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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
26 * IMC - Intel Music Coder
27 * A mdct based codec using a 256 points large transform
28 * divided into 32 bands with some mix of scale factors.
29 * Only mono is supported.
30 */
31
32
33#include <math.h>
34#include <stddef.h>
35#include <stdio.h>
36
37#include "libavutil/channel_layout.h"
38#include "libavutil/ffmath.h"
39#include "libavutil/float_dsp.h"
40#include "libavutil/internal.h"
41#include "avcodec.h"
42#include "bswapdsp.h"
43#include "get_bits.h"
44#include "fft.h"
45#include "internal.h"
46#include "sinewin.h"
47
48#include "imcdata.h"
49
50#define IMC_BLOCK_SIZE 64
51#define IMC_FRAME_ID 0x21
52#define BANDS 32
53#define COEFFS 256
54
55typedef struct IMCChannel {
56 float old_floor[BANDS];
57 float flcoeffs1[BANDS];
58 float flcoeffs2[BANDS];
59 float flcoeffs3[BANDS];
60 float flcoeffs4[BANDS];
61 float flcoeffs5[BANDS];
62 float flcoeffs6[BANDS];
63 float CWdecoded[COEFFS];
64
65 int bandWidthT[BANDS]; ///< codewords per band
66 int bitsBandT[BANDS]; ///< how many bits per codeword in band
67 int CWlengthT[COEFFS]; ///< how many bits in each codeword
68 int levlCoeffBuf[BANDS];
69 int bandFlagsBuf[BANDS]; ///< flags for each band
70 int sumLenArr[BANDS]; ///< bits for all coeffs in band
71 int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not
72 int skipFlagBits[BANDS]; ///< bits used to code skip flags
73 int skipFlagCount[BANDS]; ///< skipped coefficients per band
74 int skipFlags[COEFFS]; ///< skip coefficient decoding or not
75 int codewords[COEFFS]; ///< raw codewords read from bitstream
76
77 float last_fft_im[COEFFS];
78
79 int decoder_reset;
80} IMCChannel;
81
82typedef struct IMCContext {
83 IMCChannel chctx[2];
84
85 /** MDCT tables */
86 //@{
87 float mdct_sine_window[COEFFS];
88 float post_cos[COEFFS];
89 float post_sin[COEFFS];
90 float pre_coef1[COEFFS];
91 float pre_coef2[COEFFS];
92 //@}
93
94 float sqrt_tab[30];
95 GetBitContext gb;
96
97 BswapDSPContext bdsp;
98 AVFloatDSPContext *fdsp;
99 FFTContext fft;
100 DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS / 2];
101 float *out_samples;
102
103 int coef0_pos;
104
105 int8_t cyclTab[32], cyclTab2[32];
106 float weights1[31], weights2[31];
107} IMCContext;
108
109static VLC huffman_vlc[4][4];
110
111#define VLC_TABLES_SIZE 9512
112
113static const int vlc_offsets[17] = {
114 0, 640, 1156, 1732, 2308, 2852, 3396, 3924,
115 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE
116};
117
118static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];
119
120static inline double freq2bark(double freq)
121{
122 return 3.5 * atan((freq / 7500.0) * (freq / 7500.0)) + 13.0 * atan(freq * 0.00076);
123}
124
125static av_cold void iac_generate_tabs(IMCContext *q, int sampling_rate)
126{
127 double freqmin[32], freqmid[32], freqmax[32];
128 double scale = sampling_rate / (256.0 * 2.0 * 2.0);
129 double nyquist_freq = sampling_rate * 0.5;
130 double freq, bark, prev_bark = 0, tf, tb;
131 int i, j;
132
133 for (i = 0; i < 32; i++) {
134 freq = (band_tab[i] + band_tab[i + 1] - 1) * scale;
135 bark = freq2bark(freq);
136
137 if (i > 0) {
138 tb = bark - prev_bark;
139 q->weights1[i - 1] = ff_exp10(-1.0 * tb);
140 q->weights2[i - 1] = ff_exp10(-2.7 * tb);
141 }
142 prev_bark = bark;
143
144 freqmid[i] = freq;
145
146 tf = freq;
147 while (tf < nyquist_freq) {
148 tf += 0.5;
149 tb = freq2bark(tf);
150 if (tb > bark + 0.5)
151 break;
152 }
153 freqmax[i] = tf;
154
155 tf = freq;
156 while (tf > 0.0) {
157 tf -= 0.5;
158 tb = freq2bark(tf);
159 if (tb <= bark - 0.5)
160 break;
161 }
162 freqmin[i] = tf;
163 }
164
165 for (i = 0; i < 32; i++) {
166 freq = freqmax[i];
167 for (j = 31; j > 0 && freq <= freqmid[j]; j--);
168 q->cyclTab[i] = j + 1;
169
170 freq = freqmin[i];
171 for (j = 0; j < 32 && freq >= freqmid[j]; j++);
172 q->cyclTab2[i] = j - 1;
173 }
174}
175
176static av_cold int imc_decode_init(AVCodecContext *avctx)
177{
178 int i, j, ret;
179 IMCContext *q = avctx->priv_data;
180 double r1, r2;
181
182 if (avctx->codec_id == AV_CODEC_ID_IAC && avctx->sample_rate > 96000) {
183 av_log(avctx, AV_LOG_ERROR,
184 "Strange sample rate of %i, file likely corrupt or "
185 "needing a new table derivation method.\n",
186 avctx->sample_rate);
187 return AVERROR_PATCHWELCOME;
188 }
189
190 if (avctx->codec_id == AV_CODEC_ID_IMC)
191 avctx->channels = 1;
192
193 if (avctx->channels > 2) {
194 avpriv_request_sample(avctx, "Number of channels > 2");
195 return AVERROR_PATCHWELCOME;
196 }
197
198 for (j = 0; j < avctx->channels; j++) {
199 q->chctx[j].decoder_reset = 1;
200
201 for (i = 0; i < BANDS; i++)
202 q->chctx[j].old_floor[i] = 1.0;
203
204 for (i = 0; i < COEFFS / 2; i++)
205 q->chctx[j].last_fft_im[i] = 0;
206 }
207
208 /* Build mdct window, a simple sine window normalized with sqrt(2) */
209 ff_sine_window_init(q->mdct_sine_window, COEFFS);
210 for (i = 0; i < COEFFS; i++)
211 q->mdct_sine_window[i] *= sqrt(2.0);
212 for (i = 0; i < COEFFS / 2; i++) {
213 q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI);
214 q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI);
215
216 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
217 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
218
219 if (i & 0x1) {
220 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
221 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
222 } else {
223 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
224 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
225 }
226 }
227
228 /* Generate a square root table */
229
230 for (i = 0; i < 30; i++)
231 q->sqrt_tab[i] = sqrt(i);
232
233 /* initialize the VLC tables */
234 for (i = 0; i < 4 ; i++) {
235 for (j = 0; j < 4; j++) {
236 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]];
237 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];
238 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i],
239 imc_huffman_lens[i][j], 1, 1,
240 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC);
241 }
242 }
243
244 if (avctx->codec_id == AV_CODEC_ID_IAC) {
245 iac_generate_tabs(q, avctx->sample_rate);
246 } else {
247 memcpy(q->cyclTab, cyclTab, sizeof(cyclTab));
248 memcpy(q->cyclTab2, cyclTab2, sizeof(cyclTab2));
249 memcpy(q->weights1, imc_weights1, sizeof(imc_weights1));
250 memcpy(q->weights2, imc_weights2, sizeof(imc_weights2));
251 }
252
253 if ((ret = ff_fft_init(&q->fft, 7, 1))) {
254 av_log(avctx, AV_LOG_INFO, "FFT init failed\n");
255 return ret;
256 }
257 ff_bswapdsp_init(&q->bdsp);
258 q->fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
259 if (!q->fdsp) {
260 ff_fft_end(&q->fft);
261
262 return AVERROR(ENOMEM);
263 }
264
265 avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
266 avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
267 : AV_CH_LAYOUT_STEREO;
268
269 return 0;
270}
271
272static void imc_calculate_coeffs(IMCContext *q, float *flcoeffs1,
273 float *flcoeffs2, int *bandWidthT,
274 float *flcoeffs3, float *flcoeffs5)
275{
276 float workT1[BANDS];
277 float workT2[BANDS];
278 float workT3[BANDS];
279 float snr_limit = 1.e-30;
280 float accum = 0.0;
281 int i, cnt2;
282
283 for (i = 0; i < BANDS; i++) {
284 flcoeffs5[i] = workT2[i] = 0.0;
285 if (bandWidthT[i]) {
286 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
287 flcoeffs3[i] = 2.0 * flcoeffs2[i];
288 } else {
289 workT1[i] = 0.0;
290 flcoeffs3[i] = -30000.0;
291 }
292 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
293 if (workT3[i] <= snr_limit)
294 workT3[i] = 0.0;
295 }
296
297 for (i = 0; i < BANDS; i++) {
298 for (cnt2 = i; cnt2 < q->cyclTab[i]; cnt2++)
299 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
300 workT2[cnt2 - 1] = workT2[cnt2 - 1] + workT3[i];
301 }
302
303 for (i = 1; i < BANDS; i++) {
304 accum = (workT2[i - 1] + accum) * q->weights1[i - 1];
305 flcoeffs5[i] += accum;
306 }
307
308 for (i = 0; i < BANDS; i++)
309 workT2[i] = 0.0;
310
311 for (i = 0; i < BANDS; i++) {
312 for (cnt2 = i - 1; cnt2 > q->cyclTab2[i]; cnt2--)
313 flcoeffs5[cnt2] += workT3[i];
314 workT2[cnt2+1] += workT3[i];
315 }
316
317 accum = 0.0;
318
319 for (i = BANDS-2; i >= 0; i--) {
320 accum = (workT2[i+1] + accum) * q->weights2[i];
321 flcoeffs5[i] += accum;
322 // there is missing code here, but it seems to never be triggered
323 }
324}
325
326
327static void imc_read_level_coeffs(IMCContext *q, int stream_format_code,
328 int *levlCoeffs)
329{
330 int i;
331 VLC *hufftab[4];
332 int start = 0;
333 const uint8_t *cb_sel;
334 int s;
335
336 s = stream_format_code >> 1;
337 hufftab[0] = &huffman_vlc[s][0];
338 hufftab[1] = &huffman_vlc[s][1];
339 hufftab[2] = &huffman_vlc[s][2];
340 hufftab[3] = &huffman_vlc[s][3];
341 cb_sel = imc_cb_select[s];
342
343 if (stream_format_code & 4)
344 start = 1;
345 if (start)
346 levlCoeffs[0] = get_bits(&q->gb, 7);
347 for (i = start; i < BANDS; i++) {
348 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table,
349 hufftab[cb_sel[i]]->bits, 2);
350 if (levlCoeffs[i] == 17)
351 levlCoeffs[i] += get_bits(&q->gb, 4);
352 }
353}
354
355static void imc_read_level_coeffs_raw(IMCContext *q, int stream_format_code,
356 int *levlCoeffs)
357{
358 int i;
359
360 q->coef0_pos = get_bits(&q->gb, 5);
361 levlCoeffs[0] = get_bits(&q->gb, 7);
362 for (i = 1; i < BANDS; i++)
363 levlCoeffs[i] = get_bits(&q->gb, 4);
364}
365
366static void imc_decode_level_coefficients(IMCContext *q, int *levlCoeffBuf,
367 float *flcoeffs1, float *flcoeffs2)
368{
369 int i, level;
370 float tmp, tmp2;
371 // maybe some frequency division thingy
372
373 flcoeffs1[0] = 20000.0 / exp2 (levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
374 flcoeffs2[0] = log2f(flcoeffs1[0]);
375 tmp = flcoeffs1[0];
376 tmp2 = flcoeffs2[0];
377
378 for (i = 1; i < BANDS; i++) {
379 level = levlCoeffBuf[i];
380 if (level == 16) {
381 flcoeffs1[i] = 1.0;
382 flcoeffs2[i] = 0.0;
383 } else {
384 if (level < 17)
385 level -= 7;
386 else if (level <= 24)
387 level -= 32;
388 else
389 level -= 16;
390
391 tmp *= imc_exp_tab[15 + level];
392 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
393 flcoeffs1[i] = tmp;
394 flcoeffs2[i] = tmp2;
395 }
396 }
397}
398
399
400static void imc_decode_level_coefficients2(IMCContext *q, int *levlCoeffBuf,
401 float *old_floor, float *flcoeffs1,
402 float *flcoeffs2)
403{
404 int i;
405 /* FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
406 * and flcoeffs2 old scale factors
407 * might be incomplete due to a missing table that is in the binary code
408 */
409 for (i = 0; i < BANDS; i++) {
410 flcoeffs1[i] = 0;
411 if (levlCoeffBuf[i] < 16) {
412 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
413 flcoeffs2[i] = (levlCoeffBuf[i] - 7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
414 } else {
415 flcoeffs1[i] = old_floor[i];
416 }
417 }
418}
419
420static void imc_decode_level_coefficients_raw(IMCContext *q, int *levlCoeffBuf,
421 float *flcoeffs1, float *flcoeffs2)
422{
423 int i, level, pos;
424 float tmp, tmp2;
425
426 pos = q->coef0_pos;
427 flcoeffs1[pos] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
428 flcoeffs2[pos] = log2f(flcoeffs1[pos]);
429 tmp = flcoeffs1[pos];
430 tmp2 = flcoeffs2[pos];
431
432 levlCoeffBuf++;
433 for (i = 0; i < BANDS; i++) {
434 if (i == pos)
435 continue;
436 level = *levlCoeffBuf++;
437 flcoeffs1[i] = tmp * powf(10.0, -level * 0.4375); //todo tab
438 flcoeffs2[i] = tmp2 - 1.4533435415 * level; // 1.4533435415 = log2(10) * 0.4375
439 }
440}
441
442/**
443 * Perform bit allocation depending on bits available
444 */
445static int bit_allocation(IMCContext *q, IMCChannel *chctx,
446 int stream_format_code, int freebits, int flag)
447{
448 int i, j;
449 const float limit = -1.e20;
450 float highest = 0.0;
451 int indx;
452 int t1 = 0;
453 int t2 = 1;
454 float summa = 0.0;
455 int iacc = 0;
456 int summer = 0;
457 int rres, cwlen;
458 float lowest = 1.e10;
459 int low_indx = 0;
460 float workT[32];
461 int flg;
462 int found_indx = 0;
463
464 for (i = 0; i < BANDS; i++)
465 highest = FFMAX(highest, chctx->flcoeffs1[i]);
466
467 for (i = 0; i < BANDS - 1; i++) {
468 if (chctx->flcoeffs5[i] <= 0) {
469 av_log(NULL, AV_LOG_ERROR, "flcoeffs5 %f invalid\n", chctx->flcoeffs5[i]);
470 return AVERROR_INVALIDDATA;
471 }
472 chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log2f(chctx->flcoeffs5[i]);
473 }
474 chctx->flcoeffs4[BANDS - 1] = limit;
475
476 highest = highest * 0.25;
477
478 for (i = 0; i < BANDS; i++) {
479 indx = -1;
480 if ((band_tab[i + 1] - band_tab[i]) == chctx->bandWidthT[i])
481 indx = 0;
482
483 if ((band_tab[i + 1] - band_tab[i]) > chctx->bandWidthT[i])
484 indx = 1;
485
486 if (((band_tab[i + 1] - band_tab[i]) / 2) >= chctx->bandWidthT[i])
487 indx = 2;
488
489 if (indx == -1)
490 return AVERROR_INVALIDDATA;
491
492 chctx->flcoeffs4[i] += xTab[(indx * 2 + (chctx->flcoeffs1[i] < highest)) * 2 + flag];
493 }
494
495 if (stream_format_code & 0x2) {
496 chctx->flcoeffs4[0] = limit;
497 chctx->flcoeffs4[1] = limit;
498 chctx->flcoeffs4[2] = limit;
499 chctx->flcoeffs4[3] = limit;
500 }
501
502 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS - 1; i++) {
503 iacc += chctx->bandWidthT[i];
504 summa += chctx->bandWidthT[i] * chctx->flcoeffs4[i];
505 }
506
507 if (!iacc)
508 return AVERROR_INVALIDDATA;
509
510 chctx->bandWidthT[BANDS - 1] = 0;
511 summa = (summa * 0.5 - freebits) / iacc;
512
513
514 for (i = 0; i < BANDS / 2; i++) {
515 rres = summer - freebits;
516 if ((rres >= -8) && (rres <= 8))
517 break;
518
519 summer = 0;
520 iacc = 0;
521
522 for (j = (stream_format_code & 0x2) ? 4 : 0; j < BANDS; j++) {
523 cwlen = av_clipf(((chctx->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
524
525 chctx->bitsBandT[j] = cwlen;
526 summer += chctx->bandWidthT[j] * cwlen;
527
528 if (cwlen > 0)
529 iacc += chctx->bandWidthT[j];
530 }
531
532 flg = t2;
533 t2 = 1;
534 if (freebits < summer)
535 t2 = -1;
536 if (i == 0)
537 flg = t2;
538 if (flg != t2)
539 t1++;
540
541 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
542 }
543
544 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS; i++) {
545 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
546 chctx->CWlengthT[j] = chctx->bitsBandT[i];
547 }
548
549 if (freebits > summer) {
550 for (i = 0; i < BANDS; i++) {
551 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
552 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
553 }
554
555 highest = 0.0;
556
557 do {
558 if (highest <= -1.e20)
559 break;
560
561 found_indx = 0;
562 highest = -1.e20;
563
564 for (i = 0; i < BANDS; i++) {
565 if (workT[i] > highest) {
566 highest = workT[i];
567 found_indx = i;
568 }
569 }
570
571 if (highest > -1.e20) {
572 workT[found_indx] -= 2.0;
573 if (++chctx->bitsBandT[found_indx] == 6)
574 workT[found_indx] = -1.e20;
575
576 for (j = band_tab[found_indx]; j < band_tab[found_indx + 1] && (freebits > summer); j++) {
577 chctx->CWlengthT[j]++;
578 summer++;
579 }
580 }
581 } while (freebits > summer);
582 }
583 if (freebits < summer) {
584 for (i = 0; i < BANDS; i++) {
585 workT[i] = chctx->bitsBandT[i] ? (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] + 1.585)
586 : 1.e20;
587 }
588 if (stream_format_code & 0x2) {
589 workT[0] = 1.e20;
590 workT[1] = 1.e20;
591 workT[2] = 1.e20;
592 workT[3] = 1.e20;
593 }
594 while (freebits < summer) {
595 lowest = 1.e10;
596 low_indx = 0;
597 for (i = 0; i < BANDS; i++) {
598 if (workT[i] < lowest) {
599 lowest = workT[i];
600 low_indx = i;
601 }
602 }
603 // if (lowest >= 1.e10)
604 // break;
605 workT[low_indx] = lowest + 2.0;
606
607 if (!--chctx->bitsBandT[low_indx])
608 workT[low_indx] = 1.e20;
609
610 for (j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++) {
611 if (chctx->CWlengthT[j] > 0) {
612 chctx->CWlengthT[j]--;
613 summer--;
614 }
615 }
616 }
617 }
618 return 0;
619}
620
621static void imc_get_skip_coeff(IMCContext *q, IMCChannel *chctx)
622{
623 int i, j;
624
625 memset(chctx->skipFlagBits, 0, sizeof(chctx->skipFlagBits));
626 memset(chctx->skipFlagCount, 0, sizeof(chctx->skipFlagCount));
627 for (i = 0; i < BANDS; i++) {
628 if (!chctx->bandFlagsBuf[i] || !chctx->bandWidthT[i])
629 continue;
630
631 if (!chctx->skipFlagRaw[i]) {
632 chctx->skipFlagBits[i] = band_tab[i + 1] - band_tab[i];
633
634 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
635 chctx->skipFlags[j] = get_bits1(&q->gb);
636 if (chctx->skipFlags[j])
637 chctx->skipFlagCount[i]++;
638 }
639 } else {
640 for (j = band_tab[i]; j < band_tab[i + 1] - 1; j += 2) {
641 if (!get_bits1(&q->gb)) { // 0
642 chctx->skipFlagBits[i]++;
643 chctx->skipFlags[j] = 1;
644 chctx->skipFlags[j + 1] = 1;
645 chctx->skipFlagCount[i] += 2;
646 } else {
647 if (get_bits1(&q->gb)) { // 11
648 chctx->skipFlagBits[i] += 2;
649 chctx->skipFlags[j] = 0;
650 chctx->skipFlags[j + 1] = 1;
651 chctx->skipFlagCount[i]++;
652 } else {
653 chctx->skipFlagBits[i] += 3;
654 chctx->skipFlags[j + 1] = 0;
655 if (!get_bits1(&q->gb)) { // 100
656 chctx->skipFlags[j] = 1;
657 chctx->skipFlagCount[i]++;
658 } else { // 101
659 chctx->skipFlags[j] = 0;
660 }
661 }
662 }
663 }
664
665 if (j < band_tab[i + 1]) {
666 chctx->skipFlagBits[i]++;
667 if ((chctx->skipFlags[j] = get_bits1(&q->gb)))
668 chctx->skipFlagCount[i]++;
669 }
670 }
671 }
672}
673
674/**
675 * Increase highest' band coefficient sizes as some bits won't be used
676 */
677static void imc_adjust_bit_allocation(IMCContext *q, IMCChannel *chctx,
678 int summer)
679{
680 float workT[32];
681 int corrected = 0;
682 int i, j;
683 float highest = 0;
684 int found_indx = 0;
685
686 for (i = 0; i < BANDS; i++) {
687 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
688 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
689 }
690
691 while (corrected < summer) {
692 if (highest <= -1.e20)
693 break;
694
695 highest = -1.e20;
696
697 for (i = 0; i < BANDS; i++) {
698 if (workT[i] > highest) {
699 highest = workT[i];
700 found_indx = i;
701 }
702 }
703
704 if (highest > -1.e20) {
705 workT[found_indx] -= 2.0;
706 if (++(chctx->bitsBandT[found_indx]) == 6)
707 workT[found_indx] = -1.e20;
708
709 for (j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
710 if (!chctx->skipFlags[j] && (chctx->CWlengthT[j] < 6)) {
711 chctx->CWlengthT[j]++;
712 corrected++;
713 }
714 }
715 }
716 }
717}
718
719static void imc_imdct256(IMCContext *q, IMCChannel *chctx, int channels)
720{
721 int i;
722 float re, im;
723 float *dst1 = q->out_samples;
724 float *dst2 = q->out_samples + (COEFFS - 1);
725
726 /* prerotation */
727 for (i = 0; i < COEFFS / 2; i++) {
728 q->samples[i].re = -(q->pre_coef1[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
729 (q->pre_coef2[i] * chctx->CWdecoded[i * 2]);
730 q->samples[i].im = (q->pre_coef2[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
731 (q->pre_coef1[i] * chctx->CWdecoded[i * 2]);
732 }
733
734 /* FFT */
735 q->fft.fft_permute(&q->fft, q->samples);
736 q->fft.fft_calc(&q->fft, q->samples);
737
738 /* postrotation, window and reorder */
739 for (i = 0; i < COEFFS / 2; i++) {
740 re = ( q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
741 im = (-q->samples[i].im * q->post_cos[i]) - ( q->samples[i].re * q->post_sin[i]);
742 *dst1 = (q->mdct_sine_window[COEFFS - 1 - i * 2] * chctx->last_fft_im[i])
743 + (q->mdct_sine_window[i * 2] * re);
744 *dst2 = (q->mdct_sine_window[i * 2] * chctx->last_fft_im[i])
745 - (q->mdct_sine_window[COEFFS - 1 - i * 2] * re);
746 dst1 += 2;
747 dst2 -= 2;
748 chctx->last_fft_im[i] = im;
749 }
750}
751
752static int inverse_quant_coeff(IMCContext *q, IMCChannel *chctx,
753 int stream_format_code)
754{
755 int i, j;
756 int middle_value, cw_len, max_size;
757 const float *quantizer;
758
759 for (i = 0; i < BANDS; i++) {
760 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
761 chctx->CWdecoded[j] = 0;
762 cw_len = chctx->CWlengthT[j];
763
764 if (cw_len <= 0 || chctx->skipFlags[j])
765 continue;
766
767 max_size = 1 << cw_len;
768 middle_value = max_size >> 1;
769
770 if (chctx->codewords[j] >= max_size || chctx->codewords[j] < 0)
771 return AVERROR_INVALIDDATA;
772
773 if (cw_len >= 4) {
774 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
775 if (chctx->codewords[j] >= middle_value)
776 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 8] * chctx->flcoeffs6[i];
777 else
778 chctx->CWdecoded[j] = -quantizer[max_size - chctx->codewords[j] - 8 - 1] * chctx->flcoeffs6[i];
779 }else{
780 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (chctx->bandFlagsBuf[i] << 1)];
781 if (chctx->codewords[j] >= middle_value)
782 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 1] * chctx->flcoeffs6[i];
783 else
784 chctx->CWdecoded[j] = -quantizer[max_size - 2 - chctx->codewords[j]] * chctx->flcoeffs6[i];
785 }
786 }
787 }
788 return 0;
789}
790
791
792static void imc_get_coeffs(AVCodecContext *avctx,
793 IMCContext *q, IMCChannel *chctx)
794{
795 int i, j, cw_len, cw;
796
797 for (i = 0; i < BANDS; i++) {
798 if (!chctx->sumLenArr[i])
799 continue;
800 if (chctx->bandFlagsBuf[i] || chctx->bandWidthT[i]) {
801 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
802 cw_len = chctx->CWlengthT[j];
803 cw = 0;
804
805 if (cw_len && (!chctx->bandFlagsBuf[i] || !chctx->skipFlags[j])) {
806 if (get_bits_count(&q->gb) + cw_len > 512) {
807 av_log(avctx, AV_LOG_WARNING,
808 "Potential problem on band %i, coefficient %i"
809 ": cw_len=%i\n", i, j, cw_len);
810 } else
811 cw = get_bits(&q->gb, cw_len);
812 }
813
814 chctx->codewords[j] = cw;
815 }
816 }
817 }
818}
819
820static void imc_refine_bit_allocation(IMCContext *q, IMCChannel *chctx)
821{
822 int i, j;
823 int bits, summer;
824
825 for (i = 0; i < BANDS; i++) {
826 chctx->sumLenArr[i] = 0;
827 chctx->skipFlagRaw[i] = 0;
828 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
829 chctx->sumLenArr[i] += chctx->CWlengthT[j];
830 if (chctx->bandFlagsBuf[i])
831 if ((((band_tab[i + 1] - band_tab[i]) * 1.5) > chctx->sumLenArr[i]) && (chctx->sumLenArr[i] > 0))
832 chctx->skipFlagRaw[i] = 1;
833 }
834
835 imc_get_skip_coeff(q, chctx);
836
837 for (i = 0; i < BANDS; i++) {
838 chctx->flcoeffs6[i] = chctx->flcoeffs1[i];
839 /* band has flag set and at least one coded coefficient */
840 if (chctx->bandFlagsBuf[i] && (band_tab[i + 1] - band_tab[i]) != chctx->skipFlagCount[i]) {
841 chctx->flcoeffs6[i] *= q->sqrt_tab[ band_tab[i + 1] - band_tab[i]] /
842 q->sqrt_tab[(band_tab[i + 1] - band_tab[i] - chctx->skipFlagCount[i])];
843 }
844 }
845
846 /* calculate bits left, bits needed and adjust bit allocation */
847 bits = summer = 0;
848
849 for (i = 0; i < BANDS; i++) {
850 if (chctx->bandFlagsBuf[i]) {
851 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
852 if (chctx->skipFlags[j]) {
853 summer += chctx->CWlengthT[j];
854 chctx->CWlengthT[j] = 0;
855 }
856 }
857 bits += chctx->skipFlagBits[i];
858 summer -= chctx->skipFlagBits[i];
859 }
860 }
861 imc_adjust_bit_allocation(q, chctx, summer);
862}
863
864static int imc_decode_block(AVCodecContext *avctx, IMCContext *q, int ch)
865{
866 int stream_format_code;
867 int imc_hdr, i, j, ret;
868 int flag;
869 int bits;
870 int counter, bitscount;
871 IMCChannel *chctx = q->chctx + ch;
872
873
874 /* Check the frame header */
875 imc_hdr = get_bits(&q->gb, 9);
876 if (imc_hdr & 0x18) {
877 av_log(avctx, AV_LOG_ERROR, "frame header check failed!\n");
878 av_log(avctx, AV_LOG_ERROR, "got %X.\n", imc_hdr);
879 return AVERROR_INVALIDDATA;
880 }
881 stream_format_code = get_bits(&q->gb, 3);
882
883 if (stream_format_code & 0x04)
884 chctx->decoder_reset = 1;
885
886 if (chctx->decoder_reset) {
887 for (i = 0; i < BANDS; i++)
888 chctx->old_floor[i] = 1.0;
889 for (i = 0; i < COEFFS; i++)
890 chctx->CWdecoded[i] = 0;
891 chctx->decoder_reset = 0;
892 }
893
894 flag = get_bits1(&q->gb);
895 if (stream_format_code & 0x1)
896 imc_read_level_coeffs_raw(q, stream_format_code, chctx->levlCoeffBuf);
897 else
898 imc_read_level_coeffs(q, stream_format_code, chctx->levlCoeffBuf);
899
900 if (stream_format_code & 0x1)
901 imc_decode_level_coefficients_raw(q, chctx->levlCoeffBuf,
902 chctx->flcoeffs1, chctx->flcoeffs2);
903 else if (stream_format_code & 0x4)
904 imc_decode_level_coefficients(q, chctx->levlCoeffBuf,
905 chctx->flcoeffs1, chctx->flcoeffs2);
906 else
907 imc_decode_level_coefficients2(q, chctx->levlCoeffBuf, chctx->old_floor,
908 chctx->flcoeffs1, chctx->flcoeffs2);
909
910 for(i=0; i<BANDS; i++) {
911 if(chctx->flcoeffs1[i] > INT_MAX) {
912 av_log(avctx, AV_LOG_ERROR, "scalefactor out of range\n");
913 return AVERROR_INVALIDDATA;
914 }
915 }
916
917 memcpy(chctx->old_floor, chctx->flcoeffs1, 32 * sizeof(float));
918
919 counter = 0;
920 if (stream_format_code & 0x1) {
921 for (i = 0; i < BANDS; i++) {
922 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
923 chctx->bandFlagsBuf[i] = 0;
924 chctx->flcoeffs3[i] = chctx->flcoeffs2[i] * 2;
925 chctx->flcoeffs5[i] = 1.0;
926 }
927 } else {
928 for (i = 0; i < BANDS; i++) {
929 if (chctx->levlCoeffBuf[i] == 16) {
930 chctx->bandWidthT[i] = 0;
931 counter++;
932 } else
933 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
934 }
935
936 memset(chctx->bandFlagsBuf, 0, BANDS * sizeof(int));
937 for (i = 0; i < BANDS - 1; i++)
938 if (chctx->bandWidthT[i])
939 chctx->bandFlagsBuf[i] = get_bits1(&q->gb);
940
941 imc_calculate_coeffs(q, chctx->flcoeffs1, chctx->flcoeffs2,
942 chctx->bandWidthT, chctx->flcoeffs3,
943 chctx->flcoeffs5);
944 }
945
946 bitscount = 0;
947 /* first 4 bands will be assigned 5 bits per coefficient */
948 if (stream_format_code & 0x2) {
949 bitscount += 15;
950
951 chctx->bitsBandT[0] = 5;
952 chctx->CWlengthT[0] = 5;
953 chctx->CWlengthT[1] = 5;
954 chctx->CWlengthT[2] = 5;
955 for (i = 1; i < 4; i++) {
956 if (stream_format_code & 0x1)
957 bits = 5;
958 else
959 bits = (chctx->levlCoeffBuf[i] == 16) ? 0 : 5;
960 chctx->bitsBandT[i] = bits;
961 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
962 chctx->CWlengthT[j] = bits;
963 bitscount += bits;
964 }
965 }
966 }
967 if (avctx->codec_id == AV_CODEC_ID_IAC) {
968 bitscount += !!chctx->bandWidthT[BANDS - 1];
969 if (!(stream_format_code & 0x2))
970 bitscount += 16;
971 }
972
973 if ((ret = bit_allocation(q, chctx, stream_format_code,
974 512 - bitscount - get_bits_count(&q->gb),
975 flag)) < 0) {
976 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
977 chctx->decoder_reset = 1;
978 return ret;
979 }
980
981 if (stream_format_code & 0x1) {
982 for (i = 0; i < BANDS; i++)
983 chctx->skipFlags[i] = 0;
984 } else {
985 imc_refine_bit_allocation(q, chctx);
986 }
987
988 for (i = 0; i < BANDS; i++) {
989 chctx->sumLenArr[i] = 0;
990
991 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
992 if (!chctx->skipFlags[j])
993 chctx->sumLenArr[i] += chctx->CWlengthT[j];
994 }
995
996 memset(chctx->codewords, 0, sizeof(chctx->codewords));
997
998 imc_get_coeffs(avctx, q, chctx);
999
1000 if (inverse_quant_coeff(q, chctx, stream_format_code) < 0) {
1001 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
1002 chctx->decoder_reset = 1;
1003 return AVERROR_INVALIDDATA;
1004 }
1005
1006 memset(chctx->skipFlags, 0, sizeof(chctx->skipFlags));
1007
1008 imc_imdct256(q, chctx, avctx->channels);
1009
1010 return 0;
1011}
1012
1013static int imc_decode_frame(AVCodecContext *avctx, void *data,
1014 int *got_frame_ptr, AVPacket *avpkt)
1015{
1016 AVFrame *frame = data;
1017 const uint8_t *buf = avpkt->data;
1018 int buf_size = avpkt->size;
1019 int ret, i;
1020
1021 IMCContext *q = avctx->priv_data;
1022
1023 LOCAL_ALIGNED_16(uint16_t, buf16, [(IMC_BLOCK_SIZE + AV_INPUT_BUFFER_PADDING_SIZE) / 2]);
1024
1025 if (buf_size < IMC_BLOCK_SIZE * avctx->channels) {
1026 av_log(avctx, AV_LOG_ERROR, "frame too small!\n");
1027 return AVERROR_INVALIDDATA;
1028 }
1029
1030 /* get output buffer */
1031 frame->nb_samples = COEFFS;
1032 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1033 return ret;
1034
1035 for (i = 0; i < avctx->channels; i++) {
1036 q->out_samples = (float *)frame->extended_data[i];
1037
1038 q->bdsp.bswap16_buf(buf16, (const uint16_t *) buf, IMC_BLOCK_SIZE / 2);
1039
1040 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
1041
1042 buf += IMC_BLOCK_SIZE;
1043
1044 if ((ret = imc_decode_block(avctx, q, i)) < 0)
1045 return ret;
1046 }
1047
1048 if (avctx->channels == 2) {
1049 q->fdsp->butterflies_float((float *)frame->extended_data[0],
1050 (float *)frame->extended_data[1], COEFFS);
1051 }
1052
1053 *got_frame_ptr = 1;
1054
1055 return IMC_BLOCK_SIZE * avctx->channels;
1056}
1057
1058static av_cold int imc_decode_close(AVCodecContext * avctx)
1059{
1060 IMCContext *q = avctx->priv_data;
1061
1062 ff_fft_end(&q->fft);
1063 av_freep(&q->fdsp);
1064
1065 return 0;
1066}
1067
1068static av_cold void flush(AVCodecContext *avctx)
1069{
1070 IMCContext *q = avctx->priv_data;
1071
1072 q->chctx[0].decoder_reset =
1073 q->chctx[1].decoder_reset = 1;
1074}
1075
1076#if CONFIG_IMC_DECODER
1077AVCodec ff_imc_decoder = {
1078 .name = "imc",
1079 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
1080 .type = AVMEDIA_TYPE_AUDIO,
1081 .id = AV_CODEC_ID_IMC,
1082 .priv_data_size = sizeof(IMCContext),
1083 .init = imc_decode_init,
1084 .close = imc_decode_close,
1085 .decode = imc_decode_frame,
1086 .flush = flush,
1087 .capabilities = AV_CODEC_CAP_DR1,
1088 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1089 AV_SAMPLE_FMT_NONE },
1090};
1091#endif
1092#if CONFIG_IAC_DECODER
1093AVCodec ff_iac_decoder = {
1094 .name = "iac",
1095 .long_name = NULL_IF_CONFIG_SMALL("IAC (Indeo Audio Coder)"),
1096 .type = AVMEDIA_TYPE_AUDIO,
1097 .id = AV_CODEC_ID_IAC,
1098 .priv_data_size = sizeof(IMCContext),
1099 .init = imc_decode_init,
1100 .close = imc_decode_close,
1101 .decode = imc_decode_frame,
1102 .flush = flush,
1103 .capabilities = AV_CODEC_CAP_DR1,
1104 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1105 AV_SAMPLE_FMT_NONE },
1106};
1107#endif
1108
generated by cgit at 2024-05-17 03:08:12 (GMT)