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"
43 #include "libavutil/libm.h"
48 #define IMC_BLOCK_SIZE 64
49 #define IMC_FRAME_ID 0x21
53 typedef struct IMCChannel {
54 float old_floor[BANDS];
55 float flcoeffs1[BANDS];
56 float flcoeffs2[BANDS];
57 float flcoeffs3[BANDS];
58 float flcoeffs4[BANDS];
59 float flcoeffs5[BANDS];
60 float flcoeffs6[BANDS];
61 float CWdecoded[COEFFS];
63 int bandWidthT[BANDS]; ///< codewords per band
64 int bitsBandT[BANDS]; ///< how many bits per codeword in band
65 int CWlengthT[COEFFS]; ///< how many bits in each codeword
66 int levlCoeffBuf[BANDS];
67 int bandFlagsBuf[BANDS]; ///< flags for each band
68 int sumLenArr[BANDS]; ///< bits for all coeffs in band
69 int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not
70 int skipFlagBits[BANDS]; ///< bits used to code skip flags
71 int skipFlagCount[BANDS]; ///< skipped coeffients per band
72 int skipFlags[COEFFS]; ///< skip coefficient decoding or not
73 int codewords[COEFFS]; ///< raw codewords read from bitstream
75 float last_fft_im[COEFFS];
87 float mdct_sine_window[COEFFS];
88 float post_cos[COEFFS];
89 float post_sin[COEFFS];
90 float pre_coef1[COEFFS];
91 float pre_coef2[COEFFS];
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 == AV_CODEC_ID_IMC)
182 if (avctx->channels > 2) {
183 av_log_ask_for_sample(avctx, "Number of channels is not supported\n");
184 return AVERROR_PATCHWELCOME;
187 for (j = 0; j < avctx->channels; j++) {
188 q->chctx[j].decoder_reset = 1;
190 for (i = 0; i < BANDS; i++)
191 q->chctx[j].old_floor[i] = 1.0;
193 for (i = 0; i < COEFFS / 2; i++)
194 q->chctx[j].last_fft_im[i] = 0;
197 /* Build mdct window, a simple sine window normalized with sqrt(2) */
198 ff_sine_window_init(q->mdct_sine_window, COEFFS);
199 for (i = 0; i < COEFFS; i++)
200 q->mdct_sine_window[i] *= sqrt(2.0);
201 for (i = 0; i < COEFFS / 2; i++) {
202 q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI);
203 q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI);
205 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
206 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
209 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
210 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
212 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
213 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
217 /* Generate a square root table */
219 for (i = 0; i < 30; i++)
220 q->sqrt_tab[i] = sqrt(i);
222 /* initialize the VLC tables */
223 for (i = 0; i < 4 ; i++) {
224 for (j = 0; j < 4; j++) {
225 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]];
226 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];
227 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i],
228 imc_huffman_lens[i][j], 1, 1,
229 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC);
233 if (avctx->codec_id == AV_CODEC_ID_IAC) {
234 iac_generate_tabs(q, avctx->sample_rate);
236 memcpy(q->cyclTab, cyclTab, sizeof(cyclTab));
237 memcpy(q->cyclTab2, cyclTab2, sizeof(cyclTab2));
238 memcpy(q->weights1, imc_weights1, sizeof(imc_weights1));
239 memcpy(q->weights2, imc_weights2, sizeof(imc_weights2));
242 if ((ret = ff_fft_init(&q->fft, 7, 1))) {
243 av_log(avctx, AV_LOG_INFO, "FFT init failed\n");
246 ff_dsputil_init(&q->dsp, avctx);
247 avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
248 avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
249 : AV_CH_LAYOUT_STEREO;
251 avcodec_get_frame_defaults(&q->frame);
252 avctx->coded_frame = &q->frame;
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_decode_level_coefficients(IMCContext *q, int *levlCoeffBuf,
341 float *flcoeffs1, float *flcoeffs2)
345 // maybe some frequency division thingy
347 flcoeffs1[0] = 20000.0 / exp2 (levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
348 flcoeffs2[0] = log2f(flcoeffs1[0]);
352 for (i = 1; i < BANDS; i++) {
353 level = levlCoeffBuf[i];
360 else if (level <= 24)
365 tmp *= imc_exp_tab[15 + level];
366 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
374 static void imc_decode_level_coefficients2(IMCContext *q, int *levlCoeffBuf,
375 float *old_floor, float *flcoeffs1,
379 /* FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
380 * and flcoeffs2 old scale factors
381 * might be incomplete due to a missing table that is in the binary code
383 for (i = 0; i < BANDS; i++) {
385 if (levlCoeffBuf[i] < 16) {
386 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
387 flcoeffs2[i] = (levlCoeffBuf[i] - 7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
389 flcoeffs1[i] = old_floor[i];
395 * Perform bit allocation depending on bits available
397 static int bit_allocation(IMCContext *q, IMCChannel *chctx,
398 int stream_format_code, int freebits, int flag)
401 const float limit = -1.e20;
410 float lowest = 1.e10;
416 for (i = 0; i < BANDS; i++)
417 highest = FFMAX(highest, chctx->flcoeffs1[i]);
419 for (i = 0; i < BANDS - 1; i++)
420 chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log2f(chctx->flcoeffs5[i]);
421 chctx->flcoeffs4[BANDS - 1] = limit;
423 highest = highest * 0.25;
425 for (i = 0; i < BANDS; i++) {
427 if ((band_tab[i + 1] - band_tab[i]) == chctx->bandWidthT[i])
430 if ((band_tab[i + 1] - band_tab[i]) > chctx->bandWidthT[i])
433 if (((band_tab[i + 1] - band_tab[i]) / 2) >= chctx->bandWidthT[i])
437 return AVERROR_INVALIDDATA;
439 chctx->flcoeffs4[i] += xTab[(indx * 2 + (chctx->flcoeffs1[i] < highest)) * 2 + flag];
442 if (stream_format_code & 0x2) {
443 chctx->flcoeffs4[0] = limit;
444 chctx->flcoeffs4[1] = limit;
445 chctx->flcoeffs4[2] = limit;
446 chctx->flcoeffs4[3] = limit;
449 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS - 1; i++) {
450 iacc += chctx->bandWidthT[i];
451 summa += chctx->bandWidthT[i] * chctx->flcoeffs4[i];
453 chctx->bandWidthT[BANDS - 1] = 0;
454 summa = (summa * 0.5 - freebits) / iacc;
457 for (i = 0; i < BANDS / 2; i++) {
458 rres = summer - freebits;
459 if ((rres >= -8) && (rres <= 8))
465 for (j = (stream_format_code & 0x2) ? 4 : 0; j < BANDS; j++) {
466 cwlen = av_clipf(((chctx->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
468 chctx->bitsBandT[j] = cwlen;
469 summer += chctx->bandWidthT[j] * cwlen;
472 iacc += chctx->bandWidthT[j];
477 if (freebits < summer)
484 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
487 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS; i++) {
488 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
489 chctx->CWlengthT[j] = chctx->bitsBandT[i];
492 if (freebits > summer) {
493 for (i = 0; i < BANDS; i++) {
494 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
495 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
501 if (highest <= -1.e20)
507 for (i = 0; i < BANDS; i++) {
508 if (workT[i] > highest) {
514 if (highest > -1.e20) {
515 workT[found_indx] -= 2.0;
516 if (++chctx->bitsBandT[found_indx] == 6)
517 workT[found_indx] = -1.e20;
519 for (j = band_tab[found_indx]; j < band_tab[found_indx + 1] && (freebits > summer); j++) {
520 chctx->CWlengthT[j]++;
524 } while (freebits > summer);
526 if (freebits < summer) {
527 for (i = 0; i < BANDS; i++) {
528 workT[i] = chctx->bitsBandT[i] ? (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] + 1.585)
531 if (stream_format_code & 0x2) {
537 while (freebits < summer) {
540 for (i = 0; i < BANDS; i++) {
541 if (workT[i] < lowest) {
546 // if (lowest >= 1.e10)
548 workT[low_indx] = lowest + 2.0;
550 if (!--chctx->bitsBandT[low_indx])
551 workT[low_indx] = 1.e20;
553 for (j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++) {
554 if (chctx->CWlengthT[j] > 0) {
555 chctx->CWlengthT[j]--;
564 static void imc_get_skip_coeff(IMCContext *q, IMCChannel *chctx)
568 memset(chctx->skipFlagBits, 0, sizeof(chctx->skipFlagBits));
569 memset(chctx->skipFlagCount, 0, sizeof(chctx->skipFlagCount));
570 for (i = 0; i < BANDS; i++) {
571 if (!chctx->bandFlagsBuf[i] || !chctx->bandWidthT[i])
574 if (!chctx->skipFlagRaw[i]) {
575 chctx->skipFlagBits[i] = band_tab[i + 1] - band_tab[i];
577 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
578 chctx->skipFlags[j] = get_bits1(&q->gb);
579 if (chctx->skipFlags[j])
580 chctx->skipFlagCount[i]++;
583 for (j = band_tab[i]; j < band_tab[i + 1] - 1; j += 2) {
584 if (!get_bits1(&q->gb)) { // 0
585 chctx->skipFlagBits[i]++;
586 chctx->skipFlags[j] = 1;
587 chctx->skipFlags[j + 1] = 1;
588 chctx->skipFlagCount[i] += 2;
590 if (get_bits1(&q->gb)) { // 11
591 chctx->skipFlagBits[i] += 2;
592 chctx->skipFlags[j] = 0;
593 chctx->skipFlags[j + 1] = 1;
594 chctx->skipFlagCount[i]++;
596 chctx->skipFlagBits[i] += 3;
597 chctx->skipFlags[j + 1] = 0;
598 if (!get_bits1(&q->gb)) { // 100
599 chctx->skipFlags[j] = 1;
600 chctx->skipFlagCount[i]++;
602 chctx->skipFlags[j] = 0;
608 if (j < band_tab[i + 1]) {
609 chctx->skipFlagBits[i]++;
610 if ((chctx->skipFlags[j] = get_bits1(&q->gb)))
611 chctx->skipFlagCount[i]++;
618 * Increase highest' band coefficient sizes as some bits won't be used
620 static void imc_adjust_bit_allocation(IMCContext *q, IMCChannel *chctx,
629 for (i = 0; i < BANDS; i++) {
630 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
631 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
634 while (corrected < summer) {
635 if (highest <= -1.e20)
640 for (i = 0; i < BANDS; i++) {
641 if (workT[i] > highest) {
647 if (highest > -1.e20) {
648 workT[found_indx] -= 2.0;
649 if (++(chctx->bitsBandT[found_indx]) == 6)
650 workT[found_indx] = -1.e20;
652 for (j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
653 if (!chctx->skipFlags[j] && (chctx->CWlengthT[j] < 6)) {
654 chctx->CWlengthT[j]++;
662 static void imc_imdct256(IMCContext *q, IMCChannel *chctx, int channels)
666 float *dst1 = q->out_samples;
667 float *dst2 = q->out_samples + (COEFFS - 1);
670 for (i = 0; i < COEFFS / 2; i++) {
671 q->samples[i].re = -(q->pre_coef1[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
672 (q->pre_coef2[i] * chctx->CWdecoded[i * 2]);
673 q->samples[i].im = (q->pre_coef2[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
674 (q->pre_coef1[i] * chctx->CWdecoded[i * 2]);
678 q->fft.fft_permute(&q->fft, q->samples);
679 q->fft.fft_calc(&q->fft, q->samples);
681 /* postrotation, window and reorder */
682 for (i = 0; i < COEFFS / 2; i++) {
683 re = ( q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
684 im = (-q->samples[i].im * q->post_cos[i]) - ( q->samples[i].re * q->post_sin[i]);
685 *dst1 = (q->mdct_sine_window[COEFFS - 1 - i * 2] * chctx->last_fft_im[i])
686 + (q->mdct_sine_window[i * 2] * re);
687 *dst2 = (q->mdct_sine_window[i * 2] * chctx->last_fft_im[i])
688 - (q->mdct_sine_window[COEFFS - 1 - i * 2] * re);
691 chctx->last_fft_im[i] = im;
695 static int inverse_quant_coeff(IMCContext *q, IMCChannel *chctx,
696 int stream_format_code)
699 int middle_value, cw_len, max_size;
700 const float *quantizer;
702 for (i = 0; i < BANDS; i++) {
703 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
704 chctx->CWdecoded[j] = 0;
705 cw_len = chctx->CWlengthT[j];
707 if (cw_len <= 0 || chctx->skipFlags[j])
710 max_size = 1 << cw_len;
711 middle_value = max_size >> 1;
713 if (chctx->codewords[j] >= max_size || chctx->codewords[j] < 0)
714 return AVERROR_INVALIDDATA;
717 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
718 if (chctx->codewords[j] >= middle_value)
719 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 8] * chctx->flcoeffs6[i];
721 chctx->CWdecoded[j] = -quantizer[max_size - chctx->codewords[j] - 8 - 1] * chctx->flcoeffs6[i];
723 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (chctx->bandFlagsBuf[i] << 1)];
724 if (chctx->codewords[j] >= middle_value)
725 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 1] * chctx->flcoeffs6[i];
727 chctx->CWdecoded[j] = -quantizer[max_size - 2 - chctx->codewords[j]] * chctx->flcoeffs6[i];
735 static int imc_get_coeffs(IMCContext *q, IMCChannel *chctx)
737 int i, j, cw_len, cw;
739 for (i = 0; i < BANDS; i++) {
740 if (!chctx->sumLenArr[i])
742 if (chctx->bandFlagsBuf[i] || chctx->bandWidthT[i]) {
743 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
744 cw_len = chctx->CWlengthT[j];
747 if (get_bits_count(&q->gb) + cw_len > 512) {
748 av_dlog(NULL, "Band %i coeff %i cw_len %i\n", i, j, cw_len);
749 return AVERROR_INVALIDDATA;
752 if (cw_len && (!chctx->bandFlagsBuf[i] || !chctx->skipFlags[j]))
753 cw = get_bits(&q->gb, cw_len);
755 chctx->codewords[j] = cw;
762 static int imc_decode_block(AVCodecContext *avctx, IMCContext *q, int ch)
764 int stream_format_code;
765 int imc_hdr, i, j, ret;
768 int counter, bitscount;
769 IMCChannel *chctx = q->chctx + ch;
772 /* Check the frame header */
773 imc_hdr = get_bits(&q->gb, 9);
774 if (imc_hdr & 0x18) {
775 av_log(avctx, AV_LOG_ERROR, "frame header check failed!\n");
776 av_log(avctx, AV_LOG_ERROR, "got %X.\n", imc_hdr);
777 return AVERROR_INVALIDDATA;
779 stream_format_code = get_bits(&q->gb, 3);
781 if (stream_format_code & 1) {
782 av_log_ask_for_sample(avctx, "Stream format %X is not supported\n",
784 return AVERROR_PATCHWELCOME;
787 if (stream_format_code & 0x04)
788 chctx->decoder_reset = 1;
790 if (chctx->decoder_reset) {
791 for (i = 0; i < BANDS; i++)
792 chctx->old_floor[i] = 1.0;
793 for (i = 0; i < COEFFS; i++)
794 chctx->CWdecoded[i] = 0;
795 chctx->decoder_reset = 0;
798 flag = get_bits1(&q->gb);
799 imc_read_level_coeffs(q, stream_format_code, chctx->levlCoeffBuf);
801 if (stream_format_code & 0x4)
802 imc_decode_level_coefficients(q, chctx->levlCoeffBuf,
803 chctx->flcoeffs1, chctx->flcoeffs2);
805 imc_decode_level_coefficients2(q, chctx->levlCoeffBuf, chctx->old_floor,
806 chctx->flcoeffs1, chctx->flcoeffs2);
808 memcpy(chctx->old_floor, chctx->flcoeffs1, 32 * sizeof(float));
811 for (i = 0; i < BANDS; i++) {
812 if (chctx->levlCoeffBuf[i] == 16) {
813 chctx->bandWidthT[i] = 0;
816 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
818 memset(chctx->bandFlagsBuf, 0, BANDS * sizeof(int));
819 for (i = 0; i < BANDS - 1; i++) {
820 if (chctx->bandWidthT[i])
821 chctx->bandFlagsBuf[i] = get_bits1(&q->gb);
824 imc_calculate_coeffs(q, chctx->flcoeffs1, chctx->flcoeffs2, chctx->bandWidthT, chctx->flcoeffs3, chctx->flcoeffs5);
827 /* first 4 bands will be assigned 5 bits per coefficient */
828 if (stream_format_code & 0x2) {
831 chctx->bitsBandT[0] = 5;
832 chctx->CWlengthT[0] = 5;
833 chctx->CWlengthT[1] = 5;
834 chctx->CWlengthT[2] = 5;
835 for (i = 1; i < 4; i++) {
836 bits = (chctx->levlCoeffBuf[i] == 16) ? 0 : 5;
837 chctx->bitsBandT[i] = bits;
838 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
839 chctx->CWlengthT[j] = bits;
844 if (avctx->codec_id == AV_CODEC_ID_IAC) {
845 bitscount += !!chctx->bandWidthT[BANDS - 1];
846 if (!(stream_format_code & 0x2))
850 if ((ret = bit_allocation(q, chctx, stream_format_code,
851 512 - bitscount - get_bits_count(&q->gb),
853 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
854 chctx->decoder_reset = 1;
858 for (i = 0; i < BANDS; i++) {
859 chctx->sumLenArr[i] = 0;
860 chctx->skipFlagRaw[i] = 0;
861 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
862 chctx->sumLenArr[i] += chctx->CWlengthT[j];
863 if (chctx->bandFlagsBuf[i])
864 if ((((band_tab[i + 1] - band_tab[i]) * 1.5) > chctx->sumLenArr[i]) && (chctx->sumLenArr[i] > 0))
865 chctx->skipFlagRaw[i] = 1;
868 imc_get_skip_coeff(q, chctx);
870 for (i = 0; i < BANDS; i++) {
871 chctx->flcoeffs6[i] = chctx->flcoeffs1[i];
872 /* band has flag set and at least one coded coefficient */
873 if (chctx->bandFlagsBuf[i] && (band_tab[i + 1] - band_tab[i]) != chctx->skipFlagCount[i]) {
874 chctx->flcoeffs6[i] *= q->sqrt_tab[ band_tab[i + 1] - band_tab[i]] /
875 q->sqrt_tab[(band_tab[i + 1] - band_tab[i] - chctx->skipFlagCount[i])];
879 /* calculate bits left, bits needed and adjust bit allocation */
882 for (i = 0; i < BANDS; i++) {
883 if (chctx->bandFlagsBuf[i]) {
884 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
885 if (chctx->skipFlags[j]) {
886 summer += chctx->CWlengthT[j];
887 chctx->CWlengthT[j] = 0;
890 bits += chctx->skipFlagBits[i];
891 summer -= chctx->skipFlagBits[i];
894 imc_adjust_bit_allocation(q, chctx, summer);
896 for (i = 0; i < BANDS; i++) {
897 chctx->sumLenArr[i] = 0;
899 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
900 if (!chctx->skipFlags[j])
901 chctx->sumLenArr[i] += chctx->CWlengthT[j];
904 memset(chctx->codewords, 0, sizeof(chctx->codewords));
906 if (imc_get_coeffs(q, chctx) < 0) {
907 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");
908 chctx->decoder_reset = 1;
909 return AVERROR_INVALIDDATA;
912 if (inverse_quant_coeff(q, chctx, stream_format_code) < 0) {
913 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
914 chctx->decoder_reset = 1;
915 return AVERROR_INVALIDDATA;
918 memset(chctx->skipFlags, 0, sizeof(chctx->skipFlags));
920 imc_imdct256(q, chctx, avctx->channels);
925 static int imc_decode_frame(AVCodecContext *avctx, void *data,
926 int *got_frame_ptr, AVPacket *avpkt)
928 const uint8_t *buf = avpkt->data;
929 int buf_size = avpkt->size;
932 IMCContext *q = avctx->priv_data;
934 LOCAL_ALIGNED_16(uint16_t, buf16, [IMC_BLOCK_SIZE / 2]);
936 if (buf_size < IMC_BLOCK_SIZE * avctx->channels) {
937 av_log(avctx, AV_LOG_ERROR, "frame too small!\n");
938 return AVERROR_INVALIDDATA;
941 /* get output buffer */
942 q->frame.nb_samples = COEFFS;
943 if ((ret = avctx->get_buffer(avctx, &q->frame)) < 0) {
944 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
948 for (i = 0; i < avctx->channels; i++) {
949 q->out_samples = (float *)q->frame.extended_data[i];
951 q->dsp.bswap16_buf(buf16, (const uint16_t*)buf, IMC_BLOCK_SIZE / 2);
953 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
955 buf += IMC_BLOCK_SIZE;
957 if ((ret = imc_decode_block(avctx, q, i)) < 0)
961 if (avctx->channels == 2) {
962 q->dsp.butterflies_float((float *)q->frame.extended_data[0],
963 (float *)q->frame.extended_data[1], COEFFS);
967 *(AVFrame *)data = q->frame;
969 return IMC_BLOCK_SIZE * avctx->channels;
973 static av_cold int imc_decode_close(AVCodecContext * avctx)
975 IMCContext *q = avctx->priv_data;
982 #if CONFIG_IMC_DECODER
983 AVCodec ff_imc_decoder = {
985 .type = AVMEDIA_TYPE_AUDIO,
986 .id = AV_CODEC_ID_IMC,
987 .priv_data_size = sizeof(IMCContext),
988 .init = imc_decode_init,
989 .close = imc_decode_close,
990 .decode = imc_decode_frame,
991 .capabilities = CODEC_CAP_DR1,
992 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
993 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
994 AV_SAMPLE_FMT_NONE },
997 #if CONFIG_IAC_DECODER
998 AVCodec ff_iac_decoder = {
1000 .type = AVMEDIA_TYPE_AUDIO,
1001 .id = AV_CODEC_ID_IAC,
1002 .priv_data_size = sizeof(IMCContext),
1003 .init = imc_decode_init,
1004 .close = imc_decode_close,
1005 .decode = imc_decode_frame,
1006 .capabilities = CODEC_CAP_DR1,
1007 .long_name = NULL_IF_CONFIG_SMALL("IAC (Indeo Audio Coder)"),
1008 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1009 AV_SAMPLE_FMT_NONE },