2 * IMC compatible decoder
3 * Copyright (c) 2002-2004 Maxim Poliakovski
4 * Copyright (c) 2006 Benjamin Larsson
5 * Copyright (c) 2006 Konstantin Shishkov
7 * This file is part of FFmpeg.
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.
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.
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
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.
37 #include "libavutil/channel_layout.h"
38 #include "libavutil/ffmath.h"
39 #include "libavutil/float_dsp.h"
40 #include "libavutil/internal.h"
50 #define IMC_BLOCK_SIZE 64
51 #define IMC_FRAME_ID 0x21
55 typedef 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];
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
77 float last_fft_im[COEFFS];
82 typedef struct IMCContext {
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];
98 void (*butterflies_float)(float *av_restrict v1, float *av_restrict v2, int len);
100 DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS / 2];
105 int8_t cyclTab[32], cyclTab2[32];
106 float weights1[31], weights2[31];
108 AVCodecContext *avctx;
111 static VLC huffman_vlc[4][4];
113 #define IMC_VLC_BITS 9
114 #define VLC_TABLES_SIZE 9512
116 static const int vlc_offsets[17] = {
117 0, 640, 1156, 1732, 2308, 2852, 3396, 3924,
118 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE
121 static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];
123 static inline double freq2bark(double freq)
125 return 3.5 * atan((freq / 7500.0) * (freq / 7500.0)) + 13.0 * atan(freq * 0.00076);
128 static av_cold void iac_generate_tabs(IMCContext *q, int sampling_rate)
130 double freqmin[32], freqmid[32], freqmax[32];
131 double scale = sampling_rate / (256.0 * 2.0 * 2.0);
132 double nyquist_freq = sampling_rate * 0.5;
133 double freq, bark, prev_bark = 0, tf, tb;
136 for (i = 0; i < 32; i++) {
137 freq = (band_tab[i] + band_tab[i + 1] - 1) * scale;
138 bark = freq2bark(freq);
141 tb = bark - prev_bark;
142 q->weights1[i - 1] = ff_exp10(-1.0 * tb);
143 q->weights2[i - 1] = ff_exp10(-2.7 * tb);
150 while (tf < nyquist_freq) {
162 if (tb <= bark - 0.5)
168 for (i = 0; i < 32; i++) {
170 for (j = 31; j > 0 && freq <= freqmid[j]; j--);
171 q->cyclTab[i] = j + 1;
174 for (j = 0; j < 32 && freq >= freqmid[j]; j++);
175 q->cyclTab2[i] = j - 1;
179 static av_cold int imc_decode_init(AVCodecContext *avctx)
182 IMCContext *q = avctx->priv_data;
183 AVFloatDSPContext *fdsp;
186 if (avctx->codec_id == AV_CODEC_ID_IAC && avctx->sample_rate > 96000) {
187 av_log(avctx, AV_LOG_ERROR,
188 "Strange sample rate of %i, file likely corrupt or "
189 "needing a new table derivation method.\n",
191 return AVERROR_PATCHWELCOME;
194 if (avctx->codec_id == AV_CODEC_ID_IMC)
197 if (avctx->channels > 2) {
198 avpriv_request_sample(avctx, "Number of channels > 2");
199 return AVERROR_PATCHWELCOME;
202 for (j = 0; j < avctx->channels; j++) {
203 q->chctx[j].decoder_reset = 1;
205 for (i = 0; i < BANDS; i++)
206 q->chctx[j].old_floor[i] = 1.0;
208 for (i = 0; i < COEFFS / 2; i++)
209 q->chctx[j].last_fft_im[i] = 0;
212 /* Build mdct window, a simple sine window normalized with sqrt(2) */
213 ff_sine_window_init(q->mdct_sine_window, COEFFS);
214 for (i = 0; i < COEFFS; i++)
215 q->mdct_sine_window[i] *= sqrt(2.0);
216 for (i = 0; i < COEFFS / 2; i++) {
217 q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI);
218 q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI);
220 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
221 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
224 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
225 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
227 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
228 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
232 /* Generate a square root table */
234 for (i = 0; i < 30; i++)
235 q->sqrt_tab[i] = sqrt(i);
237 /* initialize the VLC tables */
238 for (i = 0; i < 4 ; i++) {
239 for (j = 0; j < 4; j++) {
240 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]];
241 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];
242 init_vlc(&huffman_vlc[i][j], IMC_VLC_BITS, imc_huffman_sizes[i],
243 imc_huffman_lens[i][j], 1, 1,
244 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC);
248 if (avctx->codec_id == AV_CODEC_ID_IAC) {
249 iac_generate_tabs(q, avctx->sample_rate);
251 memcpy(q->cyclTab, cyclTab, sizeof(cyclTab));
252 memcpy(q->cyclTab2, cyclTab2, sizeof(cyclTab2));
253 memcpy(q->weights1, imc_weights1, sizeof(imc_weights1));
254 memcpy(q->weights2, imc_weights2, sizeof(imc_weights2));
257 fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
259 return AVERROR(ENOMEM);
260 q->butterflies_float = fdsp->butterflies_float;
262 if ((ret = ff_fft_init(&q->fft, 7, 1))) {
263 av_log(avctx, AV_LOG_INFO, "FFT init failed\n");
266 ff_bswapdsp_init(&q->bdsp);
268 avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
269 avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
270 : AV_CH_LAYOUT_STEREO;
275 static void imc_calculate_coeffs(IMCContext *q, float *flcoeffs1,
276 float *flcoeffs2, int *bandWidthT,
277 float *flcoeffs3, float *flcoeffs5)
282 float snr_limit = 1.e-30;
286 for (i = 0; i < BANDS; i++) {
287 flcoeffs5[i] = workT2[i] = 0.0;
289 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
290 flcoeffs3[i] = 2.0 * flcoeffs2[i];
293 flcoeffs3[i] = -30000.0;
295 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
296 if (workT3[i] <= snr_limit)
300 for (i = 0; i < BANDS; i++) {
301 for (cnt2 = i; cnt2 < q->cyclTab[i]; cnt2++)
302 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
303 workT2[cnt2 - 1] = workT2[cnt2 - 1] + workT3[i];
306 for (i = 1; i < BANDS; i++) {
307 accum = (workT2[i - 1] + accum) * q->weights1[i - 1];
308 flcoeffs5[i] += accum;
311 for (i = 0; i < BANDS; i++)
314 for (i = 0; i < BANDS; i++) {
315 for (cnt2 = i - 1; cnt2 > q->cyclTab2[i]; cnt2--)
316 flcoeffs5[cnt2] += workT3[i];
317 workT2[cnt2+1] += workT3[i];
322 for (i = BANDS-2; i >= 0; i--) {
323 accum = (workT2[i+1] + accum) * q->weights2[i];
324 flcoeffs5[i] += accum;
325 // there is missing code here, but it seems to never be triggered
330 static void imc_read_level_coeffs(IMCContext *q, int stream_format_code,
336 const uint8_t *cb_sel;
339 s = stream_format_code >> 1;
340 hufftab[0] = &huffman_vlc[s][0];
341 hufftab[1] = &huffman_vlc[s][1];
342 hufftab[2] = &huffman_vlc[s][2];
343 hufftab[3] = &huffman_vlc[s][3];
344 cb_sel = imc_cb_select[s];
346 if (stream_format_code & 4)
349 levlCoeffs[0] = get_bits(&q->gb, 7);
350 for (i = start; i < BANDS; i++) {
351 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table,
353 if (levlCoeffs[i] == 17)
354 levlCoeffs[i] += get_bits(&q->gb, 4);
358 static void imc_read_level_coeffs_raw(IMCContext *q, int stream_format_code,
363 q->coef0_pos = get_bits(&q->gb, 5);
364 levlCoeffs[0] = get_bits(&q->gb, 7);
365 for (i = 1; i < BANDS; i++)
366 levlCoeffs[i] = get_bits(&q->gb, 4);
369 static void imc_decode_level_coefficients(IMCContext *q, int *levlCoeffBuf,
370 float *flcoeffs1, float *flcoeffs2)
374 // maybe some frequency division thingy
376 flcoeffs1[0] = 20000.0 / exp2 (levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
377 flcoeffs2[0] = log2f(flcoeffs1[0]);
381 for (i = 1; i < BANDS; i++) {
382 level = levlCoeffBuf[i];
389 else if (level <= 24)
394 tmp *= imc_exp_tab[15 + level];
395 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
403 static void imc_decode_level_coefficients2(IMCContext *q, int *levlCoeffBuf,
404 float *old_floor, float *flcoeffs1,
408 /* FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
409 * and flcoeffs2 old scale factors
410 * might be incomplete due to a missing table that is in the binary code
412 for (i = 0; i < BANDS; i++) {
414 if (levlCoeffBuf[i] < 16) {
415 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
416 flcoeffs2[i] = (levlCoeffBuf[i] - 7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
418 flcoeffs1[i] = old_floor[i];
423 static void imc_decode_level_coefficients_raw(IMCContext *q, int *levlCoeffBuf,
424 float *flcoeffs1, float *flcoeffs2)
430 flcoeffs1[pos] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
431 flcoeffs2[pos] = log2f(flcoeffs1[pos]);
432 tmp = flcoeffs1[pos];
433 tmp2 = flcoeffs2[pos];
436 for (i = 0; i < BANDS; i++) {
439 level = *levlCoeffBuf++;
440 flcoeffs1[i] = tmp * powf(10.0, -level * 0.4375); //todo tab
441 flcoeffs2[i] = tmp2 - 1.4533435415 * level; // 1.4533435415 = log2(10) * 0.4375
446 * Perform bit allocation depending on bits available
448 static int bit_allocation(IMCContext *q, IMCChannel *chctx,
449 int stream_format_code, int freebits, int flag)
452 const float limit = -1.e20;
461 float lowest = 1.e10;
467 for (i = 0; i < BANDS; i++)
468 highest = FFMAX(highest, chctx->flcoeffs1[i]);
470 for (i = 0; i < BANDS - 1; i++) {
471 if (chctx->flcoeffs5[i] <= 0) {
472 av_log(q->avctx, AV_LOG_ERROR, "flcoeffs5 %f invalid\n", chctx->flcoeffs5[i]);
473 return AVERROR_INVALIDDATA;
475 chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log2f(chctx->flcoeffs5[i]);
477 chctx->flcoeffs4[BANDS - 1] = limit;
479 highest = highest * 0.25;
481 for (i = 0; i < BANDS; i++) {
483 if ((band_tab[i + 1] - band_tab[i]) == chctx->bandWidthT[i])
486 if ((band_tab[i + 1] - band_tab[i]) > chctx->bandWidthT[i])
489 if (((band_tab[i + 1] - band_tab[i]) / 2) >= chctx->bandWidthT[i])
493 return AVERROR_INVALIDDATA;
495 chctx->flcoeffs4[i] += xTab[(indx * 2 + (chctx->flcoeffs1[i] < highest)) * 2 + flag];
498 if (stream_format_code & 0x2) {
499 chctx->flcoeffs4[0] = limit;
500 chctx->flcoeffs4[1] = limit;
501 chctx->flcoeffs4[2] = limit;
502 chctx->flcoeffs4[3] = limit;
505 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS - 1; i++) {
506 iacc += chctx->bandWidthT[i];
507 summa += chctx->bandWidthT[i] * chctx->flcoeffs4[i];
511 return AVERROR_INVALIDDATA;
513 chctx->bandWidthT[BANDS - 1] = 0;
514 summa = (summa * 0.5 - freebits) / iacc;
517 for (i = 0; i < BANDS / 2; i++) {
518 rres = summer - freebits;
519 if ((rres >= -8) && (rres <= 8))
525 for (j = (stream_format_code & 0x2) ? 4 : 0; j < BANDS; j++) {
526 cwlen = av_clipf(((chctx->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
528 chctx->bitsBandT[j] = cwlen;
529 summer += chctx->bandWidthT[j] * cwlen;
532 iacc += chctx->bandWidthT[j];
537 if (freebits < summer)
544 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
547 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS; i++) {
548 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
549 chctx->CWlengthT[j] = chctx->bitsBandT[i];
552 if (freebits > summer) {
553 for (i = 0; i < BANDS; i++) {
554 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
555 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
561 if (highest <= -1.e20)
567 for (i = 0; i < BANDS; i++) {
568 if (workT[i] > highest) {
574 if (highest > -1.e20) {
575 workT[found_indx] -= 2.0;
576 if (++chctx->bitsBandT[found_indx] == 6)
577 workT[found_indx] = -1.e20;
579 for (j = band_tab[found_indx]; j < band_tab[found_indx + 1] && (freebits > summer); j++) {
580 chctx->CWlengthT[j]++;
584 } while (freebits > summer);
586 if (freebits < summer) {
587 for (i = 0; i < BANDS; i++) {
588 workT[i] = chctx->bitsBandT[i] ? (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] + 1.585)
591 if (stream_format_code & 0x2) {
597 while (freebits < summer) {
600 for (i = 0; i < BANDS; i++) {
601 if (workT[i] < lowest) {
606 // if (lowest >= 1.e10)
608 workT[low_indx] = lowest + 2.0;
610 if (!--chctx->bitsBandT[low_indx])
611 workT[low_indx] = 1.e20;
613 for (j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++) {
614 if (chctx->CWlengthT[j] > 0) {
615 chctx->CWlengthT[j]--;
624 static void imc_get_skip_coeff(IMCContext *q, IMCChannel *chctx)
628 memset(chctx->skipFlagBits, 0, sizeof(chctx->skipFlagBits));
629 memset(chctx->skipFlagCount, 0, sizeof(chctx->skipFlagCount));
630 for (i = 0; i < BANDS; i++) {
631 if (!chctx->bandFlagsBuf[i] || !chctx->bandWidthT[i])
634 if (!chctx->skipFlagRaw[i]) {
635 chctx->skipFlagBits[i] = band_tab[i + 1] - band_tab[i];
637 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
638 chctx->skipFlags[j] = get_bits1(&q->gb);
639 if (chctx->skipFlags[j])
640 chctx->skipFlagCount[i]++;
643 for (j = band_tab[i]; j < band_tab[i + 1] - 1; j += 2) {
644 if (!get_bits1(&q->gb)) { // 0
645 chctx->skipFlagBits[i]++;
646 chctx->skipFlags[j] = 1;
647 chctx->skipFlags[j + 1] = 1;
648 chctx->skipFlagCount[i] += 2;
650 if (get_bits1(&q->gb)) { // 11
651 chctx->skipFlagBits[i] += 2;
652 chctx->skipFlags[j] = 0;
653 chctx->skipFlags[j + 1] = 1;
654 chctx->skipFlagCount[i]++;
656 chctx->skipFlagBits[i] += 3;
657 chctx->skipFlags[j + 1] = 0;
658 if (!get_bits1(&q->gb)) { // 100
659 chctx->skipFlags[j] = 1;
660 chctx->skipFlagCount[i]++;
662 chctx->skipFlags[j] = 0;
668 if (j < band_tab[i + 1]) {
669 chctx->skipFlagBits[i]++;
670 if ((chctx->skipFlags[j] = get_bits1(&q->gb)))
671 chctx->skipFlagCount[i]++;
678 * Increase highest' band coefficient sizes as some bits won't be used
680 static void imc_adjust_bit_allocation(IMCContext *q, IMCChannel *chctx,
689 for (i = 0; i < BANDS; i++) {
690 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
691 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
694 while (corrected < summer) {
695 if (highest <= -1.e20)
700 for (i = 0; i < BANDS; i++) {
701 if (workT[i] > highest) {
707 if (highest > -1.e20) {
708 workT[found_indx] -= 2.0;
709 if (++(chctx->bitsBandT[found_indx]) == 6)
710 workT[found_indx] = -1.e20;
712 for (j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
713 if (!chctx->skipFlags[j] && (chctx->CWlengthT[j] < 6)) {
714 chctx->CWlengthT[j]++;
722 static void imc_imdct256(IMCContext *q, IMCChannel *chctx, int channels)
726 float *dst1 = q->out_samples;
727 float *dst2 = q->out_samples + (COEFFS - 1);
730 for (i = 0; i < COEFFS / 2; i++) {
731 q->samples[i].re = -(q->pre_coef1[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
732 (q->pre_coef2[i] * chctx->CWdecoded[i * 2]);
733 q->samples[i].im = (q->pre_coef2[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
734 (q->pre_coef1[i] * chctx->CWdecoded[i * 2]);
738 q->fft.fft_permute(&q->fft, q->samples);
739 q->fft.fft_calc(&q->fft, q->samples);
741 /* postrotation, window and reorder */
742 for (i = 0; i < COEFFS / 2; i++) {
743 re = ( q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
744 im = (-q->samples[i].im * q->post_cos[i]) - ( q->samples[i].re * q->post_sin[i]);
745 *dst1 = (q->mdct_sine_window[COEFFS - 1 - i * 2] * chctx->last_fft_im[i])
746 + (q->mdct_sine_window[i * 2] * re);
747 *dst2 = (q->mdct_sine_window[i * 2] * chctx->last_fft_im[i])
748 - (q->mdct_sine_window[COEFFS - 1 - i * 2] * re);
751 chctx->last_fft_im[i] = im;
755 static int inverse_quant_coeff(IMCContext *q, IMCChannel *chctx,
756 int stream_format_code)
759 int middle_value, cw_len, max_size;
760 const float *quantizer;
762 for (i = 0; i < BANDS; i++) {
763 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
764 chctx->CWdecoded[j] = 0;
765 cw_len = chctx->CWlengthT[j];
767 if (cw_len <= 0 || chctx->skipFlags[j])
770 max_size = 1 << cw_len;
771 middle_value = max_size >> 1;
773 if (chctx->codewords[j] >= max_size || chctx->codewords[j] < 0)
774 return AVERROR_INVALIDDATA;
777 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
778 if (chctx->codewords[j] >= middle_value)
779 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 8] * chctx->flcoeffs6[i];
781 chctx->CWdecoded[j] = -quantizer[max_size - chctx->codewords[j] - 8 - 1] * chctx->flcoeffs6[i];
783 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (chctx->bandFlagsBuf[i] << 1)];
784 if (chctx->codewords[j] >= middle_value)
785 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 1] * chctx->flcoeffs6[i];
787 chctx->CWdecoded[j] = -quantizer[max_size - 2 - chctx->codewords[j]] * chctx->flcoeffs6[i];
795 static void imc_get_coeffs(AVCodecContext *avctx,
796 IMCContext *q, IMCChannel *chctx)
798 int i, j, cw_len, cw;
800 for (i = 0; i < BANDS; i++) {
801 if (!chctx->sumLenArr[i])
803 if (chctx->bandFlagsBuf[i] || chctx->bandWidthT[i]) {
804 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
805 cw_len = chctx->CWlengthT[j];
808 if (cw_len && (!chctx->bandFlagsBuf[i] || !chctx->skipFlags[j])) {
809 if (get_bits_count(&q->gb) + cw_len > 512) {
810 av_log(avctx, AV_LOG_WARNING,
811 "Potential problem on band %i, coefficient %i"
812 ": cw_len=%i\n", i, j, cw_len);
814 cw = get_bits(&q->gb, cw_len);
817 chctx->codewords[j] = cw;
823 static void imc_refine_bit_allocation(IMCContext *q, IMCChannel *chctx)
828 for (i = 0; i < BANDS; i++) {
829 chctx->sumLenArr[i] = 0;
830 chctx->skipFlagRaw[i] = 0;
831 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
832 chctx->sumLenArr[i] += chctx->CWlengthT[j];
833 if (chctx->bandFlagsBuf[i])
834 if (((int)((band_tab[i + 1] - band_tab[i]) * 1.5) > chctx->sumLenArr[i]) && (chctx->sumLenArr[i] > 0))
835 chctx->skipFlagRaw[i] = 1;
838 imc_get_skip_coeff(q, chctx);
840 for (i = 0; i < BANDS; i++) {
841 chctx->flcoeffs6[i] = chctx->flcoeffs1[i];
842 /* band has flag set and at least one coded coefficient */
843 if (chctx->bandFlagsBuf[i] && (band_tab[i + 1] - band_tab[i]) != chctx->skipFlagCount[i]) {
844 chctx->flcoeffs6[i] *= q->sqrt_tab[ band_tab[i + 1] - band_tab[i]] /
845 q->sqrt_tab[(band_tab[i + 1] - band_tab[i] - chctx->skipFlagCount[i])];
849 /* calculate bits left, bits needed and adjust bit allocation */
852 for (i = 0; i < BANDS; i++) {
853 if (chctx->bandFlagsBuf[i]) {
854 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
855 if (chctx->skipFlags[j]) {
856 summer += chctx->CWlengthT[j];
857 chctx->CWlengthT[j] = 0;
860 bits += chctx->skipFlagBits[i];
861 summer -= chctx->skipFlagBits[i];
864 imc_adjust_bit_allocation(q, chctx, summer);
867 static int imc_decode_block(AVCodecContext *avctx, IMCContext *q, int ch)
869 int stream_format_code;
870 int imc_hdr, i, j, ret;
873 int counter, bitscount;
874 IMCChannel *chctx = q->chctx + ch;
877 /* Check the frame header */
878 imc_hdr = get_bits(&q->gb, 9);
879 if (imc_hdr & 0x18) {
880 av_log(avctx, AV_LOG_ERROR, "frame header check failed!\n");
881 av_log(avctx, AV_LOG_ERROR, "got %X.\n", imc_hdr);
882 return AVERROR_INVALIDDATA;
884 stream_format_code = get_bits(&q->gb, 3);
886 if (stream_format_code & 0x04)
887 chctx->decoder_reset = 1;
889 if (chctx->decoder_reset) {
890 for (i = 0; i < BANDS; i++)
891 chctx->old_floor[i] = 1.0;
892 for (i = 0; i < COEFFS; i++)
893 chctx->CWdecoded[i] = 0;
894 chctx->decoder_reset = 0;
897 flag = get_bits1(&q->gb);
898 if (stream_format_code & 0x1)
899 imc_read_level_coeffs_raw(q, stream_format_code, chctx->levlCoeffBuf);
901 imc_read_level_coeffs(q, stream_format_code, chctx->levlCoeffBuf);
903 if (stream_format_code & 0x1)
904 imc_decode_level_coefficients_raw(q, chctx->levlCoeffBuf,
905 chctx->flcoeffs1, chctx->flcoeffs2);
906 else if (stream_format_code & 0x4)
907 imc_decode_level_coefficients(q, chctx->levlCoeffBuf,
908 chctx->flcoeffs1, chctx->flcoeffs2);
910 imc_decode_level_coefficients2(q, chctx->levlCoeffBuf, chctx->old_floor,
911 chctx->flcoeffs1, chctx->flcoeffs2);
913 for(i=0; i<BANDS; i++) {
914 if(chctx->flcoeffs1[i] > INT_MAX) {
915 av_log(avctx, AV_LOG_ERROR, "scalefactor out of range\n");
916 return AVERROR_INVALIDDATA;
920 memcpy(chctx->old_floor, chctx->flcoeffs1, 32 * sizeof(float));
923 if (stream_format_code & 0x1) {
924 for (i = 0; i < BANDS; i++) {
925 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
926 chctx->bandFlagsBuf[i] = 0;
927 chctx->flcoeffs3[i] = chctx->flcoeffs2[i] * 2;
928 chctx->flcoeffs5[i] = 1.0;
931 for (i = 0; i < BANDS; i++) {
932 if (chctx->levlCoeffBuf[i] == 16) {
933 chctx->bandWidthT[i] = 0;
936 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
939 memset(chctx->bandFlagsBuf, 0, BANDS * sizeof(int));
940 for (i = 0; i < BANDS - 1; i++)
941 if (chctx->bandWidthT[i])
942 chctx->bandFlagsBuf[i] = get_bits1(&q->gb);
944 imc_calculate_coeffs(q, chctx->flcoeffs1, chctx->flcoeffs2,
945 chctx->bandWidthT, chctx->flcoeffs3,
950 /* first 4 bands will be assigned 5 bits per coefficient */
951 if (stream_format_code & 0x2) {
954 chctx->bitsBandT[0] = 5;
955 chctx->CWlengthT[0] = 5;
956 chctx->CWlengthT[1] = 5;
957 chctx->CWlengthT[2] = 5;
958 for (i = 1; i < 4; i++) {
959 if (stream_format_code & 0x1)
962 bits = (chctx->levlCoeffBuf[i] == 16) ? 0 : 5;
963 chctx->bitsBandT[i] = bits;
964 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
965 chctx->CWlengthT[j] = bits;
970 if (avctx->codec_id == AV_CODEC_ID_IAC) {
971 bitscount += !!chctx->bandWidthT[BANDS - 1];
972 if (!(stream_format_code & 0x2))
976 if ((ret = bit_allocation(q, chctx, stream_format_code,
977 512 - bitscount - get_bits_count(&q->gb),
979 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
980 chctx->decoder_reset = 1;
984 if (stream_format_code & 0x1) {
985 for (i = 0; i < BANDS; i++)
986 chctx->skipFlags[i] = 0;
988 imc_refine_bit_allocation(q, chctx);
991 for (i = 0; i < BANDS; i++) {
992 chctx->sumLenArr[i] = 0;
994 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
995 if (!chctx->skipFlags[j])
996 chctx->sumLenArr[i] += chctx->CWlengthT[j];
999 memset(chctx->codewords, 0, sizeof(chctx->codewords));
1001 imc_get_coeffs(avctx, q, chctx);
1003 if (inverse_quant_coeff(q, chctx, stream_format_code) < 0) {
1004 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
1005 chctx->decoder_reset = 1;
1006 return AVERROR_INVALIDDATA;
1009 memset(chctx->skipFlags, 0, sizeof(chctx->skipFlags));
1011 imc_imdct256(q, chctx, avctx->channels);
1016 static int imc_decode_frame(AVCodecContext *avctx, void *data,
1017 int *got_frame_ptr, AVPacket *avpkt)
1019 AVFrame *frame = data;
1020 const uint8_t *buf = avpkt->data;
1021 int buf_size = avpkt->size;
1024 IMCContext *q = avctx->priv_data;
1026 LOCAL_ALIGNED_16(uint16_t, buf16, [(IMC_BLOCK_SIZE + AV_INPUT_BUFFER_PADDING_SIZE) / 2]);
1030 if (buf_size < IMC_BLOCK_SIZE * avctx->channels) {
1031 av_log(avctx, AV_LOG_ERROR, "frame too small!\n");
1032 return AVERROR_INVALIDDATA;
1035 /* get output buffer */
1036 frame->nb_samples = COEFFS;
1037 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1040 for (i = 0; i < avctx->channels; i++) {
1041 q->out_samples = (float *)frame->extended_data[i];
1043 q->bdsp.bswap16_buf(buf16, (const uint16_t *) buf, IMC_BLOCK_SIZE / 2);
1045 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
1047 buf += IMC_BLOCK_SIZE;
1049 if ((ret = imc_decode_block(avctx, q, i)) < 0)
1053 if (avctx->channels == 2) {
1054 q->butterflies_float((float *)frame->extended_data[0],
1055 (float *)frame->extended_data[1], COEFFS);
1060 return IMC_BLOCK_SIZE * avctx->channels;
1063 static av_cold int imc_decode_close(AVCodecContext * avctx)
1065 IMCContext *q = avctx->priv_data;
1067 ff_fft_end(&q->fft);
1072 static av_cold void flush(AVCodecContext *avctx)
1074 IMCContext *q = avctx->priv_data;
1076 q->chctx[0].decoder_reset =
1077 q->chctx[1].decoder_reset = 1;
1080 #if CONFIG_IMC_DECODER
1081 AVCodec ff_imc_decoder = {
1083 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
1084 .type = AVMEDIA_TYPE_AUDIO,
1085 .id = AV_CODEC_ID_IMC,
1086 .priv_data_size = sizeof(IMCContext),
1087 .init = imc_decode_init,
1088 .close = imc_decode_close,
1089 .decode = imc_decode_frame,
1091 .capabilities = AV_CODEC_CAP_DR1,
1092 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1093 AV_SAMPLE_FMT_NONE },
1096 #if CONFIG_IAC_DECODER
1097 AVCodec ff_iac_decoder = {
1099 .long_name = NULL_IF_CONFIG_SMALL("IAC (Indeo Audio Coder)"),
1100 .type = AVMEDIA_TYPE_AUDIO,
1101 .id = AV_CODEC_ID_IAC,
1102 .priv_data_size = sizeof(IMCContext),
1103 .init = imc_decode_init,
1104 .close = imc_decode_close,
1105 .decode = imc_decode_frame,
1107 .capabilities = AV_CODEC_CAP_DR1,
1108 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1109 AV_SAMPLE_FMT_NONE },