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
25 * @file imc.c IMC - Intel Music Coder
26 * A mdct based codec using a 256 points large transform
27 * divied into 32 bands with some mix of scale factors.
28 * Only mono is supported.
37 #define ALT_BITSTREAM_READER
39 #include "bitstream.h"
44 #define IMC_BLOCK_SIZE 64
45 #define IMC_FRAME_ID 0x21
50 float old_floor[BANDS];
51 float flcoeffs1[BANDS];
52 float flcoeffs2[BANDS];
53 float flcoeffs3[BANDS];
54 float flcoeffs4[BANDS];
55 float flcoeffs5[BANDS];
56 float flcoeffs6[BANDS];
57 float CWdecoded[COEFFS];
61 float mdct_sine_window[COEFFS];
62 float post_cos[COEFFS];
63 float post_sin[COEFFS];
64 float pre_coef1[COEFFS];
65 float pre_coef2[COEFFS];
66 float last_fft_im[COEFFS];
69 int bandWidthT[BANDS]; ///< codewords per band
70 int bitsBandT[BANDS]; ///< how many bits per codeword in band
71 int CWlengthT[COEFFS]; ///< how many bits in each codeword
72 int levlCoeffBuf[BANDS];
73 int bandFlagsBuf[BANDS]; ///< flags for each band
74 int sumLenArr[BANDS]; ///< bits for all coeffs in band
75 int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not
76 int skipFlagBits[BANDS]; ///< bits used to code skip flags
77 int skipFlagCount[BANDS]; ///< skipped coeffients per band
78 int skipFlags[COEFFS]; ///< skip coefficient decoding or not
79 int codewords[COEFFS]; ///< raw codewords read from bitstream
87 DECLARE_ALIGNED_16(FFTComplex, samples[COEFFS/2]);
88 DECLARE_ALIGNED_16(float, out_samples[COEFFS]);
91 static VLC huffman_vlc[4][4];
93 #define VLC_TABLES_SIZE 9512
95 static const int vlc_offsets[17] = {
96 0, 640, 1156, 1732, 2308, 2852, 3396, 3924,
97 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE};
99 static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];
101 static av_cold int imc_decode_init(AVCodecContext * avctx)
104 IMCContext *q = avctx->priv_data;
107 q->decoder_reset = 1;
109 for(i = 0; i < BANDS; i++)
110 q->old_floor[i] = 1.0;
112 /* Build mdct window, a simple sine window normalized with sqrt(2) */
113 ff_sine_window_init(q->mdct_sine_window, COEFFS);
114 for(i = 0; i < COEFFS; i++)
115 q->mdct_sine_window[i] *= sqrt(2.0);
116 for(i = 0; i < COEFFS/2; i++){
117 q->post_cos[i] = cos(i / 256.0 * M_PI);
118 q->post_sin[i] = sin(i / 256.0 * M_PI);
120 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
121 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
125 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
126 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
130 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
131 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
134 q->last_fft_im[i] = 0;
137 /* Generate a square root table */
139 for(i = 0; i < 30; i++) {
140 q->sqrt_tab[i] = sqrt(i);
143 /* initialize the VLC tables */
144 for(i = 0; i < 4 ; i++) {
145 for(j = 0; j < 4; j++) {
146 huffman_vlc[i][j].table = vlc_tables[vlc_offsets[i * 4 + j]];
147 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];
148 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i],
149 imc_huffman_lens[i][j], 1, 1,
150 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC);
153 q->one_div_log2 = 1/log(2);
155 ff_fft_init(&q->fft, 7, 1);
156 dsputil_init(&q->dsp, avctx);
157 avctx->sample_fmt = SAMPLE_FMT_S16;
161 static void imc_calculate_coeffs(IMCContext* q, float* flcoeffs1, float* flcoeffs2, int* bandWidthT,
162 float* flcoeffs3, float* flcoeffs5)
167 float snr_limit = 1.e-30;
171 for(i = 0; i < BANDS; i++) {
172 flcoeffs5[i] = workT2[i] = 0.0;
174 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
175 flcoeffs3[i] = 2.0 * flcoeffs2[i];
178 flcoeffs3[i] = -30000.0;
180 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
181 if (workT3[i] <= snr_limit)
185 for(i = 0; i < BANDS; i++) {
186 for(cnt2 = i; cnt2 < cyclTab[i]; cnt2++)
187 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
188 workT2[cnt2-1] = workT2[cnt2-1] + workT3[i];
191 for(i = 1; i < BANDS; i++) {
192 accum = (workT2[i-1] + accum) * imc_weights1[i-1];
193 flcoeffs5[i] += accum;
196 for(i = 0; i < BANDS; i++)
199 for(i = 0; i < BANDS; i++) {
200 for(cnt2 = i-1; cnt2 > cyclTab2[i]; cnt2--)
201 flcoeffs5[cnt2] += workT3[i];
202 workT2[cnt2+1] += workT3[i];
207 for(i = BANDS-2; i >= 0; i--) {
208 accum = (workT2[i+1] + accum) * imc_weights2[i];
209 flcoeffs5[i] += accum;
210 //there is missing code here, but it seems to never be triggered
215 static void imc_read_level_coeffs(IMCContext* q, int stream_format_code, int* levlCoeffs)
220 const uint8_t *cb_sel;
223 s = stream_format_code >> 1;
224 hufftab[0] = &huffman_vlc[s][0];
225 hufftab[1] = &huffman_vlc[s][1];
226 hufftab[2] = &huffman_vlc[s][2];
227 hufftab[3] = &huffman_vlc[s][3];
228 cb_sel = imc_cb_select[s];
230 if(stream_format_code & 4)
233 levlCoeffs[0] = get_bits(&q->gb, 7);
234 for(i = start; i < BANDS; i++){
235 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table, hufftab[cb_sel[i]]->bits, 2);
236 if(levlCoeffs[i] == 17)
237 levlCoeffs[i] += get_bits(&q->gb, 4);
241 static void imc_decode_level_coefficients(IMCContext* q, int* levlCoeffBuf, float* flcoeffs1,
246 //maybe some frequency division thingy
248 flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
249 flcoeffs2[0] = log(flcoeffs1[0])/log(2);
253 for(i = 1; i < BANDS; i++) {
254 level = levlCoeffBuf[i];
261 else if (level <= 24)
266 tmp *= imc_exp_tab[15 + level];
267 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
275 static void imc_decode_level_coefficients2(IMCContext* q, int* levlCoeffBuf, float* old_floor, float* flcoeffs1,
278 //FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
279 // and flcoeffs2 old scale factors
280 // might be incomplete due to a missing table that is in the binary code
281 for(i = 0; i < BANDS; i++) {
283 if(levlCoeffBuf[i] < 16) {
284 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
285 flcoeffs2[i] = (levlCoeffBuf[i]-7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
287 flcoeffs1[i] = old_floor[i];
293 * Perform bit allocation depending on bits available
295 static int bit_allocation (IMCContext* q, int stream_format_code, int freebits, int flag) {
297 const float limit = -1.e20;
306 float lowest = 1.e10;
312 for(i = 0; i < BANDS; i++)
313 highest = FFMAX(highest, q->flcoeffs1[i]);
315 for(i = 0; i < BANDS-1; i++) {
316 q->flcoeffs4[i] = q->flcoeffs3[i] - log(q->flcoeffs5[i])/log(2);
318 q->flcoeffs4[BANDS - 1] = limit;
320 highest = highest * 0.25;
322 for(i = 0; i < BANDS; i++) {
324 if ((band_tab[i+1] - band_tab[i]) == q->bandWidthT[i])
327 if ((band_tab[i+1] - band_tab[i]) > q->bandWidthT[i])
330 if (((band_tab[i+1] - band_tab[i])/2) >= q->bandWidthT[i])
336 q->flcoeffs4[i] = q->flcoeffs4[i] + xTab[(indx*2 + (q->flcoeffs1[i] < highest)) * 2 + flag];
339 if (stream_format_code & 0x2) {
340 q->flcoeffs4[0] = limit;
341 q->flcoeffs4[1] = limit;
342 q->flcoeffs4[2] = limit;
343 q->flcoeffs4[3] = limit;
346 for(i = (stream_format_code & 0x2)?4:0; i < BANDS-1; i++) {
347 iacc += q->bandWidthT[i];
348 summa += q->bandWidthT[i] * q->flcoeffs4[i];
350 q->bandWidthT[BANDS-1] = 0;
351 summa = (summa * 0.5 - freebits) / iacc;
354 for(i = 0; i < BANDS/2; i++) {
355 rres = summer - freebits;
356 if((rres >= -8) && (rres <= 8)) break;
361 for(j = (stream_format_code & 0x2)?4:0; j < BANDS; j++) {
362 cwlen = av_clip((int)((q->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
364 q->bitsBandT[j] = cwlen;
365 summer += q->bandWidthT[j] * cwlen;
368 iacc += q->bandWidthT[j];
373 if (freebits < summer)
380 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
383 for(i = (stream_format_code & 0x2)?4:0; i < BANDS; i++) {
384 for(j = band_tab[i]; j < band_tab[i+1]; j++)
385 q->CWlengthT[j] = q->bitsBandT[i];
388 if (freebits > summer) {
389 for(i = 0; i < BANDS; i++) {
390 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
396 if (highest <= -1.e20)
402 for(i = 0; i < BANDS; i++) {
403 if (workT[i] > highest) {
409 if (highest > -1.e20) {
410 workT[found_indx] -= 2.0;
411 if (++(q->bitsBandT[found_indx]) == 6)
412 workT[found_indx] = -1.e20;
414 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (freebits > summer); j++){
419 }while (freebits > summer);
421 if (freebits < summer) {
422 for(i = 0; i < BANDS; i++) {
423 workT[i] = q->bitsBandT[i] ? (q->bitsBandT[i] * -2 + q->flcoeffs4[i] + 1.585) : 1.e20;
425 if (stream_format_code & 0x2) {
431 while (freebits < summer){
434 for(i = 0; i < BANDS; i++) {
435 if (workT[i] < lowest) {
440 //if(lowest >= 1.e10) break;
441 workT[low_indx] = lowest + 2.0;
443 if (!(--q->bitsBandT[low_indx]))
444 workT[low_indx] = 1.e20;
446 for(j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++){
447 if(q->CWlengthT[j] > 0){
457 static void imc_get_skip_coeff(IMCContext* q) {
460 memset(q->skipFlagBits, 0, sizeof(q->skipFlagBits));
461 memset(q->skipFlagCount, 0, sizeof(q->skipFlagCount));
462 for(i = 0; i < BANDS; i++) {
463 if (!q->bandFlagsBuf[i] || !q->bandWidthT[i])
466 if (!q->skipFlagRaw[i]) {
467 q->skipFlagBits[i] = band_tab[i+1] - band_tab[i];
469 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
470 if ((q->skipFlags[j] = get_bits1(&q->gb)))
471 q->skipFlagCount[i]++;
474 for(j = band_tab[i]; j < (band_tab[i+1]-1); j += 2) {
475 if(!get_bits1(&q->gb)){//0
476 q->skipFlagBits[i]++;
479 q->skipFlagCount[i] += 2;
481 if(get_bits1(&q->gb)){//11
482 q->skipFlagBits[i] +=2;
485 q->skipFlagCount[i]++;
487 q->skipFlagBits[i] +=3;
489 if(!get_bits1(&q->gb)){//100
491 q->skipFlagCount[i]++;
499 if (j < band_tab[i+1]) {
500 q->skipFlagBits[i]++;
501 if ((q->skipFlags[j] = get_bits1(&q->gb)))
502 q->skipFlagCount[i]++;
509 * Increase highest' band coefficient sizes as some bits won't be used
511 static void imc_adjust_bit_allocation (IMCContext* q, int summer) {
518 for(i = 0; i < BANDS; i++) {
519 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
522 while (corrected < summer) {
523 if(highest <= -1.e20)
528 for(i = 0; i < BANDS; i++) {
529 if (workT[i] > highest) {
535 if (highest > -1.e20) {
536 workT[found_indx] -= 2.0;
537 if (++(q->bitsBandT[found_indx]) == 6)
538 workT[found_indx] = -1.e20;
540 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
541 if (!q->skipFlags[j] && (q->CWlengthT[j] < 6)) {
550 static void imc_imdct256(IMCContext *q) {
555 for(i=0; i < COEFFS/2; i++){
556 q->samples[i].re = -(q->pre_coef1[i] * q->CWdecoded[COEFFS-1-i*2]) -
557 (q->pre_coef2[i] * q->CWdecoded[i*2]);
558 q->samples[i].im = (q->pre_coef2[i] * q->CWdecoded[COEFFS-1-i*2]) -
559 (q->pre_coef1[i] * q->CWdecoded[i*2]);
563 ff_fft_permute(&q->fft, q->samples);
564 ff_fft_calc (&q->fft, q->samples);
566 /* postrotation, window and reorder */
567 for(i = 0; i < COEFFS/2; i++){
568 re = (q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
569 im = (-q->samples[i].im * q->post_cos[i]) - (q->samples[i].re * q->post_sin[i]);
570 q->out_samples[i*2] = (q->mdct_sine_window[COEFFS-1-i*2] * q->last_fft_im[i]) + (q->mdct_sine_window[i*2] * re);
571 q->out_samples[COEFFS-1-i*2] = (q->mdct_sine_window[i*2] * q->last_fft_im[i]) - (q->mdct_sine_window[COEFFS-1-i*2] * re);
572 q->last_fft_im[i] = im;
576 static int inverse_quant_coeff (IMCContext* q, int stream_format_code) {
578 int middle_value, cw_len, max_size;
579 const float* quantizer;
581 for(i = 0; i < BANDS; i++) {
582 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
584 cw_len = q->CWlengthT[j];
586 if (cw_len <= 0 || q->skipFlags[j])
589 max_size = 1 << cw_len;
590 middle_value = max_size >> 1;
592 if (q->codewords[j] >= max_size || q->codewords[j] < 0)
596 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
597 if (q->codewords[j] >= middle_value)
598 q->CWdecoded[j] = quantizer[q->codewords[j] - 8] * q->flcoeffs6[i];
600 q->CWdecoded[j] = -quantizer[max_size - q->codewords[j] - 8 - 1] * q->flcoeffs6[i];
602 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (q->bandFlagsBuf[i] << 1)];
603 if (q->codewords[j] >= middle_value)
604 q->CWdecoded[j] = quantizer[q->codewords[j] - 1] * q->flcoeffs6[i];
606 q->CWdecoded[j] = -quantizer[max_size - 2 - q->codewords[j]] * q->flcoeffs6[i];
614 static int imc_get_coeffs (IMCContext* q) {
615 int i, j, cw_len, cw;
617 for(i = 0; i < BANDS; i++) {
618 if(!q->sumLenArr[i]) continue;
619 if (q->bandFlagsBuf[i] || q->bandWidthT[i]) {
620 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
621 cw_len = q->CWlengthT[j];
624 if (get_bits_count(&q->gb) + cw_len > 512){
625 //av_log(NULL,0,"Band %i coeff %i cw_len %i\n",i,j,cw_len);
629 if(cw_len && (!q->bandFlagsBuf[i] || !q->skipFlags[j]))
630 cw = get_bits(&q->gb, cw_len);
632 q->codewords[j] = cw;
639 static int imc_decode_frame(AVCodecContext * avctx,
640 void *data, int *data_size,
641 const uint8_t * buf, int buf_size)
644 IMCContext *q = avctx->priv_data;
646 int stream_format_code;
650 int counter, bitscount;
651 uint16_t buf16[IMC_BLOCK_SIZE / 2];
653 if (buf_size < IMC_BLOCK_SIZE) {
654 av_log(avctx, AV_LOG_ERROR, "imc frame too small!\n");
657 for(i = 0; i < IMC_BLOCK_SIZE / 2; i++)
658 buf16[i] = bswap_16(((const uint16_t*)buf)[i]);
660 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
662 /* Check the frame header */
663 imc_hdr = get_bits(&q->gb, 9);
664 if (imc_hdr != IMC_FRAME_ID) {
665 av_log(avctx, AV_LOG_ERROR, "imc frame header check failed!\n");
666 av_log(avctx, AV_LOG_ERROR, "got %x instead of 0x21.\n", imc_hdr);
669 stream_format_code = get_bits(&q->gb, 3);
671 if(stream_format_code & 1){
672 av_log(avctx, AV_LOG_ERROR, "Stream code format %X is not supported\n", stream_format_code);
676 // av_log(avctx, AV_LOG_DEBUG, "stream_format_code = %d\n", stream_format_code);
678 if (stream_format_code & 0x04)
679 q->decoder_reset = 1;
681 if(q->decoder_reset) {
682 memset(q->out_samples, 0, sizeof(q->out_samples));
683 for(i = 0; i < BANDS; i++)q->old_floor[i] = 1.0;
684 for(i = 0; i < COEFFS; i++)q->CWdecoded[i] = 0;
685 q->decoder_reset = 0;
688 flag = get_bits1(&q->gb);
689 imc_read_level_coeffs(q, stream_format_code, q->levlCoeffBuf);
691 if (stream_format_code & 0x4)
692 imc_decode_level_coefficients(q, q->levlCoeffBuf, q->flcoeffs1, q->flcoeffs2);
694 imc_decode_level_coefficients2(q, q->levlCoeffBuf, q->old_floor, q->flcoeffs1, q->flcoeffs2);
696 memcpy(q->old_floor, q->flcoeffs1, 32 * sizeof(float));
699 for (i=0 ; i<BANDS ; i++) {
700 if (q->levlCoeffBuf[i] == 16) {
701 q->bandWidthT[i] = 0;
704 q->bandWidthT[i] = band_tab[i+1] - band_tab[i];
706 memset(q->bandFlagsBuf, 0, BANDS * sizeof(int));
707 for(i = 0; i < BANDS-1; i++) {
708 if (q->bandWidthT[i])
709 q->bandFlagsBuf[i] = get_bits1(&q->gb);
712 imc_calculate_coeffs(q, q->flcoeffs1, q->flcoeffs2, q->bandWidthT, q->flcoeffs3, q->flcoeffs5);
715 /* first 4 bands will be assigned 5 bits per coefficient */
716 if (stream_format_code & 0x2) {
723 for(i = 1; i < 4; i++){
724 bits = (q->levlCoeffBuf[i] == 16) ? 0 : 5;
725 q->bitsBandT[i] = bits;
726 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
727 q->CWlengthT[j] = bits;
733 if(bit_allocation (q, stream_format_code, 512 - bitscount - get_bits_count(&q->gb), flag) < 0) {
734 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
735 q->decoder_reset = 1;
739 for(i = 0; i < BANDS; i++) {
741 q->skipFlagRaw[i] = 0;
742 for(j = band_tab[i]; j < band_tab[i+1]; j++)
743 q->sumLenArr[i] += q->CWlengthT[j];
744 if (q->bandFlagsBuf[i])
745 if( (((band_tab[i+1] - band_tab[i]) * 1.5) > q->sumLenArr[i]) && (q->sumLenArr[i] > 0))
746 q->skipFlagRaw[i] = 1;
749 imc_get_skip_coeff(q);
751 for(i = 0; i < BANDS; i++) {
752 q->flcoeffs6[i] = q->flcoeffs1[i];
753 /* band has flag set and at least one coded coefficient */
754 if (q->bandFlagsBuf[i] && (band_tab[i+1] - band_tab[i]) != q->skipFlagCount[i]){
755 q->flcoeffs6[i] *= q->sqrt_tab[band_tab[i+1] - band_tab[i]] /
756 q->sqrt_tab[(band_tab[i+1] - band_tab[i] - q->skipFlagCount[i])];
760 /* calculate bits left, bits needed and adjust bit allocation */
763 for(i = 0; i < BANDS; i++) {
764 if (q->bandFlagsBuf[i]) {
765 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
766 if(q->skipFlags[j]) {
767 summer += q->CWlengthT[j];
771 bits += q->skipFlagBits[i];
772 summer -= q->skipFlagBits[i];
775 imc_adjust_bit_allocation(q, summer);
777 for(i = 0; i < BANDS; i++) {
780 for(j = band_tab[i]; j < band_tab[i+1]; j++)
781 if (!q->skipFlags[j])
782 q->sumLenArr[i] += q->CWlengthT[j];
785 memset(q->codewords, 0, sizeof(q->codewords));
787 if(imc_get_coeffs(q) < 0) {
788 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");
789 q->decoder_reset = 1;
793 if(inverse_quant_coeff(q, stream_format_code) < 0) {
794 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
795 q->decoder_reset = 1;
799 memset(q->skipFlags, 0, sizeof(q->skipFlags));
803 q->dsp.float_to_int16(data, q->out_samples, COEFFS);
805 *data_size = COEFFS * sizeof(int16_t);
807 return IMC_BLOCK_SIZE;
811 static av_cold int imc_decode_close(AVCodecContext * avctx)
813 IMCContext *q = avctx->priv_data;
820 AVCodec imc_decoder = {
822 .type = CODEC_TYPE_AUDIO,
824 .priv_data_size = sizeof(IMCContext),
825 .init = imc_decode_init,
826 .close = imc_decode_close,
827 .decode = imc_decode_frame,
828 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),