imc: use DSPContext.bswap16_buf() to byte-swap packet data
[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 Libav.
8 *
9 * Libav 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 * Libav 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 Libav; 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
26 * IMC - Intel Music Coder
27 * A mdct based codec using a 256 points large transform
28 * divied into 32 bands with some mix of scale factors.
29 * Only mono is supported.
30 *
31 */
32
33
34 #include <math.h>
35 #include <stddef.h>
36 #include <stdio.h>
37
38 #define ALT_BITSTREAM_READER
39 #include "avcodec.h"
40 #include "get_bits.h"
41 #include "dsputil.h"
42 #include "fft.h"
43 #include "libavutil/audioconvert.h"
44 #include "sinewin.h"
45
46 #include "imcdata.h"
47
48 #define IMC_BLOCK_SIZE 64
49 #define IMC_FRAME_ID 0x21
50 #define BANDS 32
51 #define COEFFS 256
52
53 typedef struct {
54 float old_floor[BANDS];
55 float flcoeffs1[BANDS];
56 float flcoeffs2[BANDS];
57 float flcoeffs3[BANDS];
58 float flcoeffs4[BANDS];
59 float flcoeffs5[BANDS];
60 float flcoeffs6[BANDS];
61 float CWdecoded[COEFFS];
62
63 /** MDCT tables */
64 //@{
65 float mdct_sine_window[COEFFS];
66 float post_cos[COEFFS];
67 float post_sin[COEFFS];
68 float pre_coef1[COEFFS];
69 float pre_coef2[COEFFS];
70 float last_fft_im[COEFFS];
71 //@}
72
73 int bandWidthT[BANDS]; ///< codewords per band
74 int bitsBandT[BANDS]; ///< how many bits per codeword in band
75 int CWlengthT[COEFFS]; ///< how many bits in each codeword
76 int levlCoeffBuf[BANDS];
77 int bandFlagsBuf[BANDS]; ///< flags for each band
78 int sumLenArr[BANDS]; ///< bits for all coeffs in band
79 int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not
80 int skipFlagBits[BANDS]; ///< bits used to code skip flags
81 int skipFlagCount[BANDS]; ///< skipped coeffients per band
82 int skipFlags[COEFFS]; ///< skip coefficient decoding or not
83 int codewords[COEFFS]; ///< raw codewords read from bitstream
84 float sqrt_tab[30];
85 GetBitContext gb;
86 int decoder_reset;
87 float one_div_log2;
88
89 DSPContext dsp;
90 FFTContext fft;
91 DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS/2];
92 float *out_samples;
93 } IMCContext;
94
95 static VLC huffman_vlc[4][4];
96
97 #define VLC_TABLES_SIZE 9512
98
99 static const int vlc_offsets[17] = {
100 0, 640, 1156, 1732, 2308, 2852, 3396, 3924,
101 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE};
102
103 static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];
104
105 static av_cold int imc_decode_init(AVCodecContext * avctx)
106 {
107 int i, j;
108 IMCContext *q = avctx->priv_data;
109 double r1, r2;
110
111 q->decoder_reset = 1;
112
113 for(i = 0; i < BANDS; i++)
114 q->old_floor[i] = 1.0;
115
116 /* Build mdct window, a simple sine window normalized with sqrt(2) */
117 ff_sine_window_init(q->mdct_sine_window, COEFFS);
118 for(i = 0; i < COEFFS; i++)
119 q->mdct_sine_window[i] *= sqrt(2.0);
120 for(i = 0; i < COEFFS/2; i++){
121 q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI);
122 q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI);
123
124 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
125 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
126
127 if (i & 0x1)
128 {
129 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
130 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
131 }
132 else
133 {
134 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
135 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
136 }
137
138 q->last_fft_im[i] = 0;
139 }
140
141 /* Generate a square root table */
142
143 for(i = 0; i < 30; i++) {
144 q->sqrt_tab[i] = sqrt(i);
145 }
146
147 /* initialize the VLC tables */
148 for(i = 0; i < 4 ; i++) {
149 for(j = 0; j < 4; j++) {
150 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]];
151 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];
152 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i],
153 imc_huffman_lens[i][j], 1, 1,
154 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC);
155 }
156 }
157 q->one_div_log2 = 1/log(2);
158
159 ff_fft_init(&q->fft, 7, 1);
160 dsputil_init(&q->dsp, avctx);
161 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
162 avctx->channel_layout = (avctx->channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;
163 return 0;
164 }
165
166 static void imc_calculate_coeffs(IMCContext* q, float* flcoeffs1, float* flcoeffs2, int* bandWidthT,
167 float* flcoeffs3, float* flcoeffs5)
168 {
169 float workT1[BANDS];
170 float workT2[BANDS];
171 float workT3[BANDS];
172 float snr_limit = 1.e-30;
173 float accum = 0.0;
174 int i, cnt2;
175
176 for(i = 0; i < BANDS; i++) {
177 flcoeffs5[i] = workT2[i] = 0.0;
178 if (bandWidthT[i]){
179 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
180 flcoeffs3[i] = 2.0 * flcoeffs2[i];
181 } else {
182 workT1[i] = 0.0;
183 flcoeffs3[i] = -30000.0;
184 }
185 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
186 if (workT3[i] <= snr_limit)
187 workT3[i] = 0.0;
188 }
189
190 for(i = 0; i < BANDS; i++) {
191 for(cnt2 = i; cnt2 < cyclTab[i]; cnt2++)
192 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
193 workT2[cnt2-1] = workT2[cnt2-1] + workT3[i];
194 }
195
196 for(i = 1; i < BANDS; i++) {
197 accum = (workT2[i-1] + accum) * imc_weights1[i-1];
198 flcoeffs5[i] += accum;
199 }
200
201 for(i = 0; i < BANDS; i++)
202 workT2[i] = 0.0;
203
204 for(i = 0; i < BANDS; i++) {
205 for(cnt2 = i-1; cnt2 > cyclTab2[i]; cnt2--)
206 flcoeffs5[cnt2] += workT3[i];
207 workT2[cnt2+1] += workT3[i];
208 }
209
210 accum = 0.0;
211
212 for(i = BANDS-2; i >= 0; i--) {
213 accum = (workT2[i+1] + accum) * imc_weights2[i];
214 flcoeffs5[i] += accum;
215 //there is missing code here, but it seems to never be triggered
216 }
217 }
218
219
220 static void imc_read_level_coeffs(IMCContext* q, int stream_format_code, int* levlCoeffs)
221 {
222 int i;
223 VLC *hufftab[4];
224 int start = 0;
225 const uint8_t *cb_sel;
226 int s;
227
228 s = stream_format_code >> 1;
229 hufftab[0] = &huffman_vlc[s][0];
230 hufftab[1] = &huffman_vlc[s][1];
231 hufftab[2] = &huffman_vlc[s][2];
232 hufftab[3] = &huffman_vlc[s][3];
233 cb_sel = imc_cb_select[s];
234
235 if(stream_format_code & 4)
236 start = 1;
237 if(start)
238 levlCoeffs[0] = get_bits(&q->gb, 7);
239 for(i = start; i < BANDS; i++){
240 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table, hufftab[cb_sel[i]]->bits, 2);
241 if(levlCoeffs[i] == 17)
242 levlCoeffs[i] += get_bits(&q->gb, 4);
243 }
244 }
245
246 static void imc_decode_level_coefficients(IMCContext* q, int* levlCoeffBuf, float* flcoeffs1,
247 float* flcoeffs2)
248 {
249 int i, level;
250 float tmp, tmp2;
251 //maybe some frequency division thingy
252
253 flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
254 flcoeffs2[0] = log(flcoeffs1[0])/log(2);
255 tmp = flcoeffs1[0];
256 tmp2 = flcoeffs2[0];
257
258 for(i = 1; i < BANDS; i++) {
259 level = levlCoeffBuf[i];
260 if (level == 16) {
261 flcoeffs1[i] = 1.0;
262 flcoeffs2[i] = 0.0;
263 } else {
264 if (level < 17)
265 level -=7;
266 else if (level <= 24)
267 level -=32;
268 else
269 level -=16;
270
271 tmp *= imc_exp_tab[15 + level];
272 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
273 flcoeffs1[i] = tmp;
274 flcoeffs2[i] = tmp2;
275 }
276 }
277 }
278
279
280 static void imc_decode_level_coefficients2(IMCContext* q, int* levlCoeffBuf, float* old_floor, float* flcoeffs1,
281 float* flcoeffs2) {
282 int i;
283 //FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
284 // and flcoeffs2 old scale factors
285 // might be incomplete due to a missing table that is in the binary code
286 for(i = 0; i < BANDS; i++) {
287 flcoeffs1[i] = 0;
288 if(levlCoeffBuf[i] < 16) {
289 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
290 flcoeffs2[i] = (levlCoeffBuf[i]-7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
291 } else {
292 flcoeffs1[i] = old_floor[i];
293 }
294 }
295 }
296
297 /**
298 * Perform bit allocation depending on bits available
299 */
300 static int bit_allocation (IMCContext* q, int stream_format_code, int freebits, int flag) {
301 int i, j;
302 const float limit = -1.e20;
303 float highest = 0.0;
304 int indx;
305 int t1 = 0;
306 int t2 = 1;
307 float summa = 0.0;
308 int iacc = 0;
309 int summer = 0;
310 int rres, cwlen;
311 float lowest = 1.e10;
312 int low_indx = 0;
313 float workT[32];
314 int flg;
315 int found_indx = 0;
316
317 for(i = 0; i < BANDS; i++)
318 highest = FFMAX(highest, q->flcoeffs1[i]);
319
320 for(i = 0; i < BANDS-1; i++) {
321 q->flcoeffs4[i] = q->flcoeffs3[i] - log(q->flcoeffs5[i])/log(2);
322 }
323 q->flcoeffs4[BANDS - 1] = limit;
324
325 highest = highest * 0.25;
326
327 for(i = 0; i < BANDS; i++) {
328 indx = -1;
329 if ((band_tab[i+1] - band_tab[i]) == q->bandWidthT[i])
330 indx = 0;
331
332 if ((band_tab[i+1] - band_tab[i]) > q->bandWidthT[i])
333 indx = 1;
334
335 if (((band_tab[i+1] - band_tab[i])/2) >= q->bandWidthT[i])
336 indx = 2;
337
338 if (indx == -1)
339 return -1;
340
341 q->flcoeffs4[i] = q->flcoeffs4[i] + xTab[(indx*2 + (q->flcoeffs1[i] < highest)) * 2 + flag];
342 }
343
344 if (stream_format_code & 0x2) {
345 q->flcoeffs4[0] = limit;
346 q->flcoeffs4[1] = limit;
347 q->flcoeffs4[2] = limit;
348 q->flcoeffs4[3] = limit;
349 }
350
351 for(i = (stream_format_code & 0x2)?4:0; i < BANDS-1; i++) {
352 iacc += q->bandWidthT[i];
353 summa += q->bandWidthT[i] * q->flcoeffs4[i];
354 }
355 q->bandWidthT[BANDS-1] = 0;
356 summa = (summa * 0.5 - freebits) / iacc;
357
358
359 for(i = 0; i < BANDS/2; i++) {
360 rres = summer - freebits;
361 if((rres >= -8) && (rres <= 8)) break;
362
363 summer = 0;
364 iacc = 0;
365
366 for(j = (stream_format_code & 0x2)?4:0; j < BANDS; j++) {
367 cwlen = av_clipf(((q->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
368
369 q->bitsBandT[j] = cwlen;
370 summer += q->bandWidthT[j] * cwlen;
371
372 if (cwlen > 0)
373 iacc += q->bandWidthT[j];
374 }
375
376 flg = t2;
377 t2 = 1;
378 if (freebits < summer)
379 t2 = -1;
380 if (i == 0)
381 flg = t2;
382 if(flg != t2)
383 t1++;
384
385 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
386 }
387
388 for(i = (stream_format_code & 0x2)?4:0; i < BANDS; i++) {
389 for(j = band_tab[i]; j < band_tab[i+1]; j++)
390 q->CWlengthT[j] = q->bitsBandT[i];
391 }
392
393 if (freebits > summer) {
394 for(i = 0; i < BANDS; i++) {
395 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
396 }
397
398 highest = 0.0;
399
400 do{
401 if (highest <= -1.e20)
402 break;
403
404 found_indx = 0;
405 highest = -1.e20;
406
407 for(i = 0; i < BANDS; i++) {
408 if (workT[i] > highest) {
409 highest = workT[i];
410 found_indx = i;
411 }
412 }
413
414 if (highest > -1.e20) {
415 workT[found_indx] -= 2.0;
416 if (++(q->bitsBandT[found_indx]) == 6)
417 workT[found_indx] = -1.e20;
418
419 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (freebits > summer); j++){
420 q->CWlengthT[j]++;
421 summer++;
422 }
423 }
424 }while (freebits > summer);
425 }
426 if (freebits < summer) {
427 for(i = 0; i < BANDS; i++) {
428 workT[i] = q->bitsBandT[i] ? (q->bitsBandT[i] * -2 + q->flcoeffs4[i] + 1.585) : 1.e20;
429 }
430 if (stream_format_code & 0x2) {
431 workT[0] = 1.e20;
432 workT[1] = 1.e20;
433 workT[2] = 1.e20;
434 workT[3] = 1.e20;
435 }
436 while (freebits < summer){
437 lowest = 1.e10;
438 low_indx = 0;
439 for(i = 0; i < BANDS; i++) {
440 if (workT[i] < lowest) {
441 lowest = workT[i];
442 low_indx = i;
443 }
444 }
445 //if(lowest >= 1.e10) break;
446 workT[low_indx] = lowest + 2.0;
447
448 if (!(--q->bitsBandT[low_indx]))
449 workT[low_indx] = 1.e20;
450
451 for(j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++){
452 if(q->CWlengthT[j] > 0){
453 q->CWlengthT[j]--;
454 summer--;
455 }
456 }
457 }
458 }
459 return 0;
460 }
461
462 static void imc_get_skip_coeff(IMCContext* q) {
463 int i, j;
464
465 memset(q->skipFlagBits, 0, sizeof(q->skipFlagBits));
466 memset(q->skipFlagCount, 0, sizeof(q->skipFlagCount));
467 for(i = 0; i < BANDS; i++) {
468 if (!q->bandFlagsBuf[i] || !q->bandWidthT[i])
469 continue;
470
471 if (!q->skipFlagRaw[i]) {
472 q->skipFlagBits[i] = band_tab[i+1] - band_tab[i];
473
474 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
475 if ((q->skipFlags[j] = get_bits1(&q->gb)))
476 q->skipFlagCount[i]++;
477 }
478 } else {
479 for(j = band_tab[i]; j < (band_tab[i+1]-1); j += 2) {
480 if(!get_bits1(&q->gb)){//0
481 q->skipFlagBits[i]++;
482 q->skipFlags[j]=1;
483 q->skipFlags[j+1]=1;
484 q->skipFlagCount[i] += 2;
485 }else{
486 if(get_bits1(&q->gb)){//11
487 q->skipFlagBits[i] +=2;
488 q->skipFlags[j]=0;
489 q->skipFlags[j+1]=1;
490 q->skipFlagCount[i]++;
491 }else{
492 q->skipFlagBits[i] +=3;
493 q->skipFlags[j+1]=0;
494 if(!get_bits1(&q->gb)){//100
495 q->skipFlags[j]=1;
496 q->skipFlagCount[i]++;
497 }else{//101
498 q->skipFlags[j]=0;
499 }
500 }
501 }
502 }
503
504 if (j < band_tab[i+1]) {
505 q->skipFlagBits[i]++;
506 if ((q->skipFlags[j] = get_bits1(&q->gb)))
507 q->skipFlagCount[i]++;
508 }
509 }
510 }
511 }
512
513 /**
514 * Increase highest' band coefficient sizes as some bits won't be used
515 */
516 static void imc_adjust_bit_allocation (IMCContext* q, int summer) {
517 float workT[32];
518 int corrected = 0;
519 int i, j;
520 float highest = 0;
521 int found_indx=0;
522
523 for(i = 0; i < BANDS; i++) {
524 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
525 }
526
527 while (corrected < summer) {
528 if(highest <= -1.e20)
529 break;
530
531 highest = -1.e20;
532
533 for(i = 0; i < BANDS; i++) {
534 if (workT[i] > highest) {
535 highest = workT[i];
536 found_indx = i;
537 }
538 }
539
540 if (highest > -1.e20) {
541 workT[found_indx] -= 2.0;
542 if (++(q->bitsBandT[found_indx]) == 6)
543 workT[found_indx] = -1.e20;
544
545 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
546 if (!q->skipFlags[j] && (q->CWlengthT[j] < 6)) {
547 q->CWlengthT[j]++;
548 corrected++;
549 }
550 }
551 }
552 }
553 }
554
555 static void imc_imdct256(IMCContext *q) {
556 int i;
557 float re, im;
558
559 /* prerotation */
560 for(i=0; i < COEFFS/2; i++){
561 q->samples[i].re = -(q->pre_coef1[i] * q->CWdecoded[COEFFS-1-i*2]) -
562 (q->pre_coef2[i] * q->CWdecoded[i*2]);
563 q->samples[i].im = (q->pre_coef2[i] * q->CWdecoded[COEFFS-1-i*2]) -
564 (q->pre_coef1[i] * q->CWdecoded[i*2]);
565 }
566
567 /* FFT */
568 q->fft.fft_permute(&q->fft, q->samples);
569 q->fft.fft_calc (&q->fft, q->samples);
570
571 /* postrotation, window and reorder */
572 for(i = 0; i < COEFFS/2; i++){
573 re = (q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
574 im = (-q->samples[i].im * q->post_cos[i]) - (q->samples[i].re * q->post_sin[i]);
575 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);
576 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);
577 q->last_fft_im[i] = im;
578 }
579 }
580
581 static int inverse_quant_coeff (IMCContext* q, int stream_format_code) {
582 int i, j;
583 int middle_value, cw_len, max_size;
584 const float* quantizer;
585
586 for(i = 0; i < BANDS; i++) {
587 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
588 q->CWdecoded[j] = 0;
589 cw_len = q->CWlengthT[j];
590
591 if (cw_len <= 0 || q->skipFlags[j])
592 continue;
593
594 max_size = 1 << cw_len;
595 middle_value = max_size >> 1;
596
597 if (q->codewords[j] >= max_size || q->codewords[j] < 0)
598 return -1;
599
600 if (cw_len >= 4){
601 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
602 if (q->codewords[j] >= middle_value)
603 q->CWdecoded[j] = quantizer[q->codewords[j] - 8] * q->flcoeffs6[i];
604 else
605 q->CWdecoded[j] = -quantizer[max_size - q->codewords[j] - 8 - 1] * q->flcoeffs6[i];
606 }else{
607 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (q->bandFlagsBuf[i] << 1)];
608 if (q->codewords[j] >= middle_value)
609 q->CWdecoded[j] = quantizer[q->codewords[j] - 1] * q->flcoeffs6[i];
610 else
611 q->CWdecoded[j] = -quantizer[max_size - 2 - q->codewords[j]] * q->flcoeffs6[i];
612 }
613 }
614 }
615 return 0;
616 }
617
618
619 static int imc_get_coeffs (IMCContext* q) {
620 int i, j, cw_len, cw;
621
622 for(i = 0; i < BANDS; i++) {
623 if(!q->sumLenArr[i]) continue;
624 if (q->bandFlagsBuf[i] || q->bandWidthT[i]) {
625 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
626 cw_len = q->CWlengthT[j];
627 cw = 0;
628
629 if (get_bits_count(&q->gb) + cw_len > 512){
630 //av_log(NULL,0,"Band %i coeff %i cw_len %i\n",i,j,cw_len);
631 return -1;
632 }
633
634 if(cw_len && (!q->bandFlagsBuf[i] || !q->skipFlags[j]))
635 cw = get_bits(&q->gb, cw_len);
636
637 q->codewords[j] = cw;
638 }
639 }
640 }
641 return 0;
642 }
643
644 static int imc_decode_frame(AVCodecContext * avctx,
645 void *data, int *data_size,
646 AVPacket *avpkt)
647 {
648 const uint8_t *buf = avpkt->data;
649 int buf_size = avpkt->size;
650
651 IMCContext *q = avctx->priv_data;
652
653 int stream_format_code;
654 int imc_hdr, i, j;
655 int flag;
656 int bits, summer;
657 int counter, bitscount;
658 LOCAL_ALIGNED_16(uint16_t, buf16, [IMC_BLOCK_SIZE / 2]);
659
660 if (buf_size < IMC_BLOCK_SIZE) {
661 av_log(avctx, AV_LOG_ERROR, "imc frame too small!\n");
662 return -1;
663 }
664
665 q->dsp.bswap16_buf(buf16, (const uint16_t*)buf, IMC_BLOCK_SIZE / 2);
666
667 q->out_samples = data;
668 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
669
670 /* Check the frame header */
671 imc_hdr = get_bits(&q->gb, 9);
672 if (imc_hdr != IMC_FRAME_ID) {
673 av_log(avctx, AV_LOG_ERROR, "imc frame header check failed!\n");
674 av_log(avctx, AV_LOG_ERROR, "got %x instead of 0x21.\n", imc_hdr);
675 return -1;
676 }
677 stream_format_code = get_bits(&q->gb, 3);
678
679 if(stream_format_code & 1){
680 av_log(avctx, AV_LOG_ERROR, "Stream code format %X is not supported\n", stream_format_code);
681 return -1;
682 }
683
684 // av_log(avctx, AV_LOG_DEBUG, "stream_format_code = %d\n", stream_format_code);
685
686 if (stream_format_code & 0x04)
687 q->decoder_reset = 1;
688
689 if(q->decoder_reset) {
690 memset(q->out_samples, 0, sizeof(q->out_samples));
691 for(i = 0; i < BANDS; i++)q->old_floor[i] = 1.0;
692 for(i = 0; i < COEFFS; i++)q->CWdecoded[i] = 0;
693 q->decoder_reset = 0;
694 }
695
696 flag = get_bits1(&q->gb);
697 imc_read_level_coeffs(q, stream_format_code, q->levlCoeffBuf);
698
699 if (stream_format_code & 0x4)
700 imc_decode_level_coefficients(q, q->levlCoeffBuf, q->flcoeffs1, q->flcoeffs2);
701 else
702 imc_decode_level_coefficients2(q, q->levlCoeffBuf, q->old_floor, q->flcoeffs1, q->flcoeffs2);
703
704 memcpy(q->old_floor, q->flcoeffs1, 32 * sizeof(float));
705
706 counter = 0;
707 for (i=0 ; i<BANDS ; i++) {
708 if (q->levlCoeffBuf[i] == 16) {
709 q->bandWidthT[i] = 0;
710 counter++;
711 } else
712 q->bandWidthT[i] = band_tab[i+1] - band_tab[i];
713 }
714 memset(q->bandFlagsBuf, 0, BANDS * sizeof(int));
715 for(i = 0; i < BANDS-1; i++) {
716 if (q->bandWidthT[i])
717 q->bandFlagsBuf[i] = get_bits1(&q->gb);
718 }
719
720 imc_calculate_coeffs(q, q->flcoeffs1, q->flcoeffs2, q->bandWidthT, q->flcoeffs3, q->flcoeffs5);
721
722 bitscount = 0;
723 /* first 4 bands will be assigned 5 bits per coefficient */
724 if (stream_format_code & 0x2) {
725 bitscount += 15;
726
727 q->bitsBandT[0] = 5;
728 q->CWlengthT[0] = 5;
729 q->CWlengthT[1] = 5;
730 q->CWlengthT[2] = 5;
731 for(i = 1; i < 4; i++){
732 bits = (q->levlCoeffBuf[i] == 16) ? 0 : 5;
733 q->bitsBandT[i] = bits;
734 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
735 q->CWlengthT[j] = bits;
736 bitscount += bits;
737 }
738 }
739 }
740
741 if(bit_allocation (q, stream_format_code, 512 - bitscount - get_bits_count(&q->gb), flag) < 0) {
742 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
743 q->decoder_reset = 1;
744 return -1;
745 }
746
747 for(i = 0; i < BANDS; i++) {
748 q->sumLenArr[i] = 0;
749 q->skipFlagRaw[i] = 0;
750 for(j = band_tab[i]; j < band_tab[i+1]; j++)
751 q->sumLenArr[i] += q->CWlengthT[j];
752 if (q->bandFlagsBuf[i])
753 if( (((band_tab[i+1] - band_tab[i]) * 1.5) > q->sumLenArr[i]) && (q->sumLenArr[i] > 0))
754 q->skipFlagRaw[i] = 1;
755 }
756
757 imc_get_skip_coeff(q);
758
759 for(i = 0; i < BANDS; i++) {
760 q->flcoeffs6[i] = q->flcoeffs1[i];
761 /* band has flag set and at least one coded coefficient */
762 if (q->bandFlagsBuf[i] && (band_tab[i+1] - band_tab[i]) != q->skipFlagCount[i]){
763 q->flcoeffs6[i] *= q->sqrt_tab[band_tab[i+1] - band_tab[i]] /
764 q->sqrt_tab[(band_tab[i+1] - band_tab[i] - q->skipFlagCount[i])];
765 }
766 }
767
768 /* calculate bits left, bits needed and adjust bit allocation */
769 bits = summer = 0;
770
771 for(i = 0; i < BANDS; i++) {
772 if (q->bandFlagsBuf[i]) {
773 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
774 if(q->skipFlags[j]) {
775 summer += q->CWlengthT[j];
776 q->CWlengthT[j] = 0;
777 }
778 }
779 bits += q->skipFlagBits[i];
780 summer -= q->skipFlagBits[i];
781 }
782 }
783 imc_adjust_bit_allocation(q, summer);
784
785 for(i = 0; i < BANDS; i++) {
786 q->sumLenArr[i] = 0;
787
788 for(j = band_tab[i]; j < band_tab[i+1]; j++)
789 if (!q->skipFlags[j])
790 q->sumLenArr[i] += q->CWlengthT[j];
791 }
792
793 memset(q->codewords, 0, sizeof(q->codewords));
794
795 if(imc_get_coeffs(q) < 0) {
796 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");
797 q->decoder_reset = 1;
798 return 0;
799 }
800
801 if(inverse_quant_coeff(q, stream_format_code) < 0) {
802 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
803 q->decoder_reset = 1;
804 return 0;
805 }
806
807 memset(q->skipFlags, 0, sizeof(q->skipFlags));
808
809 imc_imdct256(q);
810
811 *data_size = COEFFS * sizeof(float);
812
813 return IMC_BLOCK_SIZE;
814 }
815
816
817 static av_cold int imc_decode_close(AVCodecContext * avctx)
818 {
819 IMCContext *q = avctx->priv_data;
820
821 ff_fft_end(&q->fft);
822 return 0;
823 }
824
825
826 AVCodec ff_imc_decoder = {
827 .name = "imc",
828 .type = AVMEDIA_TYPE_AUDIO,
829 .id = CODEC_ID_IMC,
830 .priv_data_size = sizeof(IMCContext),
831 .init = imc_decode_init,
832 .close = imc_decode_close,
833 .decode = imc_decode_frame,
834 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
835 };