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/libm.h"
50 #define IMC_BLOCK_SIZE 64
51 #define IMC_FRAME_ID 0x21
55 typedef struct IMCChannel {
56 float old_floor[BANDS];
57 float flcoeffs1[BANDS];
58 float flcoeffs2[BANDS];
59 float flcoeffs3[BANDS];
60 float flcoeffs4[BANDS];
61 float flcoeffs5[BANDS];
62 float flcoeffs6[BANDS];
63 float CWdecoded[COEFFS];
65 int bandWidthT[BANDS]; ///< codewords per band
66 int bitsBandT[BANDS]; ///< how many bits per codeword in band
67 int CWlengthT[COEFFS]; ///< how many bits in each codeword
68 int levlCoeffBuf[BANDS];
69 int bandFlagsBuf[BANDS]; ///< flags for each band
70 int sumLenArr[BANDS]; ///< bits for all coeffs in band
71 int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not
72 int skipFlagBits[BANDS]; ///< bits used to code skip flags
73 int skipFlagCount[BANDS]; ///< skipped coeffients per band
74 int skipFlags[COEFFS]; ///< skip coefficient decoding or not
75 int codewords[COEFFS]; ///< raw codewords read from bitstream
77 float last_fft_im[COEFFS];
89 float mdct_sine_window[COEFFS];
90 float post_cos[COEFFS];
91 float post_sin[COEFFS];
92 float pre_coef1[COEFFS];
93 float pre_coef2[COEFFS];
100 AVFloatDSPContext fdsp;
102 DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS / 2];
105 int8_t cyclTab[32], cyclTab2[32];
106 float weights1[31], weights2[31];
109 static VLC huffman_vlc[4][4];
111 #define VLC_TABLES_SIZE 9512
113 static const int vlc_offsets[17] = {
114 0, 640, 1156, 1732, 2308, 2852, 3396, 3924,
115 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE
118 static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];
120 static inline double freq2bark(double freq)
122 return 3.5 * atan((freq / 7500.0) * (freq / 7500.0)) + 13.0 * atan(freq * 0.00076);
125 static av_cold void iac_generate_tabs(IMCContext *q, int sampling_rate)
127 double freqmin[32], freqmid[32], freqmax[32];
128 double scale = sampling_rate / (256.0 * 2.0 * 2.0);
129 double nyquist_freq = sampling_rate * 0.5;
130 double freq, bark, prev_bark = 0, tf, tb;
133 for (i = 0; i < 32; i++) {
134 freq = (band_tab[i] + band_tab[i + 1] - 1) * scale;
135 bark = freq2bark(freq);
138 tb = bark - prev_bark;
139 q->weights1[i - 1] = pow(10.0, -1.0 * tb);
140 q->weights2[i - 1] = pow(10.0, -2.7 * tb);
147 while (tf < nyquist_freq) {
159 if (tb <= bark - 0.5)
165 for (i = 0; i < 32; i++) {
167 for (j = 31; j > 0 && freq <= freqmid[j]; j--);
168 q->cyclTab[i] = j + 1;
171 for (j = 0; j < 32 && freq >= freqmid[j]; j++);
172 q->cyclTab2[i] = j - 1;
176 static av_cold int imc_decode_init(AVCodecContext *avctx)
179 IMCContext *q = avctx->priv_data;
182 if (avctx->codec_id == AV_CODEC_ID_IMC)
185 if (avctx->channels > 2) {
186 av_log_ask_for_sample(avctx, "Number of channels is not supported\n");
187 return AVERROR_PATCHWELCOME;
190 for (j = 0; j < avctx->channels; j++) {
191 q->chctx[j].decoder_reset = 1;
193 for (i = 0; i < BANDS; i++)
194 q->chctx[j].old_floor[i] = 1.0;
196 for (i = 0; i < COEFFS / 2; i++)
197 q->chctx[j].last_fft_im[i] = 0;
200 /* Build mdct window, a simple sine window normalized with sqrt(2) */
201 ff_sine_window_init(q->mdct_sine_window, COEFFS);
202 for (i = 0; i < COEFFS; i++)
203 q->mdct_sine_window[i] *= sqrt(2.0);
204 for (i = 0; i < COEFFS / 2; i++) {
205 q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI);
206 q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI);
208 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
209 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
212 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
213 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
215 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
216 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
220 /* Generate a square root table */
222 for (i = 0; i < 30; i++)
223 q->sqrt_tab[i] = sqrt(i);
225 /* initialize the VLC tables */
226 for (i = 0; i < 4 ; i++) {
227 for (j = 0; j < 4; j++) {
228 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]];
229 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];
230 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i],
231 imc_huffman_lens[i][j], 1, 1,
232 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC);
236 if (avctx->codec_id == AV_CODEC_ID_IAC) {
237 iac_generate_tabs(q, avctx->sample_rate);
239 memcpy(q->cyclTab, cyclTab, sizeof(cyclTab));
240 memcpy(q->cyclTab2, cyclTab2, sizeof(cyclTab2));
241 memcpy(q->weights1, imc_weights1, sizeof(imc_weights1));
242 memcpy(q->weights2, imc_weights2, sizeof(imc_weights2));
245 if ((ret = ff_fft_init(&q->fft, 7, 1))) {
246 av_log(avctx, AV_LOG_INFO, "FFT init failed\n");
249 ff_dsputil_init(&q->dsp, avctx);
250 avpriv_float_dsp_init(&q->fdsp, avctx->flags & CODEC_FLAG_BITEXACT);
251 avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
252 avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
253 : AV_CH_LAYOUT_STEREO;
255 avcodec_get_frame_defaults(&q->frame);
256 avctx->coded_frame = &q->frame;
261 static void imc_calculate_coeffs(IMCContext *q, float *flcoeffs1,
262 float *flcoeffs2, int *bandWidthT,
263 float *flcoeffs3, float *flcoeffs5)
268 float snr_limit = 1.e-30;
272 for (i = 0; i < BANDS; i++) {
273 flcoeffs5[i] = workT2[i] = 0.0;
275 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
276 flcoeffs3[i] = 2.0 * flcoeffs2[i];
279 flcoeffs3[i] = -30000.0;
281 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
282 if (workT3[i] <= snr_limit)
286 for (i = 0; i < BANDS; i++) {
287 for (cnt2 = i; cnt2 < q->cyclTab[i]; cnt2++)
288 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
289 workT2[cnt2 - 1] = workT2[cnt2 - 1] + workT3[i];
292 for (i = 1; i < BANDS; i++) {
293 accum = (workT2[i - 1] + accum) * q->weights1[i - 1];
294 flcoeffs5[i] += accum;
297 for (i = 0; i < BANDS; i++)
300 for (i = 0; i < BANDS; i++) {
301 for (cnt2 = i - 1; cnt2 > q->cyclTab2[i]; cnt2--)
302 flcoeffs5[cnt2] += workT3[i];
303 workT2[cnt2+1] += workT3[i];
308 for (i = BANDS-2; i >= 0; i--) {
309 accum = (workT2[i+1] + accum) * q->weights2[i];
310 flcoeffs5[i] += accum;
311 // there is missing code here, but it seems to never be triggered
316 static void imc_read_level_coeffs(IMCContext *q, int stream_format_code,
322 const uint8_t *cb_sel;
325 s = stream_format_code >> 1;
326 hufftab[0] = &huffman_vlc[s][0];
327 hufftab[1] = &huffman_vlc[s][1];
328 hufftab[2] = &huffman_vlc[s][2];
329 hufftab[3] = &huffman_vlc[s][3];
330 cb_sel = imc_cb_select[s];
332 if (stream_format_code & 4)
335 levlCoeffs[0] = get_bits(&q->gb, 7);
336 for (i = start; i < BANDS; i++) {
337 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table,
338 hufftab[cb_sel[i]]->bits, 2);
339 if (levlCoeffs[i] == 17)
340 levlCoeffs[i] += get_bits(&q->gb, 4);
344 static void imc_decode_level_coefficients(IMCContext *q, int *levlCoeffBuf,
345 float *flcoeffs1, float *flcoeffs2)
349 // maybe some frequency division thingy
351 flcoeffs1[0] = 20000.0 / exp2 (levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
352 flcoeffs2[0] = log2f(flcoeffs1[0]);
356 for (i = 1; i < BANDS; i++) {
357 level = levlCoeffBuf[i];
364 else if (level <= 24)
369 tmp *= imc_exp_tab[15 + level];
370 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
378 static void imc_decode_level_coefficients2(IMCContext *q, int *levlCoeffBuf,
379 float *old_floor, float *flcoeffs1,
383 /* FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
384 * and flcoeffs2 old scale factors
385 * might be incomplete due to a missing table that is in the binary code
387 for (i = 0; i < BANDS; i++) {
389 if (levlCoeffBuf[i] < 16) {
390 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
391 flcoeffs2[i] = (levlCoeffBuf[i] - 7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
393 flcoeffs1[i] = old_floor[i];
399 * Perform bit allocation depending on bits available
401 static int bit_allocation(IMCContext *q, IMCChannel *chctx,
402 int stream_format_code, int freebits, int flag)
405 const float limit = -1.e20;
414 float lowest = 1.e10;
420 for (i = 0; i < BANDS; i++)
421 highest = FFMAX(highest, chctx->flcoeffs1[i]);
423 for (i = 0; i < BANDS - 1; i++)
424 chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log2f(chctx->flcoeffs5[i]);
425 chctx->flcoeffs4[BANDS - 1] = limit;
427 highest = highest * 0.25;
429 for (i = 0; i < BANDS; i++) {
431 if ((band_tab[i + 1] - band_tab[i]) == chctx->bandWidthT[i])
434 if ((band_tab[i + 1] - band_tab[i]) > chctx->bandWidthT[i])
437 if (((band_tab[i + 1] - band_tab[i]) / 2) >= chctx->bandWidthT[i])
441 return AVERROR_INVALIDDATA;
443 chctx->flcoeffs4[i] += xTab[(indx * 2 + (chctx->flcoeffs1[i] < highest)) * 2 + flag];
446 if (stream_format_code & 0x2) {
447 chctx->flcoeffs4[0] = limit;
448 chctx->flcoeffs4[1] = limit;
449 chctx->flcoeffs4[2] = limit;
450 chctx->flcoeffs4[3] = limit;
453 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS - 1; i++) {
454 iacc += chctx->bandWidthT[i];
455 summa += chctx->bandWidthT[i] * chctx->flcoeffs4[i];
457 chctx->bandWidthT[BANDS - 1] = 0;
458 summa = (summa * 0.5 - freebits) / iacc;
461 for (i = 0; i < BANDS / 2; i++) {
462 rres = summer - freebits;
463 if ((rres >= -8) && (rres <= 8))
469 for (j = (stream_format_code & 0x2) ? 4 : 0; j < BANDS; j++) {
470 cwlen = av_clipf(((chctx->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
472 chctx->bitsBandT[j] = cwlen;
473 summer += chctx->bandWidthT[j] * cwlen;
476 iacc += chctx->bandWidthT[j];
481 if (freebits < summer)
488 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
491 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS; i++) {
492 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
493 chctx->CWlengthT[j] = chctx->bitsBandT[i];
496 if (freebits > summer) {
497 for (i = 0; i < BANDS; i++) {
498 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
499 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
505 if (highest <= -1.e20)
511 for (i = 0; i < BANDS; i++) {
512 if (workT[i] > highest) {
518 if (highest > -1.e20) {
519 workT[found_indx] -= 2.0;
520 if (++chctx->bitsBandT[found_indx] == 6)
521 workT[found_indx] = -1.e20;
523 for (j = band_tab[found_indx]; j < band_tab[found_indx + 1] && (freebits > summer); j++) {
524 chctx->CWlengthT[j]++;
528 } while (freebits > summer);
530 if (freebits < summer) {
531 for (i = 0; i < BANDS; i++) {
532 workT[i] = chctx->bitsBandT[i] ? (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] + 1.585)
535 if (stream_format_code & 0x2) {
541 while (freebits < summer) {
544 for (i = 0; i < BANDS; i++) {
545 if (workT[i] < lowest) {
550 // if (lowest >= 1.e10)
552 workT[low_indx] = lowest + 2.0;
554 if (!--chctx->bitsBandT[low_indx])
555 workT[low_indx] = 1.e20;
557 for (j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++) {
558 if (chctx->CWlengthT[j] > 0) {
559 chctx->CWlengthT[j]--;
568 static void imc_get_skip_coeff(IMCContext *q, IMCChannel *chctx)
572 memset(chctx->skipFlagBits, 0, sizeof(chctx->skipFlagBits));
573 memset(chctx->skipFlagCount, 0, sizeof(chctx->skipFlagCount));
574 for (i = 0; i < BANDS; i++) {
575 if (!chctx->bandFlagsBuf[i] || !chctx->bandWidthT[i])
578 if (!chctx->skipFlagRaw[i]) {
579 chctx->skipFlagBits[i] = band_tab[i + 1] - band_tab[i];
581 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
582 chctx->skipFlags[j] = get_bits1(&q->gb);
583 if (chctx->skipFlags[j])
584 chctx->skipFlagCount[i]++;
587 for (j = band_tab[i]; j < band_tab[i + 1] - 1; j += 2) {
588 if (!get_bits1(&q->gb)) { // 0
589 chctx->skipFlagBits[i]++;
590 chctx->skipFlags[j] = 1;
591 chctx->skipFlags[j + 1] = 1;
592 chctx->skipFlagCount[i] += 2;
594 if (get_bits1(&q->gb)) { // 11
595 chctx->skipFlagBits[i] += 2;
596 chctx->skipFlags[j] = 0;
597 chctx->skipFlags[j + 1] = 1;
598 chctx->skipFlagCount[i]++;
600 chctx->skipFlagBits[i] += 3;
601 chctx->skipFlags[j + 1] = 0;
602 if (!get_bits1(&q->gb)) { // 100
603 chctx->skipFlags[j] = 1;
604 chctx->skipFlagCount[i]++;
606 chctx->skipFlags[j] = 0;
612 if (j < band_tab[i + 1]) {
613 chctx->skipFlagBits[i]++;
614 if ((chctx->skipFlags[j] = get_bits1(&q->gb)))
615 chctx->skipFlagCount[i]++;
622 * Increase highest' band coefficient sizes as some bits won't be used
624 static void imc_adjust_bit_allocation(IMCContext *q, IMCChannel *chctx,
633 for (i = 0; i < BANDS; i++) {
634 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
635 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
638 while (corrected < summer) {
639 if (highest <= -1.e20)
644 for (i = 0; i < BANDS; i++) {
645 if (workT[i] > highest) {
651 if (highest > -1.e20) {
652 workT[found_indx] -= 2.0;
653 if (++(chctx->bitsBandT[found_indx]) == 6)
654 workT[found_indx] = -1.e20;
656 for (j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
657 if (!chctx->skipFlags[j] && (chctx->CWlengthT[j] < 6)) {
658 chctx->CWlengthT[j]++;
666 static void imc_imdct256(IMCContext *q, IMCChannel *chctx, int channels)
670 float *dst1 = q->out_samples;
671 float *dst2 = q->out_samples + (COEFFS - 1);
674 for (i = 0; i < COEFFS / 2; i++) {
675 q->samples[i].re = -(q->pre_coef1[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
676 (q->pre_coef2[i] * chctx->CWdecoded[i * 2]);
677 q->samples[i].im = (q->pre_coef2[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
678 (q->pre_coef1[i] * chctx->CWdecoded[i * 2]);
682 q->fft.fft_permute(&q->fft, q->samples);
683 q->fft.fft_calc(&q->fft, q->samples);
685 /* postrotation, window and reorder */
686 for (i = 0; i < COEFFS / 2; i++) {
687 re = ( q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
688 im = (-q->samples[i].im * q->post_cos[i]) - ( q->samples[i].re * q->post_sin[i]);
689 *dst1 = (q->mdct_sine_window[COEFFS - 1 - i * 2] * chctx->last_fft_im[i])
690 + (q->mdct_sine_window[i * 2] * re);
691 *dst2 = (q->mdct_sine_window[i * 2] * chctx->last_fft_im[i])
692 - (q->mdct_sine_window[COEFFS - 1 - i * 2] * re);
695 chctx->last_fft_im[i] = im;
699 static int inverse_quant_coeff(IMCContext *q, IMCChannel *chctx,
700 int stream_format_code)
703 int middle_value, cw_len, max_size;
704 const float *quantizer;
706 for (i = 0; i < BANDS; i++) {
707 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
708 chctx->CWdecoded[j] = 0;
709 cw_len = chctx->CWlengthT[j];
711 if (cw_len <= 0 || chctx->skipFlags[j])
714 max_size = 1 << cw_len;
715 middle_value = max_size >> 1;
717 if (chctx->codewords[j] >= max_size || chctx->codewords[j] < 0)
718 return AVERROR_INVALIDDATA;
721 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
722 if (chctx->codewords[j] >= middle_value)
723 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 8] * chctx->flcoeffs6[i];
725 chctx->CWdecoded[j] = -quantizer[max_size - chctx->codewords[j] - 8 - 1] * chctx->flcoeffs6[i];
727 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (chctx->bandFlagsBuf[i] << 1)];
728 if (chctx->codewords[j] >= middle_value)
729 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 1] * chctx->flcoeffs6[i];
731 chctx->CWdecoded[j] = -quantizer[max_size - 2 - chctx->codewords[j]] * chctx->flcoeffs6[i];
739 static int imc_get_coeffs(IMCContext *q, IMCChannel *chctx)
741 int i, j, cw_len, cw;
743 for (i = 0; i < BANDS; i++) {
744 if (!chctx->sumLenArr[i])
746 if (chctx->bandFlagsBuf[i] || chctx->bandWidthT[i]) {
747 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
748 cw_len = chctx->CWlengthT[j];
751 if (get_bits_count(&q->gb) + cw_len > 512) {
752 av_dlog(NULL, "Band %i coeff %i cw_len %i\n", i, j, cw_len);
753 return AVERROR_INVALIDDATA;
756 if (cw_len && (!chctx->bandFlagsBuf[i] || !chctx->skipFlags[j]))
757 cw = get_bits(&q->gb, cw_len);
759 chctx->codewords[j] = cw;
766 static int imc_decode_block(AVCodecContext *avctx, IMCContext *q, int ch)
768 int stream_format_code;
769 int imc_hdr, i, j, ret;
772 int counter, bitscount;
773 IMCChannel *chctx = q->chctx + ch;
776 /* Check the frame header */
777 imc_hdr = get_bits(&q->gb, 9);
778 if (imc_hdr & 0x18) {
779 av_log(avctx, AV_LOG_ERROR, "frame header check failed!\n");
780 av_log(avctx, AV_LOG_ERROR, "got %X.\n", imc_hdr);
781 return AVERROR_INVALIDDATA;
783 stream_format_code = get_bits(&q->gb, 3);
785 if (stream_format_code & 1) {
786 av_log_ask_for_sample(avctx, "Stream format %X is not supported\n",
788 return AVERROR_PATCHWELCOME;
791 if (stream_format_code & 0x04)
792 chctx->decoder_reset = 1;
794 if (chctx->decoder_reset) {
795 for (i = 0; i < BANDS; i++)
796 chctx->old_floor[i] = 1.0;
797 for (i = 0; i < COEFFS; i++)
798 chctx->CWdecoded[i] = 0;
799 chctx->decoder_reset = 0;
802 flag = get_bits1(&q->gb);
803 imc_read_level_coeffs(q, stream_format_code, chctx->levlCoeffBuf);
805 if (stream_format_code & 0x4)
806 imc_decode_level_coefficients(q, chctx->levlCoeffBuf,
807 chctx->flcoeffs1, chctx->flcoeffs2);
809 imc_decode_level_coefficients2(q, chctx->levlCoeffBuf, chctx->old_floor,
810 chctx->flcoeffs1, chctx->flcoeffs2);
812 for(i=0; i<BANDS; i++) {
813 if(chctx->flcoeffs1[i] > INT_MAX) {
814 av_log(avctx, AV_LOG_ERROR, "scalefactor out of range\n");
815 return AVERROR_INVALIDDATA;
819 memcpy(chctx->old_floor, chctx->flcoeffs1, 32 * sizeof(float));
822 for (i = 0; i < BANDS; i++) {
823 if (chctx->levlCoeffBuf[i] == 16) {
824 chctx->bandWidthT[i] = 0;
827 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
829 memset(chctx->bandFlagsBuf, 0, BANDS * sizeof(int));
830 for (i = 0; i < BANDS - 1; i++) {
831 if (chctx->bandWidthT[i])
832 chctx->bandFlagsBuf[i] = get_bits1(&q->gb);
835 imc_calculate_coeffs(q, chctx->flcoeffs1, chctx->flcoeffs2, chctx->bandWidthT, chctx->flcoeffs3, chctx->flcoeffs5);
838 /* first 4 bands will be assigned 5 bits per coefficient */
839 if (stream_format_code & 0x2) {
842 chctx->bitsBandT[0] = 5;
843 chctx->CWlengthT[0] = 5;
844 chctx->CWlengthT[1] = 5;
845 chctx->CWlengthT[2] = 5;
846 for (i = 1; i < 4; i++) {
847 bits = (chctx->levlCoeffBuf[i] == 16) ? 0 : 5;
848 chctx->bitsBandT[i] = bits;
849 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
850 chctx->CWlengthT[j] = bits;
855 if (avctx->codec_id == AV_CODEC_ID_IAC) {
856 bitscount += !!chctx->bandWidthT[BANDS - 1];
857 if (!(stream_format_code & 0x2))
861 if ((ret = bit_allocation(q, chctx, stream_format_code,
862 512 - bitscount - get_bits_count(&q->gb),
864 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
865 chctx->decoder_reset = 1;
869 for (i = 0; i < BANDS; i++) {
870 chctx->sumLenArr[i] = 0;
871 chctx->skipFlagRaw[i] = 0;
872 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
873 chctx->sumLenArr[i] += chctx->CWlengthT[j];
874 if (chctx->bandFlagsBuf[i])
875 if ((((band_tab[i + 1] - band_tab[i]) * 1.5) > chctx->sumLenArr[i]) && (chctx->sumLenArr[i] > 0))
876 chctx->skipFlagRaw[i] = 1;
879 imc_get_skip_coeff(q, chctx);
881 for (i = 0; i < BANDS; i++) {
882 chctx->flcoeffs6[i] = chctx->flcoeffs1[i];
883 /* band has flag set and at least one coded coefficient */
884 if (chctx->bandFlagsBuf[i] && (band_tab[i + 1] - band_tab[i]) != chctx->skipFlagCount[i]) {
885 chctx->flcoeffs6[i] *= q->sqrt_tab[ band_tab[i + 1] - band_tab[i]] /
886 q->sqrt_tab[(band_tab[i + 1] - band_tab[i] - chctx->skipFlagCount[i])];
890 /* calculate bits left, bits needed and adjust bit allocation */
893 for (i = 0; i < BANDS; i++) {
894 if (chctx->bandFlagsBuf[i]) {
895 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
896 if (chctx->skipFlags[j]) {
897 summer += chctx->CWlengthT[j];
898 chctx->CWlengthT[j] = 0;
901 bits += chctx->skipFlagBits[i];
902 summer -= chctx->skipFlagBits[i];
905 imc_adjust_bit_allocation(q, chctx, summer);
907 for (i = 0; i < BANDS; i++) {
908 chctx->sumLenArr[i] = 0;
910 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
911 if (!chctx->skipFlags[j])
912 chctx->sumLenArr[i] += chctx->CWlengthT[j];
915 memset(chctx->codewords, 0, sizeof(chctx->codewords));
917 if (imc_get_coeffs(q, chctx) < 0) {
918 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");
919 chctx->decoder_reset = 1;
920 return AVERROR_INVALIDDATA;
923 if (inverse_quant_coeff(q, chctx, stream_format_code) < 0) {
924 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
925 chctx->decoder_reset = 1;
926 return AVERROR_INVALIDDATA;
929 memset(chctx->skipFlags, 0, sizeof(chctx->skipFlags));
931 imc_imdct256(q, chctx, avctx->channels);
936 static int imc_decode_frame(AVCodecContext *avctx, void *data,
937 int *got_frame_ptr, AVPacket *avpkt)
939 const uint8_t *buf = avpkt->data;
940 int buf_size = avpkt->size;
943 IMCContext *q = avctx->priv_data;
945 LOCAL_ALIGNED_16(uint16_t, buf16, [IMC_BLOCK_SIZE / 2]);
947 if (buf_size < IMC_BLOCK_SIZE * avctx->channels) {
948 av_log(avctx, AV_LOG_ERROR, "frame too small!\n");
949 return AVERROR_INVALIDDATA;
952 /* get output buffer */
953 q->frame.nb_samples = COEFFS;
954 if ((ret = ff_get_buffer(avctx, &q->frame)) < 0) {
955 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
959 for (i = 0; i < avctx->channels; i++) {
960 q->out_samples = (float *)q->frame.extended_data[i];
962 q->dsp.bswap16_buf(buf16, (const uint16_t*)buf, IMC_BLOCK_SIZE / 2);
964 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
966 buf += IMC_BLOCK_SIZE;
968 if ((ret = imc_decode_block(avctx, q, i)) < 0)
972 if (avctx->channels == 2) {
973 q->fdsp.butterflies_float((float *)q->frame.extended_data[0],
974 (float *)q->frame.extended_data[1], COEFFS);
978 *(AVFrame *)data = q->frame;
980 return IMC_BLOCK_SIZE * avctx->channels;
984 static av_cold int imc_decode_close(AVCodecContext * avctx)
986 IMCContext *q = avctx->priv_data;
993 static av_cold void flush(AVCodecContext *avctx)
995 IMCContext *q = avctx->priv_data;
997 q->chctx[0].decoder_reset =
998 q->chctx[1].decoder_reset = 1;
1001 #if CONFIG_IMC_DECODER
1002 AVCodec ff_imc_decoder = {
1004 .type = AVMEDIA_TYPE_AUDIO,
1005 .id = AV_CODEC_ID_IMC,
1006 .priv_data_size = sizeof(IMCContext),
1007 .init = imc_decode_init,
1008 .close = imc_decode_close,
1009 .decode = imc_decode_frame,
1011 .capabilities = CODEC_CAP_DR1,
1012 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
1013 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1014 AV_SAMPLE_FMT_NONE },
1017 #if CONFIG_IAC_DECODER
1018 AVCodec ff_iac_decoder = {
1020 .type = AVMEDIA_TYPE_AUDIO,
1021 .id = AV_CODEC_ID_IAC,
1022 .priv_data_size = sizeof(IMCContext),
1023 .init = imc_decode_init,
1024 .close = imc_decode_close,
1025 .decode = imc_decode_frame,
1027 .capabilities = CODEC_CAP_DR1,
1028 .long_name = NULL_IF_CONFIG_SMALL("IAC (Indeo Audio Coder)"),
1029 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1030 AV_SAMPLE_FMT_NONE },