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FFmpeg/libavcodec/imc.c
Andreas Rheinhardt a247ac640d avcodec: Constify AVCodecs 
Given that the AVCodec.next pointer has now been removed, most of the
AVCodecs are not modified at all any more and can therefore be made
const (as this patch does); the only exceptions are the very few codecs
for external libraries that have a init_static_data callback.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>
2021-04-27 10:43:15 -03:00

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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 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
* divided into 32 bands with some mix of scale factors.
* Only mono is supported.
*/
#include <math.h>
#include <stddef.h>
#include <stdio.h>
#include "libavutil/channel_layout.h"
#include "libavutil/ffmath.h"
#include "libavutil/float_dsp.h"
#include "libavutil/internal.h"
#include "libavutil/mem_internal.h"
#include "libavutil/thread.h"
#include "avcodec.h"
#include "bswapdsp.h"
#include "get_bits.h"
#include "fft.h"
#include "internal.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 IMCChannel {
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];
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 coefficients per band
int skipFlags[COEFFS]; ///< skip coefficient decoding or not
int codewords[COEFFS]; ///< raw codewords read from bitstream
float last_fft_im[COEFFS];
int decoder_reset;
} IMCChannel;
typedef struct IMCContext {
IMCChannel chctx[2];
/** MDCT tables */
//@{
float mdct_sine_window[COEFFS];
float post_cos[COEFFS];
float post_sin[COEFFS];
float pre_coef1[COEFFS];
float pre_coef2[COEFFS];
//@}
float sqrt_tab[30];
GetBitContext gb;
BswapDSPContext bdsp;
void (*butterflies_float)(float *av_restrict v1, float *av_restrict v2, int len);
FFTContext fft;
DECLARE_ALIGNED(32, FFTComplex, samples)[COEFFS / 2];
float *out_samples;
int coef0_pos;
int8_t cyclTab[32], cyclTab2[32];
float weights1[31], weights2[31];
AVCodecContext *avctx;
} IMCContext;
static VLC huffman_vlc[4][4];
#define IMC_VLC_BITS 9
#define VLC_TABLES_SIZE 9512
static VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2];
static inline double freq2bark(double freq)
{
return 3.5 * atan((freq / 7500.0) * (freq / 7500.0)) + 13.0 * atan(freq * 0.00076);
}
static av_cold void iac_generate_tabs(IMCContext *q, int sampling_rate)
{
double freqmin[32], freqmid[32], freqmax[32];
double scale = sampling_rate / (256.0 * 2.0 * 2.0);
double nyquist_freq = sampling_rate * 0.5;
double freq, bark, prev_bark = 0, tf, tb;
int i, j;
for (i = 0; i < 32; i++) {
freq = (band_tab[i] + band_tab[i + 1] - 1) * scale;
bark = freq2bark(freq);
if (i > 0) {
tb = bark - prev_bark;
q->weights1[i - 1] = ff_exp10(-1.0 * tb);
q->weights2[i - 1] = ff_exp10(-2.7 * tb);
}
prev_bark = bark;
freqmid[i] = freq;
tf = freq;
while (tf < nyquist_freq) {
tf += 0.5;
tb = freq2bark(tf);
if (tb > bark + 0.5)
break;
}
freqmax[i] = tf;
tf = freq;
while (tf > 0.0) {
tf -= 0.5;
tb = freq2bark(tf);
if (tb <= bark - 0.5)
break;
}
freqmin[i] = tf;
}
for (i = 0; i < 32; i++) {
freq = freqmax[i];
for (j = 31; j > 0 && freq <= freqmid[j]; j--);
q->cyclTab[i] = j + 1;
freq = freqmin[i];
for (j = 0; j < 32 && freq >= freqmid[j]; j++);
q->cyclTab2[i] = j - 1;
}
}
static av_cold void imc_init_static(void)
{
/* initialize the VLC tables */
for (int i = 0, offset = 0; i < 4 ; i++) {
for (int j = 0; j < 4; j++) {
huffman_vlc[i][j].table = &vlc_tables[offset];
huffman_vlc[i][j].table_allocated = VLC_TABLES_SIZE - offset;
ff_init_vlc_from_lengths(&huffman_vlc[i][j], IMC_VLC_BITS, imc_huffman_sizes[i],
imc_huffman_lens[i][j], 1,
imc_huffman_syms[i][j], 1, 1,
0, INIT_VLC_STATIC_OVERLONG, NULL);
offset += huffman_vlc[i][j].table_size;
}
}
}
static av_cold int imc_decode_init(AVCodecContext *avctx)
{
int i, j, ret;
IMCContext *q = avctx->priv_data;
static AVOnce init_static_once = AV_ONCE_INIT;
AVFloatDSPContext *fdsp;
double r1, r2;
if (avctx->codec_id == AV_CODEC_ID_IAC && avctx->sample_rate > 96000) {
av_log(avctx, AV_LOG_ERROR,
"Strange sample rate of %i, file likely corrupt or "
"needing a new table derivation method.\n",
avctx->sample_rate);
return AVERROR_PATCHWELCOME;
}
if (avctx->codec_id == AV_CODEC_ID_IMC)
avctx->channels = 1;
if (avctx->channels > 2) {
avpriv_request_sample(avctx, "Number of channels > 2");
return AVERROR_PATCHWELCOME;
}
for (j = 0; j < avctx->channels; j++) {
q->chctx[j].decoder_reset = 1;
for (i = 0; i < BANDS; i++)
q->chctx[j].old_floor[i] = 1.0;
for (i = 0; i < COEFFS / 2; i++)
q->chctx[j].last_fft_im[i] = 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);
}
}
/* Generate a square root table */
for (i = 0; i < 30; i++)
q->sqrt_tab[i] = sqrt(i);
if (avctx->codec_id == AV_CODEC_ID_IAC) {
iac_generate_tabs(q, avctx->sample_rate);
} else {
memcpy(q->cyclTab, cyclTab, sizeof(cyclTab));
memcpy(q->cyclTab2, cyclTab2, sizeof(cyclTab2));
memcpy(q->weights1, imc_weights1, sizeof(imc_weights1));
memcpy(q->weights2, imc_weights2, sizeof(imc_weights2));
}
fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
if (!fdsp)
return AVERROR(ENOMEM);
q->butterflies_float = fdsp->butterflies_float;
av_free(fdsp);
if ((ret = ff_fft_init(&q->fft, 7, 1))) {
av_log(avctx, AV_LOG_INFO, "FFT init failed\n");
return ret;
}
ff_bswapdsp_init(&q->bdsp);
avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
: AV_CH_LAYOUT_STEREO;
ff_thread_once(&init_static_once, imc_init_static);
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 < q->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) * q->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 > q->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) * q->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,
IMC_VLC_BITS, 2);
if (levlCoeffs[i] == 17)
levlCoeffs[i] += get_bits(&q->gb, 4);
}
}
static void imc_read_level_coeffs_raw(IMCContext *q, int stream_format_code,
int *levlCoeffs)
{
int i;
q->coef0_pos = get_bits(&q->gb, 5);
levlCoeffs[0] = get_bits(&q->gb, 7);
for (i = 1; i < BANDS; i++)
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 / exp2 (levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
flcoeffs2[0] = log2f(flcoeffs1[0]);
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];
}
}
}
static void imc_decode_level_coefficients_raw(IMCContext *q, int *levlCoeffBuf,
float *flcoeffs1, float *flcoeffs2)
{
int i, level, pos;
float tmp, tmp2;
pos = q->coef0_pos;
flcoeffs1[pos] = 20000.0 / pow (2, levlCoeffBuf[0] * 0.18945); // 0.18945 = log2(10) * 0.05703125
flcoeffs2[pos] = log2f(flcoeffs1[pos]);
tmp = flcoeffs1[pos];
tmp2 = flcoeffs2[pos];
levlCoeffBuf++;
for (i = 0; i < BANDS; i++) {
if (i == pos)
continue;
level = *levlCoeffBuf++;
flcoeffs1[i] = tmp * powf(10.0, -level * 0.4375); //todo tab
flcoeffs2[i] = tmp2 - 1.4533435415 * level; // 1.4533435415 = log2(10) * 0.4375
}
}
/**
* Perform bit allocation depending on bits available
*/
static int bit_allocation(IMCContext *q, IMCChannel *chctx,
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, chctx->flcoeffs1[i]);
for (i = 0; i < BANDS - 1; i++) {
if (chctx->flcoeffs5[i] <= 0) {
av_log(q->avctx, AV_LOG_ERROR, "flcoeffs5 %f invalid\n", chctx->flcoeffs5[i]);
return AVERROR_INVALIDDATA;
}
chctx->flcoeffs4[i] = chctx->flcoeffs3[i] - log2f(chctx->flcoeffs5[i]);
}
chctx->flcoeffs4[BANDS - 1] = limit;
highest = highest * 0.25;
for (i = 0; i < BANDS; i++) {
indx = -1;
if ((band_tab[i + 1] - band_tab[i]) == chctx->bandWidthT[i])
indx = 0;
if ((band_tab[i + 1] - band_tab[i]) > chctx->bandWidthT[i])
indx = 1;
if (((band_tab[i + 1] - band_tab[i]) / 2) >= chctx->bandWidthT[i])
indx = 2;
if (indx == -1)
return AVERROR_INVALIDDATA;
chctx->flcoeffs4[i] += xTab[(indx * 2 + (chctx->flcoeffs1[i] < highest)) * 2 + flag];
}
if (stream_format_code & 0x2) {
chctx->flcoeffs4[0] = limit;
chctx->flcoeffs4[1] = limit;
chctx->flcoeffs4[2] = limit;
chctx->flcoeffs4[3] = limit;
}
for (i = (stream_format_code & 0x2) ? 4 : 0; i < BANDS - 1; i++) {
iacc += chctx->bandWidthT[i];
summa += chctx->bandWidthT[i] * chctx->flcoeffs4[i];
}
if (!iacc)
return AVERROR_INVALIDDATA;
chctx->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(((chctx->flcoeffs4[j] * 0.5) - summa + 0.5), 0, 6);
chctx->bitsBandT[j] = cwlen;
summer += chctx->bandWidthT[j] * cwlen;
if (cwlen > 0)
iacc += chctx->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++)
chctx->CWlengthT[j] = chctx->bitsBandT[i];
}
if (freebits > summer) {
for (i = 0; i < BANDS; i++) {
workT[i] = (chctx->bitsBandT[i] == 6) ? -1.e20
: (chctx->bitsBandT[i] * -2 + chctx->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 (++chctx->bitsBandT[found_indx] == 6)
workT[found_indx] = -1.e20;
for (j = band_tab[found_indx]; j < band_tab[found_indx + 1] && (freebits > summer); j++) {
chctx->CWlengthT[j]++;
summer++;
}
}
} while (freebits > summer);
}
if (freebits < summer) {
for (i = 0; i < BANDS; i++) {
workT[i] = chctx->bitsBandT[i] ? (chctx->bitsBandT[i] * -2 + chctx->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 (!--chctx->bitsBandT[low_indx])
workT[low_indx] = 1.e20;
for (j = band_tab[low_indx]; j < band_tab[low_indx+1] && (freebits < summer); j++) {
if (chctx->CWlengthT[j] > 0) {
chctx->CWlengthT[j]--;
summer--;
}
}
}
}
return 0;
}
static void imc_get_skip_coeff(IMCContext *q, IMCChannel *chctx)
{
int i, j;
memset(chctx->skipFlagBits, 0, sizeof(chctx->skipFlagBits));
memset(chctx->skipFlagCount, 0, sizeof(chctx->skipFlagCount));
for (i = 0; i < BANDS; i++) {
if (!chctx->bandFlagsBuf[i] || !chctx->bandWidthT[i])
continue;
if (!chctx->skipFlagRaw[i]) {
chctx->skipFlagBits[i] = band_tab[i + 1] - band_tab[i];
for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
chctx->skipFlags[j] = get_bits1(&q->gb);
if (chctx->skipFlags[j])
chctx->skipFlagCount[i]++;
}
} else {
for (j = band_tab[i]; j < band_tab[i + 1] - 1; j += 2) {
if (!get_bits1(&q->gb)) { // 0
chctx->skipFlagBits[i]++;
chctx->skipFlags[j] = 1;
chctx->skipFlags[j + 1] = 1;
chctx->skipFlagCount[i] += 2;
} else {
if (get_bits1(&q->gb)) { // 11
chctx->skipFlagBits[i] += 2;
chctx->skipFlags[j] = 0;
chctx->skipFlags[j + 1] = 1;
chctx->skipFlagCount[i]++;
} else {
chctx->skipFlagBits[i] += 3;
chctx->skipFlags[j + 1] = 0;
if (!get_bits1(&q->gb)) { // 100
chctx->skipFlags[j] = 1;
chctx->skipFlagCount[i]++;
} else { // 101
chctx->skipFlags[j] = 0;
}
}
}
}
if (j < band_tab[i + 1]) {
chctx->skipFlagBits[i]++;
if ((chctx->skipFlags[j] = get_bits1(&q->gb)))
chctx->skipFlagCount[i]++;
}
}
}
}
/**
* Increase highest' band coefficient sizes as some bits won't be used
*/
static void imc_adjust_bit_allocation(IMCContext *q, IMCChannel *chctx,
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] = (chctx->bitsBandT[i] == 6) ? -1.e20
: (chctx->bitsBandT[i] * -2 + chctx->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 (++(chctx->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 (!chctx->skipFlags[j] && (chctx->CWlengthT[j] < 6)) {
chctx->CWlengthT[j]++;
corrected++;
}
}
}
}
}
static void imc_imdct256(IMCContext *q, IMCChannel *chctx, int channels)
{
int i;
float re, im;
float *dst1 = q->out_samples;
float *dst2 = q->out_samples + (COEFFS - 1);
/* prerotation */
for (i = 0; i < COEFFS / 2; i++) {
q->samples[i].re = -(q->pre_coef1[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
(q->pre_coef2[i] * chctx->CWdecoded[i * 2]);
q->samples[i].im = (q->pre_coef2[i] * chctx->CWdecoded[COEFFS - 1 - i * 2]) -
(q->pre_coef1[i] * chctx->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]);
*dst1 = (q->mdct_sine_window[COEFFS - 1 - i * 2] * chctx->last_fft_im[i])
+ (q->mdct_sine_window[i * 2] * re);
*dst2 = (q->mdct_sine_window[i * 2] * chctx->last_fft_im[i])
- (q->mdct_sine_window[COEFFS - 1 - i * 2] * re);
dst1 += 2;
dst2 -= 2;
chctx->last_fft_im[i] = im;
}
}
static int inverse_quant_coeff(IMCContext *q, IMCChannel *chctx,
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++) {
chctx->CWdecoded[j] = 0;
cw_len = chctx->CWlengthT[j];
if (cw_len <= 0 || chctx->skipFlags[j])
continue;
max_size = 1 << cw_len;
middle_value = max_size >> 1;
if (chctx->codewords[j] >= max_size || chctx->codewords[j] < 0)
return AVERROR_INVALIDDATA;
if (cw_len >= 4) {
quantizer = imc_quantizer2[(stream_format_code & 2) >> 1];
if (chctx->codewords[j] >= middle_value)
chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 8] * chctx->flcoeffs6[i];
else
chctx->CWdecoded[j] = -quantizer[max_size - chctx->codewords[j] - 8 - 1] * chctx->flcoeffs6[i];
}else{
quantizer = imc_quantizer1[((stream_format_code & 2) >> 1) | (chctx->bandFlagsBuf[i] << 1)];
if (chctx->codewords[j] >= middle_value)
chctx->CWdecoded[j] = quantizer[chctx->codewords[j] - 1] * chctx->flcoeffs6[i];
else
chctx->CWdecoded[j] = -quantizer[max_size - 2 - chctx->codewords[j]] * chctx->flcoeffs6[i];
}
}
}
return 0;
}
static void imc_get_coeffs(AVCodecContext *avctx,
IMCContext *q, IMCChannel *chctx)
{
int i, j, cw_len, cw;
for (i = 0; i < BANDS; i++) {
if (!chctx->sumLenArr[i])
continue;
if (chctx->bandFlagsBuf[i] || chctx->bandWidthT[i]) {
for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
cw_len = chctx->CWlengthT[j];
cw = 0;
if (cw_len && (!chctx->bandFlagsBuf[i] || !chctx->skipFlags[j])) {
if (get_bits_count(&q->gb) + cw_len > 512) {
av_log(avctx, AV_LOG_WARNING,
"Potential problem on band %i, coefficient %i"
": cw_len=%i\n", i, j, cw_len);
} else
cw = get_bits(&q->gb, cw_len);
}
chctx->codewords[j] = cw;
}
}
}
}
static void imc_refine_bit_allocation(IMCContext *q, IMCChannel *chctx)
{
int i, j;
int bits, summer;
for (i = 0; i < BANDS; i++) {
chctx->sumLenArr[i] = 0;
chctx->skipFlagRaw[i] = 0;
for (j = band_tab[i]; j < band_tab[i + 1]; j++)
chctx->sumLenArr[i] += chctx->CWlengthT[j];
if (chctx->bandFlagsBuf[i])
if (((int)((band_tab[i + 1] - band_tab[i]) * 1.5) > chctx->sumLenArr[i]) && (chctx->sumLenArr[i] > 0))
chctx->skipFlagRaw[i] = 1;
}
imc_get_skip_coeff(q, chctx);
for (i = 0; i < BANDS; i++) {
chctx->flcoeffs6[i] = chctx->flcoeffs1[i];
/* band has flag set and at least one coded coefficient */
if (chctx->bandFlagsBuf[i] && (band_tab[i + 1] - band_tab[i]) != chctx->skipFlagCount[i]) {
chctx->flcoeffs6[i] *= q->sqrt_tab[ band_tab[i + 1] - band_tab[i]] /
q->sqrt_tab[(band_tab[i + 1] - band_tab[i] - chctx->skipFlagCount[i])];
}
}
/* calculate bits left, bits needed and adjust bit allocation */
bits = summer = 0;
for (i = 0; i < BANDS; i++) {
if (chctx->bandFlagsBuf[i]) {
for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
if (chctx->skipFlags[j]) {
summer += chctx->CWlengthT[j];
chctx->CWlengthT[j] = 0;
}
}
bits += chctx->skipFlagBits[i];
summer -= chctx->skipFlagBits[i];
}
}
imc_adjust_bit_allocation(q, chctx, summer);
}
static int imc_decode_block(AVCodecContext *avctx, IMCContext *q, int ch)
{
int stream_format_code;
int imc_hdr, i, j, ret;
int flag;
int bits;
int counter, bitscount;
IMCChannel *chctx = q->chctx + ch;
/* Check the frame header */
imc_hdr = get_bits(&q->gb, 9);
if (imc_hdr & 0x18) {
av_log(avctx, AV_LOG_ERROR, "frame header check failed!\n");
av_log(avctx, AV_LOG_ERROR, "got %X.\n", imc_hdr);
return AVERROR_INVALIDDATA;
}
stream_format_code = get_bits(&q->gb, 3);
if (stream_format_code & 0x04)
chctx->decoder_reset = 1;
if (chctx->decoder_reset) {
for (i = 0; i < BANDS; i++)
chctx->old_floor[i] = 1.0;
for (i = 0; i < COEFFS; i++)
chctx->CWdecoded[i] = 0;
chctx->decoder_reset = 0;
}
flag = get_bits1(&q->gb);
if (stream_format_code & 0x1)
imc_read_level_coeffs_raw(q, stream_format_code, chctx->levlCoeffBuf);
else
imc_read_level_coeffs(q, stream_format_code, chctx->levlCoeffBuf);
if (stream_format_code & 0x1)
imc_decode_level_coefficients_raw(q, chctx->levlCoeffBuf,
chctx->flcoeffs1, chctx->flcoeffs2);
else if (stream_format_code & 0x4)
imc_decode_level_coefficients(q, chctx->levlCoeffBuf,
chctx->flcoeffs1, chctx->flcoeffs2);
else
imc_decode_level_coefficients2(q, chctx->levlCoeffBuf, chctx->old_floor,
chctx->flcoeffs1, chctx->flcoeffs2);
for(i=0; i<BANDS; i++) {
if(chctx->flcoeffs1[i] > INT_MAX) {
av_log(avctx, AV_LOG_ERROR, "scalefactor out of range\n");
return AVERROR_INVALIDDATA;
}
}
memcpy(chctx->old_floor, chctx->flcoeffs1, 32 * sizeof(float));
counter = 0;
if (stream_format_code & 0x1) {
for (i = 0; i < BANDS; i++) {
chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
chctx->bandFlagsBuf[i] = 0;
chctx->flcoeffs3[i] = chctx->flcoeffs2[i] * 2;
chctx->flcoeffs5[i] = 1.0;
}
} else {
for (i = 0; i < BANDS; i++) {
if (chctx->levlCoeffBuf[i] == 16) {
chctx->bandWidthT[i] = 0;
counter++;
} else
chctx->bandWidthT[i] = band_tab[i + 1] - band_tab[i];
}
memset(chctx->bandFlagsBuf, 0, BANDS * sizeof(int));
for (i = 0; i < BANDS - 1; i++)
if (chctx->bandWidthT[i])
chctx->bandFlagsBuf[i] = get_bits1(&q->gb);
imc_calculate_coeffs(q, chctx->flcoeffs1, chctx->flcoeffs2,
chctx->bandWidthT, chctx->flcoeffs3,
chctx->flcoeffs5);
}
bitscount = 0;
/* first 4 bands will be assigned 5 bits per coefficient */
if (stream_format_code & 0x2) {
bitscount += 15;
chctx->bitsBandT[0] = 5;
chctx->CWlengthT[0] = 5;
chctx->CWlengthT[1] = 5;
chctx->CWlengthT[2] = 5;
for (i = 1; i < 4; i++) {
if (stream_format_code & 0x1)
bits = 5;
else
bits = (chctx->levlCoeffBuf[i] == 16) ? 0 : 5;
chctx->bitsBandT[i] = bits;
for (j = band_tab[i]; j < band_tab[i + 1]; j++) {
chctx->CWlengthT[j] = bits;
bitscount += bits;
}
}
}
if (avctx->codec_id == AV_CODEC_ID_IAC) {
bitscount += !!chctx->bandWidthT[BANDS - 1];
if (!(stream_format_code & 0x2))
bitscount += 16;
}
if ((ret = bit_allocation(q, chctx, stream_format_code,
512 - bitscount - get_bits_count(&q->gb),
flag)) < 0) {
av_log(avctx, AV_LOG_ERROR, "Bit allocations failed\n");
chctx->decoder_reset = 1;
return ret;
}
if (stream_format_code & 0x1) {
for (i = 0; i < BANDS; i++)
chctx->skipFlags[i] = 0;
} else {
imc_refine_bit_allocation(q, chctx);
}
for (i = 0; i < BANDS; i++) {
chctx->sumLenArr[i] = 0;
for (j = band_tab[i]; j < band_tab[i + 1]; j++)
if (!chctx->skipFlags[j])
chctx->sumLenArr[i] += chctx->CWlengthT[j];
}
memset(chctx->codewords, 0, sizeof(chctx->codewords));
imc_get_coeffs(avctx, q, chctx);
if (inverse_quant_coeff(q, chctx, stream_format_code) < 0) {
av_log(avctx, AV_LOG_ERROR, "Inverse quantization of coefficients failed\n");
chctx->decoder_reset = 1;
return AVERROR_INVALIDDATA;
}
memset(chctx->skipFlags, 0, sizeof(chctx->skipFlags));
imc_imdct256(q, chctx, avctx->channels);
return 0;
}
static int imc_decode_frame(AVCodecContext *avctx, void *data,
int *got_frame_ptr, AVPacket *avpkt)
{
AVFrame *frame = data;
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
int ret, i;
IMCContext *q = avctx->priv_data;
LOCAL_ALIGNED_16(uint16_t, buf16, [(IMC_BLOCK_SIZE + AV_INPUT_BUFFER_PADDING_SIZE) / 2]);
q->avctx = avctx;
if (buf_size < IMC_BLOCK_SIZE * avctx->channels) {
av_log(avctx, AV_LOG_ERROR, "frame too small!\n");
return AVERROR_INVALIDDATA;
}
/* get output buffer */
frame->nb_samples = COEFFS;
if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
return ret;
for (i = 0; i < avctx->channels; i++) {
q->out_samples = (float *)frame->extended_data[i];
q->bdsp.bswap16_buf(buf16, (const uint16_t *) buf, IMC_BLOCK_SIZE / 2);
init_get_bits(&q->gb, (const uint8_t*)buf16, IMC_BLOCK_SIZE * 8);
buf += IMC_BLOCK_SIZE;
if ((ret = imc_decode_block(avctx, q, i)) < 0)
return ret;
}
if (avctx->channels == 2) {
q->butterflies_float((float *)frame->extended_data[0],
(float *)frame->extended_data[1], COEFFS);
}
*got_frame_ptr = 1;
return IMC_BLOCK_SIZE * avctx->channels;
}
static av_cold int imc_decode_close(AVCodecContext * avctx)
{
IMCContext *q = avctx->priv_data;
ff_fft_end(&q->fft);
return 0;
}
static av_cold void flush(AVCodecContext *avctx)
{
IMCContext *q = avctx->priv_data;
q->chctx[0].decoder_reset =
q->chctx[1].decoder_reset = 1;
}
#if CONFIG_IMC_DECODER
const AVCodec ff_imc_decoder = {
.name = "imc",
.long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
.type = AVMEDIA_TYPE_AUDIO,
.id = AV_CODEC_ID_IMC,
.priv_data_size = sizeof(IMCContext),
.init = imc_decode_init,
.close = imc_decode_close,
.decode = imc_decode_frame,
.flush = flush,
.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
AV_SAMPLE_FMT_NONE },
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
};
#endif
#if CONFIG_IAC_DECODER
const AVCodec ff_iac_decoder = {
.name = "iac",
.long_name = NULL_IF_CONFIG_SMALL("IAC (Indeo Audio Coder)"),
.type = AVMEDIA_TYPE_AUDIO,
.id = AV_CODEC_ID_IAC,
.priv_data_size = sizeof(IMCContext),
.init = imc_decode_init,
.close = imc_decode_close,
.decode = imc_decode_frame,
.flush = flush,
.capabilities = AV_CODEC_CAP_DR1,
.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
AV_SAMPLE_FMT_NONE },
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
};
#endif
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