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"
41 #include "libavutil/thread.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 coefficients 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];
83 typedef struct IMCContext {
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 void (*butterflies_float)(float *av_restrict v1, float *av_restrict v2, int len);
101 DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS / 2];
106 int8_t cyclTab[32], cyclTab2[32];
107 float weights1[31], weights2[31];
109 AVCodecContext *avctx;
112 static VLC huffman_vlc[4][4];
114 #define IMC_VLC_BITS 9
115 #define VLC_TABLES_SIZE 9512
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] = ff_exp10(-1.0 * tb);
139 q->weights2[i - 1] = ff_exp10(-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 void imc_init_static(void)
177 /* initialize the VLC tables */
178 for (int i = 0, offset = 0; i < 4 ; i++) {
179 for (int j = 0; j < 4; j++) {
180 huffman_vlc[i][j].table = &vlc_tables[offset];
181 huffman_vlc[i][j].table_allocated = VLC_TABLES_SIZE - offset;;
182 ff_init_vlc_from_lengths(&huffman_vlc[i][j], IMC_VLC_BITS, imc_huffman_sizes[i],
183 imc_huffman_lens[i][j], 1,
184 imc_huffman_syms[i][j], 1, 1,
185 0, INIT_VLC_STATIC_OVERLONG, NULL);
186 offset += huffman_vlc[i][j].table_size;
191 static av_cold int imc_decode_init(AVCodecContext *avctx)
194 IMCContext *q = avctx->priv_data;
195 static AVOnce init_static_once = AV_ONCE_INIT;
196 AVFloatDSPContext *fdsp;
199 if (avctx->codec_id == AV_CODEC_ID_IAC && avctx->sample_rate > 96000) {
200 av_log(avctx, AV_LOG_ERROR,
201 "Strange sample rate of %i, file likely corrupt or "
202 "needing a new table derivation method.\n",
204 return AVERROR_PATCHWELCOME;
207 if (avctx->codec_id == AV_CODEC_ID_IMC)
210 if (avctx->channels > 2) {
211 avpriv_request_sample(avctx, "Number of channels > 2");
212 return AVERROR_PATCHWELCOME;
215 for (j = 0; j < avctx->channels; j++) {
216 q->chctx[j].decoder_reset = 1;
218 for (i = 0; i < BANDS; i++)
219 q->chctx[j].old_floor[i] = 1.0;
221 for (i = 0; i < COEFFS / 2; i++)
222 q->chctx[j].last_fft_im[i] = 0;
225 /* Build mdct window, a simple sine window normalized with sqrt(2) */
226 ff_sine_window_init(q->mdct_sine_window, COEFFS);
227 for (i = 0; i < COEFFS; i++)
228 q->mdct_sine_window[i] *= sqrt(2.0);
229 for (i = 0; i < COEFFS / 2; i++) {
230 q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI);
231 q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI);
233 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
234 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
237 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
238 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
240 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
241 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
245 /* Generate a square root table */
247 for (i = 0; i < 30; i++)
248 q->sqrt_tab[i] = sqrt(i);
250 if (avctx->codec_id == AV_CODEC_ID_IAC) {
251 iac_generate_tabs(q, avctx->sample_rate);
253 memcpy(q->cyclTab, cyclTab, sizeof(cyclTab));
254 memcpy(q->cyclTab2, cyclTab2, sizeof(cyclTab2));
255 memcpy(q->weights1, imc_weights1, sizeof(imc_weights1));
256 memcpy(q->weights2, imc_weights2, sizeof(imc_weights2));
259 fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
261 return AVERROR(ENOMEM);
262 q->butterflies_float = fdsp->butterflies_float;
264 if ((ret = ff_fft_init(&q->fft, 7, 1))) {
265 av_log(avctx, AV_LOG_INFO, "FFT init failed\n");
268 ff_bswapdsp_init(&q->bdsp);
270 avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
271 avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
272 : AV_CH_LAYOUT_STEREO;
274 ff_thread_once(&init_static_once, imc_init_static);
279 static void imc_calculate_coeffs(IMCContext *q, float *flcoeffs1,
280 float *flcoeffs2, int *bandWidthT,
281 float *flcoeffs3, float *flcoeffs5)
286 float snr_limit = 1.e-30;
290 for (i = 0; i < BANDS; i++) {
291 flcoeffs5[i] = workT2[i] = 0.0;
293 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
294 flcoeffs3[i] = 2.0 * flcoeffs2[i];
297 flcoeffs3[i] = -30000.0;
299 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
300 if (workT3[i] <= snr_limit)
304 for (i = 0; i < BANDS; i++) {
305 for (cnt2 = i; cnt2 < q->cyclTab[i]; cnt2++)
306 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
307 workT2[cnt2 - 1] = workT2[cnt2 - 1] + workT3[i];
310 for (i = 1; i < BANDS; i++) {
311 accum = (workT2[i - 1] + accum) * q->weights1[i - 1];
312 flcoeffs5[i] += accum;
315 for (i = 0; i < BANDS; i++)
318 for (i = 0; i < BANDS; i++) {
319 for (cnt2 = i - 1; cnt2 > q->cyclTab2[i]; cnt2--)
320 flcoeffs5[cnt2] += workT3[i];
321 workT2[cnt2+1] += workT3[i];
326 for (i = BANDS-2; i >= 0; i--) {
327 accum = (workT2[i+1] + accum) * q->weights2[i];
328 flcoeffs5[i] += accum;
329 // there is missing code here, but it seems to never be triggered
334 static void imc_read_level_coeffs(IMCContext *q, int stream_format_code,
340 const uint8_t *cb_sel;
343 s = stream_format_code >> 1;
344 hufftab[0] = &huffman_vlc[s][0];
345 hufftab[1] = &huffman_vlc[s][1];
346 hufftab[2] = &huffman_vlc[s][2];
347 hufftab[3] = &huffman_vlc[s][3];
348 cb_sel = imc_cb_select[s];
350 if (stream_format_code & 4)
353 levlCoeffs[0] = get_bits(&q->gb, 7);
354 for (i = start; i < BANDS; i++) {
355 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table,
357 if (levlCoeffs[i] == 17)
358 levlCoeffs[i] += get_bits(&q->gb, 4);
362 static void imc_read_level_coeffs_raw(IMCContext *q, int stream_format_code,
367 q->coef0_pos = get_bits(&q->gb, 5);
368 levlCoeffs[0] = get_bits(&q->gb, 7);
369 for (i = 1; i < BANDS; i++)
370 levlCoeffs[i] = get_bits(&q->gb, 4);
373 static void imc_decode_level_coefficients(IMCContext *q, int *levlCoeffBuf,
374 float *flcoeffs1, float *flcoeffs2)
378 // maybe some frequency division thingy
380 flcoeffs1[0] = 20000.0 / exp2 (levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
381 flcoeffs2[0] = log2f(flcoeffs1[0]);
385 for (i = 1; i < BANDS; i++) {
386 level = levlCoeffBuf[i];
393 else if (level <= 24)
398 tmp *= imc_exp_tab[15 + level];
399 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
407 static void imc_decode_level_coefficients2(IMCContext *q, int *levlCoeffBuf,
408 float *old_floor, float *flcoeffs1,
412 /* FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
413 * and flcoeffs2 old scale factors
414 * might be incomplete due to a missing table that is in the binary code
416 for (i = 0; i < BANDS; i++) {
418 if (levlCoeffBuf[i] < 16) {
419 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
420 flcoeffs2[i] = (levlCoeffBuf[i] - 7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
422 flcoeffs1[i] = old_floor[i];
427 static void imc_decode_level_coefficients_raw(IMCContext *q, int *levlCoeffBuf,
428 float *flcoeffs1, float *flcoeffs2)
434 flcoeffs1[pos] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
435 flcoeffs2[pos] = log2f(flcoeffs1[pos]);
436 tmp = flcoeffs1[pos];
437 tmp2 = flcoeffs2[pos];
440 for (i = 0; i < BANDS; i++) {
443 level = *levlCoeffBuf++;
444 flcoeffs1[i] = tmp * powf(10.0, -level * 0.4375); //todo tab
445 flcoeffs2[i] = tmp2 - 1.4533435415 * level; // 1.4533435415 = log2(10) * 0.4375
450 * Perform bit allocation depending on bits available
452 static int bit_allocation(IMCContext *q, IMCChannel *chctx,
453 int stream_format_code, int freebits, int flag)
456 const float limit = -1.e20;
465 float lowest = 1.e10;
471 for (i = 0; i < BANDS; i++)
472 highest = FFMAX(highest, chctx->flcoeffs1[i]);
474 for (i = 0; i < BANDS - 1; i++) {
475 if (chctx->flcoeffs5[i] <= 0) {
476 av_log(q->avctx, AV_LOG_ERROR, "flcoeffs5 %f invalid\n", chctx->flcoeffs5[i]);
477 return AVERROR_INVALIDDATA;
479 chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log2f(chctx->flcoeffs5[i]);
481 chctx->flcoeffs4[BANDS - 1] = limit;
483 highest = highest * 0.25;
485 for (i = 0; i < BANDS; i++) {
487 if ((band_tab[i + 1] - band_tab[i]) == chctx->bandWidthT[i])
490 if ((band_tab[i + 1] - band_tab[i]) > chctx->bandWidthT[i])
493 if (((band_tab[i + 1] - band_tab[i]) / 2) >= chctx->bandWidthT[i])
497 return AVERROR_INVALIDDATA;
499 chctx->flcoeffs4[i] += xTab[(indx * 2 + (chctx->flcoeffs1[i] < highest)) * 2 + flag];
502 if (stream_format_code & 0x2) {
503 chctx->flcoeffs4[0] = limit;
504 chctx->flcoeffs4[1] = limit;
505 chctx->flcoeffs4[2] = limit;
506 chctx->flcoeffs4[3] = limit;
509 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS - 1; i++) {
510 iacc += chctx->bandWidthT[i];
511 summa += chctx->bandWidthT[i] * chctx->flcoeffs4[i];
515 return AVERROR_INVALIDDATA;
517 chctx->bandWidthT[BANDS - 1] = 0;
518 summa = (summa * 0.5 - freebits) / iacc;
521 for (i = 0; i < BANDS / 2; i++) {
522 rres = summer - freebits;
523 if ((rres >= -8) && (rres <= 8))
529 for (j = (stream_format_code & 0x2) ? 4 : 0; j < BANDS; j++) {
530 cwlen = av_clipf(((chctx->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
532 chctx->bitsBandT[j] = cwlen;
533 summer += chctx->bandWidthT[j] * cwlen;
536 iacc += chctx->bandWidthT[j];
541 if (freebits < summer)
548 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
551 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS; i++) {
552 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
553 chctx->CWlengthT[j] = chctx->bitsBandT[i];
556 if (freebits > summer) {
557 for (i = 0; i < BANDS; i++) {
558 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
559 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
565 if (highest <= -1.e20)
571 for (i = 0; i < BANDS; i++) {
572 if (workT[i] > highest) {
578 if (highest > -1.e20) {
579 workT[found_indx] -= 2.0;
580 if (++chctx->bitsBandT[found_indx] == 6)
581 workT[found_indx] = -1.e20;
583 for (j = band_tab[found_indx]; j < band_tab[found_indx + 1] && (freebits > summer); j++) {
584 chctx->CWlengthT[j]++;
588 } while (freebits > summer);
590 if (freebits < summer) {
591 for (i = 0; i < BANDS; i++) {
592 workT[i] = chctx->bitsBandT[i] ? (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] + 1.585)
595 if (stream_format_code & 0x2) {
601 while (freebits < summer) {
604 for (i = 0; i < BANDS; i++) {
605 if (workT[i] < lowest) {
610 // if (lowest >= 1.e10)
612 workT[low_indx] = lowest + 2.0;
614 if (!--chctx->bitsBandT[low_indx])
615 workT[low_indx] = 1.e20;
617 for (j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++) {
618 if (chctx->CWlengthT[j] > 0) {
619 chctx->CWlengthT[j]--;
628 static void imc_get_skip_coeff(IMCContext *q, IMCChannel *chctx)
632 memset(chctx->skipFlagBits, 0, sizeof(chctx->skipFlagBits));
633 memset(chctx->skipFlagCount, 0, sizeof(chctx->skipFlagCount));
634 for (i = 0; i < BANDS; i++) {
635 if (!chctx->bandFlagsBuf[i] || !chctx->bandWidthT[i])
638 if (!chctx->skipFlagRaw[i]) {
639 chctx->skipFlagBits[i] = band_tab[i + 1] - band_tab[i];
641 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
642 chctx->skipFlags[j] = get_bits1(&q->gb);
643 if (chctx->skipFlags[j])
644 chctx->skipFlagCount[i]++;
647 for (j = band_tab[i]; j < band_tab[i + 1] - 1; j += 2) {
648 if (!get_bits1(&q->gb)) { // 0
649 chctx->skipFlagBits[i]++;
650 chctx->skipFlags[j] = 1;
651 chctx->skipFlags[j + 1] = 1;
652 chctx->skipFlagCount[i] += 2;
654 if (get_bits1(&q->gb)) { // 11
655 chctx->skipFlagBits[i] += 2;
656 chctx->skipFlags[j] = 0;
657 chctx->skipFlags[j + 1] = 1;
658 chctx->skipFlagCount[i]++;
660 chctx->skipFlagBits[i] += 3;
661 chctx->skipFlags[j + 1] = 0;
662 if (!get_bits1(&q->gb)) { // 100
663 chctx->skipFlags[j] = 1;
664 chctx->skipFlagCount[i]++;
666 chctx->skipFlags[j] = 0;
672 if (j < band_tab[i + 1]) {
673 chctx->skipFlagBits[i]++;
674 if ((chctx->skipFlags[j] = get_bits1(&q->gb)))
675 chctx->skipFlagCount[i]++;
682 * Increase highest' band coefficient sizes as some bits won't be used
684 static void imc_adjust_bit_allocation(IMCContext *q, IMCChannel *chctx,
693 for (i = 0; i < BANDS; i++) {
694 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
695 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
698 while (corrected < summer) {
699 if (highest <= -1.e20)
704 for (i = 0; i < BANDS; i++) {
705 if (workT[i] > highest) {
711 if (highest > -1.e20) {
712 workT[found_indx] -= 2.0;
713 if (++(chctx->bitsBandT[found_indx]) == 6)
714 workT[found_indx] = -1.e20;
716 for (j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
717 if (!chctx->skipFlags[j] && (chctx->CWlengthT[j] < 6)) {
718 chctx->CWlengthT[j]++;
726 static void imc_imdct256(IMCContext *q, IMCChannel *chctx, int channels)
730 float *dst1 = q->out_samples;
731 float *dst2 = q->out_samples + (COEFFS - 1);
734 for (i = 0; i < COEFFS / 2; i++) {
735 q->samples[i].re = -(q->pre_coef1[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
736 (q->pre_coef2[i] * chctx->CWdecoded[i * 2]);
737 q->samples[i].im = (q->pre_coef2[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
738 (q->pre_coef1[i] * chctx->CWdecoded[i * 2]);
742 q->fft.fft_permute(&q->fft, q->samples);
743 q->fft.fft_calc(&q->fft, q->samples);
745 /* postrotation, window and reorder */
746 for (i = 0; i < COEFFS / 2; i++) {
747 re = ( q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
748 im = (-q->samples[i].im * q->post_cos[i]) - ( q->samples[i].re * q->post_sin[i]);
749 *dst1 = (q->mdct_sine_window[COEFFS - 1 - i * 2] * chctx->last_fft_im[i])
750 + (q->mdct_sine_window[i * 2] * re);
751 *dst2 = (q->mdct_sine_window[i * 2] * chctx->last_fft_im[i])
752 - (q->mdct_sine_window[COEFFS - 1 - i * 2] * re);
755 chctx->last_fft_im[i] = im;
759 static int inverse_quant_coeff(IMCContext *q, IMCChannel *chctx,
760 int stream_format_code)
763 int middle_value, cw_len, max_size;
764 const float *quantizer;
766 for (i = 0; i < BANDS; i++) {
767 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
768 chctx->CWdecoded[j] = 0;
769 cw_len = chctx->CWlengthT[j];
771 if (cw_len <= 0 || chctx->skipFlags[j])
774 max_size = 1 << cw_len;
775 middle_value = max_size >> 1;
777 if (chctx->codewords[j] >= max_size || chctx->codewords[j] < 0)
778 return AVERROR_INVALIDDATA;
781 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
782 if (chctx->codewords[j] >= middle_value)
783 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 8] * chctx->flcoeffs6[i];
785 chctx->CWdecoded[j] = -quantizer[max_size - chctx->codewords[j] - 8 - 1] * chctx->flcoeffs6[i];
787 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (chctx->bandFlagsBuf[i] << 1)];
788 if (chctx->codewords[j] >= middle_value)
789 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 1] * chctx->flcoeffs6[i];
791 chctx->CWdecoded[j] = -quantizer[max_size - 2 - chctx->codewords[j]] * chctx->flcoeffs6[i];
799 static void imc_get_coeffs(AVCodecContext *avctx,
800 IMCContext *q, IMCChannel *chctx)
802 int i, j, cw_len, cw;
804 for (i = 0; i < BANDS; i++) {
805 if (!chctx->sumLenArr[i])
807 if (chctx->bandFlagsBuf[i] || chctx->bandWidthT[i]) {
808 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
809 cw_len = chctx->CWlengthT[j];
812 if (cw_len && (!chctx->bandFlagsBuf[i] || !chctx->skipFlags[j])) {
813 if (get_bits_count(&q->gb) + cw_len > 512) {
814 av_log(avctx, AV_LOG_WARNING,
815 "Potential problem on band %i, coefficient %i"
816 ": cw_len=%i\n", i, j, cw_len);
818 cw = get_bits(&q->gb, cw_len);
821 chctx->codewords[j] = cw;
827 static void imc_refine_bit_allocation(IMCContext *q, IMCChannel *chctx)
832 for (i = 0; i < BANDS; i++) {
833 chctx->sumLenArr[i] = 0;
834 chctx->skipFlagRaw[i] = 0;
835 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
836 chctx->sumLenArr[i] += chctx->CWlengthT[j];
837 if (chctx->bandFlagsBuf[i])
838 if (((int)((band_tab[i + 1] - band_tab[i]) * 1.5) > chctx->sumLenArr[i]) && (chctx->sumLenArr[i] > 0))
839 chctx->skipFlagRaw[i] = 1;
842 imc_get_skip_coeff(q, chctx);
844 for (i = 0; i < BANDS; i++) {
845 chctx->flcoeffs6[i] = chctx->flcoeffs1[i];
846 /* band has flag set and at least one coded coefficient */
847 if (chctx->bandFlagsBuf[i] && (band_tab[i + 1] - band_tab[i]) != chctx->skipFlagCount[i]) {
848 chctx->flcoeffs6[i] *= q->sqrt_tab[ band_tab[i + 1] - band_tab[i]] /
849 q->sqrt_tab[(band_tab[i + 1] - band_tab[i] - chctx->skipFlagCount[i])];
853 /* calculate bits left, bits needed and adjust bit allocation */
856 for (i = 0; i < BANDS; i++) {
857 if (chctx->bandFlagsBuf[i]) {
858 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
859 if (chctx->skipFlags[j]) {
860 summer += chctx->CWlengthT[j];
861 chctx->CWlengthT[j] = 0;
864 bits += chctx->skipFlagBits[i];
865 summer -= chctx->skipFlagBits[i];
868 imc_adjust_bit_allocation(q, chctx, summer);
871 static int imc_decode_block(AVCodecContext *avctx, IMCContext *q, int ch)
873 int stream_format_code;
874 int imc_hdr, i, j, ret;
877 int counter, bitscount;
878 IMCChannel *chctx = q->chctx + ch;
881 /* Check the frame header */
882 imc_hdr = get_bits(&q->gb, 9);
883 if (imc_hdr & 0x18) {
884 av_log(avctx, AV_LOG_ERROR, "frame header check failed!\n");
885 av_log(avctx, AV_LOG_ERROR, "got %X.\n", imc_hdr);
886 return AVERROR_INVALIDDATA;
888 stream_format_code = get_bits(&q->gb, 3);
890 if (stream_format_code & 0x04)
891 chctx->decoder_reset = 1;
893 if (chctx->decoder_reset) {
894 for (i = 0; i < BANDS; i++)
895 chctx->old_floor[i] = 1.0;
896 for (i = 0; i < COEFFS; i++)
897 chctx->CWdecoded[i] = 0;
898 chctx->decoder_reset = 0;
901 flag = get_bits1(&q->gb);
902 if (stream_format_code & 0x1)
903 imc_read_level_coeffs_raw(q, stream_format_code, chctx->levlCoeffBuf);
905 imc_read_level_coeffs(q, stream_format_code, chctx->levlCoeffBuf);
907 if (stream_format_code & 0x1)
908 imc_decode_level_coefficients_raw(q, chctx->levlCoeffBuf,
909 chctx->flcoeffs1, chctx->flcoeffs2);
910 else if (stream_format_code & 0x4)
911 imc_decode_level_coefficients(q, chctx->levlCoeffBuf,
912 chctx->flcoeffs1, chctx->flcoeffs2);
914 imc_decode_level_coefficients2(q, chctx->levlCoeffBuf, chctx->old_floor,
915 chctx->flcoeffs1, chctx->flcoeffs2);
917 for(i=0; i<BANDS; i++) {
918 if(chctx->flcoeffs1[i] > INT_MAX) {
919 av_log(avctx, AV_LOG_ERROR, "scalefactor out of range\n");
920 return AVERROR_INVALIDDATA;
924 memcpy(chctx->old_floor, chctx->flcoeffs1, 32 * sizeof(float));
927 if (stream_format_code & 0x1) {
928 for (i = 0; i < BANDS; i++) {
929 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
930 chctx->bandFlagsBuf[i] = 0;
931 chctx->flcoeffs3[i] = chctx->flcoeffs2[i] * 2;
932 chctx->flcoeffs5[i] = 1.0;
935 for (i = 0; i < BANDS; i++) {
936 if (chctx->levlCoeffBuf[i] == 16) {
937 chctx->bandWidthT[i] = 0;
940 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
943 memset(chctx->bandFlagsBuf, 0, BANDS * sizeof(int));
944 for (i = 0; i < BANDS - 1; i++)
945 if (chctx->bandWidthT[i])
946 chctx->bandFlagsBuf[i] = get_bits1(&q->gb);
948 imc_calculate_coeffs(q, chctx->flcoeffs1, chctx->flcoeffs2,
949 chctx->bandWidthT, chctx->flcoeffs3,
954 /* first 4 bands will be assigned 5 bits per coefficient */
955 if (stream_format_code & 0x2) {
958 chctx->bitsBandT[0] = 5;
959 chctx->CWlengthT[0] = 5;
960 chctx->CWlengthT[1] = 5;
961 chctx->CWlengthT[2] = 5;
962 for (i = 1; i < 4; i++) {
963 if (stream_format_code & 0x1)
966 bits = (chctx->levlCoeffBuf[i] == 16) ? 0 : 5;
967 chctx->bitsBandT[i] = bits;
968 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
969 chctx->CWlengthT[j] = bits;
974 if (avctx->codec_id == AV_CODEC_ID_IAC) {
975 bitscount += !!chctx->bandWidthT[BANDS - 1];
976 if (!(stream_format_code & 0x2))
980 if ((ret = bit_allocation(q, chctx, stream_format_code,
981 512 - bitscount - get_bits_count(&q->gb),
983 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
984 chctx->decoder_reset = 1;
988 if (stream_format_code & 0x1) {
989 for (i = 0; i < BANDS; i++)
990 chctx->skipFlags[i] = 0;
992 imc_refine_bit_allocation(q, chctx);
995 for (i = 0; i < BANDS; i++) {
996 chctx->sumLenArr[i] = 0;
998 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
999 if (!chctx->skipFlags[j])
1000 chctx->sumLenArr[i] += chctx->CWlengthT[j];
1003 memset(chctx->codewords, 0, sizeof(chctx->codewords));
1005 imc_get_coeffs(avctx, q, chctx);
1007 if (inverse_quant_coeff(q, chctx, stream_format_code) < 0) {
1008 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
1009 chctx->decoder_reset = 1;
1010 return AVERROR_INVALIDDATA;
1013 memset(chctx->skipFlags, 0, sizeof(chctx->skipFlags));
1015 imc_imdct256(q, chctx, avctx->channels);
1020 static int imc_decode_frame(AVCodecContext *avctx, void *data,
1021 int *got_frame_ptr, AVPacket *avpkt)
1023 AVFrame *frame = data;
1024 const uint8_t *buf = avpkt->data;
1025 int buf_size = avpkt->size;
1028 IMCContext *q = avctx->priv_data;
1030 LOCAL_ALIGNED_16(uint16_t, buf16, [(IMC_BLOCK_SIZE + AV_INPUT_BUFFER_PADDING_SIZE) / 2]);
1034 if (buf_size < IMC_BLOCK_SIZE * avctx->channels) {
1035 av_log(avctx, AV_LOG_ERROR, "frame too small!\n");
1036 return AVERROR_INVALIDDATA;
1039 /* get output buffer */
1040 frame->nb_samples = COEFFS;
1041 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1044 for (i = 0; i < avctx->channels; i++) {
1045 q->out_samples = (float *)frame->extended_data[i];
1047 q->bdsp.bswap16_buf(buf16, (const uint16_t *) buf, IMC_BLOCK_SIZE / 2);
1049 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
1051 buf += IMC_BLOCK_SIZE;
1053 if ((ret = imc_decode_block(avctx, q, i)) < 0)
1057 if (avctx->channels == 2) {
1058 q->butterflies_float((float *)frame->extended_data[0],
1059 (float *)frame->extended_data[1], COEFFS);
1064 return IMC_BLOCK_SIZE * avctx->channels;
1067 static av_cold int imc_decode_close(AVCodecContext * avctx)
1069 IMCContext *q = avctx->priv_data;
1071 ff_fft_end(&q->fft);
1076 static av_cold void flush(AVCodecContext *avctx)
1078 IMCContext *q = avctx->priv_data;
1080 q->chctx[0].decoder_reset =
1081 q->chctx[1].decoder_reset = 1;
1084 #if CONFIG_IMC_DECODER
1085 AVCodec ff_imc_decoder = {
1087 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
1088 .type = AVMEDIA_TYPE_AUDIO,
1089 .id = AV_CODEC_ID_IMC,
1090 .priv_data_size = sizeof(IMCContext),
1091 .init = imc_decode_init,
1092 .close = imc_decode_close,
1093 .decode = imc_decode_frame,
1095 .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
1096 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1097 AV_SAMPLE_FMT_NONE },
1098 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
1101 #if CONFIG_IAC_DECODER
1102 AVCodec ff_iac_decoder = {
1104 .long_name = NULL_IF_CONFIG_SMALL("IAC (Indeo Audio Coder)"),
1105 .type = AVMEDIA_TYPE_AUDIO,
1106 .id = AV_CODEC_ID_IAC,
1107 .priv_data_size = sizeof(IMCContext),
1108 .init = imc_decode_init,
1109 .close = imc_decode_close,
1110 .decode = imc_decode_frame,
1112 .capabilities = AV_CODEC_CAP_DR1,
1113 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1114 AV_SAMPLE_FMT_NONE },
1115 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,