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.
38 #include "libavutil/channel_layout.h"
39 #include "libavutil/float_dsp.h"
40 #include "libavutil/internal.h"
41 #include "libavutil/libm.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 coeffients 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];
90 float mdct_sine_window[COEFFS];
91 float post_cos[COEFFS];
92 float post_sin[COEFFS];
93 float pre_coef1[COEFFS];
94 float pre_coef2[COEFFS];
101 AVFloatDSPContext fdsp;
103 DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS / 2];
106 int8_t cyclTab[32], cyclTab2[32];
107 float weights1[31], weights2[31];
110 static VLC huffman_vlc[4][4];
112 #define VLC_TABLES_SIZE 9512
114 static const int vlc_offsets[17] = {
115 0, 640, 1156, 1732, 2308, 2852, 3396, 3924,
116 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE
119 static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];
121 static inline double freq2bark(double freq)
123 return 3.5 * atan((freq / 7500.0) * (freq / 7500.0)) + 13.0 * atan(freq * 0.00076);
126 static av_cold void iac_generate_tabs(IMCContext *q, int sampling_rate)
128 double freqmin[32], freqmid[32], freqmax[32];
129 double scale = sampling_rate / (256.0 * 2.0 * 2.0);
130 double nyquist_freq = sampling_rate * 0.5;
131 double freq, bark, prev_bark = 0, tf, tb;
134 for (i = 0; i < 32; i++) {
135 freq = (band_tab[i] + band_tab[i + 1] - 1) * scale;
136 bark = freq2bark(freq);
139 tb = bark - prev_bark;
140 q->weights1[i - 1] = pow(10.0, -1.0 * tb);
141 q->weights2[i - 1] = pow(10.0, -2.7 * tb);
148 while (tf < nyquist_freq) {
160 if (tb <= bark - 0.5)
166 for (i = 0; i < 32; i++) {
168 for (j = 31; j > 0 && freq <= freqmid[j]; j--);
169 q->cyclTab[i] = j + 1;
172 for (j = 0; j < 32 && freq >= freqmid[j]; j++);
173 q->cyclTab2[i] = j - 1;
177 static av_cold int imc_decode_init(AVCodecContext *avctx)
180 IMCContext *q = avctx->priv_data;
183 if (avctx->codec_id == AV_CODEC_ID_IMC)
186 if (avctx->channels > 2) {
187 av_log_ask_for_sample(avctx, "Number of channels is not supported\n");
188 return AVERROR_PATCHWELCOME;
191 for (j = 0; j < avctx->channels; j++) {
192 q->chctx[j].decoder_reset = 1;
194 for (i = 0; i < BANDS; i++)
195 q->chctx[j].old_floor[i] = 1.0;
197 for (i = 0; i < COEFFS / 2; i++)
198 q->chctx[j].last_fft_im[i] = 0;
201 /* Build mdct window, a simple sine window normalized with sqrt(2) */
202 ff_sine_window_init(q->mdct_sine_window, COEFFS);
203 for (i = 0; i < COEFFS; i++)
204 q->mdct_sine_window[i] *= sqrt(2.0);
205 for (i = 0; i < COEFFS / 2; i++) {
206 q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI);
207 q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI);
209 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
210 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
213 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
214 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
216 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
217 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
221 /* Generate a square root table */
223 for (i = 0; i < 30; i++)
224 q->sqrt_tab[i] = sqrt(i);
226 /* initialize the VLC tables */
227 for (i = 0; i < 4 ; i++) {
228 for (j = 0; j < 4; j++) {
229 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]];
230 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];
231 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i],
232 imc_huffman_lens[i][j], 1, 1,
233 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC);
237 if (avctx->codec_id == AV_CODEC_ID_IAC) {
238 iac_generate_tabs(q, avctx->sample_rate);
240 memcpy(q->cyclTab, cyclTab, sizeof(cyclTab));
241 memcpy(q->cyclTab2, cyclTab2, sizeof(cyclTab2));
242 memcpy(q->weights1, imc_weights1, sizeof(imc_weights1));
243 memcpy(q->weights2, imc_weights2, sizeof(imc_weights2));
246 if ((ret = ff_fft_init(&q->fft, 7, 1))) {
247 av_log(avctx, AV_LOG_INFO, "FFT init failed\n");
250 ff_dsputil_init(&q->dsp, avctx);
251 avpriv_float_dsp_init(&q->fdsp, avctx->flags & CODEC_FLAG_BITEXACT);
252 avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
253 avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
254 : AV_CH_LAYOUT_STEREO;
256 avcodec_get_frame_defaults(&q->frame);
257 avctx->coded_frame = &q->frame;
262 static void imc_calculate_coeffs(IMCContext *q, float *flcoeffs1,
263 float *flcoeffs2, int *bandWidthT,
264 float *flcoeffs3, float *flcoeffs5)
269 float snr_limit = 1.e-30;
273 for (i = 0; i < BANDS; i++) {
274 flcoeffs5[i] = workT2[i] = 0.0;
276 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
277 flcoeffs3[i] = 2.0 * flcoeffs2[i];
280 flcoeffs3[i] = -30000.0;
282 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
283 if (workT3[i] <= snr_limit)
287 for (i = 0; i < BANDS; i++) {
288 for (cnt2 = i; cnt2 < q->cyclTab[i]; cnt2++)
289 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
290 workT2[cnt2 - 1] = workT2[cnt2 - 1] + workT3[i];
293 for (i = 1; i < BANDS; i++) {
294 accum = (workT2[i - 1] + accum) * q->weights1[i - 1];
295 flcoeffs5[i] += accum;
298 for (i = 0; i < BANDS; i++)
301 for (i = 0; i < BANDS; i++) {
302 for (cnt2 = i - 1; cnt2 > q->cyclTab2[i]; cnt2--)
303 flcoeffs5[cnt2] += workT3[i];
304 workT2[cnt2+1] += workT3[i];
309 for (i = BANDS-2; i >= 0; i--) {
310 accum = (workT2[i+1] + accum) * q->weights2[i];
311 flcoeffs5[i] += accum;
312 // there is missing code here, but it seems to never be triggered
317 static void imc_read_level_coeffs(IMCContext *q, int stream_format_code,
323 const uint8_t *cb_sel;
326 s = stream_format_code >> 1;
327 hufftab[0] = &huffman_vlc[s][0];
328 hufftab[1] = &huffman_vlc[s][1];
329 hufftab[2] = &huffman_vlc[s][2];
330 hufftab[3] = &huffman_vlc[s][3];
331 cb_sel = imc_cb_select[s];
333 if (stream_format_code & 4)
336 levlCoeffs[0] = get_bits(&q->gb, 7);
337 for (i = start; i < BANDS; i++) {
338 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table,
339 hufftab[cb_sel[i]]->bits, 2);
340 if (levlCoeffs[i] == 17)
341 levlCoeffs[i] += get_bits(&q->gb, 4);
345 static void imc_decode_level_coefficients(IMCContext *q, int *levlCoeffBuf,
346 float *flcoeffs1, float *flcoeffs2)
350 // maybe some frequency division thingy
352 flcoeffs1[0] = 20000.0 / exp2 (levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
353 flcoeffs2[0] = log2f(flcoeffs1[0]);
357 for (i = 1; i < BANDS; i++) {
358 level = levlCoeffBuf[i];
365 else if (level <= 24)
370 tmp *= imc_exp_tab[15 + level];
371 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
379 static void imc_decode_level_coefficients2(IMCContext *q, int *levlCoeffBuf,
380 float *old_floor, float *flcoeffs1,
384 /* FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
385 * and flcoeffs2 old scale factors
386 * might be incomplete due to a missing table that is in the binary code
388 for (i = 0; i < BANDS; i++) {
390 if (levlCoeffBuf[i] < 16) {
391 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
392 flcoeffs2[i] = (levlCoeffBuf[i] - 7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
394 flcoeffs1[i] = old_floor[i];
400 * Perform bit allocation depending on bits available
402 static int bit_allocation(IMCContext *q, IMCChannel *chctx,
403 int stream_format_code, int freebits, int flag)
406 const float limit = -1.e20;
415 float lowest = 1.e10;
421 for (i = 0; i < BANDS; i++)
422 highest = FFMAX(highest, chctx->flcoeffs1[i]);
424 for (i = 0; i < BANDS - 1; i++)
425 chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log2f(chctx->flcoeffs5[i]);
426 chctx->flcoeffs4[BANDS - 1] = limit;
428 highest = highest * 0.25;
430 for (i = 0; i < BANDS; i++) {
432 if ((band_tab[i + 1] - band_tab[i]) == chctx->bandWidthT[i])
435 if ((band_tab[i + 1] - band_tab[i]) > chctx->bandWidthT[i])
438 if (((band_tab[i + 1] - band_tab[i]) / 2) >= chctx->bandWidthT[i])
442 return AVERROR_INVALIDDATA;
444 chctx->flcoeffs4[i] += xTab[(indx * 2 + (chctx->flcoeffs1[i] < highest)) * 2 + flag];
447 if (stream_format_code & 0x2) {
448 chctx->flcoeffs4[0] = limit;
449 chctx->flcoeffs4[1] = limit;
450 chctx->flcoeffs4[2] = limit;
451 chctx->flcoeffs4[3] = limit;
454 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS - 1; i++) {
455 iacc += chctx->bandWidthT[i];
456 summa += chctx->bandWidthT[i] * chctx->flcoeffs4[i];
458 chctx->bandWidthT[BANDS - 1] = 0;
459 summa = (summa * 0.5 - freebits) / iacc;
462 for (i = 0; i < BANDS / 2; i++) {
463 rres = summer - freebits;
464 if ((rres >= -8) && (rres <= 8))
470 for (j = (stream_format_code & 0x2) ? 4 : 0; j < BANDS; j++) {
471 cwlen = av_clipf(((chctx->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
473 chctx->bitsBandT[j] = cwlen;
474 summer += chctx->bandWidthT[j] * cwlen;
477 iacc += chctx->bandWidthT[j];
482 if (freebits < summer)
489 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
492 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS; i++) {
493 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
494 chctx->CWlengthT[j] = chctx->bitsBandT[i];
497 if (freebits > summer) {
498 for (i = 0; i < BANDS; i++) {
499 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
500 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
506 if (highest <= -1.e20)
512 for (i = 0; i < BANDS; i++) {
513 if (workT[i] > highest) {
519 if (highest > -1.e20) {
520 workT[found_indx] -= 2.0;
521 if (++chctx->bitsBandT[found_indx] == 6)
522 workT[found_indx] = -1.e20;
524 for (j = band_tab[found_indx]; j < band_tab[found_indx + 1] && (freebits > summer); j++) {
525 chctx->CWlengthT[j]++;
529 } while (freebits > summer);
531 if (freebits < summer) {
532 for (i = 0; i < BANDS; i++) {
533 workT[i] = chctx->bitsBandT[i] ? (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] + 1.585)
536 if (stream_format_code & 0x2) {
542 while (freebits < summer) {
545 for (i = 0; i < BANDS; i++) {
546 if (workT[i] < lowest) {
551 // if (lowest >= 1.e10)
553 workT[low_indx] = lowest + 2.0;
555 if (!--chctx->bitsBandT[low_indx])
556 workT[low_indx] = 1.e20;
558 for (j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++) {
559 if (chctx->CWlengthT[j] > 0) {
560 chctx->CWlengthT[j]--;
569 static void imc_get_skip_coeff(IMCContext *q, IMCChannel *chctx)
573 memset(chctx->skipFlagBits, 0, sizeof(chctx->skipFlagBits));
574 memset(chctx->skipFlagCount, 0, sizeof(chctx->skipFlagCount));
575 for (i = 0; i < BANDS; i++) {
576 if (!chctx->bandFlagsBuf[i] || !chctx->bandWidthT[i])
579 if (!chctx->skipFlagRaw[i]) {
580 chctx->skipFlagBits[i] = band_tab[i + 1] - band_tab[i];
582 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
583 chctx->skipFlags[j] = get_bits1(&q->gb);
584 if (chctx->skipFlags[j])
585 chctx->skipFlagCount[i]++;
588 for (j = band_tab[i]; j < band_tab[i + 1] - 1; j += 2) {
589 if (!get_bits1(&q->gb)) { // 0
590 chctx->skipFlagBits[i]++;
591 chctx->skipFlags[j] = 1;
592 chctx->skipFlags[j + 1] = 1;
593 chctx->skipFlagCount[i] += 2;
595 if (get_bits1(&q->gb)) { // 11
596 chctx->skipFlagBits[i] += 2;
597 chctx->skipFlags[j] = 0;
598 chctx->skipFlags[j + 1] = 1;
599 chctx->skipFlagCount[i]++;
601 chctx->skipFlagBits[i] += 3;
602 chctx->skipFlags[j + 1] = 0;
603 if (!get_bits1(&q->gb)) { // 100
604 chctx->skipFlags[j] = 1;
605 chctx->skipFlagCount[i]++;
607 chctx->skipFlags[j] = 0;
613 if (j < band_tab[i + 1]) {
614 chctx->skipFlagBits[i]++;
615 if ((chctx->skipFlags[j] = get_bits1(&q->gb)))
616 chctx->skipFlagCount[i]++;
623 * Increase highest' band coefficient sizes as some bits won't be used
625 static void imc_adjust_bit_allocation(IMCContext *q, IMCChannel *chctx,
634 for (i = 0; i < BANDS; i++) {
635 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
636 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
639 while (corrected < summer) {
640 if (highest <= -1.e20)
645 for (i = 0; i < BANDS; i++) {
646 if (workT[i] > highest) {
652 if (highest > -1.e20) {
653 workT[found_indx] -= 2.0;
654 if (++(chctx->bitsBandT[found_indx]) == 6)
655 workT[found_indx] = -1.e20;
657 for (j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
658 if (!chctx->skipFlags[j] && (chctx->CWlengthT[j] < 6)) {
659 chctx->CWlengthT[j]++;
667 static void imc_imdct256(IMCContext *q, IMCChannel *chctx, int channels)
671 float *dst1 = q->out_samples;
672 float *dst2 = q->out_samples + (COEFFS - 1);
675 for (i = 0; i < COEFFS / 2; i++) {
676 q->samples[i].re = -(q->pre_coef1[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
677 (q->pre_coef2[i] * chctx->CWdecoded[i * 2]);
678 q->samples[i].im = (q->pre_coef2[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
679 (q->pre_coef1[i] * chctx->CWdecoded[i * 2]);
683 q->fft.fft_permute(&q->fft, q->samples);
684 q->fft.fft_calc(&q->fft, q->samples);
686 /* postrotation, window and reorder */
687 for (i = 0; i < COEFFS / 2; i++) {
688 re = ( q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
689 im = (-q->samples[i].im * q->post_cos[i]) - ( q->samples[i].re * q->post_sin[i]);
690 *dst1 = (q->mdct_sine_window[COEFFS - 1 - i * 2] * chctx->last_fft_im[i])
691 + (q->mdct_sine_window[i * 2] * re);
692 *dst2 = (q->mdct_sine_window[i * 2] * chctx->last_fft_im[i])
693 - (q->mdct_sine_window[COEFFS - 1 - i * 2] * re);
696 chctx->last_fft_im[i] = im;
700 static int inverse_quant_coeff(IMCContext *q, IMCChannel *chctx,
701 int stream_format_code)
704 int middle_value, cw_len, max_size;
705 const float *quantizer;
707 for (i = 0; i < BANDS; i++) {
708 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
709 chctx->CWdecoded[j] = 0;
710 cw_len = chctx->CWlengthT[j];
712 if (cw_len <= 0 || chctx->skipFlags[j])
715 max_size = 1 << cw_len;
716 middle_value = max_size >> 1;
718 if (chctx->codewords[j] >= max_size || chctx->codewords[j] < 0)
719 return AVERROR_INVALIDDATA;
722 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
723 if (chctx->codewords[j] >= middle_value)
724 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 8] * chctx->flcoeffs6[i];
726 chctx->CWdecoded[j] = -quantizer[max_size - chctx->codewords[j] - 8 - 1] * chctx->flcoeffs6[i];
728 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (chctx->bandFlagsBuf[i] << 1)];
729 if (chctx->codewords[j] >= middle_value)
730 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 1] * chctx->flcoeffs6[i];
732 chctx->CWdecoded[j] = -quantizer[max_size - 2 - chctx->codewords[j]] * chctx->flcoeffs6[i];
740 static int imc_get_coeffs(IMCContext *q, IMCChannel *chctx)
742 int i, j, cw_len, cw;
744 for (i = 0; i < BANDS; i++) {
745 if (!chctx->sumLenArr[i])
747 if (chctx->bandFlagsBuf[i] || chctx->bandWidthT[i]) {
748 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
749 cw_len = chctx->CWlengthT[j];
752 if (get_bits_count(&q->gb) + cw_len > 512) {
753 av_dlog(NULL, "Band %i coeff %i cw_len %i\n", i, j, cw_len);
754 return AVERROR_INVALIDDATA;
757 if (cw_len && (!chctx->bandFlagsBuf[i] || !chctx->skipFlags[j]))
758 cw = get_bits(&q->gb, cw_len);
760 chctx->codewords[j] = cw;
767 static int imc_decode_block(AVCodecContext *avctx, IMCContext *q, int ch)
769 int stream_format_code;
770 int imc_hdr, i, j, ret;
773 int counter, bitscount;
774 IMCChannel *chctx = q->chctx + ch;
777 /* Check the frame header */
778 imc_hdr = get_bits(&q->gb, 9);
779 if (imc_hdr & 0x18) {
780 av_log(avctx, AV_LOG_ERROR, "frame header check failed!\n");
781 av_log(avctx, AV_LOG_ERROR, "got %X.\n", imc_hdr);
782 return AVERROR_INVALIDDATA;
784 stream_format_code = get_bits(&q->gb, 3);
786 if (stream_format_code & 1) {
787 av_log_ask_for_sample(avctx, "Stream format %X is not supported\n",
789 return AVERROR_PATCHWELCOME;
792 if (stream_format_code & 0x04)
793 chctx->decoder_reset = 1;
795 if (chctx->decoder_reset) {
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 for(i=0; i<BANDS; i++) {
814 if(chctx->flcoeffs1[i] > INT_MAX) {
815 av_log(avctx, AV_LOG_ERROR, "scalefactor out of range\n");
816 return AVERROR_INVALIDDATA;
820 memcpy(chctx->old_floor, chctx->flcoeffs1, 32 * sizeof(float));
823 for (i = 0; i < BANDS; i++) {
824 if (chctx->levlCoeffBuf[i] == 16) {
825 chctx->bandWidthT[i] = 0;
828 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
830 memset(chctx->bandFlagsBuf, 0, BANDS * sizeof(int));
831 for (i = 0; i < BANDS - 1; i++) {
832 if (chctx->bandWidthT[i])
833 chctx->bandFlagsBuf[i] = get_bits1(&q->gb);
836 imc_calculate_coeffs(q, chctx->flcoeffs1, chctx->flcoeffs2, chctx->bandWidthT, chctx->flcoeffs3, chctx->flcoeffs5);
839 /* first 4 bands will be assigned 5 bits per coefficient */
840 if (stream_format_code & 0x2) {
843 chctx->bitsBandT[0] = 5;
844 chctx->CWlengthT[0] = 5;
845 chctx->CWlengthT[1] = 5;
846 chctx->CWlengthT[2] = 5;
847 for (i = 1; i < 4; i++) {
848 bits = (chctx->levlCoeffBuf[i] == 16) ? 0 : 5;
849 chctx->bitsBandT[i] = bits;
850 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
851 chctx->CWlengthT[j] = bits;
856 if (avctx->codec_id == AV_CODEC_ID_IAC) {
857 bitscount += !!chctx->bandWidthT[BANDS - 1];
858 if (!(stream_format_code & 0x2))
862 if ((ret = bit_allocation(q, chctx, stream_format_code,
863 512 - bitscount - get_bits_count(&q->gb),
865 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
866 chctx->decoder_reset = 1;
870 for (i = 0; i < BANDS; i++) {
871 chctx->sumLenArr[i] = 0;
872 chctx->skipFlagRaw[i] = 0;
873 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
874 chctx->sumLenArr[i] += chctx->CWlengthT[j];
875 if (chctx->bandFlagsBuf[i])
876 if ((((band_tab[i + 1] - band_tab[i]) * 1.5) > chctx->sumLenArr[i]) && (chctx->sumLenArr[i] > 0))
877 chctx->skipFlagRaw[i] = 1;
880 imc_get_skip_coeff(q, chctx);
882 for (i = 0; i < BANDS; i++) {
883 chctx->flcoeffs6[i] = chctx->flcoeffs1[i];
884 /* band has flag set and at least one coded coefficient */
885 if (chctx->bandFlagsBuf[i] && (band_tab[i + 1] - band_tab[i]) != chctx->skipFlagCount[i]) {
886 chctx->flcoeffs6[i] *= q->sqrt_tab[ band_tab[i + 1] - band_tab[i]] /
887 q->sqrt_tab[(band_tab[i + 1] - band_tab[i] - chctx->skipFlagCount[i])];
891 /* calculate bits left, bits needed and adjust bit allocation */
894 for (i = 0; i < BANDS; i++) {
895 if (chctx->bandFlagsBuf[i]) {
896 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
897 if (chctx->skipFlags[j]) {
898 summer += chctx->CWlengthT[j];
899 chctx->CWlengthT[j] = 0;
902 bits += chctx->skipFlagBits[i];
903 summer -= chctx->skipFlagBits[i];
906 imc_adjust_bit_allocation(q, chctx, summer);
908 for (i = 0; i < BANDS; i++) {
909 chctx->sumLenArr[i] = 0;
911 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
912 if (!chctx->skipFlags[j])
913 chctx->sumLenArr[i] += chctx->CWlengthT[j];
916 memset(chctx->codewords, 0, sizeof(chctx->codewords));
918 if (imc_get_coeffs(q, chctx) < 0) {
919 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");
920 chctx->decoder_reset = 1;
921 return AVERROR_INVALIDDATA;
924 if (inverse_quant_coeff(q, chctx, stream_format_code) < 0) {
925 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
926 chctx->decoder_reset = 1;
927 return AVERROR_INVALIDDATA;
930 memset(chctx->skipFlags, 0, sizeof(chctx->skipFlags));
932 imc_imdct256(q, chctx, avctx->channels);
937 static int imc_decode_frame(AVCodecContext *avctx, void *data,
938 int *got_frame_ptr, AVPacket *avpkt)
940 const uint8_t *buf = avpkt->data;
941 int buf_size = avpkt->size;
944 IMCContext *q = avctx->priv_data;
946 LOCAL_ALIGNED_16(uint16_t, buf16, [IMC_BLOCK_SIZE / 2]);
948 if (buf_size < IMC_BLOCK_SIZE * avctx->channels) {
949 av_log(avctx, AV_LOG_ERROR, "frame too small!\n");
950 return AVERROR_INVALIDDATA;
953 /* get output buffer */
954 q->frame.nb_samples = COEFFS;
955 if ((ret = ff_get_buffer(avctx, &q->frame)) < 0) {
956 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
960 for (i = 0; i < avctx->channels; i++) {
961 q->out_samples = (float *)q->frame.extended_data[i];
963 q->dsp.bswap16_buf(buf16, (const uint16_t*)buf, IMC_BLOCK_SIZE / 2);
965 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
967 buf += IMC_BLOCK_SIZE;
969 if ((ret = imc_decode_block(avctx, q, i)) < 0)
973 if (avctx->channels == 2) {
974 q->fdsp.butterflies_float((float *)q->frame.extended_data[0],
975 (float *)q->frame.extended_data[1], COEFFS);
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 static av_cold void flush(AVCodecContext *avctx)
996 IMCContext *q = avctx->priv_data;
998 q->chctx[0].decoder_reset =
999 q->chctx[1].decoder_reset = 1;
1002 #if CONFIG_IMC_DECODER
1003 AVCodec ff_imc_decoder = {
1005 .type = AVMEDIA_TYPE_AUDIO,
1006 .id = AV_CODEC_ID_IMC,
1007 .priv_data_size = sizeof(IMCContext),
1008 .init = imc_decode_init,
1009 .close = imc_decode_close,
1010 .decode = imc_decode_frame,
1012 .capabilities = CODEC_CAP_DR1,
1013 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
1014 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1015 AV_SAMPLE_FMT_NONE },
1018 #if CONFIG_IAC_DECODER
1019 AVCodec ff_iac_decoder = {
1021 .type = AVMEDIA_TYPE_AUDIO,
1022 .id = AV_CODEC_ID_IAC,
1023 .priv_data_size = sizeof(IMCContext),
1024 .init = imc_decode_init,
1025 .close = imc_decode_close,
1026 .decode = imc_decode_frame,
1028 .capabilities = CODEC_CAP_DR1,
1029 .long_name = NULL_IF_CONFIG_SMALL("IAC (Indeo Audio Coder)"),
1030 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1031 AV_SAMPLE_FMT_NONE },