2 * IMC compatible decoder
3 * Copyright (c) 2002-2004 Maxim Poliakovski
4 * Copyright (c) 2006 Benjamin Larsson
5 * Copyright (c) 2006 Konstantin Shishkov
7 * This file is part of FFmpeg.
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26 * IMC - Intel Music Coder
27 * A mdct based codec using a 256 points large transform
28 * divided into 32 bands with some mix of scale factors.
29 * Only mono is supported.
42 #include "libavutil/audioconvert.h"
47 #define IMC_BLOCK_SIZE 64
48 #define IMC_FRAME_ID 0x21
52 typedef struct IMCChannel {
53 float old_floor[BANDS];
54 float flcoeffs1[BANDS];
55 float flcoeffs2[BANDS];
56 float flcoeffs3[BANDS];
57 float flcoeffs4[BANDS];
58 float flcoeffs5[BANDS];
59 float flcoeffs6[BANDS];
60 float CWdecoded[COEFFS];
62 int bandWidthT[BANDS]; ///< codewords per band
63 int bitsBandT[BANDS]; ///< how many bits per codeword in band
64 int CWlengthT[COEFFS]; ///< how many bits in each codeword
65 int levlCoeffBuf[BANDS];
66 int bandFlagsBuf[BANDS]; ///< flags for each band
67 int sumLenArr[BANDS]; ///< bits for all coeffs in band
68 int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not
69 int skipFlagBits[BANDS]; ///< bits used to code skip flags
70 int skipFlagCount[BANDS]; ///< skipped coeffients per band
71 int skipFlags[COEFFS]; ///< skip coefficient decoding or not
72 int codewords[COEFFS]; ///< raw codewords read from bitstream
74 float last_fft_im[COEFFS];
86 float mdct_sine_window[COEFFS];
87 float post_cos[COEFFS];
88 float post_sin[COEFFS];
89 float pre_coef1[COEFFS];
90 float pre_coef2[COEFFS];
98 DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS / 2];
101 int8_t cyclTab[32], cyclTab2[32];
102 float weights1[31], weights2[31];
105 static VLC huffman_vlc[4][4];
107 #define VLC_TABLES_SIZE 9512
109 static const int vlc_offsets[17] = {
110 0, 640, 1156, 1732, 2308, 2852, 3396, 3924,
111 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE
114 static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];
116 static inline double freq2bark(double freq)
118 return 3.5 * atan((freq / 7500.0) * (freq / 7500.0)) + 13.0 * atan(freq * 0.00076);
121 static av_cold void iac_generate_tabs(IMCContext *q, int sampling_rate)
123 double freqmin[32], freqmid[32], freqmax[32];
124 double scale = sampling_rate / (256.0 * 2.0 * 2.0);
125 double nyquist_freq = sampling_rate * 0.5;
126 double freq, bark, prev_bark = 0, tf, tb;
129 for (i = 0; i < 32; i++) {
130 freq = (band_tab[i] + band_tab[i + 1] - 1) * scale;
131 bark = freq2bark(freq);
134 tb = bark - prev_bark;
135 q->weights1[i - 1] = pow(10.0, -1.0 * tb);
136 q->weights2[i - 1] = pow(10.0, -2.7 * tb);
143 while (tf < nyquist_freq) {
155 if (tb <= bark - 0.5)
161 for (i = 0; i < 32; i++) {
163 for (j = 31; j > 0 && freq <= freqmid[j]; j--);
164 q->cyclTab[i] = j + 1;
167 for (j = 0; j < 32 && freq >= freqmid[j]; j++);
168 q->cyclTab2[i] = j - 1;
172 static av_cold int imc_decode_init(AVCodecContext *avctx)
175 IMCContext *q = avctx->priv_data;
178 if ((avctx->codec_id == CODEC_ID_IMC && avctx->channels != 1)
179 || (avctx->codec_id == CODEC_ID_IAC && avctx->channels > 2)) {
180 av_log_ask_for_sample(avctx, "Number of channels is not supported\n");
181 return AVERROR_PATCHWELCOME;
184 for (j = 0; j < avctx->channels; j++) {
185 q->chctx[j].decoder_reset = 1;
187 for (i = 0; i < BANDS; i++)
188 q->chctx[j].old_floor[i] = 1.0;
190 for (i = 0; i < COEFFS / 2; i++)
191 q->chctx[j].last_fft_im[i] = 0;
194 /* Build mdct window, a simple sine window normalized with sqrt(2) */
195 ff_sine_window_init(q->mdct_sine_window, COEFFS);
196 for (i = 0; i < COEFFS; i++)
197 q->mdct_sine_window[i] *= sqrt(2.0);
198 for (i = 0; i < COEFFS / 2; i++) {
199 q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI);
200 q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI);
202 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
203 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
206 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
207 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
209 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
210 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
214 /* Generate a square root table */
216 for (i = 0; i < 30; i++)
217 q->sqrt_tab[i] = sqrt(i);
219 /* initialize the VLC tables */
220 for (i = 0; i < 4 ; i++) {
221 for (j = 0; j < 4; j++) {
222 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]];
223 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];
224 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i],
225 imc_huffman_lens[i][j], 1, 1,
226 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC);
230 if (avctx->codec_id == CODEC_ID_IAC) {
231 iac_generate_tabs(q, avctx->sample_rate);
233 memcpy(q->cyclTab, cyclTab, sizeof(cyclTab));
234 memcpy(q->cyclTab2, cyclTab2, sizeof(cyclTab2));
235 memcpy(q->weights1, imc_weights1, sizeof(imc_weights1));
236 memcpy(q->weights2, imc_weights2, sizeof(imc_weights2));
239 if ((ret = ff_fft_init(&q->fft, 7, 1))) {
240 av_log(avctx, AV_LOG_INFO, "FFT init failed\n");
243 ff_dsputil_init(&q->dsp, avctx);
244 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
245 avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
246 : AV_CH_LAYOUT_STEREO;
248 avcodec_get_frame_defaults(&q->frame);
249 avctx->coded_frame = &q->frame;
254 static void imc_calculate_coeffs(IMCContext *q, float *flcoeffs1,
255 float *flcoeffs2, int *bandWidthT,
256 float *flcoeffs3, float *flcoeffs5)
261 float snr_limit = 1.e-30;
265 for (i = 0; i < BANDS; i++) {
266 flcoeffs5[i] = workT2[i] = 0.0;
268 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
269 flcoeffs3[i] = 2.0 * flcoeffs2[i];
272 flcoeffs3[i] = -30000.0;
274 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
275 if (workT3[i] <= snr_limit)
279 for (i = 0; i < BANDS; i++) {
280 for (cnt2 = i; cnt2 < q->cyclTab[i]; cnt2++)
281 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
282 workT2[cnt2 - 1] = workT2[cnt2 - 1] + workT3[i];
285 for (i = 1; i < BANDS; i++) {
286 accum = (workT2[i - 1] + accum) * q->weights1[i - 1];
287 flcoeffs5[i] += accum;
290 for (i = 0; i < BANDS; i++)
293 for (i = 0; i < BANDS; i++) {
294 for (cnt2 = i - 1; cnt2 > q->cyclTab2[i]; cnt2--)
295 flcoeffs5[cnt2] += workT3[i];
296 workT2[cnt2+1] += workT3[i];
301 for (i = BANDS-2; i >= 0; i--) {
302 accum = (workT2[i+1] + accum) * q->weights2[i];
303 flcoeffs5[i] += accum;
304 // there is missing code here, but it seems to never be triggered
309 static void imc_read_level_coeffs(IMCContext *q, int stream_format_code,
315 const uint8_t *cb_sel;
318 s = stream_format_code >> 1;
319 hufftab[0] = &huffman_vlc[s][0];
320 hufftab[1] = &huffman_vlc[s][1];
321 hufftab[2] = &huffman_vlc[s][2];
322 hufftab[3] = &huffman_vlc[s][3];
323 cb_sel = imc_cb_select[s];
325 if (stream_format_code & 4)
328 levlCoeffs[0] = get_bits(&q->gb, 7);
329 for (i = start; i < BANDS; i++) {
330 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table,
331 hufftab[cb_sel[i]]->bits, 2);
332 if (levlCoeffs[i] == 17)
333 levlCoeffs[i] += get_bits(&q->gb, 4);
337 static void imc_decode_level_coefficients(IMCContext *q, int *levlCoeffBuf,
338 float *flcoeffs1, float *flcoeffs2)
342 // maybe some frequency division thingy
344 flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
345 flcoeffs2[0] = log(flcoeffs1[0]) / log(2);
349 for (i = 1; i < BANDS; i++) {
350 level = levlCoeffBuf[i];
357 else if (level <= 24)
362 tmp *= imc_exp_tab[15 + level];
363 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
371 static void imc_decode_level_coefficients2(IMCContext *q, int *levlCoeffBuf,
372 float *old_floor, float *flcoeffs1,
376 /* FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
377 * and flcoeffs2 old scale factors
378 * might be incomplete due to a missing table that is in the binary code
380 for (i = 0; i < BANDS; i++) {
382 if (levlCoeffBuf[i] < 16) {
383 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
384 flcoeffs2[i] = (levlCoeffBuf[i] - 7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
386 flcoeffs1[i] = old_floor[i];
392 * Perform bit allocation depending on bits available
394 static int bit_allocation(IMCContext *q, IMCChannel *chctx,
395 int stream_format_code, int freebits, int flag)
398 const float limit = -1.e20;
407 float lowest = 1.e10;
413 for (i = 0; i < BANDS; i++)
414 highest = FFMAX(highest, chctx->flcoeffs1[i]);
416 for (i = 0; i < BANDS - 1; i++)
417 chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log(chctx->flcoeffs5[i]) / log(2);
418 chctx->flcoeffs4[BANDS - 1] = limit;
420 highest = highest * 0.25;
422 for (i = 0; i < BANDS; i++) {
424 if ((band_tab[i + 1] - band_tab[i]) == chctx->bandWidthT[i])
427 if ((band_tab[i + 1] - band_tab[i]) > chctx->bandWidthT[i])
430 if (((band_tab[i + 1] - band_tab[i]) / 2) >= chctx->bandWidthT[i])
434 return AVERROR_INVALIDDATA;
436 chctx->flcoeffs4[i] += xTab[(indx * 2 + (chctx->flcoeffs1[i] < highest)) * 2 + flag];
439 if (stream_format_code & 0x2) {
440 chctx->flcoeffs4[0] = limit;
441 chctx->flcoeffs4[1] = limit;
442 chctx->flcoeffs4[2] = limit;
443 chctx->flcoeffs4[3] = limit;
446 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS - 1; i++) {
447 iacc += chctx->bandWidthT[i];
448 summa += chctx->bandWidthT[i] * chctx->flcoeffs4[i];
450 chctx->bandWidthT[BANDS - 1] = 0;
451 summa = (summa * 0.5 - freebits) / iacc;
454 for (i = 0; i < BANDS / 2; i++) {
455 rres = summer - freebits;
456 if ((rres >= -8) && (rres <= 8))
462 for (j = (stream_format_code & 0x2) ? 4 : 0; j < BANDS; j++) {
463 cwlen = av_clipf(((chctx->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
465 chctx->bitsBandT[j] = cwlen;
466 summer += chctx->bandWidthT[j] * cwlen;
469 iacc += chctx->bandWidthT[j];
474 if (freebits < summer)
481 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
484 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS; i++) {
485 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
486 chctx->CWlengthT[j] = chctx->bitsBandT[i];
489 if (freebits > summer) {
490 for (i = 0; i < BANDS; i++) {
491 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
492 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
498 if (highest <= -1.e20)
504 for (i = 0; i < BANDS; i++) {
505 if (workT[i] > highest) {
511 if (highest > -1.e20) {
512 workT[found_indx] -= 2.0;
513 if (++chctx->bitsBandT[found_indx] == 6)
514 workT[found_indx] = -1.e20;
516 for (j = band_tab[found_indx]; j < band_tab[found_indx + 1] && (freebits > summer); j++) {
517 chctx->CWlengthT[j]++;
521 } while (freebits > summer);
523 if (freebits < summer) {
524 for (i = 0; i < BANDS; i++) {
525 workT[i] = chctx->bitsBandT[i] ? (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] + 1.585)
528 if (stream_format_code & 0x2) {
534 while (freebits < summer) {
537 for (i = 0; i < BANDS; i++) {
538 if (workT[i] < lowest) {
543 // if (lowest >= 1.e10)
545 workT[low_indx] = lowest + 2.0;
547 if (!--chctx->bitsBandT[low_indx])
548 workT[low_indx] = 1.e20;
550 for (j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++) {
551 if (chctx->CWlengthT[j] > 0) {
552 chctx->CWlengthT[j]--;
561 static void imc_get_skip_coeff(IMCContext *q, IMCChannel *chctx)
565 memset(chctx->skipFlagBits, 0, sizeof(chctx->skipFlagBits));
566 memset(chctx->skipFlagCount, 0, sizeof(chctx->skipFlagCount));
567 for (i = 0; i < BANDS; i++) {
568 if (!chctx->bandFlagsBuf[i] || !chctx->bandWidthT[i])
571 if (!chctx->skipFlagRaw[i]) {
572 chctx->skipFlagBits[i] = band_tab[i + 1] - band_tab[i];
574 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
575 chctx->skipFlags[j] = get_bits1(&q->gb);
576 if (chctx->skipFlags[j])
577 chctx->skipFlagCount[i]++;
580 for (j = band_tab[i]; j < band_tab[i + 1] - 1; j += 2) {
581 if (!get_bits1(&q->gb)) { // 0
582 chctx->skipFlagBits[i]++;
583 chctx->skipFlags[j] = 1;
584 chctx->skipFlags[j + 1] = 1;
585 chctx->skipFlagCount[i] += 2;
587 if (get_bits1(&q->gb)) { // 11
588 chctx->skipFlagBits[i] += 2;
589 chctx->skipFlags[j] = 0;
590 chctx->skipFlags[j + 1] = 1;
591 chctx->skipFlagCount[i]++;
593 chctx->skipFlagBits[i] += 3;
594 chctx->skipFlags[j + 1] = 0;
595 if (!get_bits1(&q->gb)) { // 100
596 chctx->skipFlags[j] = 1;
597 chctx->skipFlagCount[i]++;
599 chctx->skipFlags[j] = 0;
605 if (j < band_tab[i + 1]) {
606 chctx->skipFlagBits[i]++;
607 if ((chctx->skipFlags[j] = get_bits1(&q->gb)))
608 chctx->skipFlagCount[i]++;
615 * Increase highest' band coefficient sizes as some bits won't be used
617 static void imc_adjust_bit_allocation(IMCContext *q, IMCChannel *chctx,
626 for (i = 0; i < BANDS; i++) {
627 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
628 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
631 while (corrected < summer) {
632 if (highest <= -1.e20)
637 for (i = 0; i < BANDS; i++) {
638 if (workT[i] > highest) {
644 if (highest > -1.e20) {
645 workT[found_indx] -= 2.0;
646 if (++(chctx->bitsBandT[found_indx]) == 6)
647 workT[found_indx] = -1.e20;
649 for (j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
650 if (!chctx->skipFlags[j] && (chctx->CWlengthT[j] < 6)) {
651 chctx->CWlengthT[j]++;
659 static void imc_imdct256(IMCContext *q, IMCChannel *chctx, int channels)
663 float *dst1 = q->out_samples;
664 float *dst2 = q->out_samples + (COEFFS - 1) * channels;
667 for (i = 0; i < COEFFS / 2; i++) {
668 q->samples[i].re = -(q->pre_coef1[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
669 (q->pre_coef2[i] * chctx->CWdecoded[i * 2]);
670 q->samples[i].im = (q->pre_coef2[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
671 (q->pre_coef1[i] * chctx->CWdecoded[i * 2]);
675 q->fft.fft_permute(&q->fft, q->samples);
676 q->fft.fft_calc(&q->fft, q->samples);
678 /* postrotation, window and reorder */
679 for (i = 0; i < COEFFS / 2; i++) {
680 re = ( q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
681 im = (-q->samples[i].im * q->post_cos[i]) - ( q->samples[i].re * q->post_sin[i]);
682 *dst1 = (q->mdct_sine_window[COEFFS - 1 - i * 2] * chctx->last_fft_im[i])
683 + (q->mdct_sine_window[i * 2] * re);
684 *dst2 = (q->mdct_sine_window[i * 2] * chctx->last_fft_im[i])
685 - (q->mdct_sine_window[COEFFS - 1 - i * 2] * re);
686 dst1 += channels * 2;
687 dst2 -= channels * 2;
688 chctx->last_fft_im[i] = im;
692 static int inverse_quant_coeff(IMCContext *q, IMCChannel *chctx,
693 int stream_format_code)
696 int middle_value, cw_len, max_size;
697 const float *quantizer;
699 for (i = 0; i < BANDS; i++) {
700 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
701 chctx->CWdecoded[j] = 0;
702 cw_len = chctx->CWlengthT[j];
704 if (cw_len <= 0 || chctx->skipFlags[j])
707 max_size = 1 << cw_len;
708 middle_value = max_size >> 1;
710 if (chctx->codewords[j] >= max_size || chctx->codewords[j] < 0)
711 return AVERROR_INVALIDDATA;
714 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
715 if (chctx->codewords[j] >= middle_value)
716 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 8] * chctx->flcoeffs6[i];
718 chctx->CWdecoded[j] = -quantizer[max_size - chctx->codewords[j] - 8 - 1] * chctx->flcoeffs6[i];
720 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (chctx->bandFlagsBuf[i] << 1)];
721 if (chctx->codewords[j] >= middle_value)
722 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 1] * chctx->flcoeffs6[i];
724 chctx->CWdecoded[j] = -quantizer[max_size - 2 - chctx->codewords[j]] * chctx->flcoeffs6[i];
732 static int imc_get_coeffs(IMCContext *q, IMCChannel *chctx)
734 int i, j, cw_len, cw;
736 for (i = 0; i < BANDS; i++) {
737 if (!chctx->sumLenArr[i])
739 if (chctx->bandFlagsBuf[i] || chctx->bandWidthT[i]) {
740 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
741 cw_len = chctx->CWlengthT[j];
744 if (get_bits_count(&q->gb) + cw_len > 512) {
745 // av_log(NULL, 0, "Band %i coeff %i cw_len %i\n", i, j, cw_len);
746 return AVERROR_INVALIDDATA;
749 if (cw_len && (!chctx->bandFlagsBuf[i] || !chctx->skipFlags[j]))
750 cw = get_bits(&q->gb, cw_len);
752 chctx->codewords[j] = cw;
759 static int imc_decode_block(AVCodecContext *avctx, IMCContext *q, int ch)
761 int stream_format_code;
762 int imc_hdr, i, j, ret;
765 int counter, bitscount;
766 IMCChannel *chctx = q->chctx + ch;
769 /* Check the frame header */
770 imc_hdr = get_bits(&q->gb, 9);
771 if (imc_hdr & 0x18) {
772 av_log(avctx, AV_LOG_ERROR, "frame header check failed!\n");
773 av_log(avctx, AV_LOG_ERROR, "got %X.\n", imc_hdr);
774 return AVERROR_INVALIDDATA;
776 stream_format_code = get_bits(&q->gb, 3);
778 if (stream_format_code & 1) {
779 av_log_ask_for_sample(avctx, "Stream format %X is not supported\n",
781 return AVERROR_PATCHWELCOME;
784 // av_log(avctx, AV_LOG_DEBUG, "stream_format_code = %d\n", stream_format_code);
786 if (stream_format_code & 0x04)
787 chctx->decoder_reset = 1;
789 if (chctx->decoder_reset) {
790 memset(q->out_samples, 0, COEFFS * sizeof(*q->out_samples));
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 == 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.data[0] + 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 float *src = (float*)q->frame.data[0], t1, t2;
964 for (i = 0; i < COEFFS; i++) {
974 *(AVFrame *)data = q->frame;
976 return IMC_BLOCK_SIZE * avctx->channels;
980 static av_cold int imc_decode_close(AVCodecContext * avctx)
982 IMCContext *q = avctx->priv_data;
989 #if CONFIG_IMC_DECODER
990 AVCodec ff_imc_decoder = {
992 .type = AVMEDIA_TYPE_AUDIO,
994 .priv_data_size = sizeof(IMCContext),
995 .init = imc_decode_init,
996 .close = imc_decode_close,
997 .decode = imc_decode_frame,
998 .capabilities = CODEC_CAP_DR1,
999 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
1002 #if CONFIG_IAC_DECODER
1003 AVCodec ff_iac_decoder = {
1005 .type = AVMEDIA_TYPE_AUDIO,
1007 .priv_data_size = sizeof(IMCContext),
1008 .init = imc_decode_init,
1009 .close = imc_decode_close,
1010 .decode = imc_decode_frame,
1011 .capabilities = CODEC_CAP_DR1,
1012 .long_name = NULL_IF_CONFIG_SMALL("IAC (Indeo Audio Coder)"),