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.
38 #include "libavutil/channel_layout.h"
39 #include "libavutil/float_dsp.h"
40 #include "libavutil/internal.h"
41 #include "libavutil/libm.h"
51 #define IMC_BLOCK_SIZE 64
52 #define IMC_FRAME_ID 0x21
56 typedef struct IMCChannel {
57 float old_floor[BANDS];
58 float flcoeffs1[BANDS];
59 float flcoeffs2[BANDS];
60 float flcoeffs3[BANDS];
61 float flcoeffs4[BANDS];
62 float flcoeffs5[BANDS];
63 float flcoeffs6[BANDS];
64 float CWdecoded[COEFFS];
66 int bandWidthT[BANDS]; ///< codewords per band
67 int bitsBandT[BANDS]; ///< how many bits per codeword in band
68 int CWlengthT[COEFFS]; ///< how many bits in each codeword
69 int levlCoeffBuf[BANDS];
70 int bandFlagsBuf[BANDS]; ///< flags for each band
71 int sumLenArr[BANDS]; ///< bits for all coeffs in band
72 int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not
73 int skipFlagBits[BANDS]; ///< bits used to code skip flags
74 int skipFlagCount[BANDS]; ///< skipped coeffients per band
75 int skipFlags[COEFFS]; ///< skip coefficient decoding or not
76 int codewords[COEFFS]; ///< raw codewords read from bitstream
78 float last_fft_im[COEFFS];
88 float mdct_sine_window[COEFFS];
89 float post_cos[COEFFS];
90 float post_sin[COEFFS];
91 float pre_coef1[COEFFS];
92 float pre_coef2[COEFFS];
99 AVFloatDSPContext fdsp;
101 DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS / 2];
106 int8_t cyclTab[32], cyclTab2[32];
107 float weights1[31], weights2[31];
110 static VLC huffman_vlc[4][4];
112 #define VLC_TABLES_SIZE 9512
114 static const int vlc_offsets[17] = {
115 0, 640, 1156, 1732, 2308, 2852, 3396, 3924,
116 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE
119 static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];
121 static inline double freq2bark(double freq)
123 return 3.5 * atan((freq / 7500.0) * (freq / 7500.0)) + 13.0 * atan(freq * 0.00076);
126 static av_cold void iac_generate_tabs(IMCContext *q, int sampling_rate)
128 double freqmin[32], freqmid[32], freqmax[32];
129 double scale = sampling_rate / (256.0 * 2.0 * 2.0);
130 double nyquist_freq = sampling_rate * 0.5;
131 double freq, bark, prev_bark = 0, tf, tb;
134 for (i = 0; i < 32; i++) {
135 freq = (band_tab[i] + band_tab[i + 1] - 1) * scale;
136 bark = freq2bark(freq);
139 tb = bark - prev_bark;
140 q->weights1[i - 1] = pow(10.0, -1.0 * tb);
141 q->weights2[i - 1] = pow(10.0, -2.7 * tb);
148 while (tf < nyquist_freq) {
160 if (tb <= bark - 0.5)
166 for (i = 0; i < 32; i++) {
168 for (j = 31; j > 0 && freq <= freqmid[j]; j--);
169 q->cyclTab[i] = j + 1;
172 for (j = 0; j < 32 && freq >= freqmid[j]; j++);
173 q->cyclTab2[i] = j - 1;
177 static av_cold int imc_decode_init(AVCodecContext *avctx)
180 IMCContext *q = avctx->priv_data;
183 if (avctx->codec_id == AV_CODEC_ID_IMC)
186 if (avctx->channels > 2) {
187 avpriv_request_sample(avctx, "Number of channels > 2");
188 return AVERROR_PATCHWELCOME;
191 for (j = 0; j < avctx->channels; j++) {
192 q->chctx[j].decoder_reset = 1;
194 for (i = 0; i < BANDS; i++)
195 q->chctx[j].old_floor[i] = 1.0;
197 for (i = 0; i < COEFFS / 2; i++)
198 q->chctx[j].last_fft_im[i] = 0;
201 /* Build mdct window, a simple sine window normalized with sqrt(2) */
202 ff_sine_window_init(q->mdct_sine_window, COEFFS);
203 for (i = 0; i < COEFFS; i++)
204 q->mdct_sine_window[i] *= sqrt(2.0);
205 for (i = 0; i < COEFFS / 2; i++) {
206 q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI);
207 q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI);
209 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
210 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
213 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
214 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
216 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
217 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
221 /* Generate a square root table */
223 for (i = 0; i < 30; i++)
224 q->sqrt_tab[i] = sqrt(i);
226 /* initialize the VLC tables */
227 for (i = 0; i < 4 ; i++) {
228 for (j = 0; j < 4; j++) {
229 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]];
230 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];
231 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i],
232 imc_huffman_lens[i][j], 1, 1,
233 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC);
237 if (avctx->codec_id == AV_CODEC_ID_IAC) {
238 iac_generate_tabs(q, avctx->sample_rate);
240 memcpy(q->cyclTab, cyclTab, sizeof(cyclTab));
241 memcpy(q->cyclTab2, cyclTab2, sizeof(cyclTab2));
242 memcpy(q->weights1, imc_weights1, sizeof(imc_weights1));
243 memcpy(q->weights2, imc_weights2, sizeof(imc_weights2));
246 if ((ret = ff_fft_init(&q->fft, 7, 1))) {
247 av_log(avctx, AV_LOG_INFO, "FFT init failed\n");
250 ff_dsputil_init(&q->dsp, avctx);
251 avpriv_float_dsp_init(&q->fdsp, avctx->flags & CODEC_FLAG_BITEXACT);
252 avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
253 avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
254 : AV_CH_LAYOUT_STEREO;
259 static void imc_calculate_coeffs(IMCContext *q, float *flcoeffs1,
260 float *flcoeffs2, int *bandWidthT,
261 float *flcoeffs3, float *flcoeffs5)
266 float snr_limit = 1.e-30;
270 for (i = 0; i < BANDS; i++) {
271 flcoeffs5[i] = workT2[i] = 0.0;
273 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
274 flcoeffs3[i] = 2.0 * flcoeffs2[i];
277 flcoeffs3[i] = -30000.0;
279 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
280 if (workT3[i] <= snr_limit)
284 for (i = 0; i < BANDS; i++) {
285 for (cnt2 = i; cnt2 < q->cyclTab[i]; cnt2++)
286 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
287 workT2[cnt2 - 1] = workT2[cnt2 - 1] + workT3[i];
290 for (i = 1; i < BANDS; i++) {
291 accum = (workT2[i - 1] + accum) * q->weights1[i - 1];
292 flcoeffs5[i] += accum;
295 for (i = 0; i < BANDS; i++)
298 for (i = 0; i < BANDS; i++) {
299 for (cnt2 = i - 1; cnt2 > q->cyclTab2[i]; cnt2--)
300 flcoeffs5[cnt2] += workT3[i];
301 workT2[cnt2+1] += workT3[i];
306 for (i = BANDS-2; i >= 0; i--) {
307 accum = (workT2[i+1] + accum) * q->weights2[i];
308 flcoeffs5[i] += accum;
309 // there is missing code here, but it seems to never be triggered
314 static void imc_read_level_coeffs(IMCContext *q, int stream_format_code,
320 const uint8_t *cb_sel;
323 s = stream_format_code >> 1;
324 hufftab[0] = &huffman_vlc[s][0];
325 hufftab[1] = &huffman_vlc[s][1];
326 hufftab[2] = &huffman_vlc[s][2];
327 hufftab[3] = &huffman_vlc[s][3];
328 cb_sel = imc_cb_select[s];
330 if (stream_format_code & 4)
333 levlCoeffs[0] = get_bits(&q->gb, 7);
334 for (i = start; i < BANDS; i++) {
335 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table,
336 hufftab[cb_sel[i]]->bits, 2);
337 if (levlCoeffs[i] == 17)
338 levlCoeffs[i] += get_bits(&q->gb, 4);
342 static void imc_read_level_coeffs_raw(IMCContext *q, int stream_format_code,
347 q->coef0_pos = get_bits(&q->gb, 5);
348 levlCoeffs[0] = get_bits(&q->gb, 7);
349 for (i = 1; i < BANDS; i++)
350 levlCoeffs[i] = get_bits(&q->gb, 4);
353 static void imc_decode_level_coefficients(IMCContext *q, int *levlCoeffBuf,
354 float *flcoeffs1, float *flcoeffs2)
358 // maybe some frequency division thingy
360 flcoeffs1[0] = 20000.0 / exp2 (levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
361 flcoeffs2[0] = log2f(flcoeffs1[0]);
365 for (i = 1; i < BANDS; i++) {
366 level = levlCoeffBuf[i];
373 else if (level <= 24)
378 tmp *= imc_exp_tab[15 + level];
379 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
387 static void imc_decode_level_coefficients2(IMCContext *q, int *levlCoeffBuf,
388 float *old_floor, float *flcoeffs1,
392 /* FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
393 * and flcoeffs2 old scale factors
394 * might be incomplete due to a missing table that is in the binary code
396 for (i = 0; i < BANDS; i++) {
398 if (levlCoeffBuf[i] < 16) {
399 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
400 flcoeffs2[i] = (levlCoeffBuf[i] - 7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
402 flcoeffs1[i] = old_floor[i];
407 static void imc_decode_level_coefficients_raw(IMCContext *q, int *levlCoeffBuf,
408 float *flcoeffs1, float *flcoeffs2)
414 flcoeffs1[pos] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
415 flcoeffs2[pos] = log2f(flcoeffs1[0]);
416 tmp = flcoeffs1[pos];
417 tmp2 = flcoeffs2[pos];
420 for (i = 0; i < BANDS; i++) {
423 level = *levlCoeffBuf++;
424 flcoeffs1[i] = tmp * powf(10.0, -level * 0.4375); //todo tab
425 flcoeffs2[i] = tmp2 - 1.4533435415 * level; // 1.4533435415 = log2(10) * 0.4375
430 * Perform bit allocation depending on bits available
432 static int bit_allocation(IMCContext *q, IMCChannel *chctx,
433 int stream_format_code, int freebits, int flag)
436 const float limit = -1.e20;
445 float lowest = 1.e10;
451 for (i = 0; i < BANDS; i++)
452 highest = FFMAX(highest, chctx->flcoeffs1[i]);
454 for (i = 0; i < BANDS - 1; i++)
455 chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log2f(chctx->flcoeffs5[i]);
456 chctx->flcoeffs4[BANDS - 1] = limit;
458 highest = highest * 0.25;
460 for (i = 0; i < BANDS; i++) {
462 if ((band_tab[i + 1] - band_tab[i]) == chctx->bandWidthT[i])
465 if ((band_tab[i + 1] - band_tab[i]) > chctx->bandWidthT[i])
468 if (((band_tab[i + 1] - band_tab[i]) / 2) >= chctx->bandWidthT[i])
472 return AVERROR_INVALIDDATA;
474 chctx->flcoeffs4[i] += xTab[(indx * 2 + (chctx->flcoeffs1[i] < highest)) * 2 + flag];
477 if (stream_format_code & 0x2) {
478 chctx->flcoeffs4[0] = limit;
479 chctx->flcoeffs4[1] = limit;
480 chctx->flcoeffs4[2] = limit;
481 chctx->flcoeffs4[3] = limit;
484 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS - 1; i++) {
485 iacc += chctx->bandWidthT[i];
486 summa += chctx->bandWidthT[i] * chctx->flcoeffs4[i];
490 return AVERROR_INVALIDDATA;
492 chctx->bandWidthT[BANDS - 1] = 0;
493 summa = (summa * 0.5 - freebits) / iacc;
496 for (i = 0; i < BANDS / 2; i++) {
497 rres = summer - freebits;
498 if ((rres >= -8) && (rres <= 8))
504 for (j = (stream_format_code & 0x2) ? 4 : 0; j < BANDS; j++) {
505 cwlen = av_clipf(((chctx->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
507 chctx->bitsBandT[j] = cwlen;
508 summer += chctx->bandWidthT[j] * cwlen;
511 iacc += chctx->bandWidthT[j];
516 if (freebits < summer)
523 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
526 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS; i++) {
527 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
528 chctx->CWlengthT[j] = chctx->bitsBandT[i];
531 if (freebits > summer) {
532 for (i = 0; i < BANDS; i++) {
533 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
534 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
540 if (highest <= -1.e20)
546 for (i = 0; i < BANDS; i++) {
547 if (workT[i] > highest) {
553 if (highest > -1.e20) {
554 workT[found_indx] -= 2.0;
555 if (++chctx->bitsBandT[found_indx] == 6)
556 workT[found_indx] = -1.e20;
558 for (j = band_tab[found_indx]; j < band_tab[found_indx + 1] && (freebits > summer); j++) {
559 chctx->CWlengthT[j]++;
563 } while (freebits > summer);
565 if (freebits < summer) {
566 for (i = 0; i < BANDS; i++) {
567 workT[i] = chctx->bitsBandT[i] ? (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] + 1.585)
570 if (stream_format_code & 0x2) {
576 while (freebits < summer) {
579 for (i = 0; i < BANDS; i++) {
580 if (workT[i] < lowest) {
585 // if (lowest >= 1.e10)
587 workT[low_indx] = lowest + 2.0;
589 if (!--chctx->bitsBandT[low_indx])
590 workT[low_indx] = 1.e20;
592 for (j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++) {
593 if (chctx->CWlengthT[j] > 0) {
594 chctx->CWlengthT[j]--;
603 static void imc_get_skip_coeff(IMCContext *q, IMCChannel *chctx)
607 memset(chctx->skipFlagBits, 0, sizeof(chctx->skipFlagBits));
608 memset(chctx->skipFlagCount, 0, sizeof(chctx->skipFlagCount));
609 for (i = 0; i < BANDS; i++) {
610 if (!chctx->bandFlagsBuf[i] || !chctx->bandWidthT[i])
613 if (!chctx->skipFlagRaw[i]) {
614 chctx->skipFlagBits[i] = band_tab[i + 1] - band_tab[i];
616 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
617 chctx->skipFlags[j] = get_bits1(&q->gb);
618 if (chctx->skipFlags[j])
619 chctx->skipFlagCount[i]++;
622 for (j = band_tab[i]; j < band_tab[i + 1] - 1; j += 2) {
623 if (!get_bits1(&q->gb)) { // 0
624 chctx->skipFlagBits[i]++;
625 chctx->skipFlags[j] = 1;
626 chctx->skipFlags[j + 1] = 1;
627 chctx->skipFlagCount[i] += 2;
629 if (get_bits1(&q->gb)) { // 11
630 chctx->skipFlagBits[i] += 2;
631 chctx->skipFlags[j] = 0;
632 chctx->skipFlags[j + 1] = 1;
633 chctx->skipFlagCount[i]++;
635 chctx->skipFlagBits[i] += 3;
636 chctx->skipFlags[j + 1] = 0;
637 if (!get_bits1(&q->gb)) { // 100
638 chctx->skipFlags[j] = 1;
639 chctx->skipFlagCount[i]++;
641 chctx->skipFlags[j] = 0;
647 if (j < band_tab[i + 1]) {
648 chctx->skipFlagBits[i]++;
649 if ((chctx->skipFlags[j] = get_bits1(&q->gb)))
650 chctx->skipFlagCount[i]++;
657 * Increase highest' band coefficient sizes as some bits won't be used
659 static void imc_adjust_bit_allocation(IMCContext *q, IMCChannel *chctx,
668 for (i = 0; i < BANDS; i++) {
669 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
670 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
673 while (corrected < summer) {
674 if (highest <= -1.e20)
679 for (i = 0; i < BANDS; i++) {
680 if (workT[i] > highest) {
686 if (highest > -1.e20) {
687 workT[found_indx] -= 2.0;
688 if (++(chctx->bitsBandT[found_indx]) == 6)
689 workT[found_indx] = -1.e20;
691 for (j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
692 if (!chctx->skipFlags[j] && (chctx->CWlengthT[j] < 6)) {
693 chctx->CWlengthT[j]++;
701 static void imc_imdct256(IMCContext *q, IMCChannel *chctx, int channels)
705 float *dst1 = q->out_samples;
706 float *dst2 = q->out_samples + (COEFFS - 1);
709 for (i = 0; i < COEFFS / 2; i++) {
710 q->samples[i].re = -(q->pre_coef1[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
711 (q->pre_coef2[i] * chctx->CWdecoded[i * 2]);
712 q->samples[i].im = (q->pre_coef2[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
713 (q->pre_coef1[i] * chctx->CWdecoded[i * 2]);
717 q->fft.fft_permute(&q->fft, q->samples);
718 q->fft.fft_calc(&q->fft, q->samples);
720 /* postrotation, window and reorder */
721 for (i = 0; i < COEFFS / 2; i++) {
722 re = ( q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
723 im = (-q->samples[i].im * q->post_cos[i]) - ( q->samples[i].re * q->post_sin[i]);
724 *dst1 = (q->mdct_sine_window[COEFFS - 1 - i * 2] * chctx->last_fft_im[i])
725 + (q->mdct_sine_window[i * 2] * re);
726 *dst2 = (q->mdct_sine_window[i * 2] * chctx->last_fft_im[i])
727 - (q->mdct_sine_window[COEFFS - 1 - i * 2] * re);
730 chctx->last_fft_im[i] = im;
734 static int inverse_quant_coeff(IMCContext *q, IMCChannel *chctx,
735 int stream_format_code)
738 int middle_value, cw_len, max_size;
739 const float *quantizer;
741 for (i = 0; i < BANDS; i++) {
742 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
743 chctx->CWdecoded[j] = 0;
744 cw_len = chctx->CWlengthT[j];
746 if (cw_len <= 0 || chctx->skipFlags[j])
749 max_size = 1 << cw_len;
750 middle_value = max_size >> 1;
752 if (chctx->codewords[j] >= max_size || chctx->codewords[j] < 0)
753 return AVERROR_INVALIDDATA;
756 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
757 if (chctx->codewords[j] >= middle_value)
758 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 8] * chctx->flcoeffs6[i];
760 chctx->CWdecoded[j] = -quantizer[max_size - chctx->codewords[j] - 8 - 1] * chctx->flcoeffs6[i];
762 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (chctx->bandFlagsBuf[i] << 1)];
763 if (chctx->codewords[j] >= middle_value)
764 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 1] * chctx->flcoeffs6[i];
766 chctx->CWdecoded[j] = -quantizer[max_size - 2 - chctx->codewords[j]] * chctx->flcoeffs6[i];
774 static int imc_get_coeffs(IMCContext *q, IMCChannel *chctx)
776 int i, j, cw_len, cw;
778 for (i = 0; i < BANDS; i++) {
779 if (!chctx->sumLenArr[i])
781 if (chctx->bandFlagsBuf[i] || chctx->bandWidthT[i]) {
782 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
783 cw_len = chctx->CWlengthT[j];
786 if (get_bits_count(&q->gb) + cw_len > 512) {
787 av_dlog(NULL, "Band %i coeff %i cw_len %i\n", i, j, cw_len);
788 return AVERROR_INVALIDDATA;
791 if (cw_len && (!chctx->bandFlagsBuf[i] || !chctx->skipFlags[j]))
792 cw = get_bits(&q->gb, cw_len);
794 chctx->codewords[j] = cw;
801 static void imc_refine_bit_allocation(IMCContext *q, IMCChannel *chctx)
806 for (i = 0; i < BANDS; i++) {
807 chctx->sumLenArr[i] = 0;
808 chctx->skipFlagRaw[i] = 0;
809 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
810 chctx->sumLenArr[i] += chctx->CWlengthT[j];
811 if (chctx->bandFlagsBuf[i])
812 if ((((band_tab[i + 1] - band_tab[i]) * 1.5) > chctx->sumLenArr[i]) && (chctx->sumLenArr[i] > 0))
813 chctx->skipFlagRaw[i] = 1;
816 imc_get_skip_coeff(q, chctx);
818 for (i = 0; i < BANDS; i++) {
819 chctx->flcoeffs6[i] = chctx->flcoeffs1[i];
820 /* band has flag set and at least one coded coefficient */
821 if (chctx->bandFlagsBuf[i] && (band_tab[i + 1] - band_tab[i]) != chctx->skipFlagCount[i]) {
822 chctx->flcoeffs6[i] *= q->sqrt_tab[ band_tab[i + 1] - band_tab[i]] /
823 q->sqrt_tab[(band_tab[i + 1] - band_tab[i] - chctx->skipFlagCount[i])];
827 /* calculate bits left, bits needed and adjust bit allocation */
830 for (i = 0; i < BANDS; i++) {
831 if (chctx->bandFlagsBuf[i]) {
832 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
833 if (chctx->skipFlags[j]) {
834 summer += chctx->CWlengthT[j];
835 chctx->CWlengthT[j] = 0;
838 bits += chctx->skipFlagBits[i];
839 summer -= chctx->skipFlagBits[i];
842 imc_adjust_bit_allocation(q, chctx, summer);
845 static int imc_decode_block(AVCodecContext *avctx, IMCContext *q, int ch)
847 int stream_format_code;
848 int imc_hdr, i, j, ret;
851 int counter, bitscount;
852 IMCChannel *chctx = q->chctx + ch;
855 /* Check the frame header */
856 imc_hdr = get_bits(&q->gb, 9);
857 if (imc_hdr & 0x18) {
858 av_log(avctx, AV_LOG_ERROR, "frame header check failed!\n");
859 av_log(avctx, AV_LOG_ERROR, "got %X.\n", imc_hdr);
860 return AVERROR_INVALIDDATA;
862 stream_format_code = get_bits(&q->gb, 3);
864 if (stream_format_code & 0x04)
865 chctx->decoder_reset = 1;
867 if (chctx->decoder_reset) {
868 for (i = 0; i < BANDS; i++)
869 chctx->old_floor[i] = 1.0;
870 for (i = 0; i < COEFFS; i++)
871 chctx->CWdecoded[i] = 0;
872 chctx->decoder_reset = 0;
875 flag = get_bits1(&q->gb);
876 if (stream_format_code & 0x1)
877 imc_decode_level_coefficients_raw(q, chctx->levlCoeffBuf,
878 chctx->flcoeffs1, chctx->flcoeffs2);
879 else if (stream_format_code & 0x1)
880 imc_read_level_coeffs_raw(q, stream_format_code, chctx->levlCoeffBuf);
882 imc_read_level_coeffs(q, stream_format_code, chctx->levlCoeffBuf);
884 if (stream_format_code & 0x4)
885 imc_decode_level_coefficients(q, chctx->levlCoeffBuf,
886 chctx->flcoeffs1, chctx->flcoeffs2);
888 imc_decode_level_coefficients2(q, chctx->levlCoeffBuf, chctx->old_floor,
889 chctx->flcoeffs1, chctx->flcoeffs2);
891 for(i=0; i<BANDS; i++) {
892 if(chctx->flcoeffs1[i] > INT_MAX) {
893 av_log(avctx, AV_LOG_ERROR, "scalefactor out of range\n");
894 return AVERROR_INVALIDDATA;
898 memcpy(chctx->old_floor, chctx->flcoeffs1, 32 * sizeof(float));
901 if (stream_format_code & 0x1) {
902 for (i = 0; i < BANDS; i++) {
903 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
904 chctx->bandFlagsBuf[i] = 0;
905 chctx->flcoeffs3[i] = chctx->flcoeffs2[i] * 2;
906 chctx->flcoeffs5[i] = 1.0;
909 for (i = 0; i < BANDS; i++) {
910 if (chctx->levlCoeffBuf[i] == 16) {
911 chctx->bandWidthT[i] = 0;
914 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
917 memset(chctx->bandFlagsBuf, 0, BANDS * sizeof(int));
918 for (i = 0; i < BANDS - 1; i++)
919 if (chctx->bandWidthT[i])
920 chctx->bandFlagsBuf[i] = get_bits1(&q->gb);
922 imc_calculate_coeffs(q, chctx->flcoeffs1, chctx->flcoeffs2,
923 chctx->bandWidthT, chctx->flcoeffs3,
928 /* first 4 bands will be assigned 5 bits per coefficient */
929 if (stream_format_code & 0x2) {
932 chctx->bitsBandT[0] = 5;
933 chctx->CWlengthT[0] = 5;
934 chctx->CWlengthT[1] = 5;
935 chctx->CWlengthT[2] = 5;
936 for (i = 1; i < 4; i++) {
937 if (stream_format_code & 0x1)
940 bits = (chctx->levlCoeffBuf[i] == 16) ? 0 : 5;
941 chctx->bitsBandT[i] = bits;
942 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
943 chctx->CWlengthT[j] = bits;
948 if (avctx->codec_id == AV_CODEC_ID_IAC) {
949 bitscount += !!chctx->bandWidthT[BANDS - 1];
950 if (!(stream_format_code & 0x2))
954 if ((ret = bit_allocation(q, chctx, stream_format_code,
955 512 - bitscount - get_bits_count(&q->gb),
957 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
958 chctx->decoder_reset = 1;
962 if (stream_format_code & 0x1) {
963 for (i = 0; i < BANDS; i++)
964 chctx->skipFlags[i] = 0;
966 imc_refine_bit_allocation(q, chctx);
969 for (i = 0; i < BANDS; i++) {
970 chctx->sumLenArr[i] = 0;
972 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
973 if (!chctx->skipFlags[j])
974 chctx->sumLenArr[i] += chctx->CWlengthT[j];
977 memset(chctx->codewords, 0, sizeof(chctx->codewords));
979 if (imc_get_coeffs(q, chctx) < 0) {
980 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");
981 chctx->decoder_reset = 1;
982 return AVERROR_INVALIDDATA;
985 if (inverse_quant_coeff(q, chctx, stream_format_code) < 0) {
986 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
987 chctx->decoder_reset = 1;
988 return AVERROR_INVALIDDATA;
991 memset(chctx->skipFlags, 0, sizeof(chctx->skipFlags));
993 imc_imdct256(q, chctx, avctx->channels);
998 static int imc_decode_frame(AVCodecContext *avctx, void *data,
999 int *got_frame_ptr, AVPacket *avpkt)
1001 AVFrame *frame = data;
1002 const uint8_t *buf = avpkt->data;
1003 int buf_size = avpkt->size;
1006 IMCContext *q = avctx->priv_data;
1008 LOCAL_ALIGNED_16(uint16_t, buf16, [IMC_BLOCK_SIZE / 2]);
1010 if (buf_size < IMC_BLOCK_SIZE * avctx->channels) {
1011 av_log(avctx, AV_LOG_ERROR, "frame too small!\n");
1012 return AVERROR_INVALIDDATA;
1015 /* get output buffer */
1016 frame->nb_samples = COEFFS;
1017 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1020 for (i = 0; i < avctx->channels; i++) {
1021 q->out_samples = (float *)frame->extended_data[i];
1023 q->dsp.bswap16_buf(buf16, (const uint16_t*)buf, IMC_BLOCK_SIZE / 2);
1025 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
1027 buf += IMC_BLOCK_SIZE;
1029 if ((ret = imc_decode_block(avctx, q, i)) < 0)
1033 if (avctx->channels == 2) {
1034 q->fdsp.butterflies_float((float *)frame->extended_data[0],
1035 (float *)frame->extended_data[1], COEFFS);
1040 return IMC_BLOCK_SIZE * avctx->channels;
1044 static av_cold int imc_decode_close(AVCodecContext * avctx)
1046 IMCContext *q = avctx->priv_data;
1048 ff_fft_end(&q->fft);
1053 static av_cold void flush(AVCodecContext *avctx)
1055 IMCContext *q = avctx->priv_data;
1057 q->chctx[0].decoder_reset =
1058 q->chctx[1].decoder_reset = 1;
1061 #if CONFIG_IMC_DECODER
1062 AVCodec ff_imc_decoder = {
1064 .type = AVMEDIA_TYPE_AUDIO,
1065 .id = AV_CODEC_ID_IMC,
1066 .priv_data_size = sizeof(IMCContext),
1067 .init = imc_decode_init,
1068 .close = imc_decode_close,
1069 .decode = imc_decode_frame,
1071 .capabilities = CODEC_CAP_DR1,
1072 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
1073 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1074 AV_SAMPLE_FMT_NONE },
1077 #if CONFIG_IAC_DECODER
1078 AVCodec ff_iac_decoder = {
1080 .type = AVMEDIA_TYPE_AUDIO,
1081 .id = AV_CODEC_ID_IAC,
1082 .priv_data_size = sizeof(IMCContext),
1083 .init = imc_decode_init,
1084 .close = imc_decode_close,
1085 .decode = imc_decode_frame,
1087 .capabilities = CODEC_CAP_DR1,
1088 .long_name = NULL_IF_CONFIG_SMALL("IAC (Indeo Audio Coder)"),
1089 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1090 AV_SAMPLE_FMT_NONE },