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 && avctx->channels != 1)
180 || (avctx->codec_id == AV_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);
231 if (avctx->codec_id == AV_CODEC_ID_IAC) {
232 iac_generate_tabs(q, avctx->sample_rate);
234 memcpy(q->cyclTab, cyclTab, sizeof(cyclTab));
235 memcpy(q->cyclTab2, cyclTab2, sizeof(cyclTab2));
236 memcpy(q->weights1, imc_weights1, sizeof(imc_weights1));
237 memcpy(q->weights2, imc_weights2, sizeof(imc_weights2));
240 if ((ret = ff_fft_init(&q->fft, 7, 1))) {
241 av_log(avctx, AV_LOG_INFO, "FFT init failed\n");
244 ff_dsputil_init(&q->dsp, avctx);
245 avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
246 avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
247 : AV_CH_LAYOUT_STEREO;
249 avcodec_get_frame_defaults(&q->frame);
250 avctx->coded_frame = &q->frame;
255 static void imc_calculate_coeffs(IMCContext *q, float *flcoeffs1,
256 float *flcoeffs2, int *bandWidthT,
257 float *flcoeffs3, float *flcoeffs5)
262 float snr_limit = 1.e-30;
266 for (i = 0; i < BANDS; i++) {
267 flcoeffs5[i] = workT2[i] = 0.0;
269 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
270 flcoeffs3[i] = 2.0 * flcoeffs2[i];
273 flcoeffs3[i] = -30000.0;
275 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
276 if (workT3[i] <= snr_limit)
280 for (i = 0; i < BANDS; i++) {
281 for (cnt2 = i; cnt2 < q->cyclTab[i]; cnt2++)
282 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
283 workT2[cnt2 - 1] = workT2[cnt2 - 1] + workT3[i];
286 for (i = 1; i < BANDS; i++) {
287 accum = (workT2[i - 1] + accum) * q->weights1[i - 1];
288 flcoeffs5[i] += accum;
291 for (i = 0; i < BANDS; i++)
294 for (i = 0; i < BANDS; i++) {
295 for (cnt2 = i - 1; cnt2 > q->cyclTab2[i]; cnt2--)
296 flcoeffs5[cnt2] += workT3[i];
297 workT2[cnt2+1] += workT3[i];
302 for (i = BANDS-2; i >= 0; i--) {
303 accum = (workT2[i+1] + accum) * q->weights2[i];
304 flcoeffs5[i] += accum;
305 // there is missing code here, but it seems to never be triggered
310 static void imc_read_level_coeffs(IMCContext *q, int stream_format_code,
316 const uint8_t *cb_sel;
319 s = stream_format_code >> 1;
320 hufftab[0] = &huffman_vlc[s][0];
321 hufftab[1] = &huffman_vlc[s][1];
322 hufftab[2] = &huffman_vlc[s][2];
323 hufftab[3] = &huffman_vlc[s][3];
324 cb_sel = imc_cb_select[s];
326 if (stream_format_code & 4)
329 levlCoeffs[0] = get_bits(&q->gb, 7);
330 for (i = start; i < BANDS; i++) {
331 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table,
332 hufftab[cb_sel[i]]->bits, 2);
333 if (levlCoeffs[i] == 17)
334 levlCoeffs[i] += get_bits(&q->gb, 4);
338 static void imc_decode_level_coefficients(IMCContext *q, int *levlCoeffBuf,
339 float *flcoeffs1, float *flcoeffs2)
343 // maybe some frequency division thingy
345 flcoeffs1[0] = 20000.0 / exp2 (levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
346 flcoeffs2[0] = log2f(flcoeffs1[0]);
350 for (i = 1; i < BANDS; i++) {
351 level = levlCoeffBuf[i];
358 else if (level <= 24)
363 tmp *= imc_exp_tab[15 + level];
364 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
372 static void imc_decode_level_coefficients2(IMCContext *q, int *levlCoeffBuf,
373 float *old_floor, float *flcoeffs1,
377 /* FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
378 * and flcoeffs2 old scale factors
379 * might be incomplete due to a missing table that is in the binary code
381 for (i = 0; i < BANDS; i++) {
383 if (levlCoeffBuf[i] < 16) {
384 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
385 flcoeffs2[i] = (levlCoeffBuf[i] - 7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
387 flcoeffs1[i] = old_floor[i];
393 * Perform bit allocation depending on bits available
395 static int bit_allocation(IMCContext *q, IMCChannel *chctx,
396 int stream_format_code, int freebits, int flag)
399 const float limit = -1.e20;
408 float lowest = 1.e10;
414 for (i = 0; i < BANDS; i++)
415 highest = FFMAX(highest, chctx->flcoeffs1[i]);
417 for (i = 0; i < BANDS - 1; i++)
418 chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log2f(chctx->flcoeffs5[i]);
419 chctx->flcoeffs4[BANDS - 1] = limit;
421 highest = highest * 0.25;
423 for (i = 0; i < BANDS; i++) {
425 if ((band_tab[i + 1] - band_tab[i]) == chctx->bandWidthT[i])
428 if ((band_tab[i + 1] - band_tab[i]) > chctx->bandWidthT[i])
431 if (((band_tab[i + 1] - band_tab[i]) / 2) >= chctx->bandWidthT[i])
435 return AVERROR_INVALIDDATA;
437 chctx->flcoeffs4[i] += xTab[(indx * 2 + (chctx->flcoeffs1[i] < highest)) * 2 + flag];
440 if (stream_format_code & 0x2) {
441 chctx->flcoeffs4[0] = limit;
442 chctx->flcoeffs4[1] = limit;
443 chctx->flcoeffs4[2] = limit;
444 chctx->flcoeffs4[3] = limit;
447 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS - 1; i++) {
448 iacc += chctx->bandWidthT[i];
449 summa += chctx->bandWidthT[i] * chctx->flcoeffs4[i];
451 chctx->bandWidthT[BANDS - 1] = 0;
452 summa = (summa * 0.5 - freebits) / iacc;
455 for (i = 0; i < BANDS / 2; i++) {
456 rres = summer - freebits;
457 if ((rres >= -8) && (rres <= 8))
463 for (j = (stream_format_code & 0x2) ? 4 : 0; j < BANDS; j++) {
464 cwlen = av_clipf(((chctx->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
466 chctx->bitsBandT[j] = cwlen;
467 summer += chctx->bandWidthT[j] * cwlen;
470 iacc += chctx->bandWidthT[j];
475 if (freebits < summer)
482 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
485 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS; i++) {
486 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
487 chctx->CWlengthT[j] = chctx->bitsBandT[i];
490 if (freebits > summer) {
491 for (i = 0; i < BANDS; i++) {
492 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
493 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
499 if (highest <= -1.e20)
505 for (i = 0; i < BANDS; i++) {
506 if (workT[i] > highest) {
512 if (highest > -1.e20) {
513 workT[found_indx] -= 2.0;
514 if (++chctx->bitsBandT[found_indx] == 6)
515 workT[found_indx] = -1.e20;
517 for (j = band_tab[found_indx]; j < band_tab[found_indx + 1] && (freebits > summer); j++) {
518 chctx->CWlengthT[j]++;
522 } while (freebits > summer);
524 if (freebits < summer) {
525 for (i = 0; i < BANDS; i++) {
526 workT[i] = chctx->bitsBandT[i] ? (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] + 1.585)
529 if (stream_format_code & 0x2) {
535 while (freebits < summer) {
538 for (i = 0; i < BANDS; i++) {
539 if (workT[i] < lowest) {
544 // if (lowest >= 1.e10)
546 workT[low_indx] = lowest + 2.0;
548 if (!--chctx->bitsBandT[low_indx])
549 workT[low_indx] = 1.e20;
551 for (j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++) {
552 if (chctx->CWlengthT[j] > 0) {
553 chctx->CWlengthT[j]--;
562 static void imc_get_skip_coeff(IMCContext *q, IMCChannel *chctx)
566 memset(chctx->skipFlagBits, 0, sizeof(chctx->skipFlagBits));
567 memset(chctx->skipFlagCount, 0, sizeof(chctx->skipFlagCount));
568 for (i = 0; i < BANDS; i++) {
569 if (!chctx->bandFlagsBuf[i] || !chctx->bandWidthT[i])
572 if (!chctx->skipFlagRaw[i]) {
573 chctx->skipFlagBits[i] = band_tab[i + 1] - band_tab[i];
575 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
576 chctx->skipFlags[j] = get_bits1(&q->gb);
577 if (chctx->skipFlags[j])
578 chctx->skipFlagCount[i]++;
581 for (j = band_tab[i]; j < band_tab[i + 1] - 1; j += 2) {
582 if (!get_bits1(&q->gb)) { // 0
583 chctx->skipFlagBits[i]++;
584 chctx->skipFlags[j] = 1;
585 chctx->skipFlags[j + 1] = 1;
586 chctx->skipFlagCount[i] += 2;
588 if (get_bits1(&q->gb)) { // 11
589 chctx->skipFlagBits[i] += 2;
590 chctx->skipFlags[j] = 0;
591 chctx->skipFlags[j + 1] = 1;
592 chctx->skipFlagCount[i]++;
594 chctx->skipFlagBits[i] += 3;
595 chctx->skipFlags[j + 1] = 0;
596 if (!get_bits1(&q->gb)) { // 100
597 chctx->skipFlags[j] = 1;
598 chctx->skipFlagCount[i]++;
600 chctx->skipFlags[j] = 0;
606 if (j < band_tab[i + 1]) {
607 chctx->skipFlagBits[i]++;
608 if ((chctx->skipFlags[j] = get_bits1(&q->gb)))
609 chctx->skipFlagCount[i]++;
616 * Increase highest' band coefficient sizes as some bits won't be used
618 static void imc_adjust_bit_allocation(IMCContext *q, IMCChannel *chctx,
627 for (i = 0; i < BANDS; i++) {
628 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
629 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
632 while (corrected < summer) {
633 if (highest <= -1.e20)
638 for (i = 0; i < BANDS; i++) {
639 if (workT[i] > highest) {
645 if (highest > -1.e20) {
646 workT[found_indx] -= 2.0;
647 if (++(chctx->bitsBandT[found_indx]) == 6)
648 workT[found_indx] = -1.e20;
650 for (j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
651 if (!chctx->skipFlags[j] && (chctx->CWlengthT[j] < 6)) {
652 chctx->CWlengthT[j]++;
660 static void imc_imdct256(IMCContext *q, IMCChannel *chctx, int channels)
664 float *dst1 = q->out_samples;
665 float *dst2 = q->out_samples + (COEFFS - 1);
668 for (i = 0; i < COEFFS / 2; i++) {
669 q->samples[i].re = -(q->pre_coef1[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
670 (q->pre_coef2[i] * chctx->CWdecoded[i * 2]);
671 q->samples[i].im = (q->pre_coef2[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
672 (q->pre_coef1[i] * chctx->CWdecoded[i * 2]);
676 q->fft.fft_permute(&q->fft, q->samples);
677 q->fft.fft_calc(&q->fft, q->samples);
679 /* postrotation, window and reorder */
680 for (i = 0; i < COEFFS / 2; i++) {
681 re = ( q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
682 im = (-q->samples[i].im * q->post_cos[i]) - ( q->samples[i].re * q->post_sin[i]);
683 *dst1 = (q->mdct_sine_window[COEFFS - 1 - i * 2] * chctx->last_fft_im[i])
684 + (q->mdct_sine_window[i * 2] * re);
685 *dst2 = (q->mdct_sine_window[i * 2] * chctx->last_fft_im[i])
686 - (q->mdct_sine_window[COEFFS - 1 - i * 2] * re);
689 chctx->last_fft_im[i] = im;
693 static int inverse_quant_coeff(IMCContext *q, IMCChannel *chctx,
694 int stream_format_code)
697 int middle_value, cw_len, max_size;
698 const float *quantizer;
700 for (i = 0; i < BANDS; i++) {
701 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
702 chctx->CWdecoded[j] = 0;
703 cw_len = chctx->CWlengthT[j];
705 if (cw_len <= 0 || chctx->skipFlags[j])
708 max_size = 1 << cw_len;
709 middle_value = max_size >> 1;
711 if (chctx->codewords[j] >= max_size || chctx->codewords[j] < 0)
712 return AVERROR_INVALIDDATA;
715 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
716 if (chctx->codewords[j] >= middle_value)
717 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 8] * chctx->flcoeffs6[i];
719 chctx->CWdecoded[j] = -quantizer[max_size - chctx->codewords[j] - 8 - 1] * chctx->flcoeffs6[i];
721 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (chctx->bandFlagsBuf[i] << 1)];
722 if (chctx->codewords[j] >= middle_value)
723 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 1] * chctx->flcoeffs6[i];
725 chctx->CWdecoded[j] = -quantizer[max_size - 2 - chctx->codewords[j]] * chctx->flcoeffs6[i];
733 static int imc_get_coeffs(IMCContext *q, IMCChannel *chctx)
735 int i, j, cw_len, cw;
737 for (i = 0; i < BANDS; i++) {
738 if (!chctx->sumLenArr[i])
740 if (chctx->bandFlagsBuf[i] || chctx->bandWidthT[i]) {
741 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
742 cw_len = chctx->CWlengthT[j];
745 if (get_bits_count(&q->gb) + cw_len > 512) {
746 av_dlog(NULL, "Band %i coeff %i cw_len %i\n", i, j, cw_len);
747 return AVERROR_INVALIDDATA;
750 if (cw_len && (!chctx->bandFlagsBuf[i] || !chctx->skipFlags[j]))
751 cw = get_bits(&q->gb, cw_len);
753 chctx->codewords[j] = cw;
760 static int imc_decode_block(AVCodecContext *avctx, IMCContext *q, int ch)
762 int stream_format_code;
763 int imc_hdr, i, j, ret;
766 int counter, bitscount;
767 IMCChannel *chctx = q->chctx + ch;
770 /* Check the frame header */
771 imc_hdr = get_bits(&q->gb, 9);
772 if (imc_hdr & 0x18) {
773 av_log(avctx, AV_LOG_ERROR, "frame header check failed!\n");
774 av_log(avctx, AV_LOG_ERROR, "got %X.\n", imc_hdr);
775 return AVERROR_INVALIDDATA;
777 stream_format_code = get_bits(&q->gb, 3);
779 if (stream_format_code & 1) {
780 av_log_ask_for_sample(avctx, "Stream format %X is not supported\n",
782 return AVERROR_PATCHWELCOME;
785 if (stream_format_code & 0x04)
786 chctx->decoder_reset = 1;
788 if (chctx->decoder_reset) {
789 for (i = 0; i < BANDS; i++)
790 chctx->old_floor[i] = 1.0;
791 for (i = 0; i < COEFFS; i++)
792 chctx->CWdecoded[i] = 0;
793 chctx->decoder_reset = 0;
796 flag = get_bits1(&q->gb);
797 imc_read_level_coeffs(q, stream_format_code, chctx->levlCoeffBuf);
799 if (stream_format_code & 0x4)
800 imc_decode_level_coefficients(q, chctx->levlCoeffBuf,
801 chctx->flcoeffs1, chctx->flcoeffs2);
803 imc_decode_level_coefficients2(q, chctx->levlCoeffBuf, chctx->old_floor,
804 chctx->flcoeffs1, chctx->flcoeffs2);
806 memcpy(chctx->old_floor, chctx->flcoeffs1, 32 * sizeof(float));
809 for (i = 0; i < BANDS; i++) {
810 if (chctx->levlCoeffBuf[i] == 16) {
811 chctx->bandWidthT[i] = 0;
814 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
816 memset(chctx->bandFlagsBuf, 0, BANDS * sizeof(int));
817 for (i = 0; i < BANDS - 1; i++) {
818 if (chctx->bandWidthT[i])
819 chctx->bandFlagsBuf[i] = get_bits1(&q->gb);
822 imc_calculate_coeffs(q, chctx->flcoeffs1, chctx->flcoeffs2, chctx->bandWidthT, chctx->flcoeffs3, chctx->flcoeffs5);
825 /* first 4 bands will be assigned 5 bits per coefficient */
826 if (stream_format_code & 0x2) {
829 chctx->bitsBandT[0] = 5;
830 chctx->CWlengthT[0] = 5;
831 chctx->CWlengthT[1] = 5;
832 chctx->CWlengthT[2] = 5;
833 for (i = 1; i < 4; i++) {
834 bits = (chctx->levlCoeffBuf[i] == 16) ? 0 : 5;
835 chctx->bitsBandT[i] = bits;
836 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
837 chctx->CWlengthT[j] = bits;
842 if (avctx->codec_id == AV_CODEC_ID_IAC) {
843 bitscount += !!chctx->bandWidthT[BANDS - 1];
844 if (!(stream_format_code & 0x2))
848 if ((ret = bit_allocation(q, chctx, stream_format_code,
849 512 - bitscount - get_bits_count(&q->gb),
851 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
852 chctx->decoder_reset = 1;
856 for (i = 0; i < BANDS; i++) {
857 chctx->sumLenArr[i] = 0;
858 chctx->skipFlagRaw[i] = 0;
859 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
860 chctx->sumLenArr[i] += chctx->CWlengthT[j];
861 if (chctx->bandFlagsBuf[i])
862 if ((((band_tab[i + 1] - band_tab[i]) * 1.5) > chctx->sumLenArr[i]) && (chctx->sumLenArr[i] > 0))
863 chctx->skipFlagRaw[i] = 1;
866 imc_get_skip_coeff(q, chctx);
868 for (i = 0; i < BANDS; i++) {
869 chctx->flcoeffs6[i] = chctx->flcoeffs1[i];
870 /* band has flag set and at least one coded coefficient */
871 if (chctx->bandFlagsBuf[i] && (band_tab[i + 1] - band_tab[i]) != chctx->skipFlagCount[i]) {
872 chctx->flcoeffs6[i] *= q->sqrt_tab[ band_tab[i + 1] - band_tab[i]] /
873 q->sqrt_tab[(band_tab[i + 1] - band_tab[i] - chctx->skipFlagCount[i])];
877 /* calculate bits left, bits needed and adjust bit allocation */
880 for (i = 0; i < BANDS; i++) {
881 if (chctx->bandFlagsBuf[i]) {
882 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
883 if (chctx->skipFlags[j]) {
884 summer += chctx->CWlengthT[j];
885 chctx->CWlengthT[j] = 0;
888 bits += chctx->skipFlagBits[i];
889 summer -= chctx->skipFlagBits[i];
892 imc_adjust_bit_allocation(q, chctx, summer);
894 for (i = 0; i < BANDS; i++) {
895 chctx->sumLenArr[i] = 0;
897 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
898 if (!chctx->skipFlags[j])
899 chctx->sumLenArr[i] += chctx->CWlengthT[j];
902 memset(chctx->codewords, 0, sizeof(chctx->codewords));
904 if (imc_get_coeffs(q, chctx) < 0) {
905 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");
906 chctx->decoder_reset = 1;
907 return AVERROR_INVALIDDATA;
910 if (inverse_quant_coeff(q, chctx, stream_format_code) < 0) {
911 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
912 chctx->decoder_reset = 1;
913 return AVERROR_INVALIDDATA;
916 memset(chctx->skipFlags, 0, sizeof(chctx->skipFlags));
918 imc_imdct256(q, chctx, avctx->channels);
923 static int imc_decode_frame(AVCodecContext *avctx, void *data,
924 int *got_frame_ptr, AVPacket *avpkt)
926 const uint8_t *buf = avpkt->data;
927 int buf_size = avpkt->size;
930 IMCContext *q = avctx->priv_data;
932 LOCAL_ALIGNED_16(uint16_t, buf16, [IMC_BLOCK_SIZE / 2]);
934 if (buf_size < IMC_BLOCK_SIZE * avctx->channels) {
935 av_log(avctx, AV_LOG_ERROR, "frame too small!\n");
936 return AVERROR_INVALIDDATA;
939 /* get output buffer */
940 q->frame.nb_samples = COEFFS;
941 if ((ret = avctx->get_buffer(avctx, &q->frame)) < 0) {
942 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
946 for (i = 0; i < avctx->channels; i++) {
947 q->out_samples = (float *)q->frame.extended_data[i];
949 q->dsp.bswap16_buf(buf16, (const uint16_t*)buf, IMC_BLOCK_SIZE / 2);
951 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
953 buf += IMC_BLOCK_SIZE;
955 if ((ret = imc_decode_block(avctx, q, i)) < 0)
959 if (avctx->channels == 2) {
960 q->dsp.butterflies_float((float *)q->frame.extended_data[0],
961 (float *)q->frame.extended_data[1], COEFFS);
965 *(AVFrame *)data = q->frame;
967 return IMC_BLOCK_SIZE * avctx->channels;
971 static av_cold int imc_decode_close(AVCodecContext * avctx)
973 IMCContext *q = avctx->priv_data;
980 #if CONFIG_IMC_DECODER
981 AVCodec ff_imc_decoder = {
983 .type = AVMEDIA_TYPE_AUDIO,
984 .id = AV_CODEC_ID_IMC,
985 .priv_data_size = sizeof(IMCContext),
986 .init = imc_decode_init,
987 .close = imc_decode_close,
988 .decode = imc_decode_frame,
989 .capabilities = CODEC_CAP_DR1,
990 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
991 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
992 AV_SAMPLE_FMT_NONE },
995 #if CONFIG_IAC_DECODER
996 AVCodec ff_iac_decoder = {
998 .type = AVMEDIA_TYPE_AUDIO,
999 .id = AV_CODEC_ID_IAC,
1000 .priv_data_size = sizeof(IMCContext),
1001 .init = imc_decode_init,
1002 .close = imc_decode_close,
1003 .decode = imc_decode_frame,
1004 .capabilities = CODEC_CAP_DR1,
1005 .long_name = NULL_IF_CONFIG_SMALL("IAC (Indeo Audio Coder)"),
1006 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1007 AV_SAMPLE_FMT_NONE },