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cosmetics: rename a table
[FFMpeg-mirror/lagarith.git] / libavcodec / imc.c
blob436a5c95528055b8716a2b8add44a91973acab30
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 int decoder_reset;
83 float one_div_log2;
84
85 DSPContext dsp;
86 FFTContext fft;
87 DECLARE_ALIGNED_16(FFTComplex, samples[COEFFS/2]);
88 DECLARE_ALIGNED_16(float, out_samples[COEFFS]);
89 } IMCContext;
90
91 static VLC huffman_vlc[4][4];
92
93 #define VLC_TABLES_SIZE 9512
94
95 static const int vlc_offsets[17] = {
96 0, 640, 1156, 1732, 2308, 2852, 3396, 3924,
97 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE};
98
99 static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];
100
101 static av_cold int imc_decode_init(AVCodecContext * avctx)
102 {
103 int i, j;
104 IMCContext *q = avctx->priv_data;
105 double r1, r2;
106
107 q->decoder_reset = 1;
108
109 for(i = 0; i < BANDS; i++)
110 q->old_floor[i] = 1.0;
111
112 /* Build mdct window, a simple sine window normalized with sqrt(2) */
113 ff_sine_window_init(q->mdct_sine_window, COEFFS);
114 for(i = 0; i < COEFFS; i++)
115 q->mdct_sine_window[i] *= sqrt(2.0);
116 for(i = 0; i < COEFFS/2; i++){
117 q->post_cos[i] = cos(i / 256.0 * M_PI);
118 q->post_sin[i] = sin(i / 256.0 * M_PI);
119
120 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
121 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
122
123 if (i & 0x1)
124 {
125 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
126 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
127 }
128 else
129 {
130 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
131 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
132 }
133
134 q->last_fft_im[i] = 0;
135 }
136
137 /* Generate a square root table */
138
139 for(i = 0; i < 30; i++) {
140 q->sqrt_tab[i] = sqrt(i);
141 }
142
143 /* initialize the VLC tables */
144 for(i = 0; i < 4 ; i++) {
145 for(j = 0; j < 4; j++) {
146 huffman_vlc[i][j].table = vlc_tables[vlc_offsets[i * 4 + j]];
147 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];
148 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i],
149 imc_huffman_lens[i][j], 1, 1,
150 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC);
151 }
152 }
153 q->one_div_log2 = 1/log(2);
154
155 ff_fft_init(&q->fft, 7, 1);
156 dsputil_init(&q->dsp, avctx);
157 avctx->sample_fmt = SAMPLE_FMT_S16;
158 return 0;
159 }
160
161 static void imc_calculate_coeffs(IMCContext* q, float* flcoeffs1, float* flcoeffs2, int* bandWidthT,
162 float* flcoeffs3, float* flcoeffs5)
163 {
164 float workT1[BANDS];
165 float workT2[BANDS];
166 float workT3[BANDS];
167 float snr_limit = 1.e-30;
168 float accum = 0.0;
169 int i, cnt2;
170
171 for(i = 0; i < BANDS; i++) {
172 flcoeffs5[i] = workT2[i] = 0.0;
173 if (bandWidthT[i]){
174 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
175 flcoeffs3[i] = 2.0 * flcoeffs2[i];
176 } else {
177 workT1[i] = 0.0;
178 flcoeffs3[i] = -30000.0;
179 }
180 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
181 if (workT3[i] <= snr_limit)
182 workT3[i] = 0.0;
183 }
184
185 for(i = 0; i < BANDS; i++) {
186 for(cnt2 = i; cnt2 < cyclTab[i]; cnt2++)
187 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
188 workT2[cnt2-1] = workT2[cnt2-1] + workT3[i];
189 }
190
191 for(i = 1; i < BANDS; i++) {
192 accum = (workT2[i-1] + accum) * imc_weights1[i-1];
193 flcoeffs5[i] += accum;
194 }
195
196 for(i = 0; i < BANDS; i++)
197 workT2[i] = 0.0;
198
199 for(i = 0; i < BANDS; i++) {
200 for(cnt2 = i-1; cnt2 > cyclTab2[i]; cnt2--)
201 flcoeffs5[cnt2] += workT3[i];
202 workT2[cnt2+1] += workT3[i];
203 }
204
205 accum = 0.0;
206
207 for(i = BANDS-2; i >= 0; i--) {
208 accum = (workT2[i+1] + accum) * imc_weights2[i];
209 flcoeffs5[i] += accum;
210 //there is missing code here, but it seems to never be triggered
211 }
212 }
213
214
215 static void imc_read_level_coeffs(IMCContext* q, int stream_format_code, int* levlCoeffs)
216 {
217 int i;
218 VLC *hufftab[4];
219 int start = 0;
220 const uint8_t *cb_sel;
221 int s;
222
223 s = stream_format_code >> 1;
224 hufftab[0] = &huffman_vlc[s][0];
225 hufftab[1] = &huffman_vlc[s][1];
226 hufftab[2] = &huffman_vlc[s][2];
227 hufftab[3] = &huffman_vlc[s][3];
228 cb_sel = imc_cb_select[s];
229
230 if(stream_format_code & 4)
231 start = 1;
232 if(start)
233 levlCoeffs[0] = get_bits(&q->gb, 7);
234 for(i = start; i < BANDS; i++){
235 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table, hufftab[cb_sel[i]]->bits, 2);
236 if(levlCoeffs[i] == 17)
237 levlCoeffs[i] += get_bits(&q->gb, 4);
238 }
239 }
240
241 static void imc_decode_level_coefficients(IMCContext* q, int* levlCoeffBuf, float* flcoeffs1,
242 float* flcoeffs2)
243 {
244 int i, level;
245 float tmp, tmp2;
246 //maybe some frequency division thingy
247
248 flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
249 flcoeffs2[0] = log(flcoeffs1[0])/log(2);
250 tmp = flcoeffs1[0];
251 tmp2 = flcoeffs2[0];
252
253 for(i = 1; i < BANDS; i++) {
254 level = levlCoeffBuf[i];
255 if (level == 16) {
256 flcoeffs1[i] = 1.0;
257 flcoeffs2[i] = 0.0;
258 } else {
259 if (level < 17)
260 level -=7;
261 else if (level <= 24)
262 level -=32;
263 else
264 level -=16;
265
266 tmp *= imc_exp_tab[15 + level];
267 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
268 flcoeffs1[i] = tmp;
269 flcoeffs2[i] = tmp2;
270 }
271 }
272 }
273
274
275 static void imc_decode_level_coefficients2(IMCContext* q, int* levlCoeffBuf, float* old_floor, float* flcoeffs1,
276 float* flcoeffs2) {
277 int i;
278 //FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
279 // and flcoeffs2 old scale factors
280 // might be incomplete due to a missing table that is in the binary code
281 for(i = 0; i < BANDS; i++) {
282 flcoeffs1[i] = 0;
283 if(levlCoeffBuf[i] < 16) {
284 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
285 flcoeffs2[i] = (levlCoeffBuf[i]-7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
286 } else {
287 flcoeffs1[i] = old_floor[i];
288 }
289 }
290 }
291
292 /**
293 * Perform bit allocation depending on bits available
294 */
295 static int bit_allocation (IMCContext* q, int stream_format_code, int freebits, int flag) {
296 int i, j;
297 const float limit = -1.e20;
298 float highest = 0.0;
299 int indx;
300 int t1 = 0;
301 int t2 = 1;
302 float summa = 0.0;
303 int iacc = 0;
304 int summer = 0;
305 int rres, cwlen;
306 float lowest = 1.e10;
307 int low_indx = 0;
308 float workT[32];
309 int flg;
310 int found_indx = 0;
311
312 for(i = 0; i < BANDS; i++)
313 highest = FFMAX(highest, q->flcoeffs1[i]);
314
315 for(i = 0; i < BANDS-1; i++) {
316 q->flcoeffs4[i] = q->flcoeffs3[i] - log(q->flcoeffs5[i])/log(2);
317 }
318 q->flcoeffs4[BANDS - 1] = limit;
319
320 highest = highest * 0.25;
321
322 for(i = 0; i < BANDS; i++) {
323 indx = -1;
324 if ((band_tab[i+1] - band_tab[i]) == q->bandWidthT[i])
325 indx = 0;
326
327 if ((band_tab[i+1] - band_tab[i]) > q->bandWidthT[i])
328 indx = 1;
329
330 if (((band_tab[i+1] - band_tab[i])/2) >= q->bandWidthT[i])
331 indx = 2;
332
333 if (indx == -1)
334 return -1;
335
336 q->flcoeffs4[i] = q->flcoeffs4[i] + xTab[(indx*2 + (q->flcoeffs1[i] < highest)) * 2 + flag];
337 }
338
339 if (stream_format_code & 0x2) {
340 q->flcoeffs4[0] = limit;
341 q->flcoeffs4[1] = limit;
342 q->flcoeffs4[2] = limit;
343 q->flcoeffs4[3] = limit;
344 }
345
346 for(i = (stream_format_code & 0x2)?4:0; i < BANDS-1; i++) {
347 iacc += q->bandWidthT[i];
348 summa += q->bandWidthT[i] * q->flcoeffs4[i];
349 }
350 q->bandWidthT[BANDS-1] = 0;
351 summa = (summa * 0.5 - freebits) / iacc;
352
353
354 for(i = 0; i < BANDS/2; i++) {
355 rres = summer - freebits;
356 if((rres >= -8) && (rres <= 8)) break;
357
358 summer = 0;
359 iacc = 0;
360
361 for(j = (stream_format_code & 0x2)?4:0; j < BANDS; j++) {
362 cwlen = av_clip((int)((q->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
363
364 q->bitsBandT[j] = cwlen;
365 summer += q->bandWidthT[j] * cwlen;
366
367 if (cwlen > 0)
368 iacc += q->bandWidthT[j];
369 }
370
371 flg = t2;
372 t2 = 1;
373 if (freebits < summer)
374 t2 = -1;
375 if (i == 0)
376 flg = t2;
377 if(flg != t2)
378 t1++;
379
380 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
381 }
382
383 for(i = (stream_format_code & 0x2)?4:0; i < BANDS; i++) {
384 for(j = band_tab[i]; j < band_tab[i+1]; j++)
385 q->CWlengthT[j] = q->bitsBandT[i];
386 }
387
388 if (freebits > summer) {
389 for(i = 0; i < BANDS; i++) {
390 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
391 }
392
393 highest = 0.0;
394
395 do{
396 if (highest <= -1.e20)
397 break;
398
399 found_indx = 0;
400 highest = -1.e20;
401
402 for(i = 0; i < BANDS; i++) {
403 if (workT[i] > highest) {
404 highest = workT[i];
405 found_indx = i;
406 }
407 }
408
409 if (highest > -1.e20) {
410 workT[found_indx] -= 2.0;
411 if (++(q->bitsBandT[found_indx]) == 6)
412 workT[found_indx] = -1.e20;
413
414 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (freebits > summer); j++){
415 q->CWlengthT[j]++;
416 summer++;
417 }
418 }
419 }while (freebits > summer);
420 }
421 if (freebits < summer) {
422 for(i = 0; i < BANDS; i++) {
423 workT[i] = q->bitsBandT[i] ? (q->bitsBandT[i] * -2 + q->flcoeffs4[i] + 1.585) : 1.e20;
424 }
425 if (stream_format_code & 0x2) {
426 workT[0] = 1.e20;
427 workT[1] = 1.e20;
428 workT[2] = 1.e20;
429 workT[3] = 1.e20;
430 }
431 while (freebits < summer){
432 lowest = 1.e10;
433 low_indx = 0;
434 for(i = 0; i < BANDS; i++) {
435 if (workT[i] < lowest) {
436 lowest = workT[i];
437 low_indx = i;
438 }
439 }
440 //if(lowest >= 1.e10) break;
441 workT[low_indx] = lowest + 2.0;
442
443 if (!(--q->bitsBandT[low_indx]))
444 workT[low_indx] = 1.e20;
445
446 for(j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++){
447 if(q->CWlengthT[j] > 0){
448 q->CWlengthT[j]--;
449 summer--;
450 }
451 }
452 }
453 }
454 return 0;
455 }
456
457 static void imc_get_skip_coeff(IMCContext* q) {
458 int i, j;
459
460 memset(q->skipFlagBits, 0, sizeof(q->skipFlagBits));
461 memset(q->skipFlagCount, 0, sizeof(q->skipFlagCount));
462 for(i = 0; i < BANDS; i++) {
463 if (!q->bandFlagsBuf[i] || !q->bandWidthT[i])
464 continue;
465
466 if (!q->skipFlagRaw[i]) {
467 q->skipFlagBits[i] = band_tab[i+1] - band_tab[i];
468
469 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
470 if ((q->skipFlags[j] = get_bits1(&q->gb)))
471 q->skipFlagCount[i]++;
472 }
473 } else {
474 for(j = band_tab[i]; j < (band_tab[i+1]-1); j += 2) {
475 if(!get_bits1(&q->gb)){//0
476 q->skipFlagBits[i]++;
477 q->skipFlags[j]=1;
478 q->skipFlags[j+1]=1;
479 q->skipFlagCount[i] += 2;
480 }else{
481 if(get_bits1(&q->gb)){//11
482 q->skipFlagBits[i] +=2;
483 q->skipFlags[j]=0;
484 q->skipFlags[j+1]=1;
485 q->skipFlagCount[i]++;
486 }else{
487 q->skipFlagBits[i] +=3;
488 q->skipFlags[j+1]=0;
489 if(!get_bits1(&q->gb)){//100
490 q->skipFlags[j]=1;
491 q->skipFlagCount[i]++;
492 }else{//101
493 q->skipFlags[j]=0;
494 }
495 }
496 }
497 }
498
499 if (j < band_tab[i+1]) {
500 q->skipFlagBits[i]++;
501 if ((q->skipFlags[j] = get_bits1(&q->gb)))
502 q->skipFlagCount[i]++;
503 }
504 }
505 }
506 }
507
508 /**
509 * Increase highest' band coefficient sizes as some bits won't be used
510 */
511 static void imc_adjust_bit_allocation (IMCContext* q, int summer) {
512 float workT[32];
513 int corrected = 0;
514 int i, j;
515 float highest = 0;
516 int found_indx=0;
517
518 for(i = 0; i < BANDS; i++) {
519 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
520 }
521
522 while (corrected < summer) {
523 if(highest <= -1.e20)
524 break;
525
526 highest = -1.e20;
527
528 for(i = 0; i < BANDS; i++) {
529 if (workT[i] > highest) {
530 highest = workT[i];
531 found_indx = i;
532 }
533 }
534
535 if (highest > -1.e20) {
536 workT[found_indx] -= 2.0;
537 if (++(q->bitsBandT[found_indx]) == 6)
538 workT[found_indx] = -1.e20;
539
540 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
541 if (!q->skipFlags[j] && (q->CWlengthT[j] < 6)) {
542 q->CWlengthT[j]++;
543 corrected++;
544 }
545 }
546 }
547 }
548 }
549
550 static void imc_imdct256(IMCContext *q) {
551 int i;
552 float re, im;
553
554 /* prerotation */
555 for(i=0; i < COEFFS/2; i++){
556 q->samples[i].re = -(q->pre_coef1[i] * q->CWdecoded[COEFFS-1-i*2]) -
557 (q->pre_coef2[i] * q->CWdecoded[i*2]);
558 q->samples[i].im = (q->pre_coef2[i] * q->CWdecoded[COEFFS-1-i*2]) -
559 (q->pre_coef1[i] * q->CWdecoded[i*2]);
560 }
561
562 /* FFT */
563 ff_fft_permute(&q->fft, q->samples);
564 ff_fft_calc (&q->fft, q->samples);
565
566 /* postrotation, window and reorder */
567 for(i = 0; i < COEFFS/2; i++){
568 re = (q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
569 im = (-q->samples[i].im * q->post_cos[i]) - (q->samples[i].re * q->post_sin[i]);
570 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);
571 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);
572 q->last_fft_im[i] = im;
573 }
574 }
575
576 static int inverse_quant_coeff (IMCContext* q, int stream_format_code) {
577 int i, j;
578 int middle_value, cw_len, max_size;
579 const float* quantizer;
580
581 for(i = 0; i < BANDS; i++) {
582 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
583 q->CWdecoded[j] = 0;
584 cw_len = q->CWlengthT[j];
585
586 if (cw_len <= 0 || q->skipFlags[j])
587 continue;
588
589 max_size = 1 << cw_len;
590 middle_value = max_size >> 1;
591
592 if (q->codewords[j] >= max_size || q->codewords[j] < 0)
593 return -1;
594
595 if (cw_len >= 4){
596 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
597 if (q->codewords[j] >= middle_value)
598 q->CWdecoded[j] = quantizer[q->codewords[j] - 8] * q->flcoeffs6[i];
599 else
600 q->CWdecoded[j] = -quantizer[max_size - q->codewords[j] - 8 - 1] * q->flcoeffs6[i];
601 }else{
602 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (q->bandFlagsBuf[i] << 1)];
603 if (q->codewords[j] >= middle_value)
604 q->CWdecoded[j] = quantizer[q->codewords[j] - 1] * q->flcoeffs6[i];
605 else
606 q->CWdecoded[j] = -quantizer[max_size - 2 - q->codewords[j]] * q->flcoeffs6[i];
607 }
608 }
609 }
610 return 0;
611 }
612
613
614 static int imc_get_coeffs (IMCContext* q) {
615 int i, j, cw_len, cw;
616
617 for(i = 0; i < BANDS; i++) {
618 if(!q->sumLenArr[i]) continue;
619 if (q->bandFlagsBuf[i] || q->bandWidthT[i]) {
620 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
621 cw_len = q->CWlengthT[j];
622 cw = 0;
623
624 if (get_bits_count(&q->gb) + cw_len > 512){
625 //av_log(NULL,0,"Band %i coeff %i cw_len %i\n",i,j,cw_len);
626 return -1;
627 }
628
629 if(cw_len && (!q->bandFlagsBuf[i] || !q->skipFlags[j]))
630 cw = get_bits(&q->gb, cw_len);
631
632 q->codewords[j] = cw;
633 }
634 }
635 }
636 return 0;
637 }
638
639 static int imc_decode_frame(AVCodecContext * avctx,
640 void *data, int *data_size,
641 const uint8_t * buf, int buf_size)
642 {
643
644 IMCContext *q = avctx->priv_data;
645
646 int stream_format_code;
647 int imc_hdr, i, j;
648 int flag;
649 int bits, summer;
650 int counter, bitscount;
651 uint16_t buf16[IMC_BLOCK_SIZE / 2];
652
653 if (buf_size < IMC_BLOCK_SIZE) {
654 av_log(avctx, AV_LOG_ERROR, "imc frame too small!\n");
655 return -1;
656 }
657 for(i = 0; i < IMC_BLOCK_SIZE / 2; i++)
658 buf16[i] = bswap_16(((const uint16_t*)buf)[i]);
659
660 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
661
662 /* Check the frame header */
663 imc_hdr = get_bits(&q->gb, 9);
664 if (imc_hdr != IMC_FRAME_ID) {
665 av_log(avctx, AV_LOG_ERROR, "imc frame header check failed!\n");
666 av_log(avctx, AV_LOG_ERROR, "got %x instead of 0x21.\n", imc_hdr);
667 return -1;
668 }
669 stream_format_code = get_bits(&q->gb, 3);
670
671 if(stream_format_code & 1){
672 av_log(avctx, AV_LOG_ERROR, "Stream code format %X is not supported\n", stream_format_code);
673 return -1;
674 }
675
676 // av_log(avctx, AV_LOG_DEBUG, "stream_format_code = %d\n", stream_format_code);
677
678 if (stream_format_code & 0x04)
679 q->decoder_reset = 1;
680
681 if(q->decoder_reset) {
682 memset(q->out_samples, 0, sizeof(q->out_samples));
683 for(i = 0; i < BANDS; i++)q->old_floor[i] = 1.0;
684 for(i = 0; i < COEFFS; i++)q->CWdecoded[i] = 0;
685 q->decoder_reset = 0;
686 }
687
688 flag = get_bits1(&q->gb);
689 imc_read_level_coeffs(q, stream_format_code, q->levlCoeffBuf);
690
691 if (stream_format_code & 0x4)
692 imc_decode_level_coefficients(q, q->levlCoeffBuf, q->flcoeffs1, q->flcoeffs2);
693 else
694 imc_decode_level_coefficients2(q, q->levlCoeffBuf, q->old_floor, q->flcoeffs1, q->flcoeffs2);
695
696 memcpy(q->old_floor, q->flcoeffs1, 32 * sizeof(float));
697
698 counter = 0;
699 for (i=0 ; i<BANDS ; i++) {
700 if (q->levlCoeffBuf[i] == 16) {
701 q->bandWidthT[i] = 0;
702 counter++;
703 } else
704 q->bandWidthT[i] = band_tab[i+1] - band_tab[i];
705 }
706 memset(q->bandFlagsBuf, 0, BANDS * sizeof(int));
707 for(i = 0; i < BANDS-1; i++) {
708 if (q->bandWidthT[i])
709 q->bandFlagsBuf[i] = get_bits1(&q->gb);
710 }
711
712 imc_calculate_coeffs(q, q->flcoeffs1, q->flcoeffs2, q->bandWidthT, q->flcoeffs3, q->flcoeffs5);
713
714 bitscount = 0;
715 /* first 4 bands will be assigned 5 bits per coefficient */
716 if (stream_format_code & 0x2) {
717 bitscount += 15;
718
719 q->bitsBandT[0] = 5;
720 q->CWlengthT[0] = 5;
721 q->CWlengthT[1] = 5;
722 q->CWlengthT[2] = 5;
723 for(i = 1; i < 4; i++){
724 bits = (q->levlCoeffBuf[i] == 16) ? 0 : 5;
725 q->bitsBandT[i] = bits;
726 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
727 q->CWlengthT[j] = bits;
728 bitscount += bits;
729 }
730 }
731 }
732
733 if(bit_allocation (q, stream_format_code, 512 - bitscount - get_bits_count(&q->gb), flag) < 0) {
734 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
735 q->decoder_reset = 1;
736 return -1;
737 }
738
739 for(i = 0; i < BANDS; i++) {
740 q->sumLenArr[i] = 0;
741 q->skipFlagRaw[i] = 0;
742 for(j = band_tab[i]; j < band_tab[i+1]; j++)
743 q->sumLenArr[i] += q->CWlengthT[j];
744 if (q->bandFlagsBuf[i])
745 if( (((band_tab[i+1] - band_tab[i]) * 1.5) > q->sumLenArr[i]) && (q->sumLenArr[i] > 0))
746 q->skipFlagRaw[i] = 1;
747 }
748
749 imc_get_skip_coeff(q);
750
751 for(i = 0; i < BANDS; i++) {
752 q->flcoeffs6[i] = q->flcoeffs1[i];
753 /* band has flag set and at least one coded coefficient */
754 if (q->bandFlagsBuf[i] && (band_tab[i+1] - band_tab[i]) != q->skipFlagCount[i]){
755 q->flcoeffs6[i] *= q->sqrt_tab[band_tab[i+1] - band_tab[i]] /
756 q->sqrt_tab[(band_tab[i+1] - band_tab[i] - q->skipFlagCount[i])];
757 }
758 }
759
760 /* calculate bits left, bits needed and adjust bit allocation */
761 bits = summer = 0;
762
763 for(i = 0; i < BANDS; i++) {
764 if (q->bandFlagsBuf[i]) {
765 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
766 if(q->skipFlags[j]) {
767 summer += q->CWlengthT[j];
768 q->CWlengthT[j] = 0;
769 }
770 }
771 bits += q->skipFlagBits[i];
772 summer -= q->skipFlagBits[i];
773 }
774 }
775 imc_adjust_bit_allocation(q, summer);
776
777 for(i = 0; i < BANDS; i++) {
778 q->sumLenArr[i] = 0;
779
780 for(j = band_tab[i]; j < band_tab[i+1]; j++)
781 if (!q->skipFlags[j])
782 q->sumLenArr[i] += q->CWlengthT[j];
783 }
784
785 memset(q->codewords, 0, sizeof(q->codewords));
786
787 if(imc_get_coeffs(q) < 0) {
788 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");
789 q->decoder_reset = 1;
790 return 0;
791 }
792
793 if(inverse_quant_coeff(q, stream_format_code) < 0) {
794 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
795 q->decoder_reset = 1;
796 return 0;
797 }
798
799 memset(q->skipFlags, 0, sizeof(q->skipFlags));
800
801 imc_imdct256(q);
802
803 q->dsp.float_to_int16(data, q->out_samples, COEFFS);
804
805 *data_size = COEFFS * sizeof(int16_t);
806
807 return IMC_BLOCK_SIZE;
808 }
809
810
811 static av_cold int imc_decode_close(AVCodecContext * avctx)
812 {
813 IMCContext *q = avctx->priv_data;
814
815 ff_fft_end(&q->fft);
816 return 0;
817 }
818
819
820 AVCodec imc_decoder = {
821 .name = "imc",
822 .type = CODEC_TYPE_AUDIO,
823 .id = CODEC_ID_IMC,
824 .priv_data_size = sizeof(IMCContext),
825 .init = imc_decode_init,
826 .close = imc_decode_close,
827 .decode = imc_decode_frame,
828 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
829 };
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