipFlagBits[i]++;
479 q->skipFlags[j]=1;
480 q->skipFlags[j+1]=1;
481 q->skipFlagCount[i] += 2;
482 }else{
483 if(get_bits1(&q->gb)){//11
484 q->skipFlagBits[i] +=2;
485 q->skipFlags[j]=0;
486 q->skipFlags[j+1]=1;
487 q->skipFlagCount[i]++;
488 }else{
489 q->skipFlagBits[i] +=3;
490 q->skipFlags[j+1]=0;
491 if(!get_bits1(&q->gb)){//100
492 q->skipFlags[j]=1;
493 q->skipFlagCount[i]++;
494 }else{//101
495 q->skipFlags[j]=0;
496 }
497 }
498 }
499 }
500
501 if (j < band_tab[i+1]) {
502 q->skipFlagBits[i]++;
503 if ((q->skipFlags[j] = get_bits1(&q->gb)))
504 q->skipFlagCount[i]++;
505 }
506 }
507 }
508 }
509
510 /**
511 * Increase highest' band coefficient sizes as some bits won't be used
512 */
513 static void imc_adjust_bit_allocation (IMCContext* q, int summer) {
514 float workT[32];
515 int corrected = 0;
516 int i, j;
517 float highest = 0;
518 int found_indx=0;
519
520 for(i = 0; i < BANDS; i++) {
521 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
522 }
523
524 while (corrected < summer) {
525 if(highest <= -1.e20)
526 break;
527
528 highest = -1.e20;
529
530 for(i = 0; i < BANDS; i++) {
531 if (workT[i] > highest) {
532 highest = workT[i];
533 found_indx = i;
534 }
535 }
536
537 if (highest > -1.e20) {
538 workT[found_indx] -= 2.0;
539 if (++(q->bitsBandT[found_indx]) == 6)
540 workT[found_indx] = -1.e20;
541
542 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
543 if (!q->skipFlags[j] && (q->CWlengthT[j] < 6)) {
544 q->CWlengthT[j]++;
545 corrected++;
546 }
547 }
548 }
549 }
550 }
551
552 static void imc_imdct256(IMCContext *q) {
553 int i;
554 float re, im;
555
556 /* prerotation */
557 for(i=0; i < COEFFS/2; i++){
558 q->samples[i].re = -(q->pre_coef1[i] * q->CWdecoded[COEFFS-1-i*2]) -
559 (q->pre_coef2[i] * q->CWdecoded[i*2]);
560 q->samples[i].im = (q->pre_coef2[i] * q->CWdecoded[COEFFS-1-i*2]) -
561 (q->pre_coef1[i] * q->CWdecoded[i*2]);
562 }
563
564 /* FFT */
565 ff_fft_permute(&q->fft, q->samples);
566 ff_fft_calc (&q->fft, q->samples);
567
568 /* postrotation, window and reorder */
569 for(i = 0; i < COEFFS/2; i++){
570 re = (q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
571 im = (-q->samples[i].im * q->post_cos[i]) - (q->samples[i].re * q->post_sin[i]);
572 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);
573 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);
574 q->last_fft_im[i] = im;
575 }
576 }
577
578 static int inverse_quant_coeff (IMCContext* q, int stream_format_code) {
579 int i, j;
580 int middle_value, cw_len, max_size;
581 const float* quantizer;
582
583 for(i = 0; i < BANDS; i++) {
584 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
585 q->CWdecoded[j] = 0;
586 cw_len = q->CWlengthT[j];
587
588 if (cw_len <= 0 || q->skipFlags[j])
589 continue;
590
591 max_size = 1 << cw_len;
592 middle_value = max_size >> 1;
593
594 if (q->codewords[j] >= max_size || q->codewords[j] < 0)
595 return -1;
596
597 if (cw_len >= 4){
598 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
599 if (q->codewords[j] >= middle_value)
600 q->CWdecoded[j] = quantizer[q->codewords[j] - 8] * q->flcoeffs6[i];
601 else
602 q->CWdecoded[j] = -quantizer[max_size - q->codewords[j] - 8 - 1] * q->flcoeffs6[i];
603 }else{
604 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (q->bandFlagsBuf[i] << 1)];
605 if (q->codewords[j] >= middle_value)
606 q->CWdecoded[j] = quantizer[q->codewords[j] - 1] * q->flcoeffs6[i];
607 else
608 q->CWdecoded[j] = -quantizer[max_size - 2 - q->codewords[j]] * q->flcoeffs6[i];
609 }
610 }
611 }
612 return 0;
613 }
614
615
616 static int imc_get_coeffs (IMCContext* q) {
617 int i, j, cw_len, cw;
618
619 for(i = 0; i < BANDS; i++) {
620 if(!q->sumLenArr[i]) continue;
621 if (q->bandFlagsBuf[i] || q->bandWidthT[i]) {
622 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
623 cw_len = q->CWlengthT[j];
624 cw = 0;
625
626 if (get_bits_count(&q->gb) + cw_len > 512){
627 //av_log(NULL,0,"Band %i coeff %i cw_len %i\n",i,j,cw_len);
628 return -1;
629 }
630
631 if(cw_len && (!q->bandFlagsBuf[i] || !q->skipFlags[j]))
632 cw = get_bits(&q->gb, cw_len);
633
634 q->codewords[j] = cw;
635 }
636 }
637 }
638 return 0;
639 }
640
641 static int imc_decode_frame(AVCodecContext * avctx,
642 void *data, int *data_size,
643 AVPacket *avpkt)
644 {
645 const uint8_t *buf = avpkt->data;
646 int buf_size = avpkt->size;
647
648 IMCContext *q = avctx->priv_data;
649
650 int stream_format_code;
651 int imc_hdr, i, j;
652 int flag;
653 int bits, summer;
654 int counter, bitscount;
655 uint16_t buf16[IMC_BLOCK_SIZE / 2];
656
657 if (buf_size < IMC_BLOCK_SIZE) {
658 av_log(avctx, AV_LOG_ERROR, "imc frame too small!\n");
659 return -1;
660 }
661 for(i = 0; i < IMC_BLOCK_SIZE / 2; i++)
662 buf16[i] = bswap_16(((const uint16_t*)buf)[i]);
663
664 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
665
666 /* Check the frame header */
667 imc_hdr = get_bits(&q->gb, 9);
668 if (imc_hdr != IMC_FRAME_ID) {
669 av_log(avctx, AV_LOG_ERROR, "imc frame header check failed!\n");
670 av_log(avctx, AV_LOG_ERROR, "got %x instead of 0x21.\n", imc_hdr);
671 return -1;
672 }
673 stream_format_code = get_bits(&q->gb, 3);
674
675 if(stream_format_code & 1){
676 av_log(avctx, AV_LOG_ERROR, "Stream code format %X is not supported\n", stream_format_code);
677 return -1;
678 }
679
680 // av_log(avctx, AV_LOG_DEBUG, "stream_format_code = %d\n", stream_format_code);
681
682 if (stream_format_code & 0x04)
683 q->decoder_reset = 1;
684
685 if(q->decoder_reset) {
686 memset(q->out_samples, 0, sizeof(q->out_samples));
687 for(i = 0; i < BANDS; i++)q->old_floor[i] = 1.0;
688 for(i = 0; i < COEFFS; i++)q->CWdecoded[i] = 0;
689 q->decoder_reset = 0;
690 }
691
692 flag = get_bits1(&q->gb);
693 imc_read_level_coeffs(q, stream_format_code, q->levlCoeffBuf);
694
695 if (stream_format_code & 0x4)
696 imc_decode_level_coefficients(q, q->levlCoeffBuf, q->flcoeffs1, q->flcoeffs2);
697 else
698 imc_decode_level_coefficients2(q, q->levlCoeffBuf, q->old_floor, q->flcoeffs1, q->flcoeffs2);
699
700 memcpy(q->old_floor, q->flcoeffs1, 32 * sizeof(float));
701
702 counter = 0;
703 for (i=0 ; i<BANDS ; i++) {
704 if (q->levlCoeffBuf[i] == 16) {
705 q->bandWidthT[i] = 0;
706 counter++;
707 } else
708 q->bandWidthT[i] = band_tab[i+1] - band_tab[i];
709 }
710 memset(q->bandFlagsBuf, 0, BANDS * sizeof(int));
711 for(i = 0; i < BANDS-1; i++) {
712 if (q->bandWidthT[i])
713 q->bandFlagsBuf[i] = get_bits1(&q->gb);
714 }
715
716 imc_calculate_coeffs(q, q->flcoeffs1, q->flcoeffs2, q->bandWidthT, q->flcoeffs3, q->flcoeffs5);
717
718 bitscount = 0;
719 /* first 4 bands will be assigned 5 bits per coefficient */
720 if (stream_format_code & 0x2) {
721 bitscount += 15;
722
723 q->bitsBandT[0] = 5;
724 q->CWlengthT[0] = 5;
725 q->CWlengthT[1] = 5;
726 q->CWlengthT[2] = 5;
727 for(i = 1; i < 4; i++){
728 bits = (q->levlCoeffBuf[i] == 16) ? 0 : 5;
729 q->bitsBandT[i] = bits;
730 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
731 q->CWlengthT[j] = bits;
732 bitscount += bits;
733 }
734 }
735 }
736
737 if(bit_allocation (q, stream_format_code, 512 - bitscount - get_bits_count(&q->gb), flag) < 0) {
738 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
739 q->decoder_reset = 1;
740 return -1;
741 }
742
743 for(i = 0; i < BANDS; i++) {
744 q->sumLenArr[i] = 0;
745 q->skipFlagRaw[i] = 0;
746 for(j = band_tab[i]; j < band_tab[i+1]; j++)
747 q->sumLenArr[i] += q->CWlengthT[j];
748 if (q->bandFlagsBuf[i])
749 if( (((band_tab[i+1] - band_tab[i]) * 1.5) > q->sumLenArr[i]) && (q->sumLenArr[i] > 0))
750 q->skipFlagRaw[i] = 1;
751 }
752
753 imc_get_skip_coeff(q);
754
755 for(i = 0; i < BANDS; i++) {
756 q->flcoeffs6[i] = q->flcoeffs1[i];
757 /* band has flag set and at least one coded coefficient */
758 if (q->bandFlagsBuf[i] && (band_tab[i+1] - band_tab[i]) != q->skipFlagCount[i]){
759 q->flcoeffs6[i] *= q->sqrt_tab[band_tab[i+1] - band_tab[i]] /
760 q->sqrt_tab[(band_tab[i+1] - band_tab[i] - q->skipFlagCount[i])];
761 }
762 }
763
764 /* calculate bits left, bits needed and adjust bit allocation */
765 bits = summer = 0;
766
767 for(i = 0; i < BANDS; i++) {
768 if (q->bandFlagsBuf[i]) {
769 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
770 if(q->skipFlags[j]) {
771 summer += q->CWlengthT[j];
772 q->CWlengthT[j] = 0;
773 }
774 }
775 bits += q->skipFlagBits[i];
776 summer -= q->skipFlagBits[i];
777 }
778 }
779 imc_adjust_bit_allocation(q, summer);
780
781 for(i = 0; i < BANDS; i++) {
782 q->sumLenArr[i] = 0;
783
784 for(j = band_tab[i]; j < band_tab[i+1]; j++)
785 if (!q->skipFlags[j])
786 q->sumLenArr[i] += q->CWlengthT[j];
787 }
788
789 memset(q->codewords, 0, sizeof(q->codewords));
790
791 if(imc_get_coeffs(q) < 0) {
792 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");
793 q->decoder_reset = 1;
794 return 0;
795 }
796
797 if(inverse_quant_coeff(q, stream_format_code) < 0) {
798 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
799 q->decoder_reset = 1;
800 return 0;
801 }
802
803 memset(q->skipFlags, 0, sizeof(q->skipFlags));
804
805 imc_imdct256(q);
806
807 q->dsp.float_to_int16(data, q->out_samples, COEFFS);
808
809 *data_size = COEFFS * sizeof(int16_t);
810
811 return IMC_BLOCK_SIZE;
812 }
813
814
815 static av_cold int imc_decode_close(AVCodecContext * avctx)
816 {
817 IMCContext *q = avctx->priv_data;
818
819 ff_fft_end(&q->fft);
820 return 0;
821 }
822
823
824 AVCodec imc_decoder = {
825 .name = "imc",
826 .type = CODEC_TYPE_AUDIO,
827 .id = CODEC_ID_IMC,
828 .priv_data_size = sizeof(IMCContext),
829 .init = imc_decode_init,
830 .close = imc_decode_close,
831 .decode = imc_decode_frame,
832 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
833 };