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FFmpeg/libavcodec/imc.c
Mans Rullgard a1e98f198e get_bits: remove A32 variant 
The A32 bitstream reader variant is only used on ARMv5 and for
Prores due to the larger bit cache this decoder requires.

In benchmarks on ARMv5 (Marvell Sheeva) with gcc 4.6, the only
statistically significant difference between ALT and A32 is
a 4% advantage for ALT in FLAC decoding.  There is thus no (longer)
any reason to keep the A32 reader from this point of view.

This patch adds an option to the ALT reader increasing the bit
cache to 32 bits as required by the Prores decoder.  Benchmarking
shows no significant change in speed on Intel i7.  Again, the
A32 reader fails to justify its existence.

Signed-off-by: Mans Rullgard <mans@mansr.com>
2011-12-16 21:21:48 +00:00

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/*
* IMC compatible decoder
* Copyright (c) 2002-2004 Maxim Poliakovski
* Copyright (c) 2006 Benjamin Larsson
* Copyright (c) 2006 Konstantin Shishkov
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* IMC - Intel Music Coder
* A mdct based codec using a 256 points large transform
* divied into 32 bands with some mix of scale factors.
* Only mono is supported.
*
*/
#include <math.h>
#include <stddef.h>
#include <stdio.h>
#include "avcodec.h"
#include "get_bits.h"
#include "dsputil.h"
#include "fft.h"
#include "libavutil/audioconvert.h"
#include "sinewin.h"
#include "imcdata.h"
#define IMC_BLOCK_SIZE 64
#define IMC_FRAME_ID 0x21
#define BANDS 32
#define COEFFS 256
typedef struct {
AVFrame frame;
float old_floor[BANDS];
float flcoeffs1[BANDS];
float flcoeffs2[BANDS];
float flcoeffs3[BANDS];
float flcoeffs4[BANDS];
float flcoeffs5[BANDS];
float flcoeffs6[BANDS];
float CWdecoded[COEFFS];
/** MDCT tables */
//@{
float mdct_sine_window[COEFFS];
float post_cos[COEFFS];
float post_sin[COEFFS];
float pre_coef1[COEFFS];
float pre_coef2[COEFFS];
float last_fft_im[COEFFS];
//@}
int bandWidthT[BANDS]; ///< codewords per band
int bitsBandT[BANDS]; ///< how many bits per codeword in band
int CWlengthT[COEFFS]; ///< how many bits in each codeword
int levlCoeffBuf[BANDS];
int bandFlagsBuf[BANDS]; ///< flags for each band
int sumLenArr[BANDS]; ///< bits for all coeffs in band
int skipFlagRaw[BANDS]; ///< skip flags are stored in raw form or not
int skipFlagBits[BANDS]; ///< bits used to code skip flags
int skipFlagCount[BANDS]; ///< skipped coeffients per band
int skipFlags[COEFFS]; ///< skip coefficient decoding or not
int codewords[COEFFS]; ///< raw codewords read from bitstream
float sqrt_tab[30];
GetBitContext gb;
int decoder_reset;
float one_div_log2;
DSPContext dsp;
FFTContext fft;
DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS/2];
float *out_samples;
} IMCContext;
static VLC huffman_vlc[4][4];
#define VLC_TABLES_SIZE 9512
static const int vlc_offsets[17] = {
0, 640, 1156, 1732, 2308, 2852, 3396, 3924,
4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE};
static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];
static av_cold int imc_decode_init(AVCodecContext * avctx)
{
int i, j, ret;
IMCContext *q = avctx->priv_data;
double r1, r2;
if (avctx->channels != 1) {
av_log_ask_for_sample(avctx, "Number of channels is not supported\n");
return AVERROR_PATCHWELCOME;
}
q->decoder_reset = 1;
for(i = 0; i < BANDS; i++)
q->old_floor[i] = 1.0;
/* Build mdct window, a simple sine window normalized with sqrt(2) */
ff_sine_window_init(q->mdct_sine_window, COEFFS);
for(i = 0; i < COEFFS; i++)
q->mdct_sine_window[i] *= sqrt(2.0);
for(i = 0; i < COEFFS/2; i++){
q->post_cos[i] = (1.0f / 32768) * cos(i / 256.0 * M_PI);
q->post_sin[i] = (1.0f / 32768) * sin(i / 256.0 * M_PI);
r1 = sin((i * 4.0 + 1.0) / 1024.0 * M_PI);
r2 = cos((i * 4.0 + 1.0) / 1024.0 * M_PI);
if (i & 0x1)
{
q->pre_coef1[i] = (r1 + r2) * sqrt(2.0);
q->pre_coef2[i] = -(r1 - r2) * sqrt(2.0);
}
else
{
q->pre_coef1[i] = -(r1 + r2) * sqrt(2.0);
q->pre_coef2[i] = (r1 - r2) * sqrt(2.0);
}
q->last_fft_im[i] = 0;
}
/* Generate a square root table */
for(i = 0; i < 30; i++) {
q->sqrt_tab[i] = sqrt(i);
}
/* initialize the VLC tables */
for(i = 0; i < 4 ; i++) {
for(j = 0; j < 4; j++) {
huffman_vlc[i][j].table = &vlc_tables[vlc_offsets[i * 4 + j]];
huffman_vlc[i][j].table_allocated = vlc_offsets[i * 4 + j + 1] - vlc_offsets[i * 4 + j];
init_vlc(&huffman_vlc[i][j], 9, imc_huffman_sizes[i],
imc_huffman_lens[i][j], 1, 1,
imc_huffman_bits[i][j], 2, 2, INIT_VLC_USE_NEW_STATIC);
}
}
q->one_div_log2 = 1/log(2);
if ((ret = ff_fft_init(&q->fft, 7, 1))) {
av_log(avctx, AV_LOG_INFO, "FFT init failed\n");
return ret;
}
dsputil_init(&q->dsp, avctx);
avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
avctx->channel_layout = AV_CH_LAYOUT_MONO;
avcodec_get_frame_defaults(&q->frame);
avctx->coded_frame = &q->frame;
return 0;
}
static void imc_calculate_coeffs(IMCContext* q, float* flcoeffs1, float* flcoeffs2, int* bandWidthT,
float* flcoeffs3, float* flcoeffs5)
{
float workT1[BANDS];
float workT2[BANDS];
float workT3[BANDS];
float snr_limit = 1.e-30;
float accum = 0.0;
int i, cnt2;
for(i = 0; i < BANDS; i++) {
flcoeffs5[i] = workT2[i] = 0.0;
if (bandWidthT[i]){
workT1[i] = flcoeffs1[i] * flcoeffs1[i];
flcoeffs3[i] = 2.0 * flcoeffs2[i];
} else {
workT1[i] = 0.0;
flcoeffs3[i] = -30000.0;
}
workT3[i] = bandWidthT[i] * workT1[i] * 0.01;
if (workT3[i] <= snr_limit)
workT3[i] = 0.0;
}
for(i = 0; i < BANDS; i++) {
for(cnt2 = i; cnt2 < cyclTab[i]; cnt2++)
flcoeffs5[cnt2] = flcoeffs5[cnt2] + workT3[i];
workT2[cnt2-1] = workT2[cnt2-1] + workT3[i];
}
for(i = 1; i < BANDS; i++) {
accum = (workT2[i-1] + accum) * imc_weights1[i-1];
flcoeffs5[i] += accum;
}
for(i = 0; i < BANDS; i++)
workT2[i] = 0.0;
for(i = 0; i < BANDS; i++) {
for(cnt2 = i-1; cnt2 > cyclTab2[i]; cnt2--)
flcoeffs5[cnt2] += workT3[i];
workT2[cnt2+1] += workT3[i];
}
accum = 0.0;
for(i = BANDS-2; i >= 0; i--) {
accum = (workT2[i+1] + accum) * imc_weights2[i];
flcoeffs5[i] += accum;
//there is missing code here, but it seems to never be triggered
}
}
static void imc_read_level_coeffs(IMCContext* q, int stream_format_code, int* levlCoeffs)
{
int i;
VLC *hufftab[4];
int start = 0;
const uint8_t *cb_sel;
int s;
s = stream_format_code >> 1;
hufftab[0] = &huffman_vlc[s][0];
hufftab[1] = &huffman_vlc[s][1];
hufftab[2] = &huffman_vlc[s][2];
hufftab[3] = &huffman_vlc[s][3];
cb_sel = imc_cb_select[s];
if(stream_format_code & 4)
start = 1;
if(start)
levlCoeffs[0] = get_bits(&q->gb, 7);
for(i = start; i < BANDS; i++){
levlCoeffs[i] = get_vlc2(&q->gb, hufftab[cb_sel[i]]->table, hufftab[cb_sel[i]]->bits, 2);
if(levlCoeffs[i] == 17)
levlCoeffs[i] += get_bits(&q->gb, 4);
}
}
static void imc_decode_level_coefficients(IMCContext* q, int* levlCoeffBuf, float* flcoeffs1,
float* flcoeffs2)
{
int i, level;
float tmp, tmp2;
//maybe some frequency division thingy
flcoeffs1[0] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
flcoeffs2[0] = log(flcoeffs1[0])/log(2);
tmp = flcoeffs1[0];
tmp2 = flcoeffs2[0];
for(i = 1; i < BANDS; i++) {
level = levlCoeffBuf[i];
if (level == 16) {
flcoeffs1[i] = 1.0;
flcoeffs2[i] = 0.0;
} else {
if (level < 17)
level -=7;
else if (level <= 24)
level -=32;
else
level -=16;
tmp *= imc_exp_tab[15 + level];
tmp2 += 0.83048 * level; // 0.83048 = log2(10) * 0.25
flcoeffs1[i] = tmp;
flcoeffs2[i] = tmp2;
}
}
}
static void imc_decode_level_coefficients2(IMCContext* q, int* levlCoeffBuf, float* old_floor, float* flcoeffs1,
float* flcoeffs2) {
int i;
//FIXME maybe flag_buf = noise coding and flcoeffs1 = new scale factors
// and flcoeffs2 old scale factors
// might be incomplete due to a missing table that is in the binary code
for(i = 0; i < BANDS; i++) {
flcoeffs1[i] = 0;
if(levlCoeffBuf[i] < 16) {
flcoeffs1[i] = imc_exp_tab2[levlCoeffBuf[i]] * old_floor[i];
flcoeffs2[i] = (levlCoeffBuf[i]-7) * 0.83048 + flcoeffs2[i]; // 0.83048 = log2(10) * 0.25
} else {
flcoeffs1[i] = old_floor[i];
}
}
}
/**
* Perform bit allocation depending on bits available
*/
static int bit_allocation (IMCContext* q, int stream_format_code, int freebits, int flag) {
int i, j;
const float limit = -1.e20;
float highest = 0.0;
int indx;
int t1 = 0;
int t2 = 1;
float summa = 0.0;
int iacc = 0;
int summer = 0;
int rres, cwlen;
float lowest = 1.e10;
int low_indx = 0;
float workT[32];
int flg;
int found_indx = 0;
for(i = 0; i < BANDS; i++)
highest = FFMAX(highest, q->flcoeffs1[i]);
for(i = 0; i < BANDS-1; i++) {
q->flcoeffs4[i] = q->flcoeffs3[i] - log(q->flcoeffs5[i])/log(2);
}
q->flcoeffs4[BANDS - 1] = limit;
highest = highest * 0.25;
for(i = 0; i < BANDS; i++) {
indx = -1;
if ((band_tab[i+1] - band_tab[i]) == q->bandWidthT[i])
indx = 0;
if ((band_tab[i+1] - band_tab[i]) > q->bandWidthT[i])
indx = 1;
if (((band_tab[i+1] - band_tab[i])/2) >= q->bandWidthT[i])
indx = 2;
if (indx == -1)
return AVERROR_INVALIDDATA;
q->flcoeffs4[i] = q->flcoeffs4[i] + xTab[(indx*2 + (q->flcoeffs1[i] < highest)) * 2 + flag];
}
if (stream_format_code & 0x2) {
q->flcoeffs4[0] = limit;
q->flcoeffs4[1] = limit;
q->flcoeffs4[2] = limit;
q->flcoeffs4[3] = limit;
}
for(i = (stream_format_code & 0x2)?4:0; i < BANDS-1; i++) {
iacc += q->bandWidthT[i];
summa += q->bandWidthT[i] * q->flcoeffs4[i];
}
q->bandWidthT[BANDS-1] = 0;
summa = (summa * 0.5 - freebits) / iacc;
for(i = 0; i < BANDS/2; i++) {
rres = summer - freebits;
if((rres >= -8) && (rres <= 8)) break;
summer = 0;
iacc = 0;
for(j = (stream_format_code & 0x2)?4:0; j < BANDS; j++) {
cwlen = av_clipf(((q->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
q->bitsBandT[j] = cwlen;
summer += q->bandWidthT[j] * cwlen;
if (cwlen > 0)
iacc += q->bandWidthT[j];
}
flg = t2;
t2 = 1;
if (freebits < summer)
t2 = -1;
if (i == 0)
flg = t2;
if(flg != t2)
t1++;
summa = (float)(summer - freebits) / ((t1 + 1) * iacc) + summa;
}
for(i = (stream_format_code & 0x2)?4:0; i < BANDS; i++) {
for(j = band_tab[i]; j < band_tab[i+1]; j++)
q->CWlengthT[j] = q->bitsBandT[i];
}
if (freebits > summer) {
for(i = 0; i < BANDS; i++) {
workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
}
highest = 0.0;
do{
if (highest <= -1.e20)
break;
found_indx = 0;
highest = -1.e20;
for(i = 0; i < BANDS; i++) {
if (workT[i] > highest) {
highest = workT[i];
found_indx = i;
}
}
if (highest > -1.e20) {
workT[found_indx] -= 2.0;
if (++(q->bitsBandT[found_indx]) == 6)
workT[found_indx] = -1.e20;
for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (freebits > summer); j++){
q->CWlengthT[j]++;
summer++;
}
}
}while (freebits > summer);
}
if (freebits < summer) {
for(i = 0; i < BANDS; i++) {
workT[i] = q->bitsBandT[i] ? (q->bitsBandT[i] * -2 + q->flcoeffs4[i] + 1.585) : 1.e20;
}
if (stream_format_code & 0x2) {
workT[0] = 1.e20;
workT[1] = 1.e20;
workT[2] = 1.e20;
workT[3] = 1.e20;
}
while (freebits < summer){
lowest = 1.e10;
low_indx = 0;
for(i = 0; i < BANDS; i++) {
if (workT[i] < lowest) {
lowest = workT[i];
low_indx = i;
}
}
//if(lowest >= 1.e10) break;
workT[low_indx] = lowest + 2.0;
if (!(--q->bitsBandT[low_indx]))
workT[low_indx] = 1.e20;
for(j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++){
if(q->CWlengthT[j] > 0){
q->CWlengthT[j]--;
summer--;
}
}
}
}
return 0;
}
static void imc_get_skip_coeff(IMCContext* q) {
int i, j;
memset(q->skipFlagBits, 0, sizeof(q->skipFlagBits));
memset(q->skipFlagCount, 0, sizeof(q->skipFlagCount));
for(i = 0; i < BANDS; i++) {
if (!q->bandFlagsBuf[i] || !q->bandWidthT[i])
continue;
if (!q->skipFlagRaw[i]) {
q->skipFlagBits[i] = band_tab[i+1] - band_tab[i];
for(j = band_tab[i]; j < band_tab[i+1]; j++) {
if ((q->skipFlags[j] = get_bits1(&q->gb)))
q->skipFlagCount[i]++;
}
} else {
for(j = band_tab[i]; j < (band_tab[i+1]-1); j += 2) {
if(!get_bits1(&q->gb)){//0
q->skipFlagBits[i]++;
q->skipFlags[j]=1;
q->skipFlags[j+1]=1;
q->skipFlagCount[i] += 2;
}else{
if(get_bits1(&q->gb)){//11
q->skipFlagBits[i] +=2;
q->skipFlags[j]=0;
q->skipFlags[j+1]=1;
q->skipFlagCount[i]++;
}else{
q->skipFlagBits[i] +=3;
q->skipFlags[j+1]=0;
if(!get_bits1(&q->gb)){//100
q->skipFlags[j]=1;
q->skipFlagCount[i]++;
}else{//101
q->skipFlags[j]=0;
}
}
}
}
if (j < band_tab[i+1]) {
q->skipFlagBits[i]++;
if ((q->skipFlags[j] = get_bits1(&q->gb)))
q->skipFlagCount[i]++;
}
}
}
}
/**
* Increase highest' band coefficient sizes as some bits won't be used
*/
static void imc_adjust_bit_allocation (IMCContext* q, int summer) {
float workT[32];
int corrected = 0;
int i, j;
float highest = 0;
int found_indx=0;
for(i = 0; i < BANDS; i++) {
workT[i] = (q->bitsBandT[i] == 6) ? -1.e20 : (q->bitsBandT[i] * -2 + q->flcoeffs4[i] - 0.415);
}
while (corrected < summer) {
if(highest <= -1.e20)
break;
highest = -1.e20;
for(i = 0; i < BANDS; i++) {
if (workT[i] > highest) {
highest = workT[i];
found_indx = i;
}
}
if (highest > -1.e20) {
workT[found_indx] -= 2.0;
if (++(q->bitsBandT[found_indx]) == 6)
workT[found_indx] = -1.e20;
for(j = band_tab[found_indx]; j < band_tab[found_indx+1] && (corrected < summer); j++) {
if (!q->skipFlags[j] && (q->CWlengthT[j] < 6)) {
q->CWlengthT[j]++;
corrected++;
}
}
}
}
}
static void imc_imdct256(IMCContext *q) {
int i;
float re, im;
/* prerotation */
for(i=0; i < COEFFS/2; i++){
q->samples[i].re = -(q->pre_coef1[i] * q->CWdecoded[COEFFS-1-i*2]) -
(q->pre_coef2[i] * q->CWdecoded[i*2]);
q->samples[i].im = (q->pre_coef2[i] * q->CWdecoded[COEFFS-1-i*2]) -
(q->pre_coef1[i] * q->CWdecoded[i*2]);
}
/* FFT */
q->fft.fft_permute(&q->fft, q->samples);
q->fft.fft_calc (&q->fft, q->samples);
/* postrotation, window and reorder */
for(i = 0; i < COEFFS/2; i++){
re = (q->samples[i].re * q->post_cos[i]) + (-q->samples[i].im * q->post_sin[i]);
im = (-q->samples[i].im * q->post_cos[i]) - (q->samples[i].re * q->post_sin[i]);
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);
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);
q->last_fft_im[i] = im;
}
}
static int inverse_quant_coeff (IMCContext* q, int stream_format_code) {
int i, j;
int middle_value, cw_len, max_size;
const float* quantizer;
for(i = 0; i < BANDS; i++) {
for(j = band_tab[i]; j < band_tab[i+1]; j++) {
q->CWdecoded[j] = 0;
cw_len = q->CWlengthT[j];
if (cw_len <= 0 || q->skipFlags[j])
continue;
max_size = 1 << cw_len;
middle_value = max_size >> 1;
if (q->codewords[j] >= max_size || q->codewords[j] < 0)
return AVERROR_INVALIDDATA;
if (cw_len >= 4){
quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
if (q->codewords[j] >= middle_value)
q->CWdecoded[j] = quantizer[q->codewords[j] - 8] * q->flcoeffs6[i];
else
q->CWdecoded[j] = -quantizer[max_size - q->codewords[j] - 8 - 1] * q->flcoeffs6[i];
}else{
quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (q->bandFlagsBuf[i] << 1)];
if (q->codewords[j] >= middle_value)
q->CWdecoded[j] = quantizer[q->codewords[j] - 1] * q->flcoeffs6[i];
else
q->CWdecoded[j] = -quantizer[max_size - 2 - q->codewords[j]] * q->flcoeffs6[i];
}
}
}
return 0;
}
static int imc_get_coeffs (IMCContext* q) {
int i, j, cw_len, cw;
for(i = 0; i < BANDS; i++) {
if(!q->sumLenArr[i]) continue;
if (q->bandFlagsBuf[i] || q->bandWidthT[i]) {
for(j = band_tab[i]; j < band_tab[i+1]; j++) {
cw_len = q->CWlengthT[j];
cw = 0;
if (get_bits_count(&q->gb) + cw_len > 512){
//av_log(NULL,0,"Band %i coeff %i cw_len %i\n",i,j,cw_len);
return AVERROR_INVALIDDATA;
}
if(cw_len && (!q->bandFlagsBuf[i] || !q->skipFlags[j]))
cw = get_bits(&q->gb, cw_len);
q->codewords[j] = cw;
}
}
}
return 0;
}
static int imc_decode_frame(AVCodecContext * avctx, void *data,
int *got_frame_ptr, AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
IMCContext *q = avctx->priv_data;
int stream_format_code;
int imc_hdr, i, j, ret;
int flag;
int bits, summer;
int counter, bitscount;
LOCAL_ALIGNED_16(uint16_t, buf16, [IMC_BLOCK_SIZE / 2]);
if (buf_size < IMC_BLOCK_SIZE) {
av_log(avctx, AV_LOG_ERROR, "imc frame too small!\n");
return AVERROR_INVALIDDATA;
}
/* get output buffer */
q->frame.nb_samples = COEFFS;
if ((ret = avctx->get_buffer(avctx, &q->frame)) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return ret;
}
q->out_samples = (float *)q->frame.data[0];
q->dsp.bswap16_buf(buf16, (const uint16_t*)buf, IMC_BLOCK_SIZE / 2);
init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
/* Check the frame header */
imc_hdr = get_bits(&q->gb, 9);
if (imc_hdr != IMC_FRAME_ID) {
av_log(avctx, AV_LOG_ERROR, "imc frame header check failed!\n");
av_log(avctx, AV_LOG_ERROR, "got %x instead of 0x21.\n", imc_hdr);
return AVERROR_INVALIDDATA;
}
stream_format_code = get_bits(&q->gb, 3);
if(stream_format_code & 1){
av_log(avctx, AV_LOG_ERROR, "Stream code format %X is not supported\n", stream_format_code);
return AVERROR_INVALIDDATA;
}
// av_log(avctx, AV_LOG_DEBUG, "stream_format_code = %d\n", stream_format_code);
if (stream_format_code & 0x04)
q->decoder_reset = 1;
if(q->decoder_reset) {
memset(q->out_samples, 0, sizeof(q->out_samples));
for(i = 0; i < BANDS; i++)q->old_floor[i] = 1.0;
for(i = 0; i < COEFFS; i++)q->CWdecoded[i] = 0;
q->decoder_reset = 0;
}
flag = get_bits1(&q->gb);
imc_read_level_coeffs(q, stream_format_code, q->levlCoeffBuf);
if (stream_format_code & 0x4)
imc_decode_level_coefficients(q, q->levlCoeffBuf, q->flcoeffs1, q->flcoeffs2);
else
imc_decode_level_coefficients2(q, q->levlCoeffBuf, q->old_floor, q->flcoeffs1, q->flcoeffs2);
memcpy(q->old_floor, q->flcoeffs1, 32 * sizeof(float));
counter = 0;
for (i=0 ; i<BANDS ; i++) {
if (q->levlCoeffBuf[i] == 16) {
q->bandWidthT[i] = 0;
counter++;
} else
q->bandWidthT[i] = band_tab[i+1] - band_tab[i];
}
memset(q->bandFlagsBuf, 0, BANDS * sizeof(int));
for(i = 0; i < BANDS-1; i++) {
if (q->bandWidthT[i])
q->bandFlagsBuf[i] = get_bits1(&q->gb);
}
imc_calculate_coeffs(q, q->flcoeffs1, q->flcoeffs2, q->bandWidthT, q->flcoeffs3, q->flcoeffs5);
bitscount = 0;
/* first 4 bands will be assigned 5 bits per coefficient */
if (stream_format_code & 0x2) {
bitscount += 15;
q->bitsBandT[0] = 5;
q->CWlengthT[0] = 5;
q->CWlengthT[1] = 5;
q->CWlengthT[2] = 5;
for(i = 1; i < 4; i++){
bits = (q->levlCoeffBuf[i] == 16) ? 0 : 5;
q->bitsBandT[i] = bits;
for(j = band_tab[i]; j < band_tab[i+1]; j++) {
q->CWlengthT[j] = bits;
bitscount += bits;
}
}
}
if((ret = bit_allocation (q, stream_format_code,
512 - bitscount - get_bits_count(&q->gb), flag)) < 0) {
av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
q->decoder_reset = 1;
return ret;
}
for(i = 0; i < BANDS; i++) {
q->sumLenArr[i] = 0;
q->skipFlagRaw[i] = 0;
for(j = band_tab[i]; j < band_tab[i+1]; j++)
q->sumLenArr[i] += q->CWlengthT[j];
if (q->bandFlagsBuf[i])
if( (((band_tab[i+1] - band_tab[i]) * 1.5) > q->sumLenArr[i]) && (q->sumLenArr[i] > 0))
q->skipFlagRaw[i] = 1;
}
imc_get_skip_coeff(q);
for(i = 0; i < BANDS; i++) {
q->flcoeffs6[i] = q->flcoeffs1[i];
/* band has flag set and at least one coded coefficient */
if (q->bandFlagsBuf[i] && (band_tab[i+1] - band_tab[i]) != q->skipFlagCount[i]){
q->flcoeffs6[i] *= q->sqrt_tab[band_tab[i+1] - band_tab[i]] /
q->sqrt_tab[(band_tab[i+1] - band_tab[i] - q->skipFlagCount[i])];
}
}
/* calculate bits left, bits needed and adjust bit allocation */
bits = summer = 0;
for(i = 0; i < BANDS; i++) {
if (q->bandFlagsBuf[i]) {
for(j = band_tab[i]; j < band_tab[i+1]; j++) {
if(q->skipFlags[j]) {
summer += q->CWlengthT[j];
q->CWlengthT[j] = 0;
}
}
bits += q->skipFlagBits[i];
summer -= q->skipFlagBits[i];
}
}
imc_adjust_bit_allocation(q, summer);
for(i = 0; i < BANDS; i++) {
q->sumLenArr[i] = 0;
for(j = band_tab[i]; j < band_tab[i+1]; j++)
if (!q->skipFlags[j])
q->sumLenArr[i] += q->CWlengthT[j];
}
memset(q->codewords, 0, sizeof(q->codewords));
if(imc_get_coeffs(q) < 0) {
av_log(avctx, AV_LOG_ERROR, "Read coefficients failed\n");
q->decoder_reset = 1;
return AVERROR_INVALIDDATA;
}
if(inverse_quant_coeff(q, stream_format_code) < 0) {
av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
q->decoder_reset = 1;
return AVERROR_INVALIDDATA;
}
memset(q->skipFlags, 0, sizeof(q->skipFlags));
imc_imdct256(q);
*got_frame_ptr = 1;
*(AVFrame *)data = q->frame;
return IMC_BLOCK_SIZE;
}
static av_cold int imc_decode_close(AVCodecContext * avctx)
{
IMCContext *q = avctx->priv_data;
ff_fft_end(&q->fft);
return 0;
}
AVCodec ff_imc_decoder = {
.name = "imc",
.type = AVMEDIA_TYPE_AUDIO,
.id = CODEC_ID_IMC,
.priv_data_size = sizeof(IMCContext),
.init = imc_decode_init,
.close = imc_decode_close,
.decode = imc_decode_frame,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
};
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