/*
* Copyright (c) 2012 Andrew D'Addesio
* Copyright (c) 2013-2014 Mozilla Corporation
*
* 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
* Opus CELT decoder
*/
#include <stdint.h>
#include "libavutil/float_dsp.h"
#include "libavutil/libm.h"
#include "imdct15.h"
#include "opus.h"
#include "opustab.h"
enum CeltSpread {
CELT_SPREAD_NONE,
CELT_SPREAD_LIGHT,
CELT_SPREAD_NORMAL,
CELT_SPREAD_AGGRESSIVE
};
typedef struct CeltFrame {
float energy[CELT_MAX_BANDS];
float prev_energy[2][CELT_MAX_BANDS];
uint8_t collapse_masks[CELT_MAX_BANDS];
/* buffer for mdct output + postfilter */
DECLARE_ALIGNED(32, float, buf)[2048];
/* postfilter parameters */
int pf_period_new;
float pf_gains_new[3];
int pf_period;
float pf_gains[3];
int pf_period_old;
float pf_gains_old[3];
float deemph_coeff;
} CeltFrame;
struct CeltContext {
// constant values that do not change during context lifetime
AVCodecContext *avctx;
IMDCT15Context *imdct[4];
AVFloatDSPContext *dsp;
int output_channels;
// values that have inter-frame effect and must be reset on flush
CeltFrame frame[2];
uint32_t seed;
int flushed;
// values that only affect a single frame
int coded_channels;
int framebits;
int duration;
/* number of iMDCT blocks in the frame */
int blocks;
/* size of each block */
int blocksize;
int startband;
int endband;
int codedbands;
int anticollapse_bit;
int intensitystereo;
int dualstereo;
enum CeltSpread spread;
int remaining;
int remaining2;
int fine_bits [CELT_MAX_BANDS];
int fine_priority[CELT_MAX_BANDS];
int pulses [CELT_MAX_BANDS];
int tf_change [CELT_MAX_BANDS];
DECLARE_ALIGNED(32, float, coeffs)[2][CELT_MAX_FRAME_SIZE];
DECLARE_ALIGNED(32, float, scratch)[22 * 8]; // MAX(ff_celt_freq_range) * 1<<CELT_MAX_LOG_BLOCKS
};
static inline int16_t celt_cos(int16_t x)
{
x = (MUL16(x, x) + 4096) >> 13;
x = (32767-x) + ROUND_MUL16(x, (-7651 + ROUND_MUL16(x, (8277 + ROUND_MUL16(-626, x)))));
return 1+x;
}
static inline int celt_log2tan(int isin, int icos)
{
int lc, ls;
lc = opus_ilog(icos);
ls = opus_ilog(isin);
icos <<= 15 - lc;
isin <<= 15 - ls;
return (ls << 11) - (lc << 11) +
ROUND_MUL16(isin, ROUND_MUL16(isin, -2597) + 7932) -
ROUND_MUL16(icos, ROUND_MUL16(icos, -2597) + 7932);
}
static inline uint32_t celt_rng(CeltContext *s)
{
s->seed = 1664525 * s->seed + 1013904223;
return s->seed;
}
static void celt_decode_coarse_energy(CeltContext *s, OpusRangeCoder *rc)
{
int i, j;
float prev[2] = {0};
float alpha, beta;
const uint8_t *model;
/* use the 2D z-transform to apply prediction in both */
/* the time domain (alpha) and the frequency domain (beta) */
if (opus_rc_tell(rc)+3 <= s->framebits && ff_opus_rc_dec_log(rc, 3)) {
/* intra frame */
alpha = 0;
beta = 1.0f - 4915.0f/32768.0f;
model = ff_celt_coarse_energy_dist[s->duration][1];
} else {
alpha = ff_celt_alpha_coef[s->duration];
beta = 1.0f - ff_celt_beta_coef[s->duration];
model = ff_celt_coarse_energy_dist[s->duration][0];
}
for (i = 0; i < CELT_MAX_BANDS; i++) {
for (j = 0; j < s->coded_channels; j++) {
CeltFrame *frame = &s->frame[j];
float value;
int available;
if (i < s->startband || i >= s->endband) {
frame->energy[i] = 0.0;
continue;
}
available = s->framebits - opus_rc_tell(rc);
if (available >= 15) {
/* decode using a Laplace distribution */
int k = FFMIN(i, 20) << 1;
value = ff_opus_rc_dec_laplace(rc, model[k] << 7, model[k+1] << 6);
} else if (available >= 2) {
int x = ff_opus_rc_dec_cdf(rc, ff_celt_model_energy_small);
value = (x>>1) ^ -(x&1);
} else if (available >= 1) {
value = -(float)ff_opus_rc_dec_log(rc, 1);
} else value = -1;
frame->energy[i] = FFMAX(-9.0f, frame->energy[i]) * alpha + prev[j] + value;
prev[j] += beta * value;
}
}
}
static void celt_decode_fine_energy(CeltContext *s, OpusRangeCoder *rc)
{
int i;
for (i = s->startband; i < s->endband; i++) {
int j;
if (!s->fine_bits[i])
continue;
for (j = 0; j < s->coded_channels; j++) {
CeltFrame *frame = &s->frame[j];
int q2;
float offset;
q2 = ff_opus_rc_get_raw(rc, s->fine_bits[i]);
offset = (q2 + 0.5f) * (1 << (14 - s->fine_bits[i])) / 16384.0f - 0.5f;
frame->energy[i] += offset;
}
}
}
static void celt_decode_final_energy(CeltContext *s, OpusRangeCoder *rc,
int bits_left)
{
int priority, i, j;
for (priority = 0; priority < 2; priority++) {
for (i = s->startband; i < s->endband && bits_left >= s->coded_channels; i++) {
if (s->fine_priority[i] != priority || s->fine_bits[i] >= CELT_MAX_FINE_BITS)
continue;
for (j = 0; j < s->coded_channels; j++) {
int q2;
float offset;
q2 = ff_opus_rc_get_raw(rc, 1);
offset = (q2 - 0.5f) * (1 << (14 - s->fine_bits[i] - 1)) / 16384.0f;
s->frame[j].energy[i] += offset;
bits_left--;
}
}
}
}
static void celt_decode_tf_changes(CeltContext *s, OpusRangeCoder *rc,
int transient)
{
int i, diff = 0, tf_select = 0, tf_changed = 0, tf_select_bit;
int consumed, bits = transient ? 2 : 4;
consumed = opus_rc_tell(rc);
tf_select_bit = (s->duration != 0 && consumed+bits+1 <= s->framebits);
for (i = s->startband; i < s->endband; i++) {
if (consumed+bits+tf_select_bit <= s->framebits) {
diff ^= ff_opus_rc_dec_log(rc, bits);
consumed = opus_rc_tell(rc);
tf_changed |= diff;
}
s->tf_change[i] = diff;
bits = transient ? 4 : 5;
}
if (tf_select_bit && ff_celt_tf_select[s->duration][transient][0][tf_changed] !=
ff_celt_tf_select[s->duration][transient][1][tf_changed])
tf_select = ff_opus_rc_dec_log(rc, 1);
for (i = s->startband; i < s->endband; i++) {
s->tf_change[i] = ff_celt_tf_select[s->duration][transient][tf_select][s->tf_change[i]];
}
}
static void celt_decode_allocation(CeltContext *s, OpusRangeCoder *rc)
{
// approx. maximum bit allocation for each band before boost/trim
int cap[CELT_MAX_BANDS];
int boost[CELT_MAX_BANDS];
int threshold[CELT_MAX_BANDS];
int bits1[CELT_MAX_BANDS];
int bits2[CELT_MAX_BANDS];
int trim_offset[CELT_MAX_BANDS];
int skip_startband = s->startband;
int dynalloc = 6;
int alloctrim = 5;
int extrabits = 0;
int skip_bit = 0;
int intensitystereo_bit = 0;
int dualstereo_bit = 0;
int remaining, bandbits;
int low, high, total, done;
int totalbits;
int consumed;
int i, j;
consumed = opus_rc_tell(rc);
/* obtain spread flag */
s->spread = CELT_SPREAD_NORMAL;
if (consumed + 4 <= s->framebits)
s->spread = ff_opus_rc_dec_cdf(rc, ff_celt_model_spread);
/* generate static allocation caps */
for (i = 0; i < CELT_MAX_BANDS; i++) {
cap[i] = (ff_celt_static_caps[s->duration][s->coded_channels - 1][i] + 64)
* ff_celt_freq_range[i] << (s->coded_channels - 1) << s->duration >> 2;
}
/* obtain band boost */
totalbits = s->framebits << 3; // convert to 1/8 bits
consumed = opus_rc_tell_frac(rc);
for (i = s->startband; i < s->endband; i++) {
int quanta, band_dynalloc;
boost[i] = 0;
quanta = ff_celt_freq_range[i] << (s->coded_channels - 1) << s->duration;
quanta = FFMIN(quanta << 3, FFMAX(6 << 3, quanta));
band_dynalloc = dynalloc;
while (consumed + (band_dynalloc<<3) < totalbits && boost[i] < cap[i]) {
int add = ff_opus_rc_dec_log(rc, band_dynalloc);
consumed = opus_rc_tell_frac(rc);
if (!add)
break;
boost[i] += quanta;
totalbits -= quanta;
band_dynalloc = 1;
}
/* dynalloc is more likely to occur if it's already been used for earlier bands */
if (boost[i])
dynalloc = FFMAX(2, dynalloc - 1);
}
/* obtain allocation trim */
if (consumed + (6 << 3) <= totalbits)
alloctrim = ff_opus_rc_dec_cdf(rc, ff_celt_model_alloc_trim);
/* anti-collapse bit reservation */
totalbits = (s->framebits << 3) - opus_rc_tell_frac(rc) - 1;
s->anticollapse_bit = 0;
if (s->blocks > 1 && s->duration >= 2 &&
totalbits >= ((s->duration + 2) << 3))
s->anticollapse_bit = 1 << 3;
totalbits -= s->anticollapse_bit;
/* band skip bit reservation */
if (totalbits >= 1 << 3)
skip_bit = 1 << 3;
totalbits -= skip_bit;
/* intensity/dual stereo bit reservation */
if (s->coded_channels == 2) {
intensitystereo_bit = ff_celt_log2_frac[s->endband - s->startband];
if (intensitystereo_bit <= totalbits) {
totalbits -= intensitystereo_bit;
if (totalbits >= 1 << 3) {
dualstereo_bit = 1 << 3;
totalbits -= 1 << 3;
}
} else
intensitystereo_bit = 0;
}
for (i = s->startband; i < s->endband; i++) {
int trim = alloctrim - 5 - s->duration;
int band = ff_celt_freq_range[i] * (s->endband - i - 1);
int duration = s->duration + 3;
int scale = duration + s->coded_channels - 1;
/* PVQ minimum allocation threshold, below this value the band is
* skipped */
threshold[i] = FFMAX(3 * ff_celt_freq_range[i] << duration >> 4,
s->coded_channels << 3);
trim_offset[i] = trim * (band << scale) >> 6;
if (ff_celt_freq_range[i] << s->duration == 1)
trim_offset[i] -= s->coded_channels << 3;
}
/* bisection */
low = 1;
high = CELT_VECTORS - 1;
while (low <= high) {
int center = (low + high) >> 1;
done = total = 0;
for (i = s->endband - 1; i >= s->startband; i--) {
bandbits = ff_celt_freq_range[i] * ff_celt_static_alloc[center][i]
<< (s->coded_channels - 1) << s->duration >> 2;
if (bandbits)
bandbits = FFMAX(0, bandbits + trim_offset[i]);
bandbits += boost[i];
if (bandbits >= threshold[i] || done) {
done = 1;
total += FFMIN(bandbits, cap[i]);
} else if (bandbits >= s->coded_channels << 3)
total += s->coded_channels << 3;
}
if (total > totalbits)
high = center - 1;
else
low = center + 1;
}
high = low--;
for (i = s->startband; i < s->endband; i++) {
bits1[i] = ff_celt_freq_range[i] * ff_celt_static_alloc[low][i]
<< (s->coded_channels - 1) << s->duration >> 2;
bits2[i] = high >= CELT_VECTORS ? cap[i] :
ff_celt_freq_range[i] * ff_celt_static_alloc[high][i]
<< (s->coded_channels - 1) << s->duration >> 2;
if (bits1[i])
bits1[i] = FFMAX(0, bits1[i] + trim_offset[i]);
if (bits2[i])
bits2[i] = FFMAX(0, bits2[i] + trim_offset[i]);
if (low)
bits1[i] += boost[i];
bits2[i] += boost[i];
if (boost[i])
skip_startband = i;
bits2[i] = FFMAX(0, bits2[i] - bits1[i]);
}
/* bisection */
low = 0;
high = 1 << CELT_ALLOC_STEPS;
for (i = 0; i < CELT_ALLOC_STEPS; i++) {
int center = (low + high) >> 1;
done = total = 0;
for (j = s->endband - 1; j >= s->startband; j--) {
bandbits = bits1[j] + (center * bits2[j] >> CELT_ALLOC_STEPS);
if (bandbits >= threshold[j] || done) {
done = 1;
total += FFMIN(bandbits, cap[j]);
} else if (bandbits >= s->coded_channels << 3)
total += s->coded_channels << 3;
}
if (total > totalbits)
high = center;
else
low = center;
}
done = total = 0;
for (i = s->endband - 1; i >= s->startband; i--) {
bandbits = bits1[i] + (low * bits2[i] >> CELT_ALLOC_STEPS);
if (bandbits >= threshold[i] || done)
done = 1;
else
bandbits = (bandbits >= s->coded_channels << 3) ?
s->coded_channels << 3 : 0;
bandbits = FFMIN(bandbits, cap[i]);
s->pulses[i] = bandbits;
total += bandbits;
}
/* band skipping */
for (s->codedbands = s->endband; ; s->codedbands--) {
int allocation;
j = s->codedbands - 1;
if (j == skip_startband) {
/* all remaining bands are not skipped */
totalbits += skip_bit;
break;
}
/* determine the number of bits available for coding "do not skip" markers */
remaining = totalbits - total;
bandbits = remaining / (ff_celt_freq_bands[j+1] - ff_celt_freq_bands[s->startband]);
remaining -= bandbits * (ff_celt_freq_bands[j+1] - ff_celt_freq_bands[s->startband]);
allocation = s->pulses[j] + bandbits * ff_celt_freq_range[j]
+ FFMAX(0, remaining - (ff_celt_freq_bands[j] - ff_celt_freq_bands[s->startband]));
/* a "do not skip" marker is only coded if the allocation is
above the chosen threshold */
if (allocation >= FFMAX(threshold[j], (s->coded_channels + 1) <<3 )) {
if (ff_opus_rc_dec_log(rc, 1))
break;
total += 1 << 3;
allocation -= 1 << 3;
}
/* the band is skipped, so reclaim its bits */
total -= s->pulses[j];
if (intensitystereo_bit) {
total -= intensitystereo_bit;
intensitystereo_bit = ff_celt_log2_frac[j - s->startband];
total += intensitystereo_bit;
}
total += s->pulses[j] = (allocation >= s->coded_channels << 3) ?
s->coded_channels << 3 : 0;
}
/* obtain stereo flags */
s->intensitystereo = 0;
s->dualstereo = 0;
if (intensitystereo_bit)
s->intensitystereo = s->startband +
ff_opus_rc_dec_uint(rc, s->codedbands + 1 - s->startband);
if (s->intensitystereo <= s->startband)
totalbits += dualstereo_bit; /* no intensity stereo means no dual stereo */
else if (dualstereo_bit)
s->dualstereo = ff_opus_rc_dec_log(rc, 1);
/* supply the remaining bits in this frame to lower bands */
remaining = totalbits - total;
bandbits = remaining / (ff_celt_freq_bands[s->codedbands] - ff_celt_freq_bands[s->startband]);
remaining -= bandbits * (ff_celt_freq_bands[s->codedbands] - ff_celt_freq_bands[s->startband]);
for (i = s->startband; i < s->codedbands; i++) {
int bits = FFMIN(remaining, ff_celt_freq_range[i]);
s->pulses[i] += bits + bandbits * ff_celt_freq_range[i];
remaining -= bits;
}
for (i = s->startband; i < s->codedbands; i++) {
int N = ff_celt_freq_range[i] << s->duration;
int prev_extra = extrabits;
s->pulses[i] += extrabits;
if (N > 1) {
int dof; // degrees of freedom
int temp; // dof * channels * log(dof)
int offset; // fine energy quantization offset, i.e.
// extra bits assigned over the standard
// totalbits/dof
int fine_bits, max_bits;
extrabits = FFMAX(0, s->pulses[i] - cap[i]);
s->pulses[i] -= extrabits;
/* intensity stereo makes use of an extra degree of freedom */
dof = N * s->coded_channels
+ (s->coded_channels == 2 && N > 2 && !s->dualstereo && i < s->intensitystereo);
temp = dof * (ff_celt_log_freq_range[i] + (s->duration<<3));
offset = (temp >> 1) - dof * CELT_FINE_OFFSET;
if (N == 2) /* dof=2 is the only case that doesn't fit the model */
offset += dof<<1;
/* grant an additional bias for the first and second pulses */
if (s->pulses[i] + offset < 2 * (dof << 3))
offset += temp >> 2;
else if (s->pulses[i] + offset < 3 * (dof << 3))
offset += temp >> 3;
fine_bits = (s->pulses[i] + offset + (dof << 2)) / (dof << 3);
max_bits = FFMIN((s->pulses[i]>>3) >> (s->coded_channels - 1),
CELT_MAX_FINE_BITS);
max_bits = FFMAX(max_bits, 0);
s->fine_bits[i] = av_clip(fine_bits, 0, max_bits);
/* if fine_bits was rounded down or capped,
give priority for the final fine energy pass */
s->fine_priority[i] = (s->fine_bits[i] * (dof<<3) >= s->pulses[i] + offset);
/* the remaining bits are assigned to PVQ */
s->pulses[i] -= s->fine_bits[i] << (s->coded_channels - 1) << 3;
} else {
/* all bits go to fine energy except for the sign bit */
extrabits = FFMAX(0, s->pulses[i] - (s->coded_channels << 3));
s->pulses[i] -= extrabits;
s->fine_bits[i] = 0;
s->fine_priority[i] = 1;
}
/* hand back a limited number of extra fine energy bits to this band */
if (extrabits > 0) {
int fineextra = FFMIN(extrabits >> (s->coded_channels + 2),
CELT_MAX_FINE_BITS - s->fine_bits[i]);
s->fine_bits[i] += fineextra;
fineextra <<= s->coded_channels + 2;
s->fine_priority[i] = (fineextra >= extrabits - prev_extra);
extrabits -= fineextra;
}
}
s->remaining = extrabits;
/* skipped bands dedicate all of their bits for fine energy */
for (; i < s->endband; i++) {
s->fine_bits[i] = s->pulses[i] >> (s->coded_channels - 1) >> 3;
s->pulses[i] = 0;
s->fine_priority[i] = s->fine_bits[i] < 1;
}
}
static inline int celt_bits2pulses(const uint8_t *cache, int bits)
{
// TODO: Find the size of cache and make it into an array in the parameters list
int i, low = 0, high;
high = cache[0];
bits--;
for (i = 0; i < 6; i++) {
int center = (low + high + 1) >> 1;
if (cache[center] >= bits)
high = center;
else
low = center;
}
return (bits - (low == 0 ? -1 : cache[low]) <= cache[high] - bits) ? low : high;
}
static inline int celt_pulses2bits(const uint8_t *cache, int pulses)
{
// TODO: Find the size of cache and make it into an array in the parameters list
return (pulses == 0) ? 0 : cache[pulses] + 1;
}
static inline void celt_normalize_residual(const int * av_restrict iy, float * av_restrict X,
int N, float g)
{
int i;
for (i = 0; i < N; i++)
X[i] = g * iy[i];
}
static void celt_exp_rotation1(float *X, unsigned int len, unsigned int stride,
float c, float s)
{
float *Xptr;
int i;
Xptr = X;
for (i = 0; i < len - stride; i++) {
float x1, x2;
x1 = Xptr[0];
x2 = Xptr[stride];
Xptr[stride] = c * x2 + s * x1;
*Xptr++ = c * x1 - s * x2;
}
Xptr = &X[len - 2 * stride - 1];
for (i = len - 2 * stride - 1; i >= 0; i--) {
float x1, x2;
x1 = Xptr[0];
x2 = Xptr[stride];
Xptr[stride] = c * x2 + s * x1;
*Xptr-- = c * x1 - s * x2;
}
}
static inline void celt_exp_rotation(float *X, unsigned int len,
unsigned int stride, unsigned int K,
enum CeltSpread spread)
{
unsigned int stride2 = 0;
float c, s;
float gain, theta;
int i;
if (2*K >= len || spread == CELT_SPREAD_NONE)
return;
gain = (float)len / (len + (20 - 5*spread) * K);
theta = M_PI * gain * gain / 4;
c = cos(theta);
s = sin(theta);
if (len >= stride << 3) {
stride2 = 1;
/* This is just a simple (equivalent) way of computing sqrt(len/stride) with rounding.
It's basically incrementing long as (stride2+0.5)^2 < len/stride. */
while ((stride2 * stride2 + stride2) * stride + (stride >> 2) < len)
stride2++;
}
/*NOTE: As a minor optimization, we could be passing around log2(B), not B, for both this and for
extract_collapse_mask().*/
len /= stride;
for (i = 0; i < stride; i++) {
if (stride2)
celt_exp_rotation1(X + i * len, len, stride2, s, c);
celt_exp_rotation1(X + i * len, len, 1, c, s);
}
}
static inline unsigned int celt_extract_collapse_mask(const int *iy,
unsigned int N,
unsigned int B)
{
unsigned int collapse_mask;
int N0;
int i, j;
if (B <= 1)
return 1;
/*NOTE: As a minor optimization, we could be passing around log2(B), not B, for both this and for
exp_rotation().*/
N0 = N/B;
collapse_mask = 0;
for (i = 0; i < B; i++)
for (j = 0; j < N0; j++)
collapse_mask |= (iy[i*N0+j]!=0)<<i;
return collapse_mask;
}
static inline void celt_renormalize_vector(float *X, int N, float gain)
{
int i;
float g = 1e-15f;
for (i = 0; i < N; i++)
g += X[i] * X[i];
g = gain / sqrtf(g);
for (i = 0; i < N; i++)
X[i] *= g;
}
static inline void celt_stereo_merge(float *X, float *Y, float mid, int N)
{
int i;
float xp = 0, side = 0;
float E[2];
float mid2;
float t, gain[2];
/* Compute the norm of X+Y and X-Y as |X|^2 + |Y|^2 +/- sum(xy) */
for (i = 0; i < N; i++) {
xp += X[i] * Y[i];
side += Y[i] * Y[i];
}
/* Compensating for the mid normalization */
xp *= mid;
mid2 = mid;
E[0] = mid2 * mid2 + side - 2 * xp;
E[1] = mid2 * mid2 + side + 2 * xp;
if (E[0] < 6e-4f || E[1] < 6e-4f) {
for (i = 0; i < N; i++)
Y[i] = X[i];
return;
}
t = E[0];
gain[0] = 1.0f / sqrtf(t);
t = E[1];
gain[1] = 1.0f / sqrtf(t);
for (i = 0; i < N; i++) {
float value[2];
/* Apply mid scaling (side is already scaled) */
value[0] = mid * X[i];
value[1] = Y[i];
X[i] = gain[0] * (value[0] - value[1]);
Y[i] = gain[1] * (value[0] + value[1]);
}
}
static void celt_interleave_hadamard(float *tmp, float *X, int N0,
int stride, int hadamard)
{
int i, j;
int N = N0*stride;
if (hadamard) {
const uint8_t *ordery = ff_celt_hadamard_ordery + stride - 2;
for (i = 0; i < stride; i++)
for (j = 0; j < N0; j++)
tmp[j*stride+i] = X[ordery[i]*N0+j];
} else {
for (i = 0; i < stride; i++)
for (j = 0; j < N0; j++)
tmp[j*stride+i] = X[i*N0+j];
}
for (i = 0; i < N; i++)
X[i] = tmp[i];
}
static void celt_deinterleave_hadamard(float *tmp, float *X, int N0,
int stride, int hadamard)
{
int i, j;
int N = N0*stride;
if (hadamard) {
const uint8_t *ordery = ff_celt_hadamard_ordery + stride - 2;
for (i = 0; i < stride; i++)
for (j = 0; j < N0; j++)
tmp[ordery[i]*N0+j] = X[j*stride+i];
} else {
for (i = 0; i < stride; i++)
for (j = 0; j < N0; j++)
tmp[i*N0+j] = X[j*stride+i];
}
for (i = 0; i < N; i++)
X[i] = tmp[i];
}
static void celt_haar1(float *X, int N0, int stride)
{
int i, j;
N0 >>= 1;
for (i = 0; i < stride; i++) {
for (j = 0; j < N0; j++) {
float x0 = X[stride * (2 * j + 0) + i];
float x1 = X[stride * (2 * j + 1) + i];
X[stride * (2 * j + 0) + i] = (x0 + x1) * M_SQRT1_2;
X[stride * (2 * j + 1) + i] = (x0 - x1) * M_SQRT1_2;
}
}
}
static inline int celt_compute_qn(int N, int b, int offset, int pulse_cap,
int dualstereo)
{
int qn, qb;
int N2 = 2 * N - 1;
if (dualstereo && N == 2)
N2--;
/* The upper limit ensures that in a stereo split with itheta==16384, we'll
* always have enough bits left over to code at least one pulse in the
* side; otherwise it would collapse, since it doesn't get folded. */
qb = FFMIN3(b - pulse_cap - (4 << 3), (b + N2 * offset) / N2, 8 << 3);
qn = (qb < (1 << 3 >> 1)) ? 1 : ((ff_celt_qn_exp2[qb & 0x7] >> (14 - (qb >> 3))) + 1) >> 1 << 1;
return qn;
}
// this code was adapted from libopus
static inline uint64_t celt_cwrsi(unsigned int N, unsigned int K, unsigned int i, int *y)
{
uint64_t norm = 0;
uint32_t p;
int s, val;
int k0;
while (N > 2) {
uint32_t q;
/*Lots of pulses case:*/
if (K >= N) {
const uint32_t *row = ff_celt_pvq_u_row[N];
/* Are the pulses in this dimension negative? */
p = row[K + 1];
s = -(i >= p);
i -= p & s;
/*Count how many pulses were placed in this dimension.*/
k0 = K;
q = row[N];
if (q > i) {
K = N;
do {
p = ff_celt_pvq_u_row[--K][N];
} while (p > i);
} else
for (p = row[K]; p > i; p = row[K])
K--;
i -= p;
val = (k0 - K + s) ^ s;
norm += val * val;
*y++ = val;
} else { /*Lots of dimensions case:*/
/*Are there any pulses in this dimension at all?*/
p = ff_celt_pvq_u_row[K ][N];
q = ff_celt_pvq_u_row[K + 1][N];
if (p <= i && i < q) {
i -= p;
*y++ = 0;
} else {
/*Are the pulses in this dimension negative?*/
s = -(i >= q);
i -= q & s;
/*Count how many pulses were placed in this dimension.*/
k0 = K;
do p = ff_celt_pvq_u_row[--K][N];
while (p > i);
i -= p;
val = (k0 - K + s) ^ s;
norm += val * val;
*y++ = val;
}
}
N--;
}
/* N == 2 */
p = 2 * K + 1;
s = -(i >= p);
i -= p & s;
k0 = K;
K = (i + 1) / 2;
if (K)
i -= 2 * K - 1;
val = (k0 - K + s) ^ s;
norm += val * val;
*y++ = val;
/* N==1 */
s = -i;
val = (K + s) ^ s;
norm += val * val;
*y = val;
return norm;
}
static inline float celt_decode_pulses(OpusRangeCoder *rc, int *y, unsigned int N, unsigned int K)
{
unsigned int idx;
#define CELT_PVQ_U(n, k) (ff_celt_pvq_u_row[FFMIN(n, k)][FFMAX(n, k)])
#define CELT_PVQ_V(n, k) (CELT_PVQ_U(n, k) + CELT_PVQ_U(n, (k) + 1))
idx = ff_opus_rc_dec_uint(rc, CELT_PVQ_V(N, K));
return celt_cwrsi(N, K, idx, y);
}
/** Decode pulse vector and combine the result with the pitch vector to produce
the final normalised signal in the current band. */
static inline unsigned int celt_alg_unquant(OpusRangeCoder *rc, float *X,
unsigned int N, unsigned int K,
enum CeltSpread spread,
unsigned int blocks, float gain)
{
int y[176];
gain /= sqrtf(celt_decode_pulses(rc, y, N, K));
celt_normalize_residual(y, X, N, gain);
celt_exp_rotation(X, N, blocks, K, spread);
return celt_extract_collapse_mask(y, N, blocks);
}
static unsigned int celt_decode_band(CeltContext *s, OpusRangeCoder *rc,
const int band, float *X, float *Y,
int N, int b, unsigned int blocks,
float *lowband, int duration,
float *lowband_out, int level,
float gain, float *lowband_scratch,
int fill)
{
const uint8_t *cache;
int dualstereo, split;
int imid = 0, iside = 0;
unsigned int N0 = N;
int N_B;
int N_B0;
int B0 = blocks;
int time_divide = 0;
int recombine = 0;
int inv = 0;
float mid = 0, side = 0;
int longblocks = (B0 == 1);
unsigned int cm = 0;
N_B0 = N_B = N / blocks;
split = dualstereo = (Y != NULL);
if (N == 1) {
/* special case for one sample */
int i;
float *x = X;
for (i = 0; i <= dualstereo; i++) {
int sign = 0;
if (s->remaining2 >= 1<<3) {
sign = ff_opus_rc_get_raw(rc, 1);
s->remaining2 -= 1 << 3;
b -= 1 << 3;
}
x[0] = sign ? -1.0f : 1.0f;
x = Y;
}
if (lowband_out)
lowband_out[0] = X[0];
return 1;
}
if (!dualstereo && level == 0) {
int tf_change = s->tf_change[band];
int k;
if (tf_change > 0)
recombine = tf_change;
/* Band recombining to increase frequency resolution */
if (lowband &&
(recombine || ((N_B & 1) == 0 && tf_change < 0) || B0 > 1)) {
int j;
for (j = 0; j < N; j++)
lowband_scratch[j] = lowband[j];
lowband = lowband_scratch;
}
for (k = 0; k < recombine; k++) {
if (lowband)
celt_haar1(lowband, N >> k, 1 << k);
fill = ff_celt_bit_interleave[fill & 0xF] | ff_celt_bit_interleave[fill >> 4] << 2;
}
blocks >>= recombine;
N_B <<= recombine;
/* Increasing the time resolution */
while ((N_B & 1) == 0 && tf_change < 0) {
if (lowband)
celt_haar1(lowband, N_B, blocks);
fill |= fill << blocks;
blocks <<= 1;
N_B >>= 1;
time_divide++;
tf_change++;
}
B0 = blocks;
N_B0 = N_B;
/* Reorganize the samples in time order instead of frequency order */
if (B0 > 1 && lowband)
celt_deinterleave_hadamard(s->scratch, lowband, N_B >> recombine,
B0 << recombine, longblocks);
}
/* If we need 1.5 more bit than we can produce, split the band in two. */
cache = ff_celt_cache_bits +
ff_celt_cache_index[(duration + 1) * CELT_MAX_BANDS + band];
if (!dualstereo && duration >= 0 && b > cache[cache[0]] + 12 && N > 2) {
N >>= 1;
Y = X + N;
split = 1;
duration -= 1;
if (blocks == 1)
fill = (fill & 1) | (fill << 1);
blocks = (blocks + 1) >> 1;
}
if (split) {
int qn;
int itheta = 0;
int mbits, sbits, delta;
int qalloc;
int pulse_cap;
int offset;
int orig_fill;
int tell;
/* Decide on the resolution to give to the split parameter theta */
pulse_cap = ff_celt_log_freq_range[band] + duration * 8;
offset = (pulse_cap >> 1) - (dualstereo && N == 2 ? CELT_QTHETA_OFFSET_TWOPHASE :
CELT_QTHETA_OFFSET);
qn = (dualstereo && band >= s->intensitystereo) ? 1 :
celt_compute_qn(N, b, offset, pulse_cap, dualstereo);
tell = opus_rc_tell_frac(rc);
if (qn != 1) {
/* Entropy coding of the angle. We use a uniform pdf for the
time split, a step for stereo, and a triangular one for the rest. */
if (dualstereo && N > 2)
itheta = ff_opus_rc_dec_uint_step(rc, qn/2);
else if (dualstereo || B0 > 1)
itheta = ff_opus_rc_dec_uint(rc, qn+1);
else
itheta = ff_opus_rc_dec_uint_tri(rc, qn);
itheta = itheta * 16384 / qn;
/* NOTE: Renormalising X and Y *may* help fixed-point a bit at very high rate.
Let's do that at higher complexity */
} else if (dualstereo) {
inv = (b > 2 << 3 && s->remaining2 > 2 << 3) ? ff_opus_rc_dec_log(rc, 2) : 0;
itheta = 0;
}
qalloc = opus_rc_tell_frac(rc) - tell;
b -= qalloc;
orig_fill = fill;
if (itheta == 0) {
imid = 32767;
iside = 0;
fill = av_mod_uintp2(fill, blocks);
delta = -16384;
} else if (itheta == 16384) {
imid = 0;
iside = 32767;
fill &= ((1 << blocks) - 1) << blocks;
delta = 16384;
} else {
imid = celt_cos(itheta);
iside = celt_cos(16384-itheta);
/* This is the mid vs side allocation that minimizes squared error
in that band. */
delta = ROUND_MUL16((N - 1) << 7, celt_log2tan(iside, imid));
}
mid = imid / 32768.0f;
side = iside / 32768.0f;
/* This is a special case for N=2 that only works for stereo and takes
advantage of the fact that mid and side are orthogonal to encode
the side with just one bit. */
if (N == 2 && dualstereo) {
int c;
int sign = 0;
float tmp;
float *x2, *y2;
mbits = b;
/* Only need one bit for the side */
sbits = (itheta != 0 && itheta != 16384) ? 1 << 3 : 0;
mbits -= sbits;
c = (itheta > 8192);
s->remaining2 -= qalloc+sbits;
x2 = c ? Y : X;
y2 = c ? X : Y;
if (sbits)
sign = ff_opus_rc_get_raw(rc, 1);
sign = 1 - 2 * sign;
/* We use orig_fill here because we want to fold the side, but if
itheta==16384, we'll have cleared the low bits of fill. */
cm = celt_decode_band(s, rc, band, x2, NULL, N, mbits, blocks,
lowband, duration, lowband_out, level, gain,
lowband_scratch, orig_fill);
/* We don't split N=2 bands, so cm is either 1 or 0 (for a fold-collapse),
and there's no need to worry about mixing with the other channel. */
y2[0] = -sign * x2[1];
y2[1] = sign * x2[0];
X[0] *= mid;
X[1] *= mid;
Y[0] *= side;
Y[1] *= side;
tmp = X[0];
X[0] = tmp - Y[0];
Y[0] = tmp + Y[0];
tmp = X[1];
X[1] = tmp - Y[1];
Y[1] = tmp + Y[1];
} else {
/* "Normal" split code */
float *next_lowband2 = NULL;
float *next_lowband_out1 = NULL;
int next_level = 0;
int rebalance;
/* Give more bits to low-energy MDCTs than they would
* otherwise deserve */
if (B0 > 1 && !dualstereo && (itheta & 0x3fff)) {
if (itheta > 8192)
/* Rough approximation for pre-echo masking */
delta -= delta >> (4 - duration);
else
/* Corresponds to a forward-masking slope of
* 1.5 dB per 10 ms */
delta = FFMIN(0, delta + (N << 3 >> (5 - duration)));
}
mbits = av_clip((b - delta) / 2, 0, b);
sbits = b - mbits;
s->remaining2 -= qalloc;
if (lowband && !dualstereo)
next_lowband2 = lowband + N; /* >32-bit split case */
/* Only stereo needs to pass on lowband_out.
* Otherwise, it's handled at the end */
if (dualstereo)
next_lowband_out1 = lowband_out;
else
next_level = level + 1;
rebalance = s->remaining2;
if (mbits >= sbits) {
/* In stereo mode, we do not apply a scaling to the mid
* because we need the normalized mid for folding later */
cm = celt_decode_band(s, rc, band, X, NULL, N, mbits, blocks,
lowband, duration, next_lowband_out1,
next_level, dualstereo ? 1.0f : (gain * mid),
lowband_scratch, fill);
rebalance = mbits - (rebalance - s->remaining2);
if (rebalance > 3 << 3 && itheta != 0)
sbits += rebalance - (3 << 3);
/* For a stereo split, the high bits of fill are always zero,
* so no folding will be done to the side. */
cm |= celt_decode_band(s, rc, band, Y, NULL, N, sbits, blocks,
next_lowband2, duration, NULL,
next_level, gain * side, NULL,
fill >> blocks) << ((B0 >> 1) & (dualstereo - 1));
} else {
/* For a stereo split, the high bits of fill are always zero,
* so no folding will be done to the side. */
cm = celt_decode_band(s, rc, band, Y, NULL, N, sbits, blocks,
next_lowband2, duration, NULL,
next_level, gain * side, NULL,
fill >> blocks) << ((B0 >> 1) & (dualstereo - 1));
rebalance = sbits - (rebalance - s->remaining2);
if (rebalance > 3 << 3 && itheta != 16384)
mbits += rebalance - (3 << 3);
/* In stereo mode, we do not apply a scaling to the mid because
* we need the normalized mid for folding later */
cm |= celt_decode_band(s, rc, band, X, NULL, N, mbits, blocks,
lowband, duration, next_lowband_out1,
next_level, dualstereo ? 1.0f : (gain * mid),
lowband_scratch, fill);
}
}
} else {
/* This is the basic no-split case */
unsigned int q = celt_bits2pulses(cache, b);
unsigned int curr_bits = celt_pulses2bits(cache, q);
s->remaining2 -= curr_bits;
/* Ensures we can never bust the budget */
while (s->remaining2 < 0 && q > 0) {
s->remaining2 += curr_bits;
curr_bits = celt_pulses2bits(cache, --q);
s->remaining2 -= curr_bits;
}
if (q != 0) {
/* Finally do the actual quantization */
cm = celt_alg_unquant(rc, X, N, (q < 8) ? q : (8 + (q & 7)) << ((q >> 3) - 1),
s->spread, blocks, gain);
} else {
/* If there's no pulse, fill the band anyway */
int j;
unsigned int cm_mask = (1 << blocks) - 1;
fill &= cm_mask;
if (!fill) {
for (j = 0; j < N; j++)
X[j] = 0.0f;
} else {
if (!lowband) {
/* Noise */
for (j = 0; j < N; j++)
X[j] = (((int32_t)celt_rng(s)) >> 20);
cm = cm_mask;
} else {
/* Folded spectrum */
for (j = 0; j < N; j++) {
/* About 48 dB below the "normal" folding level */
X[j] = lowband[j] + (((celt_rng(s)) & 0x8000) ? 1.0f / 256 : -1.0f / 256);
}
cm = fill;
}
celt_renormalize_vector(X, N, gain);
}
}
}
/* This code is used by the decoder and by the resynthesis-enabled encoder */
if (dualstereo) {
int j;
if (N != 2)
celt_stereo_merge(X, Y, mid, N);
if (inv) {
for (j = 0; j < N; j++)
Y[j] *= -1;
}
} else if (level == 0) {
int k;
/* Undo the sample reorganization going from time order to frequency order */
if (B0 > 1)
celt_interleave_hadamard(s->scratch, X, N_B>>recombine,
B0<<recombine, longblocks);
/* Undo time-freq changes that we did earlier */
N_B = N_B0;
blocks = B0;
for (k = 0; k < time_divide; k++) {
blocks >>= 1;
N_B <<= 1;
cm |= cm >> blocks;
celt_haar1(X, N_B, blocks);
}
for (k = 0; k < recombine; k++) {
cm = ff_celt_bit_deinterleave[cm];
celt_haar1(X, N0>>k, 1<<k);
}
blocks <<= recombine;
/* Scale output for later folding */
if (lowband_out) {
int j;
float n = sqrtf(N0);
for (j = 0; j < N0; j++)
lowband_out[j] = n * X[j];
}
cm = av_mod_uintp2(cm, blocks);
}
return cm;
}
static void celt_denormalize(CeltContext *s, CeltFrame *frame, float *data)
{
int i, j;
for (i = s->startband; i < s->endband; i++) {
float *dst = data + (ff_celt_freq_bands[i] << s->duration);
float norm = exp2(frame->energy[i] + ff_celt_mean_energy[i]);
for (j = 0; j < ff_celt_freq_range[i] << s->duration; j++)
dst[j] *= norm;
}
}
static void celt_postfilter_apply_transition(CeltFrame *frame, float *data)
{
const int T0 = frame->pf_period_old;
const int T1 = frame->pf_period;
float g00, g01, g02;
float g10, g11, g12;
float x0, x1, x2, x3, x4;
int i;
if (frame->pf_gains[0] == 0.0 &&
frame->pf_gains_old[0] == 0.0)
return;
g00 = frame->pf_gains_old[0];
g01 = frame->pf_gains_old[1];
g02 = frame->pf_gains_old[2];
g10 = frame->pf_gains[0];
g11 = frame->pf_gains[1];
g12 = frame->pf_gains[2];
x1 = data[-T1 + 1];
x2 = data[-T1];
x3 = data[-T1 - 1];
x4 = data[-T1 - 2];
for (i = 0; i < CELT_OVERLAP; i++) {
float w = ff_celt_window2[i];
x0 = data[i - T1 + 2];
data[i] += (1.0 - w) * g00 * data[i - T0] +
(1.0 - w) * g01 * (data[i - T0 - 1] + data[i - T0 + 1]) +
(1.0 - w) * g02 * (data[i - T0 - 2] + data[i - T0 + 2]) +
w * g10 * x2 +
w * g11 * (x1 + x3) +
w * g12 * (x0 + x4);
x4 = x3;
x3 = x2;
x2 = x1;
x1 = x0;
}
}
static void celt_postfilter_apply(CeltFrame *frame,
float *data, int len)
{
const int T = frame->pf_period;
float g0, g1, g2;
float x0, x1, x2, x3, x4;
int i;
if (frame->pf_gains[0] == 0.0 || len <= 0)
return;
g0 = frame->pf_gains[0];
g1 = frame->pf_gains[1];
g2 = frame->pf_gains[2];
x4 = data[-T - 2];
x3 = data[-T - 1];
x2 = data[-T];
x1 = data[-T + 1];
for (i = 0; i < len; i++) {
x0 = data[i - T + 2];
data[i] += g0 * x2 +
g1 * (x1 + x3) +
g2 * (x0 + x4);
x4 = x3;
x3 = x2;
x2 = x1;
x1 = x0;
}
}
static void celt_postfilter(CeltContext *s, CeltFrame *frame)
{
int len = s->blocksize * s->blocks;
celt_postfilter_apply_transition(frame, frame->buf + 1024);
frame->pf_period_old = frame->pf_period;
memcpy(frame->pf_gains_old, frame->pf_gains, sizeof(frame->pf_gains));
frame->pf_period = frame->pf_period_new;
memcpy(frame->pf_gains, frame->pf_gains_new, sizeof(frame->pf_gains));
if (len > CELT_OVERLAP) {
celt_postfilter_apply_transition(frame, frame->buf + 1024 + CELT_OVERLAP);
celt_postfilter_apply(frame, frame->buf + 1024 + 2 * CELT_OVERLAP,
len - 2 * CELT_OVERLAP);
frame->pf_period_old = frame->pf_period;
memcpy(frame->pf_gains_old, frame->pf_gains, sizeof(frame->pf_gains));
}
memmove(frame->buf, frame->buf + len, (1024 + CELT_OVERLAP / 2) * sizeof(float));
}
static int parse_postfilter(CeltContext *s, OpusRangeCoder *rc, int consumed)
{
static const float postfilter_taps[3][3] = {
{ 0.3066406250f, 0.2170410156f, 0.1296386719f },
{ 0.4638671875f, 0.2680664062f, 0.0 },
{ 0.7998046875f, 0.1000976562f, 0.0 }
};
int i;
memset(s->frame[0].pf_gains_new, 0, sizeof(s->frame[0].pf_gains_new));
memset(s->frame[1].pf_gains_new, 0, sizeof(s->frame[1].pf_gains_new));
if (s->startband == 0 && consumed + 16 <= s->framebits) {
int has_postfilter = ff_opus_rc_dec_log(rc, 1);
if (has_postfilter) {
float gain;
int tapset, octave, period;
octave = ff_opus_rc_dec_uint(rc, 6);
period = (16 << octave) + ff_opus_rc_get_raw(rc, 4 + octave) - 1;
gain = 0.09375f * (ff_opus_rc_get_raw(rc, 3) + 1);
tapset = (opus_rc_tell(rc) + 2 <= s->framebits) ?
ff_opus_rc_dec_cdf(rc, ff_celt_model_tapset) : 0;
for (i = 0; i < 2; i++) {
CeltFrame *frame = &s->frame[i];
frame->pf_period_new = FFMAX(period, CELT_POSTFILTER_MINPERIOD);
frame->pf_gains_new[0] = gain * postfilter_taps[tapset][0];
frame->pf_gains_new[1] = gain * postfilter_taps[tapset][1];
frame->pf_gains_new[2] = gain * postfilter_taps[tapset][2];
}
}
consumed = opus_rc_tell(rc);
}
return consumed;
}
static void process_anticollapse(CeltContext *s, CeltFrame *frame, float *X)
{
int i, j, k;
for (i = s->startband; i < s->endband; i++) {
int renormalize = 0;
float *xptr;
float prev[2];
float Ediff, r;
float thresh, sqrt_1;
int depth;
/* depth in 1/8 bits */
depth = (1 + s->pulses[i]) / (ff_celt_freq_range[i] << s->duration);
thresh = exp2f(-1.0 - 0.125f * depth);
sqrt_1 = 1.0f / sqrtf(ff_celt_freq_range[i] << s->duration);
xptr = X + (ff_celt_freq_bands[i] << s->duration);
prev[0] = frame->prev_energy[0][i];
prev[1] = frame->prev_energy[1][i];
if (s->coded_channels == 1) {
CeltFrame *frame1 = &s->frame[1];
prev[0] = FFMAX(prev[0], frame1->prev_energy[0][i]);
prev[1] = FFMAX(prev[1], frame1->prev_energy[1][i]);
}
Ediff = frame->energy[i] - FFMIN(prev[0], prev[1]);
Ediff = FFMAX(0, Ediff);
/* r needs to be multiplied by 2 or 2*sqrt(2) depending on LM because
short blocks don't have the same energy as long */
r = exp2(1 - Ediff);
if (s->duration == 3)
r *= M_SQRT2;
r = FFMIN(thresh, r) * sqrt_1;
for (k = 0; k < 1 << s->duration; k++) {
/* Detect collapse */
if (!(frame->collapse_masks[i] & 1 << k)) {
/* Fill with noise */
for (j = 0; j < ff_celt_freq_range[i]; j++)
xptr[(j << s->duration) + k] = (celt_rng(s) & 0x8000) ? r : -r;
renormalize = 1;
}
}
/* We just added some energy, so we need to renormalize */
if (renormalize)
celt_renormalize_vector(xptr, ff_celt_freq_range[i] << s->duration, 1.0f);
}
}
static void celt_decode_bands(CeltContext *s, OpusRangeCoder *rc)
{
float lowband_scratch[8 * 22];
float norm[2 * 8 * 100];
int totalbits = (s->framebits << 3) - s->anticollapse_bit;
int update_lowband = 1;
int lowband_offset = 0;
int i, j;
memset(s->coeffs, 0, sizeof(s->coeffs));
for (i = s->startband; i < s->endband; i++) {
int band_offset = ff_celt_freq_bands[i] << s->duration;
int band_size = ff_celt_freq_range[i] << s->duration;
float *X = s->coeffs[0] + band_offset;
float *Y = (s->coded_channels == 2) ? s->coeffs[1] + band_offset : NULL;
int consumed = opus_rc_tell_frac(rc);
float *norm2 = norm + 8 * 100;
int effective_lowband = -1;
unsigned int cm[2];
int b;
/* Compute how many bits we want to allocate to this band */
if (i != s->startband)
s->remaining -= consumed;
s->remaining2 = totalbits - consumed - 1;
if (i <= s->codedbands - 1) {
int curr_balance = s->remaining / FFMIN(3, s->codedbands-i);
b = av_clip_uintp2(FFMIN(s->remaining2 + 1, s->pulses[i] + curr_balance), 14);
} else
b = 0;
if (ff_celt_freq_bands[i] - ff_celt_freq_range[i] >= ff_celt_freq_bands[s->startband] &&
(update_lowband || lowband_offset == 0))
lowband_offset = i;
/* Get a conservative estimate of the collapse_mask's for the bands we're
going to be folding from. */
if (lowband_offset != 0 && (s->spread != CELT_SPREAD_AGGRESSIVE ||
s->blocks > 1 || s->tf_change[i] < 0)) {
int foldstart, foldend;
/* This ensures we never repeat spectral content within one band */
effective_lowband = FFMAX(ff_celt_freq_bands[s->startband],
ff_celt_freq_bands[lowband_offset] - ff_celt_freq_range[i]);
foldstart = lowband_offset;
while (ff_celt_freq_bands[--foldstart] > effective_lowband);
foldend = lowband_offset - 1;
while (ff_celt_freq_bands[++foldend] < effective_lowband + ff_celt_freq_range[i]);
cm[0] = cm[1] = 0;
for (j = foldstart; j < foldend; j++) {
cm[0] |= s->frame[0].collapse_masks[j];
cm[1] |= s->frame[s->coded_channels - 1].collapse_masks[j];
}
} else
/* Otherwise, we'll be using the LCG to fold, so all blocks will (almost
always) be non-zero.*/
cm[0] = cm[1] = (1 << s->blocks) - 1;
if (s->dualstereo && i == s->intensitystereo) {
/* Switch off dual stereo to do intensity */
s->dualstereo = 0;
for (j = ff_celt_freq_bands[s->startband] << s->duration; j < band_offset; j++)
norm[j] = (norm[j] + norm2[j]) / 2;
}
if (s->dualstereo) {
cm[0] = celt_decode_band(s, rc, i, X, NULL, band_size, b / 2, s->blocks,
effective_lowband != -1 ? norm + (effective_lowband << s->duration) : NULL, s->duration,
norm + band_offset, 0, 1.0f, lowband_scratch, cm[0]);
cm[1] = celt_decode_band(s, rc, i, Y, NULL, band_size, b/2, s->blocks,
effective_lowband != -1 ? norm2 + (effective_lowband << s->duration) : NULL, s->duration,
norm2 + band_offset, 0, 1.0f, lowband_scratch, cm[1]);
} else {
cm[0] = celt_decode_band(s, rc, i, X, Y, band_size, b, s->blocks,
effective_lowband != -1 ? norm + (effective_lowband << s->duration) : NULL, s->duration,
norm + band_offset, 0, 1.0f, lowband_scratch, cm[0]|cm[1]);
cm[1] = cm[0];
}
s->frame[0].collapse_masks[i] = (uint8_t)cm[0];
s->frame[s->coded_channels - 1].collapse_masks[i] = (uint8_t)cm[1];
s->remaining += s->pulses[i] + consumed;
/* Update the folding position only as long as we have 1 bit/sample depth */
update_lowband = (b > band_size << 3);
}
}
int ff_celt_decode_frame(CeltContext *s, OpusRangeCoder *rc,
float **output, int coded_channels, int frame_size,
int startband, int endband)
{
int i, j;
int consumed; // bits of entropy consumed thus far for this frame
int silence = 0;
int transient = 0;
int anticollapse = 0;
IMDCT15Context *imdct;
float imdct_scale = 1.0;
if (coded_channels != 1 && coded_channels != 2) {
av_log(s->avctx, AV_LOG_ERROR, "Invalid number of coded channels: %d\n",
coded_channels);
return AVERROR_INVALIDDATA;
}
if (startband < 0 || startband > endband || endband > CELT_MAX_BANDS) {
av_log(s->avctx, AV_LOG_ERROR, "Invalid start/end band: %d %d\n",
startband, endband);
return AVERROR_INVALIDDATA;
}
s->flushed = 0;
s->coded_channels = coded_channels;
s->startband = startband;
s->endband = endband;
s->framebits = rc->rb.bytes * 8;
s->duration = av_log2(frame_size / CELT_SHORT_BLOCKSIZE);
if (s->duration > CELT_MAX_LOG_BLOCKS ||
frame_size != CELT_SHORT_BLOCKSIZE * (1 << s->duration)) {
av_log(s->avctx, AV_LOG_ERROR, "Invalid CELT frame size: %d\n",
frame_size);
return AVERROR_INVALIDDATA;
}
if (!s->output_channels)
s->output_channels = coded_channels;
memset(s->frame[0].collapse_masks, 0, sizeof(s->frame[0].collapse_masks));
memset(s->frame[1].collapse_masks, 0, sizeof(s->frame[1].collapse_masks));
consumed = opus_rc_tell(rc);
/* obtain silence flag */
if (consumed >= s->framebits)
silence = 1;
else if (consumed == 1)
silence = ff_opus_rc_dec_log(rc, 15);
if (silence) {
consumed = s->framebits;
rc->total_read_bits += s->framebits - opus_rc_tell(rc);
}
/* obtain post-filter options */
consumed = parse_postfilter(s, rc, consumed);
/* obtain transient flag */
if (s->duration != 0 && consumed+3 <= s->framebits)
transient = ff_opus_rc_dec_log(rc, 3);
s->blocks = transient ? 1 << s->duration : 1;
s->blocksize = frame_size / s->blocks;
imdct = s->imdct[transient ? 0 : s->duration];
if (coded_channels == 1) {
for (i = 0; i < CELT_MAX_BANDS; i++)
s->frame[0].energy[i] = FFMAX(s->frame[0].energy[i], s->frame[1].energy[i]);
}
celt_decode_coarse_energy(s, rc);
celt_decode_tf_changes (s, rc, transient);
celt_decode_allocation (s, rc);
celt_decode_fine_energy (s, rc);
celt_decode_bands (s, rc);
if (s->anticollapse_bit)
anticollapse = ff_opus_rc_get_raw(rc, 1);
celt_decode_final_energy(s, rc, s->framebits - opus_rc_tell(rc));
/* apply anti-collapse processing and denormalization to
* each coded channel */
for (i = 0; i < s->coded_channels; i++) {
CeltFrame *frame = &s->frame[i];
if (anticollapse)
process_anticollapse(s, frame, s->coeffs[i]);
celt_denormalize(s, frame, s->coeffs[i]);
}
/* stereo -> mono downmix */
if (s->output_channels < s->coded_channels) {
s->dsp->vector_fmac_scalar(s->coeffs[0], s->coeffs[1], 1.0, FFALIGN(frame_size, 16));
imdct_scale = 0.5;
} else if (s->output_channels > s->coded_channels)
memcpy(s->coeffs[1], s->coeffs[0], frame_size * sizeof(float));
if (silence) {
for (i = 0; i < 2; i++) {
CeltFrame *frame = &s->frame[i];
for (j = 0; j < FF_ARRAY_ELEMS(frame->energy); j++)
frame->energy[j] = CELT_ENERGY_SILENCE;
}
memset(s->coeffs, 0, sizeof(s->coeffs));
}
/* transform and output for each output channel */
for (i = 0; i < s->output_channels; i++) {
CeltFrame *frame = &s->frame[i];
float m = frame->deemph_coeff;
/* iMDCT and overlap-add */
for (j = 0; j < s->blocks; j++) {
float *dst = frame->buf + 1024 + j * s->blocksize;
imdct->imdct_half(imdct, dst + CELT_OVERLAP / 2, s->coeffs[i] + j,
s->blocks, imdct_scale);
s->dsp->vector_fmul_window(dst, dst, dst + CELT_OVERLAP / 2,
ff_celt_window, CELT_OVERLAP / 2);
}
/* postfilter */
celt_postfilter(s, frame);
/* deemphasis and output scaling */
for (j = 0; j < frame_size; j++) {
float tmp = frame->buf[1024 - frame_size + j] + m;
m = tmp * CELT_DEEMPH_COEFF;
output[i][j] = tmp / 32768.;
}
frame->deemph_coeff = m;
}
if (coded_channels == 1)
memcpy(s->frame[1].energy, s->frame[0].energy, sizeof(s->frame[0].energy));
for (i = 0; i < 2; i++ ) {
CeltFrame *frame = &s->frame[i];
if (!transient) {
memcpy(frame->prev_energy[1], frame->prev_energy[0], sizeof(frame->prev_energy[0]));
memcpy(frame->prev_energy[0], frame->energy, sizeof(frame->prev_energy[0]));
} else {
for (j = 0; j < CELT_MAX_BANDS; j++)
frame->prev_energy[0][j] = FFMIN(frame->prev_energy[0][j], frame->energy[j]);
}
for (j = 0; j < s->startband; j++) {
frame->prev_energy[0][j] = CELT_ENERGY_SILENCE;
frame->energy[j] = 0.0;
}
for (j = s->endband; j < CELT_MAX_BANDS; j++) {
frame->prev_energy[0][j] = CELT_ENERGY_SILENCE;
frame->energy[j] = 0.0;
}
}
s->seed = rc->range;
return 0;
}
void ff_celt_flush(CeltContext *s)
{
int i, j;
if (s->flushed)
return;
for (i = 0; i < 2; i++) {
CeltFrame *frame = &s->frame[i];
for (j = 0; j < CELT_MAX_BANDS; j++)
frame->prev_energy[0][j] = frame->prev_energy[1][j] = CELT_ENERGY_SILENCE;
memset(frame->energy, 0, sizeof(frame->energy));
memset(frame->buf, 0, sizeof(frame->buf));
memset(frame->pf_gains, 0, sizeof(frame->pf_gains));
memset(frame->pf_gains_old, 0, sizeof(frame->pf_gains_old));
memset(frame->pf_gains_new, 0, sizeof(frame->pf_gains_new));
frame->deemph_coeff = 0.0;
}
s->seed = 0;
s->flushed = 1;
}
void ff_celt_free(CeltContext **ps)
{
CeltContext *s = *ps;
int i;
if (!s)
return;
for (i = 0; i < FF_ARRAY_ELEMS(s->imdct); i++)
ff_imdct15_uninit(&s->imdct[i]);
av_freep(&s->dsp);
av_freep(ps);
}
int ff_celt_init(AVCodecContext *avctx, CeltContext **ps, int output_channels)
{
CeltContext *s;
int i, ret;
if (output_channels != 1 && output_channels != 2) {
av_log(avctx, AV_LOG_ERROR, "Invalid number of output channels: %d\n",
output_channels);
return AVERROR(EINVAL);
}
s = av_mallocz(sizeof(*s));
if (!s)
return AVERROR(ENOMEM);
s->avctx = avctx;
s->output_channels = output_channels;
for (i = 0; i < FF_ARRAY_ELEMS(s->imdct); i++) {
ret = ff_imdct15_init(&s->imdct[i], i + 3);
if (ret < 0)
goto fail;
}
s->dsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
if (!s->dsp) {
ret = AVERROR(ENOMEM);
goto fail;
}
ff_celt_flush(s);
*ps = s;
return 0;
fail:
ff_celt_free(&s);
return ret;
}