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.
42 #include "libavutil/audioconvert.h"
47 #define IMC_BLOCK_SIZE 64
48 #define IMC_FRAME_ID 0x21
52 typedef struct IMCChannel {
53 float old_floor[BANDS];
54 float flcoeffs1[BANDS];
55 float flcoeffs2[BANDS];
56 float flcoeffs3[BANDS];
57 float flcoeffs4[BANDS];
58 float flcoeffs5[BANDS];
59 float flcoeffs6[BANDS];
60 float CWdecoded[COEFFS];
62 int bandWidthT[BANDS]; ///< codewords per band
63 int bitsBandT[BANDS]; ///< how many bits per codeword in band
64 int CWlengthT[COEFFS]; ///< how many bits in each codeword
65 int levlCoeffBuf[BANDS];
66 int bandFlagsBuf[BANDS]; ///< flags for each band
67 int sumLenArr[BANDS]; ///< bits for all coeffs in band
68 int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not
69 int skipFlagBits[BANDS]; ///< bits used to code skip flags
70 int skipFlagCount[BANDS]; ///< skipped coeffients per band
71 int skipFlags[COEFFS]; ///< skip coefficient decoding or not
72 int codewords[COEFFS]; ///< raw codewords read from bitstream
74 float last_fft_im[COEFFS];
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];
99 DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS / 2];
102 int8_t cyclTab[32], cyclTab2[32];
103 float weights1[31], weights2[31];
106 static VLC huffman_vlc[4][4];
108 #define VLC_TABLES_SIZE 9512
110 static const int vlc_offsets[17] = {
111 0, 640, 1156, 1732, 2308, 2852, 3396, 3924,
112 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE
115 static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];
117 static inline double freq2bark(double freq)
119 return 3.5 * atan((freq / 7500.0) * (freq / 7500.0)) + 13.0 * atan(freq * 0.00076);
122 static av_cold void iac_generate_tabs(IMCContext *q, int sampling_rate)
124 double freqmin[32], freqmid[32], freqmax[32];
125 double scale = sampling_rate / (256.0 * 2.0 * 2.0);
126 double nyquist_freq = sampling_rate * 0.5;
127 double freq, bark, prev_bark = 0, tf, tb;
130 for (i = 0; i < 32; i++) {
131 freq = (band_tab[i] + band_tab[i + 1] - 1) * scale;
132 bark = freq2bark(freq);
135 tb = bark - prev_bark;
136 q->weights1[i - 1] = pow(10.0, -1.0 * tb);
137 q->weights2[i - 1] = pow(10.0, -2.7 * tb);
144 while (tf < nyquist_freq) {
156 if (tb <= bark - 0.5)
162 for (i = 0; i < 32; i++) {
164 for (j = 31; j > 0 && freq <= freqmid[j]; j--);
165 q->cyclTab[i] = j + 1;
168 for (j = 0; j < 32 && freq >= freqmid[j]; j++);
169 q->cyclTab2[i] = j - 1;
173 static av_cold int imc_decode_init(AVCodecContext *avctx)
176 IMCContext *q = avctx->priv_data;
179 if ((avctx->codec_id == CODEC_ID_IMC && avctx->channels != 1)
180 || (avctx->codec_id == CODEC_ID_IAC && avctx->channels > 2)) {
181 av_log_ask_for_sample(avctx, "Number of channels is not supported\n");
182 return AVERROR_PATCHWELCOME;
185 for (j = 0; j < avctx->channels; j++) {
186 q->chctx[j].decoder_reset = 1;
188 for (i = 0; i < BANDS; i++)
189 q->chctx[j].old_floor[i] = 1.0;
191 for (i = 0; i < COEFFS / 2; i++)
192 q->chctx[j].last_fft_im[i] = 0;
195 /* Build mdct window, a simple sine window normalized with sqrt(2) */
196 ff_sine_window_init(q->mdct_sine_window, COEFFS);
197 for (i = 0; i < COEFFS; i++)
198 q->mdct_sine_window[i] *= sqrt(2.0);
199 for (i = 0; i < COEFFS / 2; i++) {
200 q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI);
201 q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI);
203 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
204 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
207 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
208 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
210 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
211 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
215 /* Generate a square root table */
217 for (i = 0; i < 30; i++)
218 q->sqrt_tab[i] = sqrt(i);
220 /* initialize the VLC tables */
221 for (i = 0; i < 4 ; i++) {
222 for (j = 0; j < 4; j++) {
223 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]];
224 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];
225 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i],
226 imc_huffman_lens[i][j], 1, 1,
227 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC);
230 q->one_div_log2 = 1 / log(2);
232 if (avctx->codec_id == CODEC_ID_IAC) {
235 if (avctx->codec_id == 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_dsputil_init(&q->dsp, avctx);
249 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
250 avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
251 : AV_CH_LAYOUT_STEREO;
253 avcodec_get_frame_defaults(&q->frame);
254 avctx->coded_frame = &q->frame;
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_decode_level_coefficients(IMCContext *q, int *levlCoeffBuf,
343 float *flcoeffs1, float *flcoeffs2)
347 // maybe some frequency division thingy
349 flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
350 flcoeffs2[0] = log(flcoeffs1[0]) / log(2);
354 for (i = 1; i < BANDS; i++) {
355 level = levlCoeffBuf[i];
362 else if (level <= 24)
367 tmp *= imc_exp_tab[15 + level];
368 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
376 static void imc_decode_level_coefficients2(IMCContext *q, int *levlCoeffBuf,
377 float *old_floor, float *flcoeffs1,
381 /* FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
382 * and flcoeffs2 old scale factors
383 * might be incomplete due to a missing table that is in the binary code
385 for (i = 0; i < BANDS; i++) {
387 if (levlCoeffBuf[i] < 16) {
388 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
389 flcoeffs2[i] = (levlCoeffBuf[i] - 7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
391 flcoeffs1[i] = old_floor[i];
397 * Perform bit allocation depending on bits available
399 static int bit_allocation(IMCContext *q, IMCChannel *chctx,
400 int stream_format_code, int freebits, int flag)
403 const float limit = -1.e20;
412 float lowest = 1.e10;
418 for (i = 0; i < BANDS; i++)
419 highest = FFMAX(highest, chctx->flcoeffs1[i]);
421 for (i = 0; i < BANDS - 1; i++)
422 chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log(chctx->flcoeffs5[i]) / log(2);
423 chctx->flcoeffs4[BANDS - 1] = limit;
425 highest = highest * 0.25;
427 for (i = 0; i < BANDS; i++) {
429 if ((band_tab[i + 1] - band_tab[i]) == chctx->bandWidthT[i])
432 if ((band_tab[i + 1] - band_tab[i]) > chctx->bandWidthT[i])
435 if (((band_tab[i + 1] - band_tab[i]) / 2) >= chctx->bandWidthT[i])
439 return AVERROR_INVALIDDATA;
441 chctx->flcoeffs4[i] += xTab[(indx * 2 + (chctx->flcoeffs1[i] < highest)) * 2 + flag];
444 if (stream_format_code & 0x2) {
445 chctx->flcoeffs4[0] = limit;
446 chctx->flcoeffs4[1] = limit;
447 chctx->flcoeffs4[2] = limit;
448 chctx->flcoeffs4[3] = limit;
451 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS - 1; i++) {
452 iacc += chctx->bandWidthT[i];
453 summa += chctx->bandWidthT[i] * chctx->flcoeffs4[i];
455 chctx->bandWidthT[BANDS - 1] = 0;
456 summa = (summa * 0.5 - freebits) / iacc;
459 for (i = 0; i < BANDS / 2; i++) {
460 rres = summer - freebits;
461 if ((rres >= -8) && (rres <= 8))
467 for (j = (stream_format_code & 0x2) ? 4 : 0; j < BANDS; j++) {
468 cwlen = av_clipf(((chctx->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
470 chctx->bitsBandT[j] = cwlen;
471 summer += chctx->bandWidthT[j] * cwlen;
474 iacc += chctx->bandWidthT[j];
479 if (freebits < summer)
486 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
489 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS; i++) {
490 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
491 chctx->CWlengthT[j] = chctx->bitsBandT[i];
494 if (freebits > summer) {
495 for (i = 0; i < BANDS; i++) {
496 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
497 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
503 if (highest <= -1.e20)
509 for (i = 0; i < BANDS; i++) {
510 if (workT[i] > highest) {
516 if (highest > -1.e20) {
517 workT[found_indx] -= 2.0;
518 if (++chctx->bitsBandT[found_indx] == 6)
519 workT[found_indx] = -1.e20;
521 for (j = band_tab[found_indx]; j < band_tab[found_indx + 1] && (freebits > summer); j++) {
522 chctx->CWlengthT[j]++;
526 } while (freebits > summer);
528 if (freebits < summer) {
529 for (i = 0; i < BANDS; i++) {
530 workT[i] = chctx->bitsBandT[i] ? (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] + 1.585)
533 if (stream_format_code & 0x2) {
539 while (freebits < summer) {
542 for (i = 0; i < BANDS; i++) {
543 if (workT[i] < lowest) {
548 // if (lowest >= 1.e10)
550 workT[low_indx] = lowest + 2.0;
552 if (!--chctx->bitsBandT[low_indx])
553 workT[low_indx] = 1.e20;
555 for (j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++) {
556 if (chctx->CWlengthT[j] > 0) {
557 chctx->CWlengthT[j]--;
566 static void imc_get_skip_coeff(IMCContext *q, IMCChannel *chctx)
570 memset(chctx->skipFlagBits, 0, sizeof(chctx->skipFlagBits));
571 memset(chctx->skipFlagCount, 0, sizeof(chctx->skipFlagCount));
572 for (i = 0; i < BANDS; i++) {
573 if (!chctx->bandFlagsBuf[i] || !chctx->bandWidthT[i])
576 if (!chctx->skipFlagRaw[i]) {
577 chctx->skipFlagBits[i] = band_tab[i + 1] - band_tab[i];
579 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
580 chctx->skipFlags[j] = get_bits1(&q->gb);
581 if (chctx->skipFlags[j])
582 chctx->skipFlagCount[i]++;
585 for (j = band_tab[i]; j < band_tab[i + 1] - 1; j += 2) {
586 if (!get_bits1(&q->gb)) { // 0
587 chctx->skipFlagBits[i]++;
588 chctx->skipFlags[j] = 1;
589 chctx->skipFlags[j + 1] = 1;
590 chctx->skipFlagCount[i] += 2;
592 if (get_bits1(&q->gb)) { // 11
593 chctx->skipFlagBits[i] += 2;
594 chctx->skipFlags[j] = 0;
595 chctx->skipFlags[j + 1] = 1;
596 chctx->skipFlagCount[i]++;
598 chctx->skipFlagBits[i] += 3;
599 chctx->skipFlags[j + 1] = 0;
600 if (!get_bits1(&q->gb)) { // 100
601 chctx->skipFlags[j] = 1;
602 chctx->skipFlagCount[i]++;
604 chctx->skipFlags[j] = 0;
610 if (j < band_tab[i + 1]) {
611 chctx->skipFlagBits[i]++;
612 if ((chctx->skipFlags[j] = get_bits1(&q->gb)))
613 chctx->skipFlagCount[i]++;
620 * Increase highest' band coefficient sizes as some bits won't be used
622 static void imc_adjust_bit_allocation(IMCContext *q, IMCChannel *chctx,
631 for (i = 0; i < BANDS; i++) {
632 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
633 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
636 while (corrected < summer) {
637 if (highest <= -1.e20)
642 for (i = 0; i < BANDS; i++) {
643 if (workT[i] > highest) {
649 if (highest > -1.e20) {
650 workT[found_indx] -= 2.0;
651 if (++(chctx->bitsBandT[found_indx]) == 6)
652 workT[found_indx] = -1.e20;
654 for (j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
655 if (!chctx->skipFlags[j] && (chctx->CWlengthT[j] < 6)) {
656 chctx->CWlengthT[j]++;
664 static void imc_imdct256(IMCContext *q, IMCChannel *chctx, int channels)
668 float *dst1 = q->out_samples;
669 float *dst2 = q->out_samples + (COEFFS - 1) * channels;
672 for (i = 0; i < COEFFS / 2; i++) {
673 q->samples[i].re = -(q->pre_coef1[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
674 (q->pre_coef2[i] * chctx->CWdecoded[i * 2]);
675 q->samples[i].im = (q->pre_coef2[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
676 (q->pre_coef1[i] * chctx->CWdecoded[i * 2]);
680 q->fft.fft_permute(&q->fft, q->samples);
681 q->fft.fft_calc(&q->fft, q->samples);
683 /* postrotation, window and reorder */
684 for (i = 0; i < COEFFS / 2; i++) {
685 re = ( q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
686 im = (-q->samples[i].im * q->post_cos[i]) - ( q->samples[i].re * q->post_sin[i]);
687 *dst1 = (q->mdct_sine_window[COEFFS - 1 - i * 2] * chctx->last_fft_im[i])
688 + (q->mdct_sine_window[i * 2] * re);
689 *dst2 = (q->mdct_sine_window[i * 2] * chctx->last_fft_im[i])
690 - (q->mdct_sine_window[COEFFS - 1 - i * 2] * re);
691 dst1 += channels * 2;
692 dst2 -= channels * 2;
693 chctx->last_fft_im[i] = im;
697 static int inverse_quant_coeff(IMCContext *q, IMCChannel *chctx,
698 int stream_format_code)
701 int middle_value, cw_len, max_size;
702 const float *quantizer;
704 for (i = 0; i < BANDS; i++) {
705 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
706 chctx->CWdecoded[j] = 0;
707 cw_len = chctx->CWlengthT[j];
709 if (cw_len <= 0 || chctx->skipFlags[j])
712 max_size = 1 << cw_len;
713 middle_value = max_size >> 1;
715 if (chctx->codewords[j] >= max_size || chctx->codewords[j] < 0)
716 return AVERROR_INVALIDDATA;
719 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
720 if (chctx->codewords[j] >= middle_value)
721 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 8] * chctx->flcoeffs6[i];
723 chctx->CWdecoded[j] = -quantizer[max_size - chctx->codewords[j] - 8 - 1] * chctx->flcoeffs6[i];
725 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (chctx->bandFlagsBuf[i] << 1)];
726 if (chctx->codewords[j] >= middle_value)
727 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 1] * chctx->flcoeffs6[i];
729 chctx->CWdecoded[j] = -quantizer[max_size - 2 - chctx->codewords[j]] * chctx->flcoeffs6[i];
737 static int imc_get_coeffs(IMCContext *q, IMCChannel *chctx)
739 int i, j, cw_len, cw;
741 for (i = 0; i < BANDS; i++) {
742 if (!chctx->sumLenArr[i])
744 if (chctx->bandFlagsBuf[i] || chctx->bandWidthT[i]) {
745 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
746 cw_len = chctx->CWlengthT[j];
749 if (get_bits_count(&q->gb) + cw_len > 512) {
750 // av_log(NULL, 0, "Band %i coeff %i cw_len %i\n", i, j, cw_len);
751 return AVERROR_INVALIDDATA;
754 if (cw_len && (!chctx->bandFlagsBuf[i] || !chctx->skipFlags[j]))
755 cw = get_bits(&q->gb, cw_len);
757 chctx->codewords[j] = cw;
764 static int imc_decode_block(AVCodecContext *avctx, IMCContext *q, int ch)
766 int stream_format_code;
767 int imc_hdr, i, j, ret;
770 int counter, bitscount;
771 IMCChannel *chctx = q->chctx + ch;
774 /* Check the frame header */
775 imc_hdr = get_bits(&q->gb, 9);
776 if (imc_hdr & 0x18) {
777 av_log(avctx, AV_LOG_ERROR, "frame header check failed!\n");
778 av_log(avctx, AV_LOG_ERROR, "got %X.\n", imc_hdr);
779 return AVERROR_INVALIDDATA;
781 stream_format_code = get_bits(&q->gb, 3);
783 if (stream_format_code & 1) {
784 av_log_ask_for_sample(avctx, "Stream format %X is not supported\n",
786 return AVERROR_PATCHWELCOME;
789 // av_log(avctx, AV_LOG_DEBUG, "stream_format_code = %d\n", stream_format_code);
791 if (stream_format_code & 0x04)
792 chctx->decoder_reset = 1;
794 if (chctx->decoder_reset) {
795 memset(q->out_samples, 0, sizeof(q->out_samples));
796 for (i = 0; i < BANDS; i++)
797 chctx->old_floor[i] = 1.0;
798 for (i = 0; i < COEFFS; i++)
799 chctx->CWdecoded[i] = 0;
800 chctx->decoder_reset = 0;
803 flag = get_bits1(&q->gb);
804 imc_read_level_coeffs(q, stream_format_code, chctx->levlCoeffBuf);
806 if (stream_format_code & 0x4)
807 imc_decode_level_coefficients(q, chctx->levlCoeffBuf,
808 chctx->flcoeffs1, chctx->flcoeffs2);
810 imc_decode_level_coefficients2(q, chctx->levlCoeffBuf, chctx->old_floor,
811 chctx->flcoeffs1, chctx->flcoeffs2);
813 memcpy(chctx->old_floor, chctx->flcoeffs1, 32 * sizeof(float));
816 for (i = 0; i < BANDS; i++) {
817 if (chctx->levlCoeffBuf[i] == 16) {
818 chctx->bandWidthT[i] = 0;
821 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
823 memset(chctx->bandFlagsBuf, 0, BANDS * sizeof(int));
824 for (i = 0; i < BANDS - 1; i++) {
825 if (chctx->bandWidthT[i])
826 chctx->bandFlagsBuf[i] = get_bits1(&q->gb);
829 imc_calculate_coeffs(q, chctx->flcoeffs1, chctx->flcoeffs2, chctx->bandWidthT, chctx->flcoeffs3, chctx->flcoeffs5);
832 /* first 4 bands will be assigned 5 bits per coefficient */
833 if (stream_format_code & 0x2) {
836 chctx->bitsBandT[0] = 5;
837 chctx->CWlengthT[0] = 5;
838 chctx->CWlengthT[1] = 5;
839 chctx->CWlengthT[2] = 5;
840 for (i = 1; i < 4; i++) {
841 bits = (chctx->levlCoeffBuf[i] == 16) ? 0 : 5;
842 chctx->bitsBandT[i] = bits;
843 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
844 chctx->CWlengthT[j] = bits;
849 if (avctx->codec_id == CODEC_ID_IAC) {
850 bitscount += !!chctx->bandWidthT[BANDS - 1];
851 if (!(stream_format_code & 0x2))
855 if ((ret = bit_allocation(q, chctx, stream_format_code,
856 512 - bitscount - get_bits_count(&q->gb),
858 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
859 chctx->decoder_reset = 1;
863 for (i = 0; i < BANDS; i++) {
864 chctx->sumLenArr[i] = 0;
865 chctx->skipFlagRaw[i] = 0;
866 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
867 chctx->sumLenArr[i] += chctx->CWlengthT[j];
868 if (chctx->bandFlagsBuf[i])
869 if ((((band_tab[i + 1] - band_tab[i]) * 1.5) > chctx->sumLenArr[i]) && (chctx->sumLenArr[i] > 0))
870 chctx->skipFlagRaw[i] = 1;
873 imc_get_skip_coeff(q, chctx);
875 for (i = 0; i < BANDS; i++) {
876 chctx->flcoeffs6[i] = chctx->flcoeffs1[i];
877 /* band has flag set and at least one coded coefficient */
878 if (chctx->bandFlagsBuf[i] && (band_tab[i + 1] - band_tab[i]) != chctx->skipFlagCount[i]) {
879 chctx->flcoeffs6[i] *= q->sqrt_tab[ band_tab[i + 1] - band_tab[i]] /
880 q->sqrt_tab[(band_tab[i + 1] - band_tab[i] - chctx->skipFlagCount[i])];
884 /* calculate bits left, bits needed and adjust bit allocation */
887 for (i = 0; i < BANDS; i++) {
888 if (chctx->bandFlagsBuf[i]) {
889 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
890 if (chctx->skipFlags[j]) {
891 summer += chctx->CWlengthT[j];
892 chctx->CWlengthT[j] = 0;
895 bits += chctx->skipFlagBits[i];
896 summer -= chctx->skipFlagBits[i];
899 imc_adjust_bit_allocation(q, chctx, summer);
901 for (i = 0; i < BANDS; i++) {
902 chctx->sumLenArr[i] = 0;
904 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
905 if (!chctx->skipFlags[j])
906 chctx->sumLenArr[i] += chctx->CWlengthT[j];
909 memset(chctx->codewords, 0, sizeof(chctx->codewords));
911 if (imc_get_coeffs(q, chctx) < 0) {
912 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");
913 chctx->decoder_reset = 1;
914 return AVERROR_INVALIDDATA;
917 if (inverse_quant_coeff(q, chctx, stream_format_code) < 0) {
918 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
919 chctx->decoder_reset = 1;
920 return AVERROR_INVALIDDATA;
923 memset(chctx->skipFlags, 0, sizeof(chctx->skipFlags));
925 imc_imdct256(q, chctx, avctx->channels);
930 static int imc_decode_frame(AVCodecContext *avctx, void *data,
931 int *got_frame_ptr, AVPacket *avpkt)
933 const uint8_t *buf = avpkt->data;
934 int buf_size = avpkt->size;
937 IMCContext *q = avctx->priv_data;
939 LOCAL_ALIGNED_16(uint16_t, buf16, [IMC_BLOCK_SIZE / 2]);
941 if (buf_size < IMC_BLOCK_SIZE * avctx->channels) {
942 av_log(avctx, AV_LOG_ERROR, "frame too small!\n");
943 return AVERROR_INVALIDDATA;
946 /* get output buffer */
947 q->frame.nb_samples = COEFFS;
948 if ((ret = avctx->get_buffer(avctx, &q->frame)) < 0) {
949 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
953 for (i = 0; i < avctx->channels; i++) {
954 q->out_samples = (float*)q->frame.data[0] + i;
956 q->dsp.bswap16_buf(buf16, (const uint16_t*)buf, IMC_BLOCK_SIZE / 2);
958 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
960 buf += IMC_BLOCK_SIZE;
962 if ((ret = imc_decode_block(avctx, q, i)) < 0)
966 if (avctx->channels == 2) {
967 float *src = (float*)q->frame.data[0], t1, t2;
969 for (i = 0; i < COEFFS; i++) {
979 *(AVFrame *)data = q->frame;
981 return IMC_BLOCK_SIZE * avctx->channels;
985 static av_cold int imc_decode_close(AVCodecContext * avctx)
987 IMCContext *q = avctx->priv_data;
994 #if CONFIG_IMC_DECODER
995 AVCodec ff_imc_decoder = {
997 .type = AVMEDIA_TYPE_AUDIO,
999 .priv_data_size = sizeof(IMCContext),
1000 .init = imc_decode_init,
1001 .close = imc_decode_close,
1002 .decode = imc_decode_frame,
1003 .capabilities = CODEC_CAP_DR1,
1004 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
1007 #if CONFIG_IAC_DECODER
1008 AVCodec ff_iac_decoder = {
1010 .type = AVMEDIA_TYPE_AUDIO,
1012 .priv_data_size = sizeof(IMCContext),
1013 .init = imc_decode_init,
1014 .close = imc_decode_close,
1015 .decode = imc_decode_frame,
1016 .capabilities = CODEC_CAP_DR1,
1017 .long_name = NULL_IF_CONFIG_SMALL("IAC (Indeo Audio Coder)"),