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.
37 #include "libavutil/channel_layout.h"
38 #include "libavutil/ffmath.h"
39 #include "libavutil/float_dsp.h"
40 #include "libavutil/internal.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 coefficients 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];
82 typedef struct IMCContext {
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];
98 void (*butterflies_float)(float *av_restrict v1, float *av_restrict v2, int len);
100 DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS / 2];
105 int8_t cyclTab[32], cyclTab2[32];
106 float weights1[31], weights2[31];
108 AVCodecContext *avctx;
111 static VLC huffman_vlc[4][4];
113 #define IMC_VLC_BITS 9
114 #define VLC_TABLES_SIZE 9512
116 static const int vlc_offsets[17] = {
117 0, 640, 1156, 1732, 2308, 2852, 3396, 3924,
118 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE
121 static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];
123 static inline double freq2bark(double freq)
125 return 3.5 * atan((freq / 7500.0) * (freq / 7500.0)) + 13.0 * atan(freq * 0.00076);
128 static av_cold void iac_generate_tabs(IMCContext *q, int sampling_rate)
130 double freqmin[32], freqmid[32], freqmax[32];
131 double scale = sampling_rate / (256.0 * 2.0 * 2.0);
132 double nyquist_freq = sampling_rate * 0.5;
133 double freq, bark, prev_bark = 0, tf, tb;
136 for (i = 0; i < 32; i++) {
137 freq = (band_tab[i] + band_tab[i + 1] - 1) * scale;
138 bark = freq2bark(freq);
141 tb = bark - prev_bark;
142 q->weights1[i - 1] = ff_exp10(-1.0 * tb);
143 q->weights2[i - 1] = ff_exp10(-2.7 * tb);
150 while (tf < nyquist_freq) {
162 if (tb <= bark - 0.5)
168 for (i = 0; i < 32; i++) {
170 for (j = 31; j > 0 && freq <= freqmid[j]; j--);
171 q->cyclTab[i] = j + 1;
174 for (j = 0; j < 32 && freq >= freqmid[j]; j++);
175 q->cyclTab2[i] = j - 1;
179 static av_cold int imc_decode_init(AVCodecContext *avctx)
182 IMCContext *q = avctx->priv_data;
183 AVFloatDSPContext *fdsp;
186 if (avctx->codec_id == AV_CODEC_ID_IAC && avctx->sample_rate > 96000) {
187 av_log(avctx, AV_LOG_ERROR,
188 "Strange sample rate of %i, file likely corrupt or "
189 "needing a new table derivation method.\n",
191 return AVERROR_PATCHWELCOME;
194 if (avctx->codec_id == AV_CODEC_ID_IMC)
197 if (avctx->channels > 2) {
198 avpriv_request_sample(avctx, "Number of channels > 2");
199 return AVERROR_PATCHWELCOME;
202 for (j = 0; j < avctx->channels; j++) {
203 q->chctx[j].decoder_reset = 1;
205 for (i = 0; i < BANDS; i++)
206 q->chctx[j].old_floor[i] = 1.0;
208 for (i = 0; i < COEFFS / 2; i++)
209 q->chctx[j].last_fft_im[i] = 0;
212 /* Build mdct window, a simple sine window normalized with sqrt(2) */
213 ff_sine_window_init(q->mdct_sine_window, COEFFS);
214 for (i = 0; i < COEFFS; i++)
215 q->mdct_sine_window[i] *= sqrt(2.0);
216 for (i = 0; i < COEFFS / 2; i++) {
217 q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI);
218 q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI);
220 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
221 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
224 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
225 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
227 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
228 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
232 /* Generate a square root table */
234 for (i = 0; i < 30; i++)
235 q->sqrt_tab[i] = sqrt(i);
237 /* initialize the VLC tables */
238 for (i = 0; i < 4 ; i++) {
239 for (j = 0; j < 4; j++) {
240 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]];
241 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];
242 ff_init_vlc_from_lengths(&huffman_vlc[i][j], IMC_VLC_BITS, imc_huffman_sizes[i],
243 imc_huffman_lens[i][j], 1,
244 imc_huffman_syms[i][j], 1, 1,
245 0, INIT_VLC_USE_NEW_STATIC, NULL);
249 if (avctx->codec_id == AV_CODEC_ID_IAC) {
250 iac_generate_tabs(q, avctx->sample_rate);
252 memcpy(q->cyclTab, cyclTab, sizeof(cyclTab));
253 memcpy(q->cyclTab2, cyclTab2, sizeof(cyclTab2));
254 memcpy(q->weights1, imc_weights1, sizeof(imc_weights1));
255 memcpy(q->weights2, imc_weights2, sizeof(imc_weights2));
258 fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
260 return AVERROR(ENOMEM);
261 q->butterflies_float = fdsp->butterflies_float;
263 if ((ret = ff_fft_init(&q->fft, 7, 1))) {
264 av_log(avctx, AV_LOG_INFO, "FFT init failed\n");
267 ff_bswapdsp_init(&q->bdsp);
269 avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
270 avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
271 : AV_CH_LAYOUT_STEREO;
276 static void imc_calculate_coeffs(IMCContext *q, float *flcoeffs1,
277 float *flcoeffs2, int *bandWidthT,
278 float *flcoeffs3, float *flcoeffs5)
283 float snr_limit = 1.e-30;
287 for (i = 0; i < BANDS; i++) {
288 flcoeffs5[i] = workT2[i] = 0.0;
290 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
291 flcoeffs3[i] = 2.0 * flcoeffs2[i];
294 flcoeffs3[i] = -30000.0;
296 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
297 if (workT3[i] <= snr_limit)
301 for (i = 0; i < BANDS; i++) {
302 for (cnt2 = i; cnt2 < q->cyclTab[i]; cnt2++)
303 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
304 workT2[cnt2 - 1] = workT2[cnt2 - 1] + workT3[i];
307 for (i = 1; i < BANDS; i++) {
308 accum = (workT2[i - 1] + accum) * q->weights1[i - 1];
309 flcoeffs5[i] += accum;
312 for (i = 0; i < BANDS; i++)
315 for (i = 0; i < BANDS; i++) {
316 for (cnt2 = i - 1; cnt2 > q->cyclTab2[i]; cnt2--)
317 flcoeffs5[cnt2] += workT3[i];
318 workT2[cnt2+1] += workT3[i];
323 for (i = BANDS-2; i >= 0; i--) {
324 accum = (workT2[i+1] + accum) * q->weights2[i];
325 flcoeffs5[i] += accum;
326 // there is missing code here, but it seems to never be triggered
331 static void imc_read_level_coeffs(IMCContext *q, int stream_format_code,
337 const uint8_t *cb_sel;
340 s = stream_format_code >> 1;
341 hufftab[0] = &huffman_vlc[s][0];
342 hufftab[1] = &huffman_vlc[s][1];
343 hufftab[2] = &huffman_vlc[s][2];
344 hufftab[3] = &huffman_vlc[s][3];
345 cb_sel = imc_cb_select[s];
347 if (stream_format_code & 4)
350 levlCoeffs[0] = get_bits(&q->gb, 7);
351 for (i = start; i < BANDS; i++) {
352 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table,
354 if (levlCoeffs[i] == 17)
355 levlCoeffs[i] += get_bits(&q->gb, 4);
359 static void imc_read_level_coeffs_raw(IMCContext *q, int stream_format_code,
364 q->coef0_pos = get_bits(&q->gb, 5);
365 levlCoeffs[0] = get_bits(&q->gb, 7);
366 for (i = 1; i < BANDS; i++)
367 levlCoeffs[i] = get_bits(&q->gb, 4);
370 static void imc_decode_level_coefficients(IMCContext *q, int *levlCoeffBuf,
371 float *flcoeffs1, float *flcoeffs2)
375 // maybe some frequency division thingy
377 flcoeffs1[0] = 20000.0 / exp2 (levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
378 flcoeffs2[0] = log2f(flcoeffs1[0]);
382 for (i = 1; i < BANDS; i++) {
383 level = levlCoeffBuf[i];
390 else if (level <= 24)
395 tmp *= imc_exp_tab[15 + level];
396 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
404 static void imc_decode_level_coefficients2(IMCContext *q, int *levlCoeffBuf,
405 float *old_floor, float *flcoeffs1,
409 /* FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
410 * and flcoeffs2 old scale factors
411 * might be incomplete due to a missing table that is in the binary code
413 for (i = 0; i < BANDS; i++) {
415 if (levlCoeffBuf[i] < 16) {
416 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
417 flcoeffs2[i] = (levlCoeffBuf[i] - 7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
419 flcoeffs1[i] = old_floor[i];
424 static void imc_decode_level_coefficients_raw(IMCContext *q, int *levlCoeffBuf,
425 float *flcoeffs1, float *flcoeffs2)
431 flcoeffs1[pos] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
432 flcoeffs2[pos] = log2f(flcoeffs1[pos]);
433 tmp = flcoeffs1[pos];
434 tmp2 = flcoeffs2[pos];
437 for (i = 0; i < BANDS; i++) {
440 level = *levlCoeffBuf++;
441 flcoeffs1[i] = tmp * powf(10.0, -level * 0.4375); //todo tab
442 flcoeffs2[i] = tmp2 - 1.4533435415 * level; // 1.4533435415 = log2(10) * 0.4375
447 * Perform bit allocation depending on bits available
449 static int bit_allocation(IMCContext *q, IMCChannel *chctx,
450 int stream_format_code, int freebits, int flag)
453 const float limit = -1.e20;
462 float lowest = 1.e10;
468 for (i = 0; i < BANDS; i++)
469 highest = FFMAX(highest, chctx->flcoeffs1[i]);
471 for (i = 0; i < BANDS - 1; i++) {
472 if (chctx->flcoeffs5[i] <= 0) {
473 av_log(q->avctx, AV_LOG_ERROR, "flcoeffs5 %f invalid\n", chctx->flcoeffs5[i]);
474 return AVERROR_INVALIDDATA;
476 chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log2f(chctx->flcoeffs5[i]);
478 chctx->flcoeffs4[BANDS - 1] = limit;
480 highest = highest * 0.25;
482 for (i = 0; i < BANDS; i++) {
484 if ((band_tab[i + 1] - band_tab[i]) == chctx->bandWidthT[i])
487 if ((band_tab[i + 1] - band_tab[i]) > chctx->bandWidthT[i])
490 if (((band_tab[i + 1] - band_tab[i]) / 2) >= chctx->bandWidthT[i])
494 return AVERROR_INVALIDDATA;
496 chctx->flcoeffs4[i] += xTab[(indx * 2 + (chctx->flcoeffs1[i] < highest)) * 2 + flag];
499 if (stream_format_code & 0x2) {
500 chctx->flcoeffs4[0] = limit;
501 chctx->flcoeffs4[1] = limit;
502 chctx->flcoeffs4[2] = limit;
503 chctx->flcoeffs4[3] = limit;
506 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS - 1; i++) {
507 iacc += chctx->bandWidthT[i];
508 summa += chctx->bandWidthT[i] * chctx->flcoeffs4[i];
512 return AVERROR_INVALIDDATA;
514 chctx->bandWidthT[BANDS - 1] = 0;
515 summa = (summa * 0.5 - freebits) / iacc;
518 for (i = 0; i < BANDS / 2; i++) {
519 rres = summer - freebits;
520 if ((rres >= -8) && (rres <= 8))
526 for (j = (stream_format_code & 0x2) ? 4 : 0; j < BANDS; j++) {
527 cwlen = av_clipf(((chctx->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
529 chctx->bitsBandT[j] = cwlen;
530 summer += chctx->bandWidthT[j] * cwlen;
533 iacc += chctx->bandWidthT[j];
538 if (freebits < summer)
545 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
548 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS; i++) {
549 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
550 chctx->CWlengthT[j] = chctx->bitsBandT[i];
553 if (freebits > summer) {
554 for (i = 0; i < BANDS; i++) {
555 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
556 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
562 if (highest <= -1.e20)
568 for (i = 0; i < BANDS; i++) {
569 if (workT[i] > highest) {
575 if (highest > -1.e20) {
576 workT[found_indx] -= 2.0;
577 if (++chctx->bitsBandT[found_indx] == 6)
578 workT[found_indx] = -1.e20;
580 for (j = band_tab[found_indx]; j < band_tab[found_indx + 1] && (freebits > summer); j++) {
581 chctx->CWlengthT[j]++;
585 } while (freebits > summer);
587 if (freebits < summer) {
588 for (i = 0; i < BANDS; i++) {
589 workT[i] = chctx->bitsBandT[i] ? (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] + 1.585)
592 if (stream_format_code & 0x2) {
598 while (freebits < summer) {
601 for (i = 0; i < BANDS; i++) {
602 if (workT[i] < lowest) {
607 // if (lowest >= 1.e10)
609 workT[low_indx] = lowest + 2.0;
611 if (!--chctx->bitsBandT[low_indx])
612 workT[low_indx] = 1.e20;
614 for (j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++) {
615 if (chctx->CWlengthT[j] > 0) {
616 chctx->CWlengthT[j]--;
625 static void imc_get_skip_coeff(IMCContext *q, IMCChannel *chctx)
629 memset(chctx->skipFlagBits, 0, sizeof(chctx->skipFlagBits));
630 memset(chctx->skipFlagCount, 0, sizeof(chctx->skipFlagCount));
631 for (i = 0; i < BANDS; i++) {
632 if (!chctx->bandFlagsBuf[i] || !chctx->bandWidthT[i])
635 if (!chctx->skipFlagRaw[i]) {
636 chctx->skipFlagBits[i] = band_tab[i + 1] - band_tab[i];
638 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
639 chctx->skipFlags[j] = get_bits1(&q->gb);
640 if (chctx->skipFlags[j])
641 chctx->skipFlagCount[i]++;
644 for (j = band_tab[i]; j < band_tab[i + 1] - 1; j += 2) {
645 if (!get_bits1(&q->gb)) { // 0
646 chctx->skipFlagBits[i]++;
647 chctx->skipFlags[j] = 1;
648 chctx->skipFlags[j + 1] = 1;
649 chctx->skipFlagCount[i] += 2;
651 if (get_bits1(&q->gb)) { // 11
652 chctx->skipFlagBits[i] += 2;
653 chctx->skipFlags[j] = 0;
654 chctx->skipFlags[j + 1] = 1;
655 chctx->skipFlagCount[i]++;
657 chctx->skipFlagBits[i] += 3;
658 chctx->skipFlags[j + 1] = 0;
659 if (!get_bits1(&q->gb)) { // 100
660 chctx->skipFlags[j] = 1;
661 chctx->skipFlagCount[i]++;
663 chctx->skipFlags[j] = 0;
669 if (j < band_tab[i + 1]) {
670 chctx->skipFlagBits[i]++;
671 if ((chctx->skipFlags[j] = get_bits1(&q->gb)))
672 chctx->skipFlagCount[i]++;
679 * Increase highest' band coefficient sizes as some bits won't be used
681 static void imc_adjust_bit_allocation(IMCContext *q, IMCChannel *chctx,
690 for (i = 0; i < BANDS; i++) {
691 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
692 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
695 while (corrected < summer) {
696 if (highest <= -1.e20)
701 for (i = 0; i < BANDS; i++) {
702 if (workT[i] > highest) {
708 if (highest > -1.e20) {
709 workT[found_indx] -= 2.0;
710 if (++(chctx->bitsBandT[found_indx]) == 6)
711 workT[found_indx] = -1.e20;
713 for (j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
714 if (!chctx->skipFlags[j] && (chctx->CWlengthT[j] < 6)) {
715 chctx->CWlengthT[j]++;
723 static void imc_imdct256(IMCContext *q, IMCChannel *chctx, int channels)
727 float *dst1 = q->out_samples;
728 float *dst2 = q->out_samples + (COEFFS - 1);
731 for (i = 0; i < COEFFS / 2; i++) {
732 q->samples[i].re = -(q->pre_coef1[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
733 (q->pre_coef2[i] * chctx->CWdecoded[i * 2]);
734 q->samples[i].im = (q->pre_coef2[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
735 (q->pre_coef1[i] * chctx->CWdecoded[i * 2]);
739 q->fft.fft_permute(&q->fft, q->samples);
740 q->fft.fft_calc(&q->fft, q->samples);
742 /* postrotation, window and reorder */
743 for (i = 0; i < COEFFS / 2; i++) {
744 re = ( q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
745 im = (-q->samples[i].im * q->post_cos[i]) - ( q->samples[i].re * q->post_sin[i]);
746 *dst1 = (q->mdct_sine_window[COEFFS - 1 - i * 2] * chctx->last_fft_im[i])
747 + (q->mdct_sine_window[i * 2] * re);
748 *dst2 = (q->mdct_sine_window[i * 2] * chctx->last_fft_im[i])
749 - (q->mdct_sine_window[COEFFS - 1 - i * 2] * re);
752 chctx->last_fft_im[i] = im;
756 static int inverse_quant_coeff(IMCContext *q, IMCChannel *chctx,
757 int stream_format_code)
760 int middle_value, cw_len, max_size;
761 const float *quantizer;
763 for (i = 0; i < BANDS; i++) {
764 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
765 chctx->CWdecoded[j] = 0;
766 cw_len = chctx->CWlengthT[j];
768 if (cw_len <= 0 || chctx->skipFlags[j])
771 max_size = 1 << cw_len;
772 middle_value = max_size >> 1;
774 if (chctx->codewords[j] >= max_size || chctx->codewords[j] < 0)
775 return AVERROR_INVALIDDATA;
778 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
779 if (chctx->codewords[j] >= middle_value)
780 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 8] * chctx->flcoeffs6[i];
782 chctx->CWdecoded[j] = -quantizer[max_size - chctx->codewords[j] - 8 - 1] * chctx->flcoeffs6[i];
784 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (chctx->bandFlagsBuf[i] << 1)];
785 if (chctx->codewords[j] >= middle_value)
786 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 1] * chctx->flcoeffs6[i];
788 chctx->CWdecoded[j] = -quantizer[max_size - 2 - chctx->codewords[j]] * chctx->flcoeffs6[i];
796 static void imc_get_coeffs(AVCodecContext *avctx,
797 IMCContext *q, IMCChannel *chctx)
799 int i, j, cw_len, cw;
801 for (i = 0; i < BANDS; i++) {
802 if (!chctx->sumLenArr[i])
804 if (chctx->bandFlagsBuf[i] || chctx->bandWidthT[i]) {
805 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
806 cw_len = chctx->CWlengthT[j];
809 if (cw_len && (!chctx->bandFlagsBuf[i] || !chctx->skipFlags[j])) {
810 if (get_bits_count(&q->gb) + cw_len > 512) {
811 av_log(avctx, AV_LOG_WARNING,
812 "Potential problem on band %i, coefficient %i"
813 ": cw_len=%i\n", i, j, cw_len);
815 cw = get_bits(&q->gb, cw_len);
818 chctx->codewords[j] = cw;
824 static void imc_refine_bit_allocation(IMCContext *q, IMCChannel *chctx)
829 for (i = 0; i < BANDS; i++) {
830 chctx->sumLenArr[i] = 0;
831 chctx->skipFlagRaw[i] = 0;
832 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
833 chctx->sumLenArr[i] += chctx->CWlengthT[j];
834 if (chctx->bandFlagsBuf[i])
835 if (((int)((band_tab[i + 1] - band_tab[i]) * 1.5) > chctx->sumLenArr[i]) && (chctx->sumLenArr[i] > 0))
836 chctx->skipFlagRaw[i] = 1;
839 imc_get_skip_coeff(q, chctx);
841 for (i = 0; i < BANDS; i++) {
842 chctx->flcoeffs6[i] = chctx->flcoeffs1[i];
843 /* band has flag set and at least one coded coefficient */
844 if (chctx->bandFlagsBuf[i] && (band_tab[i + 1] - band_tab[i]) != chctx->skipFlagCount[i]) {
845 chctx->flcoeffs6[i] *= q->sqrt_tab[ band_tab[i + 1] - band_tab[i]] /
846 q->sqrt_tab[(band_tab[i + 1] - band_tab[i] - chctx->skipFlagCount[i])];
850 /* calculate bits left, bits needed and adjust bit allocation */
853 for (i = 0; i < BANDS; i++) {
854 if (chctx->bandFlagsBuf[i]) {
855 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
856 if (chctx->skipFlags[j]) {
857 summer += chctx->CWlengthT[j];
858 chctx->CWlengthT[j] = 0;
861 bits += chctx->skipFlagBits[i];
862 summer -= chctx->skipFlagBits[i];
865 imc_adjust_bit_allocation(q, chctx, summer);
868 static int imc_decode_block(AVCodecContext *avctx, IMCContext *q, int ch)
870 int stream_format_code;
871 int imc_hdr, i, j, ret;
874 int counter, bitscount;
875 IMCChannel *chctx = q->chctx + ch;
878 /* Check the frame header */
879 imc_hdr = get_bits(&q->gb, 9);
880 if (imc_hdr & 0x18) {
881 av_log(avctx, AV_LOG_ERROR, "frame header check failed!\n");
882 av_log(avctx, AV_LOG_ERROR, "got %X.\n", imc_hdr);
883 return AVERROR_INVALIDDATA;
885 stream_format_code = get_bits(&q->gb, 3);
887 if (stream_format_code & 0x04)
888 chctx->decoder_reset = 1;
890 if (chctx->decoder_reset) {
891 for (i = 0; i < BANDS; i++)
892 chctx->old_floor[i] = 1.0;
893 for (i = 0; i < COEFFS; i++)
894 chctx->CWdecoded[i] = 0;
895 chctx->decoder_reset = 0;
898 flag = get_bits1(&q->gb);
899 if (stream_format_code & 0x1)
900 imc_read_level_coeffs_raw(q, stream_format_code, chctx->levlCoeffBuf);
902 imc_read_level_coeffs(q, stream_format_code, chctx->levlCoeffBuf);
904 if (stream_format_code & 0x1)
905 imc_decode_level_coefficients_raw(q, chctx->levlCoeffBuf,
906 chctx->flcoeffs1, chctx->flcoeffs2);
907 else if (stream_format_code & 0x4)
908 imc_decode_level_coefficients(q, chctx->levlCoeffBuf,
909 chctx->flcoeffs1, chctx->flcoeffs2);
911 imc_decode_level_coefficients2(q, chctx->levlCoeffBuf, chctx->old_floor,
912 chctx->flcoeffs1, chctx->flcoeffs2);
914 for(i=0; i<BANDS; i++) {
915 if(chctx->flcoeffs1[i] > INT_MAX) {
916 av_log(avctx, AV_LOG_ERROR, "scalefactor out of range\n");
917 return AVERROR_INVALIDDATA;
921 memcpy(chctx->old_floor, chctx->flcoeffs1, 32 * sizeof(float));
924 if (stream_format_code & 0x1) {
925 for (i = 0; i < BANDS; i++) {
926 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
927 chctx->bandFlagsBuf[i] = 0;
928 chctx->flcoeffs3[i] = chctx->flcoeffs2[i] * 2;
929 chctx->flcoeffs5[i] = 1.0;
932 for (i = 0; i < BANDS; i++) {
933 if (chctx->levlCoeffBuf[i] == 16) {
934 chctx->bandWidthT[i] = 0;
937 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
940 memset(chctx->bandFlagsBuf, 0, BANDS * sizeof(int));
941 for (i = 0; i < BANDS - 1; i++)
942 if (chctx->bandWidthT[i])
943 chctx->bandFlagsBuf[i] = get_bits1(&q->gb);
945 imc_calculate_coeffs(q, chctx->flcoeffs1, chctx->flcoeffs2,
946 chctx->bandWidthT, chctx->flcoeffs3,
951 /* first 4 bands will be assigned 5 bits per coefficient */
952 if (stream_format_code & 0x2) {
955 chctx->bitsBandT[0] = 5;
956 chctx->CWlengthT[0] = 5;
957 chctx->CWlengthT[1] = 5;
958 chctx->CWlengthT[2] = 5;
959 for (i = 1; i < 4; i++) {
960 if (stream_format_code & 0x1)
963 bits = (chctx->levlCoeffBuf[i] == 16) ? 0 : 5;
964 chctx->bitsBandT[i] = bits;
965 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
966 chctx->CWlengthT[j] = bits;
971 if (avctx->codec_id == AV_CODEC_ID_IAC) {
972 bitscount += !!chctx->bandWidthT[BANDS - 1];
973 if (!(stream_format_code & 0x2))
977 if ((ret = bit_allocation(q, chctx, stream_format_code,
978 512 - bitscount - get_bits_count(&q->gb),
980 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
981 chctx->decoder_reset = 1;
985 if (stream_format_code & 0x1) {
986 for (i = 0; i < BANDS; i++)
987 chctx->skipFlags[i] = 0;
989 imc_refine_bit_allocation(q, chctx);
992 for (i = 0; i < BANDS; i++) {
993 chctx->sumLenArr[i] = 0;
995 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
996 if (!chctx->skipFlags[j])
997 chctx->sumLenArr[i] += chctx->CWlengthT[j];
1000 memset(chctx->codewords, 0, sizeof(chctx->codewords));
1002 imc_get_coeffs(avctx, q, chctx);
1004 if (inverse_quant_coeff(q, chctx, stream_format_code) < 0) {
1005 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
1006 chctx->decoder_reset = 1;
1007 return AVERROR_INVALIDDATA;
1010 memset(chctx->skipFlags, 0, sizeof(chctx->skipFlags));
1012 imc_imdct256(q, chctx, avctx->channels);
1017 static int imc_decode_frame(AVCodecContext *avctx, void *data,
1018 int *got_frame_ptr, AVPacket *avpkt)
1020 AVFrame *frame = data;
1021 const uint8_t *buf = avpkt->data;
1022 int buf_size = avpkt->size;
1025 IMCContext *q = avctx->priv_data;
1027 LOCAL_ALIGNED_16(uint16_t, buf16, [(IMC_BLOCK_SIZE + AV_INPUT_BUFFER_PADDING_SIZE) / 2]);
1031 if (buf_size < IMC_BLOCK_SIZE * avctx->channels) {
1032 av_log(avctx, AV_LOG_ERROR, "frame too small!\n");
1033 return AVERROR_INVALIDDATA;
1036 /* get output buffer */
1037 frame->nb_samples = COEFFS;
1038 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1041 for (i = 0; i < avctx->channels; i++) {
1042 q->out_samples = (float *)frame->extended_data[i];
1044 q->bdsp.bswap16_buf(buf16, (const uint16_t *) buf, IMC_BLOCK_SIZE / 2);
1046 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
1048 buf += IMC_BLOCK_SIZE;
1050 if ((ret = imc_decode_block(avctx, q, i)) < 0)
1054 if (avctx->channels == 2) {
1055 q->butterflies_float((float *)frame->extended_data[0],
1056 (float *)frame->extended_data[1], COEFFS);
1061 return IMC_BLOCK_SIZE * avctx->channels;
1064 static av_cold int imc_decode_close(AVCodecContext * avctx)
1066 IMCContext *q = avctx->priv_data;
1068 ff_fft_end(&q->fft);
1073 static av_cold void flush(AVCodecContext *avctx)
1075 IMCContext *q = avctx->priv_data;
1077 q->chctx[0].decoder_reset =
1078 q->chctx[1].decoder_reset = 1;
1081 #if CONFIG_IMC_DECODER
1082 AVCodec ff_imc_decoder = {
1084 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
1085 .type = AVMEDIA_TYPE_AUDIO,
1086 .id = AV_CODEC_ID_IMC,
1087 .priv_data_size = sizeof(IMCContext),
1088 .init = imc_decode_init,
1089 .close = imc_decode_close,
1090 .decode = imc_decode_frame,
1092 .capabilities = AV_CODEC_CAP_DR1,
1093 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1094 AV_SAMPLE_FMT_NONE },
1097 #if CONFIG_IAC_DECODER
1098 AVCodec ff_iac_decoder = {
1100 .long_name = NULL_IF_CONFIG_SMALL("IAC (Indeo Audio Coder)"),
1101 .type = AVMEDIA_TYPE_AUDIO,
1102 .id = AV_CODEC_ID_IAC,
1103 .priv_data_size = sizeof(IMCContext),
1104 .init = imc_decode_init,
1105 .close = imc_decode_close,
1106 .decode = imc_decode_frame,
1108 .capabilities = AV_CODEC_CAP_DR1,
1109 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1110 AV_SAMPLE_FMT_NONE },