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 Libav.
9 * Libav 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 * Libav 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 Libav; 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"
49 #define IMC_BLOCK_SIZE 64
50 #define IMC_FRAME_ID 0x21
54 typedef struct IMCChannel {
55 float old_floor[BANDS];
56 float flcoeffs1[BANDS];
57 float flcoeffs2[BANDS];
58 float flcoeffs3[BANDS];
59 float flcoeffs4[BANDS];
60 float flcoeffs5[BANDS];
61 float flcoeffs6[BANDS];
62 float CWdecoded[COEFFS];
64 int bandWidthT[BANDS]; ///< codewords per band
65 int bitsBandT[BANDS]; ///< how many bits per codeword in band
66 int CWlengthT[COEFFS]; ///< how many bits in each codeword
67 int levlCoeffBuf[BANDS];
68 int bandFlagsBuf[BANDS]; ///< flags for each band
69 int sumLenArr[BANDS]; ///< bits for all coeffs in band
70 int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not
71 int skipFlagBits[BANDS]; ///< bits used to code skip flags
72 int skipFlagCount[BANDS]; ///< skipped coeffients per band
73 int skipFlags[COEFFS]; ///< skip coefficient decoding or not
74 int codewords[COEFFS]; ///< raw codewords read from bitstream
76 float last_fft_im[COEFFS];
88 float mdct_sine_window[COEFFS];
89 float post_cos[COEFFS];
90 float post_sin[COEFFS];
91 float pre_coef1[COEFFS];
92 float pre_coef2[COEFFS];
99 AVFloatDSPContext fdsp;
101 DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS / 2];
104 int8_t cyclTab[32], cyclTab2[32];
105 float weights1[31], weights2[31];
108 static VLC huffman_vlc[4][4];
110 #define VLC_TABLES_SIZE 9512
112 static const int vlc_offsets[17] = {
113 0, 640, 1156, 1732, 2308, 2852, 3396, 3924,
114 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE
117 static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];
119 static inline double freq2bark(double freq)
121 return 3.5 * atan((freq / 7500.0) * (freq / 7500.0)) + 13.0 * atan(freq * 0.00076);
124 static av_cold void iac_generate_tabs(IMCContext *q, int sampling_rate)
126 double freqmin[32], freqmid[32], freqmax[32];
127 double scale = sampling_rate / (256.0 * 2.0 * 2.0);
128 double nyquist_freq = sampling_rate * 0.5;
129 double freq, bark, prev_bark = 0, tf, tb;
132 for (i = 0; i < 32; i++) {
133 freq = (band_tab[i] + band_tab[i + 1] - 1) * scale;
134 bark = freq2bark(freq);
137 tb = bark - prev_bark;
138 q->weights1[i - 1] = pow(10.0, -1.0 * tb);
139 q->weights2[i - 1] = pow(10.0, -2.7 * tb);
146 while (tf < nyquist_freq) {
158 if (tb <= bark - 0.5)
164 for (i = 0; i < 32; i++) {
166 for (j = 31; j > 0 && freq <= freqmid[j]; j--);
167 q->cyclTab[i] = j + 1;
170 for (j = 0; j < 32 && freq >= freqmid[j]; j++);
171 q->cyclTab2[i] = j - 1;
175 static av_cold int imc_decode_init(AVCodecContext *avctx)
178 IMCContext *q = avctx->priv_data;
181 if (avctx->codec_id == AV_CODEC_ID_IMC)
184 if (avctx->channels > 2) {
185 av_log_ask_for_sample(avctx, "Number of channels is not supported\n");
186 return AVERROR_PATCHWELCOME;
189 for (j = 0; j < avctx->channels; j++) {
190 q->chctx[j].decoder_reset = 1;
192 for (i = 0; i < BANDS; i++)
193 q->chctx[j].old_floor[i] = 1.0;
195 for (i = 0; i < COEFFS / 2; i++)
196 q->chctx[j].last_fft_im[i] = 0;
199 /* Build mdct window, a simple sine window normalized with sqrt(2) */
200 ff_sine_window_init(q->mdct_sine_window, COEFFS);
201 for (i = 0; i < COEFFS; i++)
202 q->mdct_sine_window[i] *= sqrt(2.0);
203 for (i = 0; i < COEFFS / 2; i++) {
204 q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI);
205 q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI);
207 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
208 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
211 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
212 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
214 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
215 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
219 /* Generate a square root table */
221 for (i = 0; i < 30; i++)
222 q->sqrt_tab[i] = sqrt(i);
224 /* initialize the VLC tables */
225 for (i = 0; i < 4 ; i++) {
226 for (j = 0; j < 4; j++) {
227 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]];
228 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];
229 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i],
230 imc_huffman_lens[i][j], 1, 1,
231 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC);
235 if (avctx->codec_id == AV_CODEC_ID_IAC) {
236 iac_generate_tabs(q, avctx->sample_rate);
238 memcpy(q->cyclTab, cyclTab, sizeof(cyclTab));
239 memcpy(q->cyclTab2, cyclTab2, sizeof(cyclTab2));
240 memcpy(q->weights1, imc_weights1, sizeof(imc_weights1));
241 memcpy(q->weights2, imc_weights2, sizeof(imc_weights2));
244 if ((ret = ff_fft_init(&q->fft, 7, 1))) {
245 av_log(avctx, AV_LOG_INFO, "FFT init failed\n");
248 ff_dsputil_init(&q->dsp, avctx);
249 avpriv_float_dsp_init(&q->fdsp, avctx->flags & CODEC_FLAG_BITEXACT);
250 avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
251 avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
252 : AV_CH_LAYOUT_STEREO;
254 avcodec_get_frame_defaults(&q->frame);
255 avctx->coded_frame = &q->frame;
260 static void imc_calculate_coeffs(IMCContext *q, float *flcoeffs1,
261 float *flcoeffs2, int *bandWidthT,
262 float *flcoeffs3, float *flcoeffs5)
267 float snr_limit = 1.e-30;
271 for (i = 0; i < BANDS; i++) {
272 flcoeffs5[i] = workT2[i] = 0.0;
274 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
275 flcoeffs3[i] = 2.0 * flcoeffs2[i];
278 flcoeffs3[i] = -30000.0;
280 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
281 if (workT3[i] <= snr_limit)
285 for (i = 0; i < BANDS; i++) {
286 for (cnt2 = i; cnt2 < q->cyclTab[i]; cnt2++)
287 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
288 workT2[cnt2 - 1] = workT2[cnt2 - 1] + workT3[i];
291 for (i = 1; i < BANDS; i++) {
292 accum = (workT2[i - 1] + accum) * q->weights1[i - 1];
293 flcoeffs5[i] += accum;
296 for (i = 0; i < BANDS; i++)
299 for (i = 0; i < BANDS; i++) {
300 for (cnt2 = i - 1; cnt2 > q->cyclTab2[i]; cnt2--)
301 flcoeffs5[cnt2] += workT3[i];
302 workT2[cnt2+1] += workT3[i];
307 for (i = BANDS-2; i >= 0; i--) {
308 accum = (workT2[i+1] + accum) * q->weights2[i];
309 flcoeffs5[i] += accum;
310 // there is missing code here, but it seems to never be triggered
315 static void imc_read_level_coeffs(IMCContext *q, int stream_format_code,
321 const uint8_t *cb_sel;
324 s = stream_format_code >> 1;
325 hufftab[0] = &huffman_vlc[s][0];
326 hufftab[1] = &huffman_vlc[s][1];
327 hufftab[2] = &huffman_vlc[s][2];
328 hufftab[3] = &huffman_vlc[s][3];
329 cb_sel = imc_cb_select[s];
331 if (stream_format_code & 4)
334 levlCoeffs[0] = get_bits(&q->gb, 7);
335 for (i = start; i < BANDS; i++) {
336 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table,
337 hufftab[cb_sel[i]]->bits, 2);
338 if (levlCoeffs[i] == 17)
339 levlCoeffs[i] += get_bits(&q->gb, 4);
343 static void imc_decode_level_coefficients(IMCContext *q, int *levlCoeffBuf,
344 float *flcoeffs1, float *flcoeffs2)
348 // maybe some frequency division thingy
350 flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
351 flcoeffs2[0] = log2f(flcoeffs1[0]);
355 for (i = 1; i < BANDS; i++) {
356 level = levlCoeffBuf[i];
363 else if (level <= 24)
368 tmp *= imc_exp_tab[15 + level];
369 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
377 static void imc_decode_level_coefficients2(IMCContext *q, int *levlCoeffBuf,
378 float *old_floor, float *flcoeffs1,
382 /* FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
383 * and flcoeffs2 old scale factors
384 * might be incomplete due to a missing table that is in the binary code
386 for (i = 0; i < BANDS; i++) {
388 if (levlCoeffBuf[i] < 16) {
389 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
390 flcoeffs2[i] = (levlCoeffBuf[i] - 7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
392 flcoeffs1[i] = old_floor[i];
398 * Perform bit allocation depending on bits available
400 static int bit_allocation(IMCContext *q, IMCChannel *chctx,
401 int stream_format_code, int freebits, int flag)
404 const float limit = -1.e20;
413 float lowest = 1.e10;
419 for (i = 0; i < BANDS; i++)
420 highest = FFMAX(highest, chctx->flcoeffs1[i]);
422 for (i = 0; i < BANDS - 1; i++)
423 chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log2f(chctx->flcoeffs5[i]);
424 chctx->flcoeffs4[BANDS - 1] = limit;
426 highest = highest * 0.25;
428 for (i = 0; i < BANDS; i++) {
430 if ((band_tab[i + 1] - band_tab[i]) == chctx->bandWidthT[i])
433 if ((band_tab[i + 1] - band_tab[i]) > chctx->bandWidthT[i])
436 if (((band_tab[i + 1] - band_tab[i]) / 2) >= chctx->bandWidthT[i])
440 return AVERROR_INVALIDDATA;
442 chctx->flcoeffs4[i] += xTab[(indx * 2 + (chctx->flcoeffs1[i] < highest)) * 2 + flag];
445 if (stream_format_code & 0x2) {
446 chctx->flcoeffs4[0] = limit;
447 chctx->flcoeffs4[1] = limit;
448 chctx->flcoeffs4[2] = limit;
449 chctx->flcoeffs4[3] = limit;
452 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS - 1; i++) {
453 iacc += chctx->bandWidthT[i];
454 summa += chctx->bandWidthT[i] * chctx->flcoeffs4[i];
456 chctx->bandWidthT[BANDS - 1] = 0;
457 summa = (summa * 0.5 - freebits) / iacc;
460 for (i = 0; i < BANDS / 2; i++) {
461 rres = summer - freebits;
462 if ((rres >= -8) && (rres <= 8))
468 for (j = (stream_format_code & 0x2) ? 4 : 0; j < BANDS; j++) {
469 cwlen = av_clipf(((chctx->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
471 chctx->bitsBandT[j] = cwlen;
472 summer += chctx->bandWidthT[j] * cwlen;
475 iacc += chctx->bandWidthT[j];
480 if (freebits < summer)
487 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
490 for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS; i++) {
491 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
492 chctx->CWlengthT[j] = chctx->bitsBandT[i];
495 if (freebits > summer) {
496 for (i = 0; i < BANDS; i++) {
497 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
498 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
504 if (highest <= -1.e20)
510 for (i = 0; i < BANDS; i++) {
511 if (workT[i] > highest) {
517 if (highest > -1.e20) {
518 workT[found_indx] -= 2.0;
519 if (++chctx->bitsBandT[found_indx] == 6)
520 workT[found_indx] = -1.e20;
522 for (j = band_tab[found_indx]; j < band_tab[found_indx + 1] && (freebits > summer); j++) {
523 chctx->CWlengthT[j]++;
527 } while (freebits > summer);
529 if (freebits < summer) {
530 for (i = 0; i < BANDS; i++) {
531 workT[i] = chctx->bitsBandT[i] ? (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] + 1.585)
534 if (stream_format_code & 0x2) {
540 while (freebits < summer) {
543 for (i = 0; i < BANDS; i++) {
544 if (workT[i] < lowest) {
549 // if (lowest >= 1.e10)
551 workT[low_indx] = lowest + 2.0;
553 if (!--chctx->bitsBandT[low_indx])
554 workT[low_indx] = 1.e20;
556 for (j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++) {
557 if (chctx->CWlengthT[j] > 0) {
558 chctx->CWlengthT[j]--;
567 static void imc_get_skip_coeff(IMCContext *q, IMCChannel *chctx)
571 memset(chctx->skipFlagBits, 0, sizeof(chctx->skipFlagBits));
572 memset(chctx->skipFlagCount, 0, sizeof(chctx->skipFlagCount));
573 for (i = 0; i < BANDS; i++) {
574 if (!chctx->bandFlagsBuf[i] || !chctx->bandWidthT[i])
577 if (!chctx->skipFlagRaw[i]) {
578 chctx->skipFlagBits[i] = band_tab[i + 1] - band_tab[i];
580 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
581 chctx->skipFlags[j] = get_bits1(&q->gb);
582 if (chctx->skipFlags[j])
583 chctx->skipFlagCount[i]++;
586 for (j = band_tab[i]; j < band_tab[i + 1] - 1; j += 2) {
587 if (!get_bits1(&q->gb)) { // 0
588 chctx->skipFlagBits[i]++;
589 chctx->skipFlags[j] = 1;
590 chctx->skipFlags[j + 1] = 1;
591 chctx->skipFlagCount[i] += 2;
593 if (get_bits1(&q->gb)) { // 11
594 chctx->skipFlagBits[i] += 2;
595 chctx->skipFlags[j] = 0;
596 chctx->skipFlags[j + 1] = 1;
597 chctx->skipFlagCount[i]++;
599 chctx->skipFlagBits[i] += 3;
600 chctx->skipFlags[j + 1] = 0;
601 if (!get_bits1(&q->gb)) { // 100
602 chctx->skipFlags[j] = 1;
603 chctx->skipFlagCount[i]++;
605 chctx->skipFlags[j] = 0;
611 if (j < band_tab[i + 1]) {
612 chctx->skipFlagBits[i]++;
613 if ((chctx->skipFlags[j] = get_bits1(&q->gb)))
614 chctx->skipFlagCount[i]++;
621 * Increase highest' band coefficient sizes as some bits won't be used
623 static void imc_adjust_bit_allocation(IMCContext *q, IMCChannel *chctx,
632 for (i = 0; i < BANDS; i++) {
633 workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
634 : (chctx->bitsBandT[i] * -2 + chctx->flcoeffs4[i] - 0.415);
637 while (corrected < summer) {
638 if (highest <= -1.e20)
643 for (i = 0; i < BANDS; i++) {
644 if (workT[i] > highest) {
650 if (highest > -1.e20) {
651 workT[found_indx] -= 2.0;
652 if (++(chctx->bitsBandT[found_indx]) == 6)
653 workT[found_indx] = -1.e20;
655 for (j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
656 if (!chctx->skipFlags[j] && (chctx->CWlengthT[j] < 6)) {
657 chctx->CWlengthT[j]++;
665 static void imc_imdct256(IMCContext *q, IMCChannel *chctx, int channels)
669 float *dst1 = q->out_samples;
670 float *dst2 = q->out_samples + (COEFFS - 1);
673 for (i = 0; i < COEFFS / 2; i++) {
674 q->samples[i].re = -(q->pre_coef1[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
675 (q->pre_coef2[i] * chctx->CWdecoded[i * 2]);
676 q->samples[i].im = (q->pre_coef2[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
677 (q->pre_coef1[i] * chctx->CWdecoded[i * 2]);
681 q->fft.fft_permute(&q->fft, q->samples);
682 q->fft.fft_calc(&q->fft, q->samples);
684 /* postrotation, window and reorder */
685 for (i = 0; i < COEFFS / 2; i++) {
686 re = ( q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
687 im = (-q->samples[i].im * q->post_cos[i]) - ( q->samples[i].re * q->post_sin[i]);
688 *dst1 = (q->mdct_sine_window[COEFFS - 1 - i * 2] * chctx->last_fft_im[i])
689 + (q->mdct_sine_window[i * 2] * re);
690 *dst2 = (q->mdct_sine_window[i * 2] * chctx->last_fft_im[i])
691 - (q->mdct_sine_window[COEFFS - 1 - i * 2] * re);
694 chctx->last_fft_im[i] = im;
698 static int inverse_quant_coeff(IMCContext *q, IMCChannel *chctx,
699 int stream_format_code)
702 int middle_value, cw_len, max_size;
703 const float *quantizer;
705 for (i = 0; i < BANDS; i++) {
706 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
707 chctx->CWdecoded[j] = 0;
708 cw_len = chctx->CWlengthT[j];
710 if (cw_len <= 0 || chctx->skipFlags[j])
713 max_size = 1 << cw_len;
714 middle_value = max_size >> 1;
716 if (chctx->codewords[j] >= max_size || chctx->codewords[j] < 0)
717 return AVERROR_INVALIDDATA;
720 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
721 if (chctx->codewords[j] >= middle_value)
722 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 8] * chctx->flcoeffs6[i];
724 chctx->CWdecoded[j] = -quantizer[max_size - chctx->codewords[j] - 8 - 1] * chctx->flcoeffs6[i];
726 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (chctx->bandFlagsBuf[i] << 1)];
727 if (chctx->codewords[j] >= middle_value)
728 chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 1] * chctx->flcoeffs6[i];
730 chctx->CWdecoded[j] = -quantizer[max_size - 2 - chctx->codewords[j]] * chctx->flcoeffs6[i];
738 static int imc_get_coeffs(IMCContext *q, IMCChannel *chctx)
740 int i, j, cw_len, cw;
742 for (i = 0; i < BANDS; i++) {
743 if (!chctx->sumLenArr[i])
745 if (chctx->bandFlagsBuf[i] || chctx->bandWidthT[i]) {
746 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
747 cw_len = chctx->CWlengthT[j];
750 if (get_bits_count(&q->gb) + cw_len > 512) {
751 av_dlog(NULL, "Band %i coeff %i cw_len %i\n", i, j, cw_len);
752 return AVERROR_INVALIDDATA;
755 if (cw_len && (!chctx->bandFlagsBuf[i] || !chctx->skipFlags[j]))
756 cw = get_bits(&q->gb, cw_len);
758 chctx->codewords[j] = cw;
765 static int imc_decode_block(AVCodecContext *avctx, IMCContext *q, int ch)
767 int stream_format_code;
768 int imc_hdr, i, j, ret;
771 int counter, bitscount;
772 IMCChannel *chctx = q->chctx + ch;
775 /* Check the frame header */
776 imc_hdr = get_bits(&q->gb, 9);
777 if (imc_hdr & 0x18) {
778 av_log(avctx, AV_LOG_ERROR, "frame header check failed!\n");
779 av_log(avctx, AV_LOG_ERROR, "got %X.\n", imc_hdr);
780 return AVERROR_INVALIDDATA;
782 stream_format_code = get_bits(&q->gb, 3);
784 if (stream_format_code & 1) {
785 av_log_ask_for_sample(avctx, "Stream format %X is not supported\n",
787 return AVERROR_PATCHWELCOME;
790 if (stream_format_code & 0x04)
791 chctx->decoder_reset = 1;
793 if (chctx->decoder_reset) {
794 for (i = 0; i < BANDS; i++)
795 chctx->old_floor[i] = 1.0;
796 for (i = 0; i < COEFFS; i++)
797 chctx->CWdecoded[i] = 0;
798 chctx->decoder_reset = 0;
801 flag = get_bits1(&q->gb);
802 imc_read_level_coeffs(q, stream_format_code, chctx->levlCoeffBuf);
804 if (stream_format_code & 0x4)
805 imc_decode_level_coefficients(q, chctx->levlCoeffBuf,
806 chctx->flcoeffs1, chctx->flcoeffs2);
808 imc_decode_level_coefficients2(q, chctx->levlCoeffBuf, chctx->old_floor,
809 chctx->flcoeffs1, chctx->flcoeffs2);
811 memcpy(chctx->old_floor, chctx->flcoeffs1, 32 * sizeof(float));
814 for (i = 0; i < BANDS; i++) {
815 if (chctx->levlCoeffBuf[i] == 16) {
816 chctx->bandWidthT[i] = 0;
819 chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
821 memset(chctx->bandFlagsBuf, 0, BANDS * sizeof(int));
822 for (i = 0; i < BANDS - 1; i++) {
823 if (chctx->bandWidthT[i])
824 chctx->bandFlagsBuf[i] = get_bits1(&q->gb);
827 imc_calculate_coeffs(q, chctx->flcoeffs1, chctx->flcoeffs2, chctx->bandWidthT, chctx->flcoeffs3, chctx->flcoeffs5);
830 /* first 4 bands will be assigned 5 bits per coefficient */
831 if (stream_format_code & 0x2) {
834 chctx->bitsBandT[0] = 5;
835 chctx->CWlengthT[0] = 5;
836 chctx->CWlengthT[1] = 5;
837 chctx->CWlengthT[2] = 5;
838 for (i = 1; i < 4; i++) {
839 bits = (chctx->levlCoeffBuf[i] == 16) ? 0 : 5;
840 chctx->bitsBandT[i] = bits;
841 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
842 chctx->CWlengthT[j] = bits;
847 if (avctx->codec_id == AV_CODEC_ID_IAC) {
848 bitscount += !!chctx->bandWidthT[BANDS - 1];
849 if (!(stream_format_code & 0x2))
853 if ((ret = bit_allocation(q, chctx, stream_format_code,
854 512 - bitscount - get_bits_count(&q->gb),
856 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
857 chctx->decoder_reset = 1;
861 for (i = 0; i < BANDS; i++) {
862 chctx->sumLenArr[i] = 0;
863 chctx->skipFlagRaw[i] = 0;
864 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
865 chctx->sumLenArr[i] += chctx->CWlengthT[j];
866 if (chctx->bandFlagsBuf[i])
867 if ((((band_tab[i + 1] - band_tab[i]) * 1.5) > chctx->sumLenArr[i]) && (chctx->sumLenArr[i] > 0))
868 chctx->skipFlagRaw[i] = 1;
871 imc_get_skip_coeff(q, chctx);
873 for (i = 0; i < BANDS; i++) {
874 chctx->flcoeffs6[i] = chctx->flcoeffs1[i];
875 /* band has flag set and at least one coded coefficient */
876 if (chctx->bandFlagsBuf[i] && (band_tab[i + 1] - band_tab[i]) != chctx->skipFlagCount[i]) {
877 chctx->flcoeffs6[i] *= q->sqrt_tab[ band_tab[i + 1] - band_tab[i]] /
878 q->sqrt_tab[(band_tab[i + 1] - band_tab[i] - chctx->skipFlagCount[i])];
882 /* calculate bits left, bits needed and adjust bit allocation */
885 for (i = 0; i < BANDS; i++) {
886 if (chctx->bandFlagsBuf[i]) {
887 for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
888 if (chctx->skipFlags[j]) {
889 summer += chctx->CWlengthT[j];
890 chctx->CWlengthT[j] = 0;
893 bits += chctx->skipFlagBits[i];
894 summer -= chctx->skipFlagBits[i];
897 imc_adjust_bit_allocation(q, chctx, summer);
899 for (i = 0; i < BANDS; i++) {
900 chctx->sumLenArr[i] = 0;
902 for (j = band_tab[i]; j < band_tab[i + 1]; j++)
903 if (!chctx->skipFlags[j])
904 chctx->sumLenArr[i] += chctx->CWlengthT[j];
907 memset(chctx->codewords, 0, sizeof(chctx->codewords));
909 if (imc_get_coeffs(q, chctx) < 0) {
910 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");
911 chctx->decoder_reset = 1;
912 return AVERROR_INVALIDDATA;
915 if (inverse_quant_coeff(q, chctx, stream_format_code) < 0) {
916 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
917 chctx->decoder_reset = 1;
918 return AVERROR_INVALIDDATA;
921 memset(chctx->skipFlags, 0, sizeof(chctx->skipFlags));
923 imc_imdct256(q, chctx, avctx->channels);
928 static int imc_decode_frame(AVCodecContext *avctx, void *data,
929 int *got_frame_ptr, AVPacket *avpkt)
931 const uint8_t *buf = avpkt->data;
932 int buf_size = avpkt->size;
935 IMCContext *q = avctx->priv_data;
937 LOCAL_ALIGNED_16(uint16_t, buf16, [IMC_BLOCK_SIZE / 2]);
939 if (buf_size < IMC_BLOCK_SIZE * avctx->channels) {
940 av_log(avctx, AV_LOG_ERROR, "frame too small!\n");
941 return AVERROR_INVALIDDATA;
944 /* get output buffer */
945 q->frame.nb_samples = COEFFS;
946 if ((ret = ff_get_buffer(avctx, &q->frame)) < 0) {
947 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
951 for (i = 0; i < avctx->channels; i++) {
952 q->out_samples = (float *)q->frame.extended_data[i];
954 q->dsp.bswap16_buf(buf16, (const uint16_t*)buf, IMC_BLOCK_SIZE / 2);
956 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
958 buf += IMC_BLOCK_SIZE;
960 if ((ret = imc_decode_block(avctx, q, i)) < 0)
964 if (avctx->channels == 2) {
965 q->fdsp.butterflies_float((float *)q->frame.extended_data[0],
966 (float *)q->frame.extended_data[1], COEFFS);
970 *(AVFrame *)data = q->frame;
972 return IMC_BLOCK_SIZE * avctx->channels;
976 static av_cold int imc_decode_close(AVCodecContext * avctx)
978 IMCContext *q = avctx->priv_data;
986 AVCodec ff_imc_decoder = {
988 .type = AVMEDIA_TYPE_AUDIO,
989 .id = AV_CODEC_ID_IMC,
990 .priv_data_size = sizeof(IMCContext),
991 .init = imc_decode_init,
992 .close = imc_decode_close,
993 .decode = imc_decode_frame,
994 .capabilities = CODEC_CAP_DR1,
995 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
996 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
997 AV_SAMPLE_FMT_NONE },
1000 AVCodec ff_iac_decoder = {
1002 .type = AVMEDIA_TYPE_AUDIO,
1003 .id = AV_CODEC_ID_IAC,
1004 .priv_data_size = sizeof(IMCContext),
1005 .init = imc_decode_init,
1006 .close = imc_decode_close,
1007 .decode = imc_decode_frame,
1008 .capabilities = CODEC_CAP_DR1,
1009 .long_name = NULL_IF_CONFIG_SMALL("IAC (Indeo Audio Coder)"),
1010 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1011 AV_SAMPLE_FMT_NONE },