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 Libav.
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.
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.
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
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/float_dsp.h"
39 #include "libavutil/internal.h"
49 #define IMC_BLOCK_SIZE 64
50 #define IMC_FRAME_ID 0x21
54 typedef struct IMCChannel {
55 float old_floor[BANDS];
56 float flcoeffs1[BANDS];
57 float flcoeffs2[BANDS];
58 float flcoeffs3[BANDS];
59 float flcoeffs4[BANDS];
60 float flcoeffs5[BANDS];
61 float flcoeffs6[BANDS];
62 float CWdecoded[COEFFS];
64 int bandWidthT[BANDS]; ///< codewords per band
65 int bitsBandT[BANDS]; ///< how many bits per codeword in band
66 int CWlengthT[COEFFS]; ///< how many bits in each codeword
67 int levlCoeffBuf[BANDS];
68 int bandFlagsBuf[BANDS]; ///< flags for each band
69 int sumLenArr[BANDS]; ///< bits for all coeffs in band
70 int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not
71 int skipFlagBits[BANDS]; ///< bits used to code skip flags
72 int skipFlagCount[BANDS]; ///< skipped coefficients per band
73 int skipFlags[COEFFS]; ///< skip coefficient decoding or not
74 int codewords[COEFFS]; ///< raw codewords read from bitstream
76 float last_fft_im[COEFFS];
81 typedef struct IMCContext {
86 float mdct_sine_window[COEFFS];
87 float post_cos[COEFFS];
88 float post_sin[COEFFS];
89 float pre_coef1[COEFFS];
90 float pre_coef2[COEFFS];
97 AVFloatDSPContext fdsp;
99 DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS / 2];
104 int8_t cyclTab[32], cyclTab2[32];
105 float weights1[31], weights2[31];
108 static VLC huffman_vlc[4][4];
110 #define VLC_TABLES_SIZE 9512
112 static const int vlc_offsets[17] = {
113 0, 640, 1156, 1732, 2308, 2852, 3396, 3924,
114 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE
117 static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];
119 static inline double freq2bark(double freq)
121 return 3.5 * atan((freq / 7500.0) * (freq / 7500.0)) + 13.0 * atan(freq * 0.00076);
124 static av_cold void iac_generate_tabs(IMCContext *q, int sampling_rate)
126 double freqmin[32], freqmid[32], freqmax[32];
127 double scale = sampling_rate / (256.0 * 2.0 * 2.0);
128 double nyquist_freq = sampling_rate * 0.5;
129 double freq, bark, prev_bark = 0, tf, tb;
132 for (i = 0; i < 32; i++) {
133 freq = (band_tab[i] + band_tab[i + 1] - 1) * scale;
134 bark = freq2bark(freq);
137 tb = bark - prev_bark;
138 q->weights1[i - 1] = pow(10.0, -1.0 * tb);
139 q->weights2[i - 1] = pow(10.0, -2.7 * tb);
146 while (tf < nyquist_freq) {
158 if (tb <= bark - 0.5)
164 for (i = 0; i < 32; i++) {
166 for (j = 31; j > 0 && freq <= freqmid[j]; j--);
167 q->cyclTab[i] = j + 1;
170 for (j = 0; j < 32 && freq >= freqmid[j]; j++);
171 q->cyclTab2[i] = j - 1;
175 static av_cold int imc_decode_init(AVCodecContext *avctx)
178 IMCContext *q = avctx->priv_data;
181 if (avctx->codec_id == AV_CODEC_ID_IMC)
184 if (avctx->channels > 2) {
185 avpriv_request_sample(avctx, "Number of channels > 2");
186 return AVERROR_PATCHWELCOME;
189 for (j = 0; j < avctx->channels; j++) {
190 q->chctx[j].decoder_reset = 1;
192 for (i = 0; i < BANDS; i++)
193 q->chctx[j].old_floor[i] = 1.0;
195 for (i = 0; i < COEFFS / 2; i++)
196 q->chctx[j].last_fft_im[i] = 0;
199 /* Build mdct window, a simple sine window normalized with sqrt(2) */
200 ff_sine_window_init(q->mdct_sine_window, COEFFS);
201 for (i = 0; i < COEFFS; i++)
202 q->mdct_sine_window[i] *= sqrt(2.0);
203 for (i = 0; i < COEFFS / 2; i++) {
204 q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI);
205 q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI);
207 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
208 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
211 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
212 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
214 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
215 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
219 /* Generate a square root table */
221 for (i = 0; i < 30; i++)
222 q->sqrt_tab[i] = sqrt(i);
224 /* initialize the VLC tables */
225 for (i = 0; i < 4 ; i++) {
226 for (j = 0; j < 4; j++) {
227 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]];
228 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];
229 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i],
230 imc_huffman_lens[i][j], 1, 1,
231 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC);
235 if (avctx->codec_id == AV_CODEC_ID_IAC) {
236 iac_generate_tabs(q, avctx->sample_rate);
238 memcpy(q->cyclTab, cyclTab, sizeof(cyclTab));
239 memcpy(q->cyclTab2, cyclTab2, sizeof(cyclTab2));
240 memcpy(q->weights1, imc_weights1, sizeof(imc_weights1));
241 memcpy(q->weights2, imc_weights2, sizeof(imc_weights2));
244 if ((ret = ff_fft_init(&q->fft, 7, 1))) {
245 av_log(avctx, AV_LOG_INFO, "FFT init failed\n");
248 ff_bswapdsp_init(&q->bdsp);
249 avpriv_float_dsp_init(&q->fdsp, avctx->flags & AV_CODEC_FLAG_BITEXACT);
250 avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
251 avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
252 : AV_CH_LAYOUT_STEREO;
257 static void imc_calculate_coeffs(IMCContext *q, float *flcoeffs1,
258 float *flcoeffs2, int *bandWidthT,
259 float *flcoeffs3, float *flcoeffs5)
264 float snr_limit = 1.e-30;
268 for (i = 0; i < BANDS; i++) {
269 flcoeffs5[i] = workT2[i] = 0.0;
271 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
272 flcoeffs3[i] = 2.0 * flcoeffs2[i];
275 flcoeffs3[i] = -30000.0;
277 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
278 if (workT3[i] <= snr_limit)
282 for (i = 0; i < BANDS; i++) {
283 for (cnt2 = i; cnt2 < q->cyclTab[i]; cnt2++)
284 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
285 workT2[cnt2 - 1] = workT2[cnt2 - 1] + workT3[i];
288 for (i = 1; i < BANDS; i++) {
289 accum = (workT2[i - 1] + accum) * q->weights1[i - 1];
290 flcoeffs5[i] += accum;
293 for (i = 0; i < BANDS; i++)
296 for (i = 0; i < BANDS; i++) {
297 for (cnt2 = i - 1; cnt2 > q->cyclTab2[i]; cnt2--)
298 flcoeffs5[cnt2] += workT3[i];
299 workT2[cnt2+1] += workT3[i];
304 for (i = BANDS-2; i >= 0; i--) {
305 accum = (workT2[i+1] + accum) * q->weights2[i];
306 flcoeffs5[i] += accum;
307 // there is missing code here, but it seems to never be triggered
312 static void imc_read_level_coeffs(IMCContext *q, int stream_format_code,
318 const uint8_t *cb_sel;
321 s = stream_format_code >> 1;
322 hufftab[0] = &huffman_vlc[s][0];
323 hufftab[1] = &huffman_vlc[s][1];
324 hufftab[2] = &huffman_vlc[s][2];
325 hufftab[3] = &huffman_vlc[s][3];
326 cb_sel = imc_cb_select[s];
328 if (stream_format_code & 4)
331 levlCoeffs[0] = get_bits(&q->gb, 7);
332 for (i = start; i < BANDS; i++) {
333 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table,
334 hufftab[cb_sel[i]]->bits, 2);
335 if (levlCoeffs[i] == 17)
336 levlCoeffs[i] += get_bits(&q->gb, 4);
340 static void imc_read_level_coeffs_raw(IMCContext *q, int stream_format_code,
345 q->coef0_pos = get_bits(&q->gb, 5);
346 levlCoeffs[0] = get_bits(&q->gb, 7);
347 for (i = 1; i < BANDS; i++)
348 levlCoeffs[i] = get_bits(&q->gb, 4);
351 static void imc_decode_level_coefficients(IMCContext *q, int *levlCoeffBuf,
352 float *flcoeffs1, float *flcoeffs2)
356 // maybe some frequency division thingy
358 flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
359 flcoeffs2[0] = log2f(flcoeffs1[0]);
363 for (i = 1; i < BANDS; i++) {
364 level = levlCoeffBuf[i];
371 else if (level <= 24)
376 tmp *= imc_exp_tab[15 + level];
377 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
385 static void imc_decode_level_coefficients2(IMCContext *q, int *levlCoeffBuf,
386 float *old_floor, float *flcoeffs1,
390 /* FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
391 * and flcoeffs2 old scale factors
392 * might be incomplete due to a missing table that is in the binary code
394 for (i = 0; i < BANDS; i++) {
396 if (levlCoeffBuf[i] < 16) {
397 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
398 flcoeffs2[i] = (levlCoeffBuf[i] - 7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
400 flcoeffs1[i] = old_floor[i];
405 static void imc_decode_level_coefficients_raw(IMCContext *q, int *levlCoeffBuf,
406 float *flcoeffs1, float *flcoeffs2)
412 flcoeffs1[pos] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
413 flcoeffs2[pos] = log2f(flcoeffs1[pos]);
414 tmp = flcoeffs1[pos];
415 tmp2 = flcoeffs2[pos];
418 for (i = 0; i < BANDS; i++) {
421 level = *levlCoeffBuf++;
422 flcoeffs1[i] = tmp * powf(10.0, -level * 0.4375); //todo tab
423 flcoeffs2[i] = tmp2 - 1.4533435415 * level; // 1.4533435415 = log2(10) * 0.4375
428 * Perform bit allocation depending on bits available
430 static int bit_allocation(IMCContext *q, IMCChannel *chctx,
431 int stream_format_code, int freebits, int flag)
434 const float limit = -1.e20;
443 float lowest = 1.e10;
449 for (i = 0; i < BANDS; i++)
450 highest = FFMAX(highest, chctx->flcoeffs1[i]);
452 for (i = 0; i < BANDS - 1; i++)
453 chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log2f(chctx->flcoeffs5[i]);
454 chctx->flcoeffs4[BANDS - 1] = limit;
456 highest = highest * 0.25;
458 for (i = 0; i < BANDS; i++) {
460 if ((band_tab[i + 1] - band_tab[i]) == chctx->bandWidthT[i])
463 if ((band_tab[i + 1] - band_tab[i]) > chctx->bandWidthT[i])
466 if (((band_tab[i + 1] - band_tab[i]) / 2) >= chctx->bandWidthT[i])
470 return AVERROR_INVALIDDATA;
472 chctx->flcoeffs4[i] += xTab[(indx * 2 + (chctx->flcoeffs1[i] < highest)) * 2 + flag];
475 if (stream_format_code & 0x2) {
476 chctx->flcoeffs4[0] = limit;
477 chctx->flcoeffs4[1] = limit;
478 chctx->flcoeffs4[2] = limit;
479 chctx->flcoeffs4[3] = limit;
482 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS - 1; i++) {
483 iacc += chctx->bandWidthT[i];
484 summa += chctx->bandWidthT[i] * chctx->flcoeffs4[i];
488 return AVERROR_INVALIDDATA;
490 chctx->bandWidthT[BANDS - 1] = 0;
491 summa = (summa * 0.5 - freebits) / iacc;
494 for (i = 0; i < BANDS / 2; i++) {
495 rres = summer - freebits;
496 if ((rres >= -8) && (rres <= 8))
502 for (j = (stream_format_code & 0x2) ? 4 : 0; j < BANDS; j++) {
503 cwlen = av_clipf(((chctx->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
505 chctx->bitsBandT[j] = cwlen;
506 summer += chctx->bandWidthT[j] * cwlen;
509 iacc += chctx->bandWidthT[j];
514 if (freebits < summer)
521 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
524 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS; i++) {
525 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
526 chctx->CWlengthT[j] = chctx->bitsBandT[i];
529 if (freebits > summer) {
530 for (i = 0; i < BANDS; i++) {
531 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
532 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
538 if (highest <= -1.e20)
544 for (i = 0; i < BANDS; i++) {
545 if (workT[i] > highest) {
551 if (highest > -1.e20) {
552 workT[found_indx] -= 2.0;
553 if (++chctx->bitsBandT[found_indx] == 6)
554 workT[found_indx] = -1.e20;
556 for (j = band_tab[found_indx]; j < band_tab[found_indx + 1] && (freebits > summer); j++) {
557 chctx->CWlengthT[j]++;
561 } while (freebits > summer);
563 if (freebits < summer) {
564 for (i = 0; i < BANDS; i++) {
565 workT[i] = chctx->bitsBandT[i] ? (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] + 1.585)
568 if (stream_format_code & 0x2) {
574 while (freebits < summer) {
577 for (i = 0; i < BANDS; i++) {
578 if (workT[i] < lowest) {
583 // if (lowest >= 1.e10)
585 workT[low_indx] = lowest + 2.0;
587 if (!--chctx->bitsBandT[low_indx])
588 workT[low_indx] = 1.e20;
590 for (j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++) {
591 if (chctx->CWlengthT[j] > 0) {
592 chctx->CWlengthT[j]--;
601 static void imc_get_skip_coeff(IMCContext *q, IMCChannel *chctx)
605 memset(chctx->skipFlagBits, 0, sizeof(chctx->skipFlagBits));
606 memset(chctx->skipFlagCount, 0, sizeof(chctx->skipFlagCount));
607 for (i = 0; i < BANDS; i++) {
608 if (!chctx->bandFlagsBuf[i] || !chctx->bandWidthT[i])
611 if (!chctx->skipFlagRaw[i]) {
612 chctx->skipFlagBits[i] = band_tab[i + 1] - band_tab[i];
614 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
615 chctx->skipFlags[j] = get_bits1(&q->gb);
616 if (chctx->skipFlags[j])
617 chctx->skipFlagCount[i]++;
620 for (j = band_tab[i]; j < band_tab[i + 1] - 1; j += 2) {
621 if (!get_bits1(&q->gb)) { // 0
622 chctx->skipFlagBits[i]++;
623 chctx->skipFlags[j] = 1;
624 chctx->skipFlags[j + 1] = 1;
625 chctx->skipFlagCount[i] += 2;
627 if (get_bits1(&q->gb)) { // 11
628 chctx->skipFlagBits[i] += 2;
629 chctx->skipFlags[j] = 0;
630 chctx->skipFlags[j + 1] = 1;
631 chctx->skipFlagCount[i]++;
633 chctx->skipFlagBits[i] += 3;
634 chctx->skipFlags[j + 1] = 0;
635 if (!get_bits1(&q->gb)) { // 100
636 chctx->skipFlags[j] = 1;
637 chctx->skipFlagCount[i]++;
639 chctx->skipFlags[j] = 0;
645 if (j < band_tab[i + 1]) {
646 chctx->skipFlagBits[i]++;
647 if ((chctx->skipFlags[j] = get_bits1(&q->gb)))
648 chctx->skipFlagCount[i]++;
655 * Increase highest' band coefficient sizes as some bits won't be used
657 static void imc_adjust_bit_allocation(IMCContext *q, IMCChannel *chctx,
666 for (i = 0; i < BANDS; i++) {
667 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
668 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
671 while (corrected < summer) {
672 if (highest <= -1.e20)
677 for (i = 0; i < BANDS; i++) {
678 if (workT[i] > highest) {
684 if (highest > -1.e20) {
685 workT[found_indx] -= 2.0;
686 if (++(chctx->bitsBandT[found_indx]) == 6)
687 workT[found_indx] = -1.e20;
689 for (j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
690 if (!chctx->skipFlags[j] && (chctx->CWlengthT[j] < 6)) {
691 chctx->CWlengthT[j]++;
699 static void imc_imdct256(IMCContext *q, IMCChannel *chctx, int channels)
703 float *dst1 = q->out_samples;
704 float *dst2 = q->out_samples + (COEFFS - 1);
707 for (i = 0; i < COEFFS / 2; i++) {
708 q->samples[i].re = -(q->pre_coef1[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
709 (q->pre_coef2[i] * chctx->CWdecoded[i * 2]);
710 q->samples[i].im = (q->pre_coef2[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
711 (q->pre_coef1[i] * chctx->CWdecoded[i * 2]);
715 q->fft.fft_permute(&q->fft, q->samples);
716 q->fft.fft_calc(&q->fft, q->samples);
718 /* postrotation, window and reorder */
719 for (i = 0; i < COEFFS / 2; i++) {
720 re = ( q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
721 im = (-q->samples[i].im * q->post_cos[i]) - ( q->samples[i].re * q->post_sin[i]);
722 *dst1 = (q->mdct_sine_window[COEFFS - 1 - i * 2] * chctx->last_fft_im[i])
723 + (q->mdct_sine_window[i * 2] * re);
724 *dst2 = (q->mdct_sine_window[i * 2] * chctx->last_fft_im[i])
725 - (q->mdct_sine_window[COEFFS - 1 - i * 2] * re);
728 chctx->last_fft_im[i] = im;
732 static int inverse_quant_coeff(IMCContext *q, IMCChannel *chctx,
733 int stream_format_code)
736 int middle_value, cw_len, max_size;
737 const float *quantizer;
739 for (i = 0; i < BANDS; i++) {
740 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
741 chctx->CWdecoded[j] = 0;
742 cw_len = chctx->CWlengthT[j];
744 if (cw_len <= 0 || chctx->skipFlags[j])
747 max_size = 1 << cw_len;
748 middle_value = max_size >> 1;
750 if (chctx->codewords[j] >= max_size || chctx->codewords[j] < 0)
751 return AVERROR_INVALIDDATA;
754 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
755 if (chctx->codewords[j] >= middle_value)
756 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 8] * chctx->flcoeffs6[i];
758 chctx->CWdecoded[j] = -quantizer[max_size - chctx->codewords[j] - 8 - 1] * chctx->flcoeffs6[i];
760 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (chctx->bandFlagsBuf[i] << 1)];
761 if (chctx->codewords[j] >= middle_value)
762 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 1] * chctx->flcoeffs6[i];
764 chctx->CWdecoded[j] = -quantizer[max_size - 2 - chctx->codewords[j]] * chctx->flcoeffs6[i];
772 static int imc_get_coeffs(IMCContext *q, IMCChannel *chctx)
774 int i, j, cw_len, cw;
776 for (i = 0; i < BANDS; i++) {
777 if (!chctx->sumLenArr[i])
779 if (chctx->bandFlagsBuf[i] || chctx->bandWidthT[i]) {
780 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
781 cw_len = chctx->CWlengthT[j];
784 if (get_bits_count(&q->gb) + cw_len > 512) {
785 ff_dlog(NULL, "Band %i coeff %i cw_len %i\n", i, j, cw_len);
786 return AVERROR_INVALIDDATA;
789 if (cw_len && (!chctx->bandFlagsBuf[i] || !chctx->skipFlags[j]))
790 cw = get_bits(&q->gb, cw_len);
792 chctx->codewords[j] = cw;
799 static void imc_refine_bit_allocation(IMCContext *q, IMCChannel *chctx)
804 for (i = 0; i < BANDS; i++) {
805 chctx->sumLenArr[i] = 0;
806 chctx->skipFlagRaw[i] = 0;
807 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
808 chctx->sumLenArr[i] += chctx->CWlengthT[j];
809 if (chctx->bandFlagsBuf[i])
810 if ((((band_tab[i + 1] - band_tab[i]) * 1.5) > chctx->sumLenArr[i]) && (chctx->sumLenArr[i] > 0))
811 chctx->skipFlagRaw[i] = 1;
814 imc_get_skip_coeff(q, chctx);
816 for (i = 0; i < BANDS; i++) {
817 chctx->flcoeffs6[i] = chctx->flcoeffs1[i];
818 /* band has flag set and at least one coded coefficient */
819 if (chctx->bandFlagsBuf[i] && (band_tab[i + 1] - band_tab[i]) != chctx->skipFlagCount[i]) {
820 chctx->flcoeffs6[i] *= q->sqrt_tab[ band_tab[i + 1] - band_tab[i]] /
821 q->sqrt_tab[(band_tab[i + 1] - band_tab[i] - chctx->skipFlagCount[i])];
825 /* calculate bits left, bits needed and adjust bit allocation */
828 for (i = 0; i < BANDS; i++) {
829 if (chctx->bandFlagsBuf[i]) {
830 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
831 if (chctx->skipFlags[j]) {
832 summer += chctx->CWlengthT[j];
833 chctx->CWlengthT[j] = 0;
836 bits += chctx->skipFlagBits[i];
837 summer -= chctx->skipFlagBits[i];
840 imc_adjust_bit_allocation(q, chctx, summer);
843 static int imc_decode_block(AVCodecContext *avctx, IMCContext *q, int ch)
845 int stream_format_code;
846 int imc_hdr, i, j, ret;
849 int counter, bitscount;
850 IMCChannel *chctx = q->chctx + ch;
853 /* Check the frame header */
854 imc_hdr = get_bits(&q->gb, 9);
855 if (imc_hdr & 0x18) {
856 av_log(avctx, AV_LOG_ERROR, "frame header check failed!\n");
857 av_log(avctx, AV_LOG_ERROR, "got %X.\n", imc_hdr);
858 return AVERROR_INVALIDDATA;
860 stream_format_code = get_bits(&q->gb, 3);
862 if (stream_format_code & 0x04)
863 chctx->decoder_reset = 1;
865 if (chctx->decoder_reset) {
866 for (i = 0; i < BANDS; i++)
867 chctx->old_floor[i] = 1.0;
868 for (i = 0; i < COEFFS; i++)
869 chctx->CWdecoded[i] = 0;
870 chctx->decoder_reset = 0;
873 flag = get_bits1(&q->gb);
874 if (stream_format_code & 0x1)
875 imc_read_level_coeffs_raw(q, stream_format_code, chctx->levlCoeffBuf);
877 imc_read_level_coeffs(q, stream_format_code, chctx->levlCoeffBuf);
879 if (stream_format_code & 0x1)
880 imc_decode_level_coefficients_raw(q, chctx->levlCoeffBuf,
881 chctx->flcoeffs1, chctx->flcoeffs2);
882 else if (stream_format_code & 0x4)
883 imc_decode_level_coefficients(q, chctx->levlCoeffBuf,
884 chctx->flcoeffs1, chctx->flcoeffs2);
886 imc_decode_level_coefficients2(q, chctx->levlCoeffBuf, chctx->old_floor,
887 chctx->flcoeffs1, chctx->flcoeffs2);
889 memcpy(chctx->old_floor, chctx->flcoeffs1, 32 * sizeof(float));
892 if (stream_format_code & 0x1) {
893 for (i = 0; i < BANDS; i++) {
894 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
895 chctx->bandFlagsBuf[i] = 0;
896 chctx->flcoeffs3[i] = chctx->flcoeffs2[i] * 2;
897 chctx->flcoeffs5[i] = 1.0;
900 for (i = 0; i < BANDS; i++) {
901 if (chctx->levlCoeffBuf[i] == 16) {
902 chctx->bandWidthT[i] = 0;
905 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
908 memset(chctx->bandFlagsBuf, 0, BANDS * sizeof(int));
909 for (i = 0; i < BANDS - 1; i++)
910 if (chctx->bandWidthT[i])
911 chctx->bandFlagsBuf[i] = get_bits1(&q->gb);
913 imc_calculate_coeffs(q, chctx->flcoeffs1, chctx->flcoeffs2,
914 chctx->bandWidthT, chctx->flcoeffs3,
919 /* first 4 bands will be assigned 5 bits per coefficient */
920 if (stream_format_code & 0x2) {
923 chctx->bitsBandT[0] = 5;
924 chctx->CWlengthT[0] = 5;
925 chctx->CWlengthT[1] = 5;
926 chctx->CWlengthT[2] = 5;
927 for (i = 1; i < 4; i++) {
928 if (stream_format_code & 0x1)
931 bits = (chctx->levlCoeffBuf[i] == 16) ? 0 : 5;
932 chctx->bitsBandT[i] = bits;
933 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
934 chctx->CWlengthT[j] = bits;
939 if (avctx->codec_id == AV_CODEC_ID_IAC) {
940 bitscount += !!chctx->bandWidthT[BANDS - 1];
941 if (!(stream_format_code & 0x2))
945 if ((ret = bit_allocation(q, chctx, stream_format_code,
946 512 - bitscount - get_bits_count(&q->gb),
948 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
949 chctx->decoder_reset = 1;
953 if (stream_format_code & 0x1) {
954 for (i = 0; i < BANDS; i++)
955 chctx->skipFlags[i] = 0;
957 imc_refine_bit_allocation(q, chctx);
960 for (i = 0; i < BANDS; i++) {
961 chctx->sumLenArr[i] = 0;
963 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
964 if (!chctx->skipFlags[j])
965 chctx->sumLenArr[i] += chctx->CWlengthT[j];
968 memset(chctx->codewords, 0, sizeof(chctx->codewords));
970 if (imc_get_coeffs(q, chctx) < 0) {
971 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");
972 chctx->decoder_reset = 1;
973 return AVERROR_INVALIDDATA;
976 if (inverse_quant_coeff(q, chctx, stream_format_code) < 0) {
977 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
978 chctx->decoder_reset = 1;
979 return AVERROR_INVALIDDATA;
982 memset(chctx->skipFlags, 0, sizeof(chctx->skipFlags));
984 imc_imdct256(q, chctx, avctx->channels);
989 static int imc_decode_frame(AVCodecContext *avctx, void *data,
990 int *got_frame_ptr, AVPacket *avpkt)
992 AVFrame *frame = data;
993 const uint8_t *buf = avpkt->data;
994 int buf_size = avpkt->size;
997 IMCContext *q = avctx->priv_data;
999 LOCAL_ALIGNED_16(uint16_t, buf16, [(IMC_BLOCK_SIZE + AV_INPUT_BUFFER_PADDING_SIZE) / 2]);
1001 if (buf_size < IMC_BLOCK_SIZE * avctx->channels) {
1002 av_log(avctx, AV_LOG_ERROR, "frame too small!\n");
1003 return AVERROR_INVALIDDATA;
1006 /* get output buffer */
1007 frame->nb_samples = COEFFS;
1008 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
1009 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
1013 for (i = 0; i < avctx->channels; i++) {
1014 q->out_samples = (float *)frame->extended_data[i];
1016 q->bdsp.bswap16_buf(buf16, (const uint16_t *) buf, IMC_BLOCK_SIZE / 2);
1018 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
1020 buf += IMC_BLOCK_SIZE;
1022 if ((ret = imc_decode_block(avctx, q, i)) < 0)
1026 if (avctx->channels == 2) {
1027 q->fdsp.butterflies_float((float *)frame->extended_data[0],
1028 (float *)frame->extended_data[1], COEFFS);
1033 return IMC_BLOCK_SIZE * avctx->channels;
1037 static av_cold int imc_decode_close(AVCodecContext * avctx)
1039 IMCContext *q = avctx->priv_data;
1041 ff_fft_end(&q->fft);
1047 AVCodec ff_imc_decoder = {
1049 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
1050 .type = AVMEDIA_TYPE_AUDIO,
1051 .id = AV_CODEC_ID_IMC,
1052 .priv_data_size = sizeof(IMCContext),
1053 .init = imc_decode_init,
1054 .close = imc_decode_close,
1055 .decode = imc_decode_frame,
1056 .capabilities = AV_CODEC_CAP_DR1,
1057 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1058 AV_SAMPLE_FMT_NONE },
1061 AVCodec ff_iac_decoder = {
1063 .long_name = NULL_IF_CONFIG_SMALL("IAC (Indeo Audio Coder)"),
1064 .type = AVMEDIA_TYPE_AUDIO,
1065 .id = AV_CODEC_ID_IAC,
1066 .priv_data_size = sizeof(IMCContext),
1067 .init = imc_decode_init,
1068 .close = imc_decode_close,
1069 .decode = imc_decode_frame,
1070 .capabilities = AV_CODEC_CAP_DR1,
1071 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1072 AV_SAMPLE_FMT_NONE },