mirror of
https://git.videolan.org/git/ffmpeg.git
synced 2024-08-18 07:15:04 +02:00
834 lines
25 KiB
C
834 lines
25 KiB
C
/*
|
|
* IMC compatible decoder
|
|
* Copyright (c) 2002-2004 Maxim Poliakovski
|
|
* Copyright (c) 2006 Benjamin Larsson
|
|
* Copyright (c) 2006 Konstantin Shishkov
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg 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.
|
|
*
|
|
* FFmpeg 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 FFmpeg; 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>
|
|
|
|
#define ALT_BITSTREAM_READER
|
|
#include "avcodec.h"
|
|
#include "get_bits.h"
|
|
#include "dsputil.h"
|
|
#include "fft.h"
|
|
|
|
#include "imcdata.h"
|
|
|
|
#define IMC_BLOCK_SIZE 64
|
|
#define IMC_FRAME_ID 0x21
|
|
#define BANDS 32
|
|
#define COEFFS 256
|
|
|
|
typedef struct {
|
|
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(16, 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;
|
|
IMCContext *q = avctx->priv_data;
|
|
double r1, r2;
|
|
|
|
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);
|
|
|
|
ff_fft_init(&q->fft, 7, 1);
|
|
dsputil_init(&q->dsp, avctx);
|
|
avctx->sample_fmt = SAMPLE_FMT_FLT;
|
|
avctx->channel_layout = (avctx->channels==2) ? CH_LAYOUT_STEREO : CH_LAYOUT_MONO;
|
|
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 -1;
|
|
|
|
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_clip((int)((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 */
|
|
ff_fft_permute(&q->fft, q->samples);
|
|
ff_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 -1;
|
|
|
|
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 -1;
|
|
}
|
|
|
|
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 *data_size,
|
|
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;
|
|
int flag;
|
|
int bits, summer;
|
|
int counter, bitscount;
|
|
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 -1;
|
|
}
|
|
for(i = 0; i < IMC_BLOCK_SIZE / 2; i++)
|
|
buf16[i] = av_bswap16(((const uint16_t*)buf)[i]);
|
|
|
|
q->out_samples = data;
|
|
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 -1;
|
|
}
|
|
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 -1;
|
|
}
|
|
|
|
// 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(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 -1;
|
|
}
|
|
|
|
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 0;
|
|
}
|
|
|
|
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 0;
|
|
}
|
|
|
|
memset(q->skipFlags, 0, sizeof(q->skipFlags));
|
|
|
|
imc_imdct256(q);
|
|
|
|
*data_size = COEFFS * sizeof(float);
|
|
|
|
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 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,
|
|
.long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
|
|
};
|