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cosmetics: Rename some variables to be more descriptive of their use. Do some
[ffmpeg-lucabe.git] / libavcodec / imc.c
blob93093ebd533fedf886b824355239f01854e9453b
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
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 avctx->channel_layout = (avctx->channels==2) ? CH_LAYOUT_STEREO : CH_LAYOUT_MONO;
159 return 0;
160 }
161
162 static void imc_calculate_coeffs(IMCContext* q, float* flcoeffs1, float* flcoeffs2, int* bandWidthT,
163 float* flcoeffs3, float* flcoeffs5)
164 {
165 float workT1[BANDS];
166 float workT2[BANDS];
167 float workT3[BANDS];
168 float snr_limit = 1.e-30;
169 float accum = 0.0;
170 int i, cnt2;
171
172 for(i = 0; i < BANDS; i++) {
173 flcoeffs5[i] = workT2[i] = 0.0;
174 if (bandWidthT[i]){
175 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
176 flcoeffs3[i] = 2.0 * flcoeffs2[i];
177 } else {
178 workT1[i] = 0.0;
179 flcoeffs3[i] = -30000.0;
180 }
181 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
182 if (workT3[i] <= snr_limit)
183 workT3[i] = 0.0;
184 }
185
186 for(i = 0; i < BANDS; i++) {
187 for(cnt2 = i; cnt2 < cyclTab[i]; cnt2++)
188 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
189 workT2[cnt2-1] = workT2[cnt2-1] + workT3[i];
190 }
191
192 for(i = 1; i < BANDS; i++) {
193 accum = (workT2[i-1] + accum) * imc_weights1[i-1];
194 flcoeffs5[i] += accum;
195 }
196
197 for(i = 0; i < BANDS; i++)
198 workT2[i] = 0.0;
199
200 for(i = 0; i < BANDS; i++) {
201 for(cnt2 = i-1; cnt2 > cyclTab2[i]; cnt2--)
202 flcoeffs5[cnt2] += workT3[i];
203 workT2[cnt2+1] += workT3[i];
204 }
205
206 accum = 0.0;
207
208 for(i = BANDS-2; i >= 0; i--) {
209 accum = (workT2[i+1] + accum) * imc_weights2[i];
210 flcoeffs5[i] += accum;
211 //there is missing code here, but it seems to never be triggered
212 }
213 }
214
215
216 static void imc_read_level_coeffs(IMCContext* q, int stream_format_code, int* levlCoeffs)
217 {
218 int i;
219 VLC *hufftab[4];
220 int start = 0;
221 const uint8_t *cb_sel;
222 int s;
223
224 s = stream_format_code >> 1;
225 hufftab[0] = &huffman_vlc[s][0];
226 hufftab[1] = &huffman_vlc[s][1];
227 hufftab[2] = &huffman_vlc[s][2];
228 hufftab[3] = &huffman_vlc[s][3];
229 cb_sel = imc_cb_select[s];
230
231 if(stream_format_code & 4)
232 start = 1;
233 if(start)
234 levlCoeffs[0] = get_bits(&q->gb, 7);
235 for(i = start; i < BANDS; i++){
236 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table, hufftab[cb_sel[i]]->bits, 2);
237 if(levlCoeffs[i] == 17)
238 levlCoeffs[i] += get_bits(&q->gb, 4);
239 }
240 }
241
242 static void imc_decode_level_coefficients(IMCContext* q, int* levlCoeffBuf, float* flcoeffs1,
243 float* flcoeffs2)
244 {
245 int i, level;
246 float tmp, tmp2;
247 //maybe some frequency division thingy
248
249 flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
250 flcoeffs2[0] = log(flcoeffs1[0])/log(2);
251 tmp = flcoeffs1[0];
252 tmp2 = flcoeffs2[0];
253
254 for(i = 1; i < BANDS; i++) {
255 level = levlCoeffBuf[i];
256 if (level == 16) {
257 flcoeffs1[i] = 1.0;
258 flcoeffs2[i] = 0.0;
259 } else {
260 if (level < 17)
261 level -=7;
262 else if (level <= 24)
263 level -=32;
264 else
265 level -=16;
266
267 tmp *= imc_exp_tab[15 + level];
268 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
269 flcoeffs1[i] = tmp;
270 flcoeffs2[i] = tmp2;
271 }
272 }
273 }
274
275
276 static void imc_decode_level_coefficients2(IMCContext* q, int* levlCoeffBuf, float* old_floor, float* flcoeffs1,
277 float* flcoeffs2) {
278 int i;
279 //FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
280 // and flcoeffs2 old scale factors
281 // might be incomplete due to a missing table that is in the binary code
282 for(i = 0; i < BANDS; i++) {
283 flcoeffs1[i] = 0;
284 if(levlCoeffBuf[i] < 16) {
285 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
286 flcoeffs2[i] = (levlCoeffBuf[i]-7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
287 } else {
288 flcoeffs1[i] = old_floor[i];
289 }
290 }
291 }
292
293 /**
294 * Perform bit allocation depending on bits available
295 */
296 static int bit_allocation (IMCContext* q, int stream_format_code, int freebits, int flag) {
297 int i, j;
298 const float limit = -1.e20;
299 float highest = 0.0;
300 int indx;
301 int t1 = 0;
302 int t2 = 1;
303 float summa = 0.0;
304 int iacc = 0;
305 int summer = 0;
306 int rres, cwlen;
307 float lowest = 1.e10;
308 int low_indx = 0;
309 float workT[32];
310 int flg;
311 int found_indx = 0;
312
313 for(i = 0; i < BANDS; i++)
314 highest = FFMAX(highest, q->flcoeffs1[i]);
315
316 for(i = 0; i < BANDS-1; i++) {
317 q->flcoeffs4[i] = q->flcoeffs3[i] - log(q->flcoeffs5[i])/log(2);
318 }
319 q->flcoeffs4[BANDS - 1] = limit;
320
321 highest = highest * 0.25;
322
323 for(i = 0; i < BANDS; i++) {
324 indx = -1;
325 if ((band_tab[i+1] - band_tab[i]) == q->bandWidthT[i])
326 indx = 0;
327
328 if ((band_tab[i+1] - band_tab[i]) > q->bandWidthT[i])
329 indx = 1;
330
331 if (((band_tab[i+1] - band_tab[i])/2) >= q->bandWidthT[i])
332 indx = 2;
333
334 if (indx == -1)
335 return -1;
336
337 q->flcoeffs4[i] = q->flcoeffs4[i] + xTab[(indx*2 + (q->flcoeffs1[i] < highest)) * 2 + flag];
338 }
339
340 if (stream_format_code & 0x2) {
341 q->flcoeffs4[0] = limit;
342 q->flcoeffs4[1] = limit;
343 q->flcoeffs4[2] = limit;
344 q->flcoeffs4[3] = limit;
345 }
346
347 for(i = (stream_format_code & 0x2)?4:0; i < BANDS-1; i++) {
348 iacc += q->bandWidthT[i];
349 summa += q->bandWidthT[i] * q->flcoeffs4[i];
350 }
351 q->bandWidthT[BANDS-1] = 0;
352 summa = (summa * 0.5 - freebits) / iacc;
353
354
355 for(i = 0; i < BANDS/2; i++) {
356 rres = summer - freebits;
357 if((rres >= -8) && (rres <= 8)) break;
358
359 summer = 0;
360 iacc = 0;
361
362 for(j = (stream_format_code & 0x2)?4:0; j < BANDS; j++) {
363 cwlen = av_clip((int)((q->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
364
365 q->bitsBandT[j] = cwlen;
366 summer += q->bandWidthT[j] * cwlen;
367
368 if (cwlen > 0)
369 iacc += q->bandWidthT[j];
370 }
371
372 flg = t2;
373 t2 = 1;
374 if (freebits < summer)
375 t2 = -1;
376 if (i == 0)
377 flg = t2;
378 if(flg != t2)
379 t1++;
380
381 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
382 }
383
384 for(i = (stream_format_code & 0x2)?4:0; i < BANDS; i++) {
385 for(j = band_tab[i]; j < band_tab[i+1]; j++)
386 q->CWlengthT[j] = q->bitsBandT[i];
387 }
388
389 if (freebits > summer) {
390 for(i = 0; i < BANDS; i++) {
391 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
392 }
393
394 highest = 0.0;
395
396 do{
397 if (highest <= -1.e20)
398 break;
399
400 found_indx = 0;
401 highest = -1.e20;
402
403 for(i = 0; i < BANDS; i++) {
404 if (workT[i] > highest) {
405 highest = workT[i];
406 found_indx = i;
407 }
408 }
409
410 if (highest > -1.e20) {
411 workT[found_indx] -= 2.0;
412 if (++(q->bitsBandT[found_indx]) == 6)
413 workT[found_indx] = -1.e20;
414
415 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (freebits > summer); j++){
416 q->CWlengthT[j]++;
417 summer++;
418 }
419 }
420 }while (freebits > summer);
421 }
422 if (freebits < summer) {
423 for(i = 0; i < BANDS; i++) {
424 workT[i] = q->bitsBandT[i] ? (q->bitsBandT[i] * -2 + q->flcoeffs4[i] + 1.585) : 1.e20;
425 }
426 if (stream_format_code & 0x2) {
427 workT[0] = 1.e20;
428 workT[1] = 1.e20;
429 workT[2] = 1.e20;
430 workT[3] = 1.e20;
431 }
432 while (freebits < summer){
433 lowest = 1.e10;
434 low_indx = 0;
435 for(i = 0; i < BANDS; i++) {
436 if (workT[i] < lowest) {
437 lowest = workT[i];
438 low_indx = i;
439 }
440 }
441 //if(lowest >= 1.e10) break;
442 workT[low_indx] = lowest + 2.0;
443
444 if (!(--q->bitsBandT[low_indx]))
445 workT[low_indx] = 1.e20;
446
447 for(j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++){
448 if(q->CWlengthT[j] > 0){
449 q->CWlengthT[j]--;
450 summer--;
451 }
452 }
453 }
454 }
455 return 0;
456 }
457
458 static void imc_get_skip_coeff(IMCContext* q) {
459 int i, j;
460
461 memset(q->skipFlagBits, 0, sizeof(q->skipFlagBits));
462 memset(q->skipFlagCount, 0, sizeof(q->skipFlagCount));
463 for(i = 0; i < BANDS; i++) {
464 if (!q->bandFlagsBuf[i] || !q->bandWidthT[i])
465 continue;
466
467 if (!q->skipFlagRaw[i]) {
468 q->skipFlagBits[i] = band_tab[i+1] - band_tab[i];
469
470 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
471 if ((q->skipFlags[j] = get_bits1(&q->gb)))
472 q->skipFlagCount[i]++;
473 }
474 } else {
475 for(j = band_tab[i]; j < (band_tab[i+1]-1); j += 2) {
476 if(!get_bits1(&q->gb)){//0
477 q->skipFlagBits[i]++;
478 q->skipFlags[j]=1;
479 q->skipFlags[j+1]=1;
480 q->skipFlagCount[i] += 2;
481 }else{
482 if(get_bits1(&q->gb)){//11
483 q->skipFlagBits[i] +=2;
484 q->skipFlags[j]=0;
485 q->skipFlags[j+1]=1;
486 q->skipFlagCount[i]++;
487 }else{
488 q->skipFlagBits[i] +=3;
489 q->skipFlags[j+1]=0;
490 if(!get_bits1(&q->gb)){//100
491 q->skipFlags[j]=1;
492 q->skipFlagCount[i]++;
493 }else{//101
494 q->skipFlags[j]=0;
495 }
496 }
497 }
498 }
499
500 if (j < band_tab[i+1]) {
501 q->skipFlagBits[i]++;
502 if ((q->skipFlags[j] = get_bits1(&q->gb)))
503 q->skipFlagCount[i]++;
504 }
505 }
506 }
507 }
508
509 /**
510 * Increase highest' band coefficient sizes as some bits won't be used
511 */
512 static void imc_adjust_bit_allocation (IMCContext* q, int summer) {
513 float workT[32];
514 int corrected = 0;
515 int i, j;
516 float highest = 0;
517 int found_indx=0;
518
519 for(i = 0; i < BANDS; i++) {
520 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
521 }
522
523 while (corrected < summer) {
524 if(highest <= -1.e20)
525 break;
526
527 highest = -1.e20;
528
529 for(i = 0; i < BANDS; i++) {
530 if (workT[i] > highest) {
531 highest = workT[i];
532 found_indx = i;
533 }
534 }
535
536 if (highest > -1.e20) {
537 workT[found_indx] -= 2.0;
538 if (++(q->bitsBandT[found_indx]) == 6)
539 workT[found_indx] = -1.e20;
540
541 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
542 if (!q->skipFlags[j] && (q->CWlengthT[j] < 6)) {
543 q->CWlengthT[j]++;
544 corrected++;
545 }
546 }
547 }
548 }
549 }
550
551 static void imc_imdct256(IMCContext *q) {
552 int i;
553 float re, im;
554
555 /* prerotation */
556 for(i=0; i < COEFFS/2; i++){
557 q->samples[i].re = -(q->pre_coef1[i] * q->CWdecoded[COEFFS-1-i*2]) -
558 (q->pre_coef2[i] * q->CWdecoded[i*2]);
559 q->samples[i].im = (q->pre_coef2[i] * q->CWdecoded[COEFFS-1-i*2]) -
560 (q->pre_coef1[i] * q->CWdecoded[i*2]);
561 }
562
563 /* FFT */
564 ff_fft_permute(&q->fft, q->samples);
565 ff_fft_calc (&q->fft, q->samples);
566
567 /* postrotation, window and reorder */
568 for(i = 0; i < COEFFS/2; i++){
569 re = (q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
570 im = (-q->samples[i].im * q->post_cos[i]) - (q->samples[i].re * q->post_sin[i]);
571 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);
572 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);
573 q->last_fft_im[i] = im;
574 }
575 }
576
577 static int inverse_quant_coeff (IMCContext* q, int stream_format_code) {
578 int i, j;
579 int middle_value, cw_len, max_size;
580 const float* quantizer;
581
582 for(i = 0; i < BANDS; i++) {
583 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
584 q->CWdecoded[j] = 0;
585 cw_len = q->CWlengthT[j];
586
587 if (cw_len <= 0 || q->skipFlags[j])
588 continue;
589
590 max_size = 1 << cw_len;
591 middle_value = max_size >> 1;
592
593 if (q->codewords[j] >= max_size || q->codewords[j] < 0)
594 return -1;
595
596 if (cw_len >= 4){
597 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
598 if (q->codewords[j] >= middle_value)
599 q->CWdecoded[j] = quantizer[q->codewords[j] - 8] * q->flcoeffs6[i];
600 else
601 q->CWdecoded[j] = -quantizer[max_size - q->codewords[j] - 8 - 1] * q->flcoeffs6[i];
602 }else{
603 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (q->bandFlagsBuf[i] << 1)];
604 if (q->codewords[j] >= middle_value)
605 q->CWdecoded[j] = quantizer[q->codewords[j] - 1] * q->flcoeffs6[i];
606 else
607 q->CWdecoded[j] = -quantizer[max_size - 2 - q->codewords[j]] * q->flcoeffs6[i];
608 }
609 }
610 }
611 return 0;
612 }
613
614
615 static int imc_get_coeffs (IMCContext* q) {
616 int i, j, cw_len, cw;
617
618 for(i = 0; i < BANDS; i++) {
619 if(!q->sumLenArr[i]) continue;
620 if (q->bandFlagsBuf[i] || q->bandWidthT[i]) {
621 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
622 cw_len = q->CWlengthT[j];
623 cw = 0;
624
625 if (get_bits_count(&q->gb) + cw_len > 512){
626 //av_log(NULL,0,"Band %i coeff %i cw_len %i\n",i,j,cw_len);
627 return -1;
628 }
629
630 if(cw_len && (!q->bandFlagsBuf[i] || !q->skipFlags[j]))
631 cw = get_bits(&q->gb, cw_len);
632
633 q->codewords[j] = cw;
634 }
635 }
636 }
637 return 0;
638 }
639
640 static int imc_decode_frame(AVCodecContext * avctx,
641 void *data, int *data_size,
642 AVPacket *avpkt)
643 {
644 const uint8_t *buf = avpkt->data;
645 int buf_size = avpkt->size;
646
647 IMCContext *q = avctx->priv_data;
648
649 int stream_format_code;
650 int imc_hdr, i, j;
651 int flag;
652 int bits, summer;
653 int counter, bitscount;
654 uint16_t buf16[IMC_BLOCK_SIZE / 2];
655
656 if (buf_size < IMC_BLOCK_SIZE) {
657 av_log(avctx, AV_LOG_ERROR, "imc frame too small!\n");
658 return -1;
659 }
660 for(i = 0; i < IMC_BLOCK_SIZE / 2; i++)
661 buf16[i] = bswap_16(((const uint16_t*)buf)[i]);
662
663 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
664
665 /* Check the frame header */
666 imc_hdr = get_bits(&q->gb, 9);
667 if (imc_hdr != IMC_FRAME_ID) {
668 av_log(avctx, AV_LOG_ERROR, "imc frame header check failed!\n");
669 av_log(avctx, AV_LOG_ERROR, "got %x instead of 0x21.\n", imc_hdr);
670 return -1;
671 }
672 stream_format_code = get_bits(&q->gb, 3);
673
674 if(stream_format_code & 1){
675 av_log(avctx, AV_LOG_ERROR, "Stream code format %X is not supported\n", stream_format_code);
676 return -1;
677 }
678
679 // av_log(avctx, AV_LOG_DEBUG, "stream_format_code = %d\n", stream_format_code);
680
681 if (stream_format_code & 0x04)
682 q->decoder_reset = 1;
683
684 if(q->decoder_reset) {
685 memset(q->out_samples, 0, sizeof(q->out_samples));
686 for(i = 0; i < BANDS; i++)q->old_floor[i] = 1.0;
687 for(i = 0; i < COEFFS; i++)q->CWdecoded[i] = 0;
688 q->decoder_reset = 0;
689 }
690
691 flag = get_bits1(&q->gb);
692 imc_read_level_coeffs(q, stream_format_code, q->levlCoeffBuf);
693
694 if (stream_format_code & 0x4)
695 imc_decode_level_coefficients(q, q->levlCoeffBuf, q->flcoeffs1, q->flcoeffs2);
696 else
697 imc_decode_level_coefficients2(q, q->levlCoeffBuf, q->old_floor, q->flcoeffs1, q->flcoeffs2);
698
699 memcpy(q->old_floor, q->flcoeffs1, 32 * sizeof(float));
700
701 counter = 0;
702 for (i=0 ; i<BANDS ; i++) {
703 if (q->levlCoeffBuf[i] == 16) {
704 q->bandWidthT[i] = 0;
705 counter++;
706 } else
707 q->bandWidthT[i] = band_tab[i+1] - band_tab[i];
708 }
709 memset(q->bandFlagsBuf, 0, BANDS * sizeof(int));
710 for(i = 0; i < BANDS-1; i++) {
711 if (q->bandWidthT[i])
712 q->bandFlagsBuf[i] = get_bits1(&q->gb);
713 }
714
715 imc_calculate_coeffs(q, q->flcoeffs1, q->flcoeffs2, q->bandWidthT, q->flcoeffs3, q->flcoeffs5);
716
717 bitscount = 0;
718 /* first 4 bands will be assigned 5 bits per coefficient */
719 if (stream_format_code & 0x2) {
720 bitscount += 15;
721
722 q->bitsBandT[0] = 5;
723 q->CWlengthT[0] = 5;
724 q->CWlengthT[1] = 5;
725 q->CWlengthT[2] = 5;
726 for(i = 1; i < 4; i++){
727 bits = (q->levlCoeffBuf[i] == 16) ? 0 : 5;
728 q->bitsBandT[i] = bits;
729 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
730 q->CWlengthT[j] = bits;
731 bitscount += bits;
732 }
733 }
734 }
735
736 if(bit_allocation (q, stream_format_code, 512 - bitscount - get_bits_count(&q->gb), flag) < 0) {
737 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
738 q->decoder_reset = 1;
739 return -1;
740 }
741
742 for(i = 0; i < BANDS; i++) {
743 q->sumLenArr[i] = 0;
744 q->skipFlagRaw[i] = 0;
745 for(j = band_tab[i]; j < band_tab[i+1]; j++)
746 q->sumLenArr[i] += q->CWlengthT[j];
747 if (q->bandFlagsBuf[i])
748 if( (((band_tab[i+1] - band_tab[i]) * 1.5) > q->sumLenArr[i]) && (q->sumLenArr[i] > 0))
749 q->skipFlagRaw[i] = 1;
750 }
751
752 imc_get_skip_coeff(q);
753
754 for(i = 0; i < BANDS; i++) {
755 q->flcoeffs6[i] = q->flcoeffs1[i];
756 /* band has flag set and at least one coded coefficient */
757 if (q->bandFlagsBuf[i] && (band_tab[i+1] - band_tab[i]) != q->skipFlagCount[i]){
758 q->flcoeffs6[i] *= q->sqrt_tab[band_tab[i+1] - band_tab[i]] /
759 q->sqrt_tab[(band_tab[i+1] - band_tab[i] - q->skipFlagCount[i])];
760 }
761 }
762
763 /* calculate bits left, bits needed and adjust bit allocation */
764 bits = summer = 0;
765
766 for(i = 0; i < BANDS; i++) {
767 if (q->bandFlagsBuf[i]) {
768 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
769 if(q->skipFlags[j]) {
770 summer += q->CWlengthT[j];
771 q->CWlengthT[j] = 0;
772 }
773 }
774 bits += q->skipFlagBits[i];
775 summer -= q->skipFlagBits[i];
776 }
777 }
778 imc_adjust_bit_allocation(q, summer);
779
780 for(i = 0; i < BANDS; i++) {
781 q->sumLenArr[i] = 0;
782
783 for(j = band_tab[i]; j < band_tab[i+1]; j++)
784 if (!q->skipFlags[j])
785 q->sumLenArr[i] += q->CWlengthT[j];
786 }
787
788 memset(q->codewords, 0, sizeof(q->codewords));
789
790 if(imc_get_coeffs(q) < 0) {
791 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");
792 q->decoder_reset = 1;
793 return 0;
794 }
795
796 if(inverse_quant_coeff(q, stream_format_code) < 0) {
797 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
798 q->decoder_reset = 1;
799 return 0;
800 }
801
802 memset(q->skipFlags, 0, sizeof(q->skipFlags));
803
804 imc_imdct256(q);
805
806 q->dsp.float_to_int16(data, q->out_samples, COEFFS);
807
808 *data_size = COEFFS * sizeof(int16_t);
809
810 return IMC_BLOCK_SIZE;
811 }
812
813
814 static av_cold int imc_decode_close(AVCodecContext * avctx)
815 {
816 IMCContext *q = avctx->priv_data;
817
818 ff_fft_end(&q->fft);
819 return 0;
820 }
821
822
823 AVCodec imc_decoder = {
824 .name = "imc",
825 .type = CODEC_TYPE_AUDIO,
826 .id = CODEC_ID_IMC,
827 .priv_data_size = sizeof(IMCContext),
828 .init = imc_decode_init,
829 .close = imc_decode_close,
830 .decode = imc_decode_frame,
831 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
832 };
lucabe's unfinished and experimental patches for ffmpeg