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 * divied into 32 bands with some mix of scale factors.
29 * Only mono is supported.
38 #define ALT_BITSTREAM_READER
43 #include "libavutil/audioconvert.h"
48 #define IMC_BLOCK_SIZE 64
49 #define IMC_FRAME_ID 0x21
54 float old_floor[BANDS];
55 float flcoeffs1[BANDS];
56 float flcoeffs2[BANDS];
57 float flcoeffs3[BANDS];
58 float flcoeffs4[BANDS];
59 float flcoeffs5[BANDS];
60 float flcoeffs6[BANDS];
61 float CWdecoded[COEFFS];
65 float mdct_sine_window[COEFFS];
66 float post_cos[COEFFS];
67 float post_sin[COEFFS];
68 float pre_coef1[COEFFS];
69 float pre_coef2[COEFFS];
70 float last_fft_im[COEFFS];
73 int bandWidthT[BANDS]; ///< codewords per band
74 int bitsBandT[BANDS]; ///< how many bits per codeword in band
75 int CWlengthT[COEFFS]; ///< how many bits in each codeword
76 int levlCoeffBuf[BANDS];
77 int bandFlagsBuf[BANDS]; ///< flags for each band
78 int sumLenArr[BANDS]; ///< bits for all coeffs in band
79 int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not
80 int skipFlagBits[BANDS]; ///< bits used to code skip flags
81 int skipFlagCount[BANDS]; ///< skipped coeffients per band
82 int skipFlags[COEFFS]; ///< skip coefficient decoding or not
83 int codewords[COEFFS]; ///< raw codewords read from bitstream
91 DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS/2];
95 static VLC huffman_vlc[4][4];
97 #define VLC_TABLES_SIZE 9512
99 static const int vlc_offsets[17] = {
100 0, 640, 1156, 1732, 2308, 2852, 3396, 3924,
101 4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE};
103 static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];
105 static av_cold int imc_decode_init(AVCodecContext * avctx)
108 IMCContext *q = avctx->priv_data;
111 if (avctx->channels != 1) {
112 av_log_ask_for_sample(avctx, "Number of channels is not supported\n");
113 return AVERROR_PATCHWELCOME;
116 q->decoder_reset = 1;
118 for(i = 0; i < BANDS; i++)
119 q->old_floor[i] = 1.0;
121 /* Build mdct window, a simple sine window normalized with sqrt(2) */
122 ff_sine_window_init(q->mdct_sine_window, COEFFS);
123 for(i = 0; i < COEFFS; i++)
124 q->mdct_sine_window[i] *= sqrt(2.0);
125 for(i = 0; i < COEFFS/2; i++){
126 q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI);
127 q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI);
129 r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
130 r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
134 q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
135 q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
139 q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
140 q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
143 q->last_fft_im[i] = 0;
146 /* Generate a square root table */
148 for(i = 0; i < 30; i++) {
149 q->sqrt_tab[i] = sqrt(i);
152 /* initialize the VLC tables */
153 for(i = 0; i < 4 ; i++) {
154 for(j = 0; j < 4; j++) {
155 huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]];
156 huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];
157 init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i],
158 imc_huffman_lens[i][j], 1, 1,
159 imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC);
162 q->one_div_log2 = 1/log(2);
164 if ((ret = ff_fft_init(&q->fft, 7, 1))) {
165 av_log(avctx, AV_LOG_INFO, "FFT init failed\n");
168 dsputil_init(&q->dsp, avctx);
169 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
170 avctx->channel_layout = AV_CH_LAYOUT_MONO;
174 static void imc_calculate_coeffs(IMCContext* q, float* flcoeffs1, float* flcoeffs2, int* bandWidthT,
175 float* flcoeffs3, float* flcoeffs5)
180 float snr_limit = 1.e-30;
184 for(i = 0; i < BANDS; i++) {
185 flcoeffs5[i] = workT2[i] = 0.0;
187 workT1[i] = flcoeffs1[i] * flcoeffs1[i];
188 flcoeffs3[i] = 2.0 * flcoeffs2[i];
191 flcoeffs3[i] = -30000.0;
193 workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
194 if (workT3[i] <= snr_limit)
198 for(i = 0; i < BANDS; i++) {
199 for(cnt2 = i; cnt2 < cyclTab[i]; cnt2++)
200 flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
201 workT2[cnt2-1] = workT2[cnt2-1] + workT3[i];
204 for(i = 1; i < BANDS; i++) {
205 accum = (workT2[i-1] + accum) * imc_weights1[i-1];
206 flcoeffs5[i] += accum;
209 for(i = 0; i < BANDS; i++)
212 for(i = 0; i < BANDS; i++) {
213 for(cnt2 = i-1; cnt2 > cyclTab2[i]; cnt2--)
214 flcoeffs5[cnt2] += workT3[i];
215 workT2[cnt2+1] += workT3[i];
220 for(i = BANDS-2; i >= 0; i--) {
221 accum = (workT2[i+1] + accum) * imc_weights2[i];
222 flcoeffs5[i] += accum;
223 //there is missing code here, but it seems to never be triggered
228 static void imc_read_level_coeffs(IMCContext* q, int stream_format_code, int* levlCoeffs)
233 const uint8_t *cb_sel;
236 s = stream_format_code >> 1;
237 hufftab[0] = &huffman_vlc[s][0];
238 hufftab[1] = &huffman_vlc[s][1];
239 hufftab[2] = &huffman_vlc[s][2];
240 hufftab[3] = &huffman_vlc[s][3];
241 cb_sel = imc_cb_select[s];
243 if(stream_format_code & 4)
246 levlCoeffs[0] = get_bits(&q->gb, 7);
247 for(i = start; i < BANDS; i++){
248 levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table, hufftab[cb_sel[i]]->bits, 2);
249 if(levlCoeffs[i] == 17)
250 levlCoeffs[i] += get_bits(&q->gb, 4);
254 static void imc_decode_level_coefficients(IMCContext* q, int* levlCoeffBuf, float* flcoeffs1,
259 //maybe some frequency division thingy
261 flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
262 flcoeffs2[0] = log(flcoeffs1[0])/log(2);
266 for(i = 1; i < BANDS; i++) {
267 level = levlCoeffBuf[i];
274 else if (level <= 24)
279 tmp *= imc_exp_tab[15 + level];
280 tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
288 static void imc_decode_level_coefficients2(IMCContext* q, int* levlCoeffBuf, float* old_floor, float* flcoeffs1,
291 //FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
292 // and flcoeffs2 old scale factors
293 // might be incomplete due to a missing table that is in the binary code
294 for(i = 0; i < BANDS; i++) {
296 if(levlCoeffBuf[i] < 16) {
297 flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
298 flcoeffs2[i] = (levlCoeffBuf[i]-7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
300 flcoeffs1[i] = old_floor[i];
306 * Perform bit allocation depending on bits available
308 static int bit_allocation (IMCContext* q, int stream_format_code, int freebits, int flag) {
310 const float limit = -1.e20;
319 float lowest = 1.e10;
325 for(i = 0; i < BANDS; i++)
326 highest = FFMAX(highest, q->flcoeffs1[i]);
328 for(i = 0; i < BANDS-1; i++) {
329 q->flcoeffs4[i] = q->flcoeffs3[i] - log(q->flcoeffs5[i])/log(2);
331 q->flcoeffs4[BANDS - 1] = limit;
333 highest = highest * 0.25;
335 for(i = 0; i < BANDS; i++) {
337 if ((band_tab[i+1] - band_tab[i]) == q->bandWidthT[i])
340 if ((band_tab[i+1] - band_tab[i]) > q->bandWidthT[i])
343 if (((band_tab[i+1] - band_tab[i])/2) >= q->bandWidthT[i])
347 return AVERROR_INVALIDDATA;
349 q->flcoeffs4[i] = q->flcoeffs4[i] + xTab[(indx*2 + (q->flcoeffs1[i] < highest)) * 2 + flag];
352 if (stream_format_code & 0x2) {
353 q->flcoeffs4[0] = limit;
354 q->flcoeffs4[1] = limit;
355 q->flcoeffs4[2] = limit;
356 q->flcoeffs4[3] = limit;
359 for(i = (stream_format_code & 0x2)?4:0; i < BANDS-1; i++) {
360 iacc += q->bandWidthT[i];
361 summa += q->bandWidthT[i] * q->flcoeffs4[i];
363 q->bandWidthT[BANDS-1] = 0;
364 summa = (summa * 0.5 - freebits) / iacc;
367 for(i = 0; i < BANDS/2; i++) {
368 rres = summer - freebits;
369 if((rres >= -8) && (rres <= 8)) break;
374 for(j = (stream_format_code & 0x2)?4:0; j < BANDS; j++) {
375 cwlen = av_clipf(((q->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
377 q->bitsBandT[j] = cwlen;
378 summer += q->bandWidthT[j] * cwlen;
381 iacc += q->bandWidthT[j];
386 if (freebits < summer)
393 summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
396 for(i = (stream_format_code & 0x2)?4:0; i < BANDS; i++) {
397 for(j = band_tab[i]; j < band_tab[i+1]; j++)
398 q->CWlengthT[j] = q->bitsBandT[i];
401 if (freebits > summer) {
402 for(i = 0; i < BANDS; i++) {
403 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
409 if (highest <= -1.e20)
415 for(i = 0; i < BANDS; i++) {
416 if (workT[i] > highest) {
422 if (highest > -1.e20) {
423 workT[found_indx] -= 2.0;
424 if (++(q->bitsBandT[found_indx]) == 6)
425 workT[found_indx] = -1.e20;
427 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (freebits > summer); j++){
432 }while (freebits > summer);
434 if (freebits < summer) {
435 for(i = 0; i < BANDS; i++) {
436 workT[i] = q->bitsBandT[i] ? (q->bitsBandT[i] * -2 + q->flcoeffs4[i] + 1.585) : 1.e20;
438 if (stream_format_code & 0x2) {
444 while (freebits < summer){
447 for(i = 0; i < BANDS; i++) {
448 if (workT[i] < lowest) {
453 //if(lowest >= 1.e10) break;
454 workT[low_indx] = lowest + 2.0;
456 if (!(--q->bitsBandT[low_indx]))
457 workT[low_indx] = 1.e20;
459 for(j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++){
460 if(q->CWlengthT[j] > 0){
470 static void imc_get_skip_coeff(IMCContext* q) {
473 memset(q->skipFlagBits, 0, sizeof(q->skipFlagBits));
474 memset(q->skipFlagCount, 0, sizeof(q->skipFlagCount));
475 for(i = 0; i < BANDS; i++) {
476 if (!q->bandFlagsBuf[i] || !q->bandWidthT[i])
479 if (!q->skipFlagRaw[i]) {
480 q->skipFlagBits[i] = band_tab[i+1] - band_tab[i];
482 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
483 if ((q->skipFlags[j] = get_bits1(&q->gb)))
484 q->skipFlagCount[i]++;
487 for(j = band_tab[i]; j < (band_tab[i+1]-1); j += 2) {
488 if(!get_bits1(&q->gb)){//0
489 q->skipFlagBits[i]++;
492 q->skipFlagCount[i] += 2;
494 if(get_bits1(&q->gb)){//11
495 q->skipFlagBits[i] +=2;
498 q->skipFlagCount[i]++;
500 q->skipFlagBits[i] +=3;
502 if(!get_bits1(&q->gb)){//100
504 q->skipFlagCount[i]++;
512 if (j < band_tab[i+1]) {
513 q->skipFlagBits[i]++;
514 if ((q->skipFlags[j] = get_bits1(&q->gb)))
515 q->skipFlagCount[i]++;
522 * Increase highest' band coefficient sizes as some bits won't be used
524 static void imc_adjust_bit_allocation (IMCContext* q, int summer) {
531 for(i = 0; i < BANDS; i++) {
532 workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
535 while (corrected < summer) {
536 if(highest <= -1.e20)
541 for(i = 0; i < BANDS; i++) {
542 if (workT[i] > highest) {
548 if (highest > -1.e20) {
549 workT[found_indx] -= 2.0;
550 if (++(q->bitsBandT[found_indx]) == 6)
551 workT[found_indx] = -1.e20;
553 for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
554 if (!q->skipFlags[j] && (q->CWlengthT[j] < 6)) {
563 static void imc_imdct256(IMCContext *q) {
568 for(i=0; i < COEFFS/2; i++){
569 q->samples[i].re = -(q->pre_coef1[i] * q->CWdecoded[COEFFS-1-i*2]) -
570 (q->pre_coef2[i] * q->CWdecoded[i*2]);
571 q->samples[i].im = (q->pre_coef2[i] * q->CWdecoded[COEFFS-1-i*2]) -
572 (q->pre_coef1[i] * q->CWdecoded[i*2]);
576 q->fft.fft_permute(&q->fft, q->samples);
577 q->fft.fft_calc (&q->fft, q->samples);
579 /* postrotation, window and reorder */
580 for(i = 0; i < COEFFS/2; i++){
581 re = (q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
582 im = (-q->samples[i].im * q->post_cos[i]) - (q->samples[i].re * q->post_sin[i]);
583 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);
584 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);
585 q->last_fft_im[i] = im;
589 static int inverse_quant_coeff (IMCContext* q, int stream_format_code) {
591 int middle_value, cw_len, max_size;
592 const float* quantizer;
594 for(i = 0; i < BANDS; i++) {
595 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
597 cw_len = q->CWlengthT[j];
599 if (cw_len <= 0 || q->skipFlags[j])
602 max_size = 1 << cw_len;
603 middle_value = max_size >> 1;
605 if (q->codewords[j] >= max_size || q->codewords[j] < 0)
606 return AVERROR_INVALIDDATA;
609 quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
610 if (q->codewords[j] >= middle_value)
611 q->CWdecoded[j] = quantizer[q->codewords[j] - 8] * q->flcoeffs6[i];
613 q->CWdecoded[j] = -quantizer[max_size - q->codewords[j] - 8 - 1] * q->flcoeffs6[i];
615 quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (q->bandFlagsBuf[i] << 1)];
616 if (q->codewords[j] >= middle_value)
617 q->CWdecoded[j] = quantizer[q->codewords[j] - 1] * q->flcoeffs6[i];
619 q->CWdecoded[j] = -quantizer[max_size - 2 - q->codewords[j]] * q->flcoeffs6[i];
627 static int imc_get_coeffs (IMCContext* q) {
628 int i, j, cw_len, cw;
630 for(i = 0; i < BANDS; i++) {
631 if(!q->sumLenArr[i]) continue;
632 if (q->bandFlagsBuf[i] || q->bandWidthT[i]) {
633 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
634 cw_len = q->CWlengthT[j];
637 if (get_bits_count(&q->gb) + cw_len > 512){
638 //av_log(NULL,0,"Band %i coeff %i cw_len %i\n",i,j,cw_len);
639 return AVERROR_INVALIDDATA;
642 if(cw_len && (!q->bandFlagsBuf[i] || !q->skipFlags[j]))
643 cw = get_bits(&q->gb, cw_len);
645 q->codewords[j] = cw;
652 static int imc_decode_frame(AVCodecContext * avctx,
653 void *data, int *data_size,
656 const uint8_t *buf = avpkt->data;
657 int buf_size = avpkt->size;
659 IMCContext *q = avctx->priv_data;
661 int stream_format_code;
662 int imc_hdr, i, j, out_size, ret;
665 int counter, bitscount;
666 LOCAL_ALIGNED_16(uint16_t, buf16, [IMC_BLOCK_SIZE / 2]);
668 if (buf_size < IMC_BLOCK_SIZE) {
669 av_log(avctx, AV_LOG_ERROR, "imc frame too small!\n");
670 return AVERROR_INVALIDDATA;
673 out_size = COEFFS * av_get_bytes_per_sample(avctx->sample_fmt);
674 if (*data_size < out_size) {
675 av_log(avctx, AV_LOG_ERROR, "Output buffer is too small\n");
676 return AVERROR(EINVAL);
679 q->dsp.bswap16_buf(buf16, (const uint16_t*)buf, IMC_BLOCK_SIZE / 2);
681 q->out_samples = data;
682 init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
684 /* Check the frame header */
685 imc_hdr = get_bits(&q->gb, 9);
686 if (imc_hdr != IMC_FRAME_ID) {
687 av_log(avctx, AV_LOG_ERROR, "imc frame header check failed!\n");
688 av_log(avctx, AV_LOG_ERROR, "got %x instead of 0x21.\n", imc_hdr);
689 return AVERROR_INVALIDDATA;
691 stream_format_code = get_bits(&q->gb, 3);
693 if(stream_format_code & 1){
694 av_log(avctx, AV_LOG_ERROR, "Stream code format %X is not supported\n", stream_format_code);
695 return AVERROR_INVALIDDATA;
698 // av_log(avctx, AV_LOG_DEBUG, "stream_format_code = %d\n", stream_format_code);
700 if (stream_format_code & 0x04)
701 q->decoder_reset = 1;
703 if(q->decoder_reset) {
704 memset(q->out_samples, 0, sizeof(q->out_samples));
705 for(i = 0; i < BANDS; i++)q->old_floor[i] = 1.0;
706 for(i = 0; i < COEFFS; i++)q->CWdecoded[i] = 0;
707 q->decoder_reset = 0;
710 flag = get_bits1(&q->gb);
711 imc_read_level_coeffs(q, stream_format_code, q->levlCoeffBuf);
713 if (stream_format_code & 0x4)
714 imc_decode_level_coefficients(q, q->levlCoeffBuf, q->flcoeffs1, q->flcoeffs2);
716 imc_decode_level_coefficients2(q, q->levlCoeffBuf, q->old_floor, q->flcoeffs1, q->flcoeffs2);
718 memcpy(q->old_floor, q->flcoeffs1, 32 * sizeof(float));
721 for (i=0 ; i<BANDS ; i++) {
722 if (q->levlCoeffBuf[i] == 16) {
723 q->bandWidthT[i] = 0;
726 q->bandWidthT[i] = band_tab[i+1] - band_tab[i];
728 memset(q->bandFlagsBuf, 0, BANDS * sizeof(int));
729 for(i = 0; i < BANDS-1; i++) {
730 if (q->bandWidthT[i])
731 q->bandFlagsBuf[i] = get_bits1(&q->gb);
734 imc_calculate_coeffs(q, q->flcoeffs1, q->flcoeffs2, q->bandWidthT, q->flcoeffs3, q->flcoeffs5);
737 /* first 4 bands will be assigned 5 bits per coefficient */
738 if (stream_format_code & 0x2) {
745 for(i = 1; i < 4; i++){
746 bits = (q->levlCoeffBuf[i] == 16) ? 0 : 5;
747 q->bitsBandT[i] = bits;
748 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
749 q->CWlengthT[j] = bits;
755 if((ret = bit_allocation (q, stream_format_code,
756 512 - bitscount - get_bits_count(&q->gb), flag)) < 0) {
757 av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
758 q->decoder_reset = 1;
762 for(i = 0; i < BANDS; i++) {
764 q->skipFlagRaw[i] = 0;
765 for(j = band_tab[i]; j < band_tab[i+1]; j++)
766 q->sumLenArr[i] += q->CWlengthT[j];
767 if (q->bandFlagsBuf[i])
768 if( (((band_tab[i+1] - band_tab[i]) * 1.5) > q->sumLenArr[i]) && (q->sumLenArr[i] > 0))
769 q->skipFlagRaw[i] = 1;
772 imc_get_skip_coeff(q);
774 for(i = 0; i < BANDS; i++) {
775 q->flcoeffs6[i] = q->flcoeffs1[i];
776 /* band has flag set and at least one coded coefficient */
777 if (q->bandFlagsBuf[i] && (band_tab[i+1] - band_tab[i]) != q->skipFlagCount[i]){
778 q->flcoeffs6[i] *= q->sqrt_tab[band_tab[i+1] - band_tab[i]] /
779 q->sqrt_tab[(band_tab[i+1] - band_tab[i] - q->skipFlagCount[i])];
783 /* calculate bits left, bits needed and adjust bit allocation */
786 for(i = 0; i < BANDS; i++) {
787 if (q->bandFlagsBuf[i]) {
788 for(j = band_tab[i]; j < band_tab[i+1]; j++) {
789 if(q->skipFlags[j]) {
790 summer += q->CWlengthT[j];
794 bits += q->skipFlagBits[i];
795 summer -= q->skipFlagBits[i];
798 imc_adjust_bit_allocation(q, summer);
800 for(i = 0; i < BANDS; i++) {
803 for(j = band_tab[i]; j < band_tab[i+1]; j++)
804 if (!q->skipFlags[j])
805 q->sumLenArr[i] += q->CWlengthT[j];
808 memset(q->codewords, 0, sizeof(q->codewords));
810 if(imc_get_coeffs(q) < 0) {
811 av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");
812 q->decoder_reset = 1;
813 return AVERROR_INVALIDDATA;
816 if(inverse_quant_coeff(q, stream_format_code) < 0) {
817 av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
818 q->decoder_reset = 1;
819 return AVERROR_INVALIDDATA;
822 memset(q->skipFlags, 0, sizeof(q->skipFlags));
826 *data_size = out_size;
828 return IMC_BLOCK_SIZE;
832 static av_cold int imc_decode_close(AVCodecContext * avctx)
834 IMCContext *q = avctx->priv_data;
841 AVCodec ff_imc_decoder = {
843 .type = AVMEDIA_TYPE_AUDIO,
845 .priv_data_size = sizeof(IMCContext),
846 .init = imc_decode_init,
847 .close = imc_decode_close,
848 .decode = imc_decode_frame,
849 .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),