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FFmpeg/libavcodec/opus_pvq.c
Rostislav Pehlivanov 70259737cb opus_pvq: prevent division by 0 
res was 0 and divided K which made it infinity which caused K to
overflow.

Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
2017-02-24 19:14:55 +00:00

1161 lines
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/*
* Copyright (c) 2012 Andrew D'Addesio
* Copyright (c) 2013-2014 Mozilla Corporation
* Copyright (c) 2017 Rostislav Pehlivanov <atomnuker@gmail.com>
*
* 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
*/
#include "opustab.h"
#include "opus_pvq.h"
#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))
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 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_rotation_impl(float *X, uint32_t len, uint32_t 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, uint32_t len,
uint32_t stride, uint32_t K,
enum CeltSpread spread, const int encode)
{
uint32_t 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 = cosf(theta);
s = sinf(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 (encode) {
celt_exp_rotation_impl(X + i * len, len, 1, c, -s);
if (stride2)
celt_exp_rotation_impl(X + i * len, len, stride2, s, -c);
} else {
if (stride2)
celt_exp_rotation_impl(X + i * len, len, stride2, s, c);
celt_exp_rotation_impl(X + i * len, len, 1, c, s);
}
}
}
static inline uint32_t celt_extract_collapse_mask(const int *iy, uint32_t N, uint32_t B)
{
uint32_t 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_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;
}
/* Convert the quantized vector to an index */
static inline uint32_t celt_icwrsi(uint32_t N, uint32_t K, const int *y)
{
int i, idx = 0, sum = 0;
for (i = N - 1; i >= 0; i--) {
const uint32_t i_s = CELT_PVQ_U(N - i, sum + FFABS(y[i]) + 1);
idx += CELT_PVQ_U(N - i, sum) + (y[i] < 0)*i_s;
sum += FFABS(y[i]);
}
return idx;
}
// this code was adapted from libopus
static inline uint64_t celt_cwrsi(uint32_t N, uint32_t K, uint32_t 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 void celt_encode_pulses(OpusRangeCoder *rc, int *y, uint32_t N, uint32_t K)
{
ff_opus_rc_enc_uint(rc, celt_icwrsi(N, K, y), CELT_PVQ_V(N, K));
}
static inline float celt_decode_pulses(OpusRangeCoder *rc, int *y, uint32_t N, uint32_t K)
{
const uint32_t idx = ff_opus_rc_dec_uint(rc, CELT_PVQ_V(N, K));
return celt_cwrsi(N, K, idx, y);
}
/*
* Faster than libopus's search, operates entirely in the signed domain.
* Slightly worse/better depending on N, K and the input vector.
*/
static void celt_pvq_search(float *X, int *y, int K, int N)
{
int i;
float res = 0.0f, y_norm = 0.0f, xy_norm = 0.0f;
for (i = 0; i < N; i++)
res += FFABS(X[i]);
res = K/(res + FLT_EPSILON);
for (i = 0; i < N; i++) {
y[i] = lrintf(res*X[i]);
y_norm += y[i]*y[i];
xy_norm += y[i]*X[i];
K -= FFABS(y[i]);
}
while (K) {
int max_idx = 0, phase = FFSIGN(K);
float max_den = 1.0f, max_num = 0.0f;
y_norm += 1.0f;
for (i = 0; i < N; i++) {
/* If the sum has been overshot and the best place has 0 pulses allocated
* to it, attempting to decrease it further will actually increase the
* sum. Prevent this by disregarding any 0 positions when decrementing. */
const int ca = 1 ^ ((y[i] == 0) & (phase < 0));
float xy_new = xy_norm + 1*phase*FFABS(X[i]);
float y_new = y_norm + 2*phase*FFABS(y[i]);
xy_new = xy_new * xy_new;
if (ca && (max_den*xy_new) > (y_new*max_num)) {
max_den = y_new;
max_num = xy_new;
max_idx = i;
}
}
K -= phase;
phase *= FFSIGN(X[max_idx]);
xy_norm += 1*phase*X[max_idx];
y_norm += 2*phase*y[max_idx];
y[max_idx] += phase;
}
}
static uint32_t celt_alg_quant(OpusRangeCoder *rc, float *X, uint32_t N, uint32_t K,
enum CeltSpread spread, uint32_t blocks, float gain)
{
int y[176];
celt_exp_rotation(X, N, blocks, K, spread, 1);
celt_pvq_search(X, y, K, N);
celt_encode_pulses(rc, y, N, K);
return celt_extract_collapse_mask(y, N, blocks);
}
/** Decode pulse vector and combine the result with the pitch vector to produce
the final normalised signal in the current band. */
static uint32_t celt_alg_unquant(OpusRangeCoder *rc, float *X, uint32_t N, uint32_t K,
enum CeltSpread spread, uint32_t 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, 0);
return celt_extract_collapse_mask(y, N, blocks);
}
uint32_t ff_celt_decode_band(CeltFrame *f, OpusRangeCoder *rc, const int band,
float *X, float *Y, int N, int b, uint32_t 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;
uint32_t 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);
uint32_t 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 (f->remaining2 >= 1<<3) {
sign = ff_opus_rc_get_raw(rc, 1);
f->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 = f->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(f->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 >= f->intensity_stereo) ? 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 && f->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);
f->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 = ff_celt_decode_band(f, 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;
f->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 = f->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 = ff_celt_decode_band(f, 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 - f->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 |= ff_celt_decode_band(f, 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 = ff_celt_decode_band(f, 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 - f->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 |= ff_celt_decode_band(f, 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 */
uint32_t q = celt_bits2pulses(cache, b);
uint32_t curr_bits = celt_pulses2bits(cache, q);
f->remaining2 -= curr_bits;
/* Ensures we can never bust the budget */
while (f->remaining2 < 0 && q > 0) {
f->remaining2 += curr_bits;
curr_bits = celt_pulses2bits(cache, --q);
f->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),
f->spread, blocks, gain);
} else {
/* If there's no pulse, fill the band anyway */
int j;
uint32_t 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(f)) >> 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(f)) & 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(f->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;
}
/* This has to be, AND MUST BE done by the psychoacoustic system, this has a very
* big impact on the entire quantization and especially huge on transients */
static int celt_calc_theta(const float *X, const float *Y, int coupling, int N)
{
int j;
float e[2] = { 0.0f, 0.0f };
for (j = 0; j < N; j++) {
if (coupling) { /* Coupling case */
e[0] += (X[j] + Y[j])*(X[j] + Y[j]);
e[1] += (X[j] - Y[j])*(X[j] - Y[j]);
} else {
e[0] += X[j]*X[j];
e[1] += Y[j]*Y[j];
}
}
return lrintf(32768.0f*atan2f(sqrtf(e[1]), sqrtf(e[0]))/M_PI);
}
static void celt_stereo_is_decouple(float *X, float *Y, float e_l, float e_r, int N)
{
int i;
const float energy_n = 1.0f/(sqrtf(e_l*e_l + e_r*e_r) + FLT_EPSILON);
e_l *= energy_n;
e_r *= energy_n;
for (i = 0; i < N; i++)
X[i] = e_l*X[i] + e_r*Y[i];
}
static void celt_stereo_ms_decouple(float *X, float *Y, int N)
{
int i;
const float decouple_norm = 1.0f/sqrtf(2.0f);
for (i = 0; i < N; i++) {
const float Xret = X[i];
X[i] = (X[i] + Y[i])*decouple_norm;
Y[i] = (Y[i] - Xret)*decouple_norm;
}
}
uint32_t ff_celt_encode_band(CeltFrame *f, OpusRangeCoder *rc, const int band,
float *X, float *Y, int N, int b, uint32_t 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;
//uint32_t N0 = N;
int N_B = N / blocks;
//int N_B0 = N_B;
int B0 = blocks;
int time_divide = 0;
int recombine = 0;
int inv = 0;
float mid = 0, side = 0;
int longblocks = (B0 == 1);
uint32_t cm = 0;
split = dualstereo = (Y != NULL);
if (N == 1) {
/* special case for one sample - the decoder's output will be +- 1.0f!!! */
int i;
float *x = X;
for (i = 0; i <= dualstereo; i++) {
if (f->remaining2 >= 1<<3) {
ff_opus_rc_put_raw(rc, x[0] < 0, 1);
f->remaining2 -= 1 << 3;
b -= 1 << 3;
}
x = Y;
}
if (lowband_out)
lowband_out[0] = X[0];
return 1;
}
if (!dualstereo && level == 0) {
int tf_change = f->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++) {
celt_haar1(X, 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) {
celt_haar1(X, 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)
celt_deinterleave_hadamard(f->scratch, X, 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 = celt_calc_theta(X, Y, dualstereo, N);
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 >= f->intensity_stereo) ? 1 :
celt_compute_qn(N, b, offset, pulse_cap, dualstereo);
tell = opus_rc_tell_frac(rc);
if (qn != 1) {
itheta = (itheta*qn + 8192) >> 14;
/* 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)
ff_opus_rc_enc_uint_step(rc, itheta, qn / 2);
else if (dualstereo || B0 > 1)
ff_opus_rc_enc_uint(rc, itheta, qn + 1);
else
ff_opus_rc_enc_uint_tri(rc, itheta, qn);
itheta = itheta * 16384 / qn;
if (dualstereo) {
if (itheta == 0)
celt_stereo_is_decouple(X, Y, f->block[0].lin_energy[band], f->block[1].lin_energy[band], N);
else
celt_stereo_ms_decouple(X, Y, N);
}
} else if (dualstereo) {
inv = itheta > 8192;
if (inv)
{
int j;
for (j=0;j<N;j++)
Y[j] = -Y[j];
}
celt_stereo_is_decouple(X, Y, f->block[0].lin_energy[band], f->block[1].lin_energy[band], N);
if (b > 2 << 3 && f->remaining2 > 2 << 3) {
ff_opus_rc_enc_log(rc, inv, 2);
} else {
inv = 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);
f->remaining2 -= qalloc+sbits;
x2 = c ? Y : X;
y2 = c ? X : Y;
if (sbits) {
sign = x2[0]*y2[1] - x2[1]*y2[0] < 0;
ff_opus_rc_put_raw(rc, sign, 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 = ff_celt_encode_band(f, 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;
f->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 = f->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 = ff_celt_encode_band(f, 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 - f->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 |= ff_celt_encode_band(f, 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 = ff_celt_encode_band(f, 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 - f->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 |= ff_celt_encode_band(f, 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 */
uint32_t q = celt_bits2pulses(cache, b);
uint32_t curr_bits = celt_pulses2bits(cache, q);
f->remaining2 -= curr_bits;
/* Ensures we can never bust the budget */
while (f->remaining2 < 0 && q > 0) {
f->remaining2 += curr_bits;
curr_bits = celt_pulses2bits(cache, --q);
f->remaining2 -= curr_bits;
}
if (q != 0) {
/* Finally do the actual quantization */
cm = celt_alg_quant(rc, X, N, (q < 8) ? q : (8 + (q & 7)) << ((q >> 3) - 1),
f->spread, blocks, gain);
}
}
return cm;
}
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