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-rw-r--r--src/main/jni/opus/celt/bands.c1518
1 files changed, 1518 insertions, 0 deletions
diff --git a/src/main/jni/opus/celt/bands.c b/src/main/jni/opus/celt/bands.c
new file mode 100644
index 000000000..cce56e2f6
--- /dev/null
+++ b/src/main/jni/opus/celt/bands.c
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+/* Copyright (c) 2007-2008 CSIRO
+ Copyright (c) 2007-2009 Xiph.Org Foundation
+ Copyright (c) 2008-2009 Gregory Maxwell
+ Written by Jean-Marc Valin and Gregory Maxwell */
+/*
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+
+ - Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+
+ - Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in the
+ documentation and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
+ OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <math.h>
+#include "bands.h"
+#include "modes.h"
+#include "vq.h"
+#include "cwrs.h"
+#include "stack_alloc.h"
+#include "os_support.h"
+#include "mathops.h"
+#include "rate.h"
+#include "quant_bands.h"
+#include "pitch.h"
+
+int hysteresis_decision(opus_val16 val, const opus_val16 *thresholds, const opus_val16 *hysteresis, int N, int prev)
+{
+ int i;
+ for (i=0;i<N;i++)
+ {
+ if (val < thresholds[i])
+ break;
+ }
+ if (i>prev && val < thresholds[prev]+hysteresis[prev])
+ i=prev;
+ if (i<prev && val > thresholds[prev-1]-hysteresis[prev-1])
+ i=prev;
+ return i;
+}
+
+opus_uint32 celt_lcg_rand(opus_uint32 seed)
+{
+ return 1664525 * seed + 1013904223;
+}
+
+/* This is a cos() approximation designed to be bit-exact on any platform. Bit exactness
+ with this approximation is important because it has an impact on the bit allocation */
+static opus_int16 bitexact_cos(opus_int16 x)
+{
+ opus_int32 tmp;
+ opus_int16 x2;
+ tmp = (4096+((opus_int32)(x)*(x)))>>13;
+ celt_assert(tmp<=32767);
+ x2 = tmp;
+ x2 = (32767-x2) + FRAC_MUL16(x2, (-7651 + FRAC_MUL16(x2, (8277 + FRAC_MUL16(-626, x2)))));
+ celt_assert(x2<=32766);
+ return 1+x2;
+}
+
+static int bitexact_log2tan(int isin,int icos)
+{
+ int lc;
+ int ls;
+ lc=EC_ILOG(icos);
+ ls=EC_ILOG(isin);
+ icos<<=15-lc;
+ isin<<=15-ls;
+ return (ls-lc)*(1<<11)
+ +FRAC_MUL16(isin, FRAC_MUL16(isin, -2597) + 7932)
+ -FRAC_MUL16(icos, FRAC_MUL16(icos, -2597) + 7932);
+}
+
+#ifdef FIXED_POINT
+/* Compute the amplitude (sqrt energy) in each of the bands */
+void compute_band_energies(const CELTMode *m, const celt_sig *X, celt_ener *bandE, int end, int C, int M)
+{
+ int i, c, N;
+ const opus_int16 *eBands = m->eBands;
+ N = M*m->shortMdctSize;
+ c=0; do {
+ for (i=0;i<end;i++)
+ {
+ int j;
+ opus_val32 maxval=0;
+ opus_val32 sum = 0;
+
+ j=M*eBands[i]; do {
+ maxval = MAX32(maxval, X[j+c*N]);
+ maxval = MAX32(maxval, -X[j+c*N]);
+ } while (++j<M*eBands[i+1]);
+
+ if (maxval > 0)
+ {
+ int shift = celt_ilog2(maxval)-10;
+ j=M*eBands[i]; do {
+ sum = MAC16_16(sum, EXTRACT16(VSHR32(X[j+c*N],shift)),
+ EXTRACT16(VSHR32(X[j+c*N],shift)));
+ } while (++j<M*eBands[i+1]);
+ /* We're adding one here to ensure the normalized band isn't larger than unity norm */
+ bandE[i+c*m->nbEBands] = EPSILON+VSHR32(EXTEND32(celt_sqrt(sum)),-shift);
+ } else {
+ bandE[i+c*m->nbEBands] = EPSILON;
+ }
+ /*printf ("%f ", bandE[i+c*m->nbEBands]);*/
+ }
+ } while (++c<C);
+ /*printf ("\n");*/
+}
+
+/* Normalise each band such that the energy is one. */
+void normalise_bands(const CELTMode *m, const celt_sig * OPUS_RESTRICT freq, celt_norm * OPUS_RESTRICT X, const celt_ener *bandE, int end, int C, int M)
+{
+ int i, c, N;
+ const opus_int16 *eBands = m->eBands;
+ N = M*m->shortMdctSize;
+ c=0; do {
+ i=0; do {
+ opus_val16 g;
+ int j,shift;
+ opus_val16 E;
+ shift = celt_zlog2(bandE[i+c*m->nbEBands])-13;
+ E = VSHR32(bandE[i+c*m->nbEBands], shift);
+ g = EXTRACT16(celt_rcp(SHL32(E,3)));
+ j=M*eBands[i]; do {
+ X[j+c*N] = MULT16_16_Q15(VSHR32(freq[j+c*N],shift-1),g);
+ } while (++j<M*eBands[i+1]);
+ } while (++i<end);
+ } while (++c<C);
+}
+
+#else /* FIXED_POINT */
+/* Compute the amplitude (sqrt energy) in each of the bands */
+void compute_band_energies(const CELTMode *m, const celt_sig *X, celt_ener *bandE, int end, int C, int M)
+{
+ int i, c, N;
+ const opus_int16 *eBands = m->eBands;
+ N = M*m->shortMdctSize;
+ c=0; do {
+ for (i=0;i<end;i++)
+ {
+ int j;
+ opus_val32 sum = 1e-27f;
+ for (j=M*eBands[i];j<M*eBands[i+1];j++)
+ sum += X[j+c*N]*X[j+c*N];
+ bandE[i+c*m->nbEBands] = celt_sqrt(sum);
+ /*printf ("%f ", bandE[i+c*m->nbEBands]);*/
+ }
+ } while (++c<C);
+ /*printf ("\n");*/
+}
+
+/* Normalise each band such that the energy is one. */
+void normalise_bands(const CELTMode *m, const celt_sig * OPUS_RESTRICT freq, celt_norm * OPUS_RESTRICT X, const celt_ener *bandE, int end, int C, int M)
+{
+ int i, c, N;
+ const opus_int16 *eBands = m->eBands;
+ N = M*m->shortMdctSize;
+ c=0; do {
+ for (i=0;i<end;i++)
+ {
+ int j;
+ opus_val16 g = 1.f/(1e-27f+bandE[i+c*m->nbEBands]);
+ for (j=M*eBands[i];j<M*eBands[i+1];j++)
+ X[j+c*N] = freq[j+c*N]*g;
+ }
+ } while (++c<C);
+}
+
+#endif /* FIXED_POINT */
+
+/* De-normalise the energy to produce the synthesis from the unit-energy bands */
+void denormalise_bands(const CELTMode *m, const celt_norm * OPUS_RESTRICT X,
+ celt_sig * OPUS_RESTRICT freq, const opus_val16 *bandLogE, int start, int end, int C, int M)
+{
+ int i, c, N;
+ const opus_int16 *eBands = m->eBands;
+ N = M*m->shortMdctSize;
+ celt_assert2(C<=2, "denormalise_bands() not implemented for >2 channels");
+ c=0; do {
+ celt_sig * OPUS_RESTRICT f;
+ const celt_norm * OPUS_RESTRICT x;
+ f = freq+c*N;
+ x = X+c*N+M*eBands[start];
+ for (i=0;i<M*eBands[start];i++)
+ *f++ = 0;
+ for (i=start;i<end;i++)
+ {
+ int j, band_end;
+ opus_val16 g;
+ opus_val16 lg;
+#ifdef FIXED_POINT
+ int shift;
+#endif
+ j=M*eBands[i];
+ band_end = M*eBands[i+1];
+ lg = ADD16(bandLogE[i+c*m->nbEBands], SHL16((opus_val16)eMeans[i],6));
+#ifndef FIXED_POINT
+ g = celt_exp2(lg);
+#else
+ /* Handle the integer part of the log energy */
+ shift = 16-(lg>>DB_SHIFT);
+ if (shift>31)
+ {
+ shift=0;
+ g=0;
+ } else {
+ /* Handle the fractional part. */
+ g = celt_exp2_frac(lg&((1<<DB_SHIFT)-1));
+ }
+ /* Handle extreme gains with negative shift. */
+ if (shift<0)
+ {
+ /* For shift < -2 we'd be likely to overflow, so we're capping
+ the gain here. This shouldn't happen unless the bitstream is
+ already corrupted. */
+ if (shift < -2)
+ {
+ g = 32767;
+ shift = -2;
+ }
+ do {
+ *f++ = SHL32(MULT16_16(*x++, g), -shift);
+ } while (++j<band_end);
+ } else
+#endif
+ /* Be careful of the fixed-point "else" just above when changing this code */
+ do {
+ *f++ = SHR32(MULT16_16(*x++, g), shift);
+ } while (++j<band_end);
+ }
+ celt_assert(start <= end);
+ for (i=M*eBands[end];i<N;i++)
+ *f++ = 0;
+ } while (++c<C);
+}
+
+/* This prevents energy collapse for transients with multiple short MDCTs */
+void anti_collapse(const CELTMode *m, celt_norm *X_, unsigned char *collapse_masks, int LM, int C, int size,
+ int start, int end, opus_val16 *logE, opus_val16 *prev1logE,
+ opus_val16 *prev2logE, int *pulses, opus_uint32 seed)
+{
+ int c, i, j, k;
+ for (i=start;i<end;i++)
+ {
+ int N0;
+ opus_val16 thresh, sqrt_1;
+ int depth;
+#ifdef FIXED_POINT
+ int shift;
+ opus_val32 thresh32;
+#endif
+
+ N0 = m->eBands[i+1]-m->eBands[i];
+ /* depth in 1/8 bits */
+ depth = (1+pulses[i])/((m->eBands[i+1]-m->eBands[i])<<LM);
+
+#ifdef FIXED_POINT
+ thresh32 = SHR32(celt_exp2(-SHL16(depth, 10-BITRES)),1);
+ thresh = MULT16_32_Q15(QCONST16(0.5f, 15), MIN32(32767,thresh32));
+ {
+ opus_val32 t;
+ t = N0<<LM;
+ shift = celt_ilog2(t)>>1;
+ t = SHL32(t, (7-shift)<<1);
+ sqrt_1 = celt_rsqrt_norm(t);
+ }
+#else
+ thresh = .5f*celt_exp2(-.125f*depth);
+ sqrt_1 = celt_rsqrt(N0<<LM);
+#endif
+
+ c=0; do
+ {
+ celt_norm *X;
+ opus_val16 prev1;
+ opus_val16 prev2;
+ opus_val32 Ediff;
+ opus_val16 r;
+ int renormalize=0;
+ prev1 = prev1logE[c*m->nbEBands+i];
+ prev2 = prev2logE[c*m->nbEBands+i];
+ if (C==1)
+ {
+ prev1 = MAX16(prev1,prev1logE[m->nbEBands+i]);
+ prev2 = MAX16(prev2,prev2logE[m->nbEBands+i]);
+ }
+ Ediff = EXTEND32(logE[c*m->nbEBands+i])-EXTEND32(MIN16(prev1,prev2));
+ Ediff = MAX32(0, Ediff);
+
+#ifdef FIXED_POINT
+ if (Ediff < 16384)
+ {
+ opus_val32 r32 = SHR32(celt_exp2(-EXTRACT16(Ediff)),1);
+ r = 2*MIN16(16383,r32);
+ } else {
+ r = 0;
+ }
+ if (LM==3)
+ r = MULT16_16_Q14(23170, MIN32(23169, r));
+ r = SHR16(MIN16(thresh, r),1);
+ r = SHR32(MULT16_16_Q15(sqrt_1, r),shift);
+#else
+ /* 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 = 2.f*celt_exp2(-Ediff);
+ if (LM==3)
+ r *= 1.41421356f;
+ r = MIN16(thresh, r);
+ r = r*sqrt_1;
+#endif
+ X = X_+c*size+(m->eBands[i]<<LM);
+ for (k=0;k<1<<LM;k++)
+ {
+ /* Detect collapse */
+ if (!(collapse_masks[i*C+c]&1<<k))
+ {
+ /* Fill with noise */
+ for (j=0;j<N0;j++)
+ {
+ seed = celt_lcg_rand(seed);
+ X[(j<<LM)+k] = (seed&0x8000 ? r : -r);
+ }
+ renormalize = 1;
+ }
+ }
+ /* We just added some energy, so we need to renormalise */
+ if (renormalize)
+ renormalise_vector(X, N0<<LM, Q15ONE);
+ } while (++c<C);
+ }
+}
+
+static void intensity_stereo(const CELTMode *m, celt_norm *X, celt_norm *Y, const celt_ener *bandE, int bandID, int N)
+{
+ int i = bandID;
+ int j;
+ opus_val16 a1, a2;
+ opus_val16 left, right;
+ opus_val16 norm;
+#ifdef FIXED_POINT
+ int shift = celt_zlog2(MAX32(bandE[i], bandE[i+m->nbEBands]))-13;
+#endif
+ left = VSHR32(bandE[i],shift);
+ right = VSHR32(bandE[i+m->nbEBands],shift);
+ norm = EPSILON + celt_sqrt(EPSILON+MULT16_16(left,left)+MULT16_16(right,right));
+ a1 = DIV32_16(SHL32(EXTEND32(left),14),norm);
+ a2 = DIV32_16(SHL32(EXTEND32(right),14),norm);
+ for (j=0;j<N;j++)
+ {
+ celt_norm r, l;
+ l = X[j];
+ r = Y[j];
+ X[j] = MULT16_16_Q14(a1,l) + MULT16_16_Q14(a2,r);
+ /* Side is not encoded, no need to calculate */
+ }
+}
+
+static void stereo_split(celt_norm *X, celt_norm *Y, int N)
+{
+ int j;
+ for (j=0;j<N;j++)
+ {
+ celt_norm r, l;
+ l = MULT16_16_Q15(QCONST16(.70710678f,15), X[j]);
+ r = MULT16_16_Q15(QCONST16(.70710678f,15), Y[j]);
+ X[j] = l+r;
+ Y[j] = r-l;
+ }
+}
+
+static void stereo_merge(celt_norm *X, celt_norm *Y, opus_val16 mid, int N)
+{
+ int j;
+ opus_val32 xp=0, side=0;
+ opus_val32 El, Er;
+ opus_val16 mid2;
+#ifdef FIXED_POINT
+ int kl, kr;
+#endif
+ opus_val32 t, lgain, rgain;
+
+ /* Compute the norm of X+Y and X-Y as |X|^2 + |Y|^2 +/- sum(xy) */
+ dual_inner_prod(Y, X, Y, N, &xp, &side);
+ /* Compensating for the mid normalization */
+ xp = MULT16_32_Q15(mid, xp);
+ /* mid and side are in Q15, not Q14 like X and Y */
+ mid2 = SHR32(mid, 1);
+ El = MULT16_16(mid2, mid2) + side - 2*xp;
+ Er = MULT16_16(mid2, mid2) + side + 2*xp;
+ if (Er < QCONST32(6e-4f, 28) || El < QCONST32(6e-4f, 28))
+ {
+ for (j=0;j<N;j++)
+ Y[j] = X[j];
+ return;
+ }
+
+#ifdef FIXED_POINT
+ kl = celt_ilog2(El)>>1;
+ kr = celt_ilog2(Er)>>1;
+#endif
+ t = VSHR32(El, (kl-7)<<1);
+ lgain = celt_rsqrt_norm(t);
+ t = VSHR32(Er, (kr-7)<<1);
+ rgain = celt_rsqrt_norm(t);
+
+#ifdef FIXED_POINT
+ if (kl < 7)
+ kl = 7;
+ if (kr < 7)
+ kr = 7;
+#endif
+
+ for (j=0;j<N;j++)
+ {
+ celt_norm r, l;
+ /* Apply mid scaling (side is already scaled) */
+ l = MULT16_16_Q15(mid, X[j]);
+ r = Y[j];
+ X[j] = EXTRACT16(PSHR32(MULT16_16(lgain, SUB16(l,r)), kl+1));
+ Y[j] = EXTRACT16(PSHR32(MULT16_16(rgain, ADD16(l,r)), kr+1));
+ }
+}
+
+/* Decide whether we should spread the pulses in the current frame */
+int spreading_decision(const CELTMode *m, celt_norm *X, int *average,
+ int last_decision, int *hf_average, int *tapset_decision, int update_hf,
+ int end, int C, int M)
+{
+ int i, c, N0;
+ int sum = 0, nbBands=0;
+ const opus_int16 * OPUS_RESTRICT eBands = m->eBands;
+ int decision;
+ int hf_sum=0;
+
+ celt_assert(end>0);
+
+ N0 = M*m->shortMdctSize;
+
+ if (M*(eBands[end]-eBands[end-1]) <= 8)
+ return SPREAD_NONE;
+ c=0; do {
+ for (i=0;i<end;i++)
+ {
+ int j, N, tmp=0;
+ int tcount[3] = {0,0,0};
+ celt_norm * OPUS_RESTRICT x = X+M*eBands[i]+c*N0;
+ N = M*(eBands[i+1]-eBands[i]);
+ if (N<=8)
+ continue;
+ /* Compute rough CDF of |x[j]| */
+ for (j=0;j<N;j++)
+ {
+ opus_val32 x2N; /* Q13 */
+
+ x2N = MULT16_16(MULT16_16_Q15(x[j], x[j]), N);
+ if (x2N < QCONST16(0.25f,13))
+ tcount[0]++;
+ if (x2N < QCONST16(0.0625f,13))
+ tcount[1]++;
+ if (x2N < QCONST16(0.015625f,13))
+ tcount[2]++;
+ }
+
+ /* Only include four last bands (8 kHz and up) */
+ if (i>m->nbEBands-4)
+ hf_sum += 32*(tcount[1]+tcount[0])/N;
+ tmp = (2*tcount[2] >= N) + (2*tcount[1] >= N) + (2*tcount[0] >= N);
+ sum += tmp*256;
+ nbBands++;
+ }
+ } while (++c<C);
+
+ if (update_hf)
+ {
+ if (hf_sum)
+ hf_sum /= C*(4-m->nbEBands+end);
+ *hf_average = (*hf_average+hf_sum)>>1;
+ hf_sum = *hf_average;
+ if (*tapset_decision==2)
+ hf_sum += 4;
+ else if (*tapset_decision==0)
+ hf_sum -= 4;
+ if (hf_sum > 22)
+ *tapset_decision=2;
+ else if (hf_sum > 18)
+ *tapset_decision=1;
+ else
+ *tapset_decision=0;
+ }
+ /*printf("%d %d %d\n", hf_sum, *hf_average, *tapset_decision);*/
+ celt_assert(nbBands>0); /* end has to be non-zero */
+ sum /= nbBands;
+ /* Recursive averaging */
+ sum = (sum+*average)>>1;
+ *average = sum;
+ /* Hysteresis */
+ sum = (3*sum + (((3-last_decision)<<7) + 64) + 2)>>2;
+ if (sum < 80)
+ {
+ decision = SPREAD_AGGRESSIVE;
+ } else if (sum < 256)
+ {
+ decision = SPREAD_NORMAL;
+ } else if (sum < 384)
+ {
+ decision = SPREAD_LIGHT;
+ } else {
+ decision = SPREAD_NONE;
+ }
+#ifdef FUZZING
+ decision = rand()&0x3;
+ *tapset_decision=rand()%3;
+#endif
+ return decision;
+}
+
+/* Indexing table for converting from natural Hadamard to ordery Hadamard
+ This is essentially a bit-reversed Gray, on top of which we've added
+ an inversion of the order because we want the DC at the end rather than
+ the beginning. The lines are for N=2, 4, 8, 16 */
+static const int ordery_table[] = {
+ 1, 0,
+ 3, 0, 2, 1,
+ 7, 0, 4, 3, 6, 1, 5, 2,
+ 15, 0, 8, 7, 12, 3, 11, 4, 14, 1, 9, 6, 13, 2, 10, 5,
+};
+
+static void deinterleave_hadamard(celt_norm *X, int N0, int stride, int hadamard)
+{
+ int i,j;
+ VARDECL(celt_norm, tmp);
+ int N;
+ SAVE_STACK;
+ N = N0*stride;
+ ALLOC(tmp, N, celt_norm);
+ celt_assert(stride>0);
+ if (hadamard)
+ {
+ const int *ordery = ordery_table+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 (j=0;j<N;j++)
+ X[j] = tmp[j];
+ RESTORE_STACK;
+}
+
+static void interleave_hadamard(celt_norm *X, int N0, int stride, int hadamard)
+{
+ int i,j;
+ VARDECL(celt_norm, tmp);
+ int N;
+ SAVE_STACK;
+ N = N0*stride;
+ ALLOC(tmp, N, celt_norm);
+ if (hadamard)
+ {
+ const int *ordery = ordery_table+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 (j=0;j<N;j++)
+ X[j] = tmp[j];
+ RESTORE_STACK;
+}
+
+void haar1(celt_norm *X, int N0, int stride)
+{
+ int i, j;
+ N0 >>= 1;
+ for (i=0;i<stride;i++)
+ for (j=0;j<N0;j++)
+ {
+ celt_norm tmp1, tmp2;
+ tmp1 = MULT16_16_Q15(QCONST16(.70710678f,15), X[stride*2*j+i]);
+ tmp2 = MULT16_16_Q15(QCONST16(.70710678f,15), X[stride*(2*j+1)+i]);
+ X[stride*2*j+i] = tmp1 + tmp2;
+ X[stride*(2*j+1)+i] = tmp1 - tmp2;
+ }
+}
+
+static int compute_qn(int N, int b, int offset, int pulse_cap, int stereo)
+{
+ static const opus_int16 exp2_table8[8] =
+ {16384, 17866, 19483, 21247, 23170, 25267, 27554, 30048};
+ int qn, qb;
+ int N2 = 2*N-1;
+ if (stereo && 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 = IMIN(b-pulse_cap-(4<<BITRES), (b+N2*offset)/N2);
+
+ qb = IMIN(8<<BITRES, qb);
+
+ if (qb<(1<<BITRES>>1)) {
+ qn = 1;
+ } else {
+ qn = exp2_table8[qb&0x7]>>(14-(qb>>BITRES));
+ qn = (qn+1)>>1<<1;
+ }
+ celt_assert(qn <= 256);
+ return qn;
+}
+
+struct band_ctx {
+ int encode;
+ const CELTMode *m;
+ int i;
+ int intensity;
+ int spread;
+ int tf_change;
+ ec_ctx *ec;
+ opus_int32 remaining_bits;
+ const celt_ener *bandE;
+ opus_uint32 seed;
+};
+
+struct split_ctx {
+ int inv;
+ int imid;
+ int iside;
+ int delta;
+ int itheta;
+ int qalloc;
+};
+
+static void compute_theta(struct band_ctx *ctx, struct split_ctx *sctx,
+ celt_norm *X, celt_norm *Y, int N, int *b, int B, int B0,
+ int LM,
+ int stereo, int *fill)
+{
+ int qn;
+ int itheta=0;
+ int delta;
+ int imid, iside;
+ int qalloc;
+ int pulse_cap;
+ int offset;
+ opus_int32 tell;
+ int inv=0;
+ int encode;
+ const CELTMode *m;
+ int i;
+ int intensity;
+ ec_ctx *ec;
+ const celt_ener *bandE;
+
+ encode = ctx->encode;
+ m = ctx->m;
+ i = ctx->i;
+ intensity = ctx->intensity;
+ ec = ctx->ec;
+ bandE = ctx->bandE;
+
+ /* Decide on the resolution to give to the split parameter theta */
+ pulse_cap = m->logN[i]+LM*(1<<BITRES);
+ offset = (pulse_cap>>1) - (stereo&&N==2 ? QTHETA_OFFSET_TWOPHASE : QTHETA_OFFSET);
+ qn = compute_qn(N, *b, offset, pulse_cap, stereo);
+ if (stereo && i>=intensity)
+ qn = 1;
+ if (encode)
+ {
+ /* theta is the atan() of the ratio between the (normalized)
+ side and mid. With just that parameter, we can re-scale both
+ mid and side because we know that 1) they have unit norm and
+ 2) they are orthogonal. */
+ itheta = stereo_itheta(X, Y, stereo, N);
+ }
+ tell = ec_tell_frac(ec);
+ if (qn!=1)
+ {
+ if (encode)
+ 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 (stereo && N>2)
+ {
+ int p0 = 3;
+ int x = itheta;
+ int x0 = qn/2;
+ int ft = p0*(x0+1) + x0;
+ /* Use a probability of p0 up to itheta=8192 and then use 1 after */
+ if (encode)
+ {
+ ec_encode(ec,x<=x0?p0*x:(x-1-x0)+(x0+1)*p0,x<=x0?p0*(x+1):(x-x0)+(x0+1)*p0,ft);
+ } else {
+ int fs;
+ fs=ec_decode(ec,ft);
+ if (fs<(x0+1)*p0)
+ x=fs/p0;
+ else
+ x=x0+1+(fs-(x0+1)*p0);
+ ec_dec_update(ec,x<=x0?p0*x:(x-1-x0)+(x0+1)*p0,x<=x0?p0*(x+1):(x-x0)+(x0+1)*p0,ft);
+ itheta = x;
+ }
+ } else if (B0>1 || stereo) {
+ /* Uniform pdf */
+ if (encode)
+ ec_enc_uint(ec, itheta, qn+1);
+ else
+ itheta = ec_dec_uint(ec, qn+1);
+ } else {
+ int fs=1, ft;
+ ft = ((qn>>1)+1)*((qn>>1)+1);
+ if (encode)
+ {
+ int fl;
+
+ fs = itheta <= (qn>>1) ? itheta + 1 : qn + 1 - itheta;
+ fl = itheta <= (qn>>1) ? itheta*(itheta + 1)>>1 :
+ ft - ((qn + 1 - itheta)*(qn + 2 - itheta)>>1);
+
+ ec_encode(ec, fl, fl+fs, ft);
+ } else {
+ /* Triangular pdf */
+ int fl=0;
+ int fm;
+ fm = ec_decode(ec, ft);
+
+ if (fm < ((qn>>1)*((qn>>1) + 1)>>1))
+ {
+ itheta = (isqrt32(8*(opus_uint32)fm + 1) - 1)>>1;
+ fs = itheta + 1;
+ fl = itheta*(itheta + 1)>>1;
+ }
+ else
+ {
+ itheta = (2*(qn + 1)
+ - isqrt32(8*(opus_uint32)(ft - fm - 1) + 1))>>1;
+ fs = qn + 1 - itheta;
+ fl = ft - ((qn + 1 - itheta)*(qn + 2 - itheta)>>1);
+ }
+
+ ec_dec_update(ec, fl, fl+fs, ft);
+ }
+ }
+ itheta = (opus_int32)itheta*16384/qn;
+ if (encode && stereo)
+ {
+ if (itheta==0)
+ intensity_stereo(m, X, Y, bandE, i, N);
+ else
+ stereo_split(X, Y, N);
+ }
+ /* NOTE: Renormalising X and Y *may* help fixed-point a bit at very high rate.
+ Let's do that at higher complexity */
+ } else if (stereo) {
+ if (encode)
+ {
+ inv = itheta > 8192;
+ if (inv)
+ {
+ int j;
+ for (j=0;j<N;j++)
+ Y[j] = -Y[j];
+ }
+ intensity_stereo(m, X, Y, bandE, i, N);
+ }
+ if (*b>2<<BITRES && ctx->remaining_bits > 2<<BITRES)
+ {
+ if (encode)
+ ec_enc_bit_logp(ec, inv, 2);
+ else
+ inv = ec_dec_bit_logp(ec, 2);
+ } else
+ inv = 0;
+ itheta = 0;
+ }
+ qalloc = ec_tell_frac(ec) - tell;
+ *b -= qalloc;
+
+ if (itheta == 0)
+ {
+ imid = 32767;
+ iside = 0;
+ *fill &= (1<<B)-1;
+ delta = -16384;
+ } else if (itheta == 16384)
+ {
+ imid = 0;
+ iside = 32767;
+ *fill &= ((1<<B)-1)<<B;
+ delta = 16384;
+ } else {
+ imid = bitexact_cos((opus_int16)itheta);
+ iside = bitexact_cos((opus_int16)(16384-itheta));
+ /* This is the mid vs side allocation that minimizes squared error
+ in that band. */
+ delta = FRAC_MUL16((N-1)<<7,bitexact_log2tan(iside,imid));
+ }
+
+ sctx->inv = inv;
+ sctx->imid = imid;
+ sctx->iside = iside;
+ sctx->delta = delta;
+ sctx->itheta = itheta;
+ sctx->qalloc = qalloc;
+}
+static unsigned quant_band_n1(struct band_ctx *ctx, celt_norm *X, celt_norm *Y, int b,
+ celt_norm *lowband_out)
+{
+#ifdef RESYNTH
+ int resynth = 1;
+#else
+ int resynth = !ctx->encode;
+#endif
+ int c;
+ int stereo;
+ celt_norm *x = X;
+ int encode;
+ ec_ctx *ec;
+
+ encode = ctx->encode;
+ ec = ctx->ec;
+
+ stereo = Y != NULL;
+ c=0; do {
+ int sign=0;
+ if (ctx->remaining_bits>=1<<BITRES)
+ {
+ if (encode)
+ {
+ sign = x[0]<0;
+ ec_enc_bits(ec, sign, 1);
+ } else {
+ sign = ec_dec_bits(ec, 1);
+ }
+ ctx->remaining_bits -= 1<<BITRES;
+ b-=1<<BITRES;
+ }
+ if (resynth)
+ x[0] = sign ? -NORM_SCALING : NORM_SCALING;
+ x = Y;
+ } while (++c<1+stereo);
+ if (lowband_out)
+ lowband_out[0] = SHR16(X[0],4);
+ return 1;
+}
+
+/* This function is responsible for encoding and decoding a mono partition.
+ It can split the band in two and transmit the energy difference with
+ the two half-bands. It can be called recursively so bands can end up being
+ split in 8 parts. */
+static unsigned quant_partition(struct band_ctx *ctx, celt_norm *X,
+ int N, int b, int B, celt_norm *lowband,
+ int LM,
+ opus_val16 gain, int fill)
+{
+ const unsigned char *cache;
+ int q;
+ int curr_bits;
+ int imid=0, iside=0;
+ int B0=B;
+ opus_val16 mid=0, side=0;
+ unsigned cm=0;
+#ifdef RESYNTH
+ int resynth = 1;
+#else
+ int resynth = !ctx->encode;
+#endif
+ celt_norm *Y=NULL;
+ int encode;
+ const CELTMode *m;
+ int i;
+ int spread;
+ ec_ctx *ec;
+
+ encode = ctx->encode;
+ m = ctx->m;
+ i = ctx->i;
+ spread = ctx->spread;
+ ec = ctx->ec;
+
+ /* If we need 1.5 more bit than we can produce, split the band in two. */
+ cache = m->cache.bits + m->cache.index[(LM+1)*m->nbEBands+i];
+ if (LM != -1 && b > cache[cache[0]]+12 && N>2)
+ {
+ int mbits, sbits, delta;
+ int itheta;
+ int qalloc;
+ struct split_ctx sctx;
+ celt_norm *next_lowband2=NULL;
+ opus_int32 rebalance;
+
+ N >>= 1;
+ Y = X+N;
+ LM -= 1;
+ if (B==1)
+ fill = (fill&1)|(fill<<1);
+ B = (B+1)>>1;
+
+ compute_theta(ctx, &sctx, X, Y, N, &b, B, B0,
+ LM, 0, &fill);
+ imid = sctx.imid;
+ iside = sctx.iside;
+ delta = sctx.delta;
+ itheta = sctx.itheta;
+ qalloc = sctx.qalloc;
+#ifdef FIXED_POINT
+ mid = imid;
+ side = iside;
+#else
+ mid = (1.f/32768)*imid;
+ side = (1.f/32768)*iside;
+#endif
+
+ /* Give more bits to low-energy MDCTs than they would otherwise deserve */
+ if (B0>1 && (itheta&0x3fff))
+ {
+ if (itheta > 8192)
+ /* Rough approximation for pre-echo masking */
+ delta -= delta>>(4-LM);
+ else
+ /* Corresponds to a forward-masking slope of 1.5 dB per 10 ms */
+ delta = IMIN(0, delta + (N<<BITRES>>(5-LM)));
+ }
+ mbits = IMAX(0, IMIN(b, (b-delta)/2));
+ sbits = b-mbits;
+ ctx->remaining_bits -= qalloc;
+
+ if (lowband)
+ next_lowband2 = lowband+N; /* >32-bit split case */
+
+ rebalance = ctx->remaining_bits;
+ if (mbits >= sbits)
+ {
+ cm = quant_partition(ctx, X, N, mbits, B,
+ lowband, LM,
+ MULT16_16_P15(gain,mid), fill);
+ rebalance = mbits - (rebalance-ctx->remaining_bits);
+ if (rebalance > 3<<BITRES && itheta!=0)
+ sbits += rebalance - (3<<BITRES);
+ cm |= quant_partition(ctx, Y, N, sbits, B,
+ next_lowband2, LM,
+ MULT16_16_P15(gain,side), fill>>B)<<(B0>>1);
+ } else {
+ cm = quant_partition(ctx, Y, N, sbits, B,
+ next_lowband2, LM,
+ MULT16_16_P15(gain,side), fill>>B)<<(B0>>1);
+ rebalance = sbits - (rebalance-ctx->remaining_bits);
+ if (rebalance > 3<<BITRES && itheta!=16384)
+ mbits += rebalance - (3<<BITRES);
+ cm |= quant_partition(ctx, X, N, mbits, B,
+ lowband, LM,
+ MULT16_16_P15(gain,mid), fill);
+ }
+ } else {
+ /* This is the basic no-split case */
+ q = bits2pulses(m, i, LM, b);
+ curr_bits = pulses2bits(m, i, LM, q);
+ ctx->remaining_bits -= curr_bits;
+
+ /* Ensures we can never bust the budget */
+ while (ctx->remaining_bits < 0 && q > 0)
+ {
+ ctx->remaining_bits += curr_bits;
+ q--;
+ curr_bits = pulses2bits(m, i, LM, q);
+ ctx->remaining_bits -= curr_bits;
+ }
+
+ if (q!=0)
+ {
+ int K = get_pulses(q);
+
+ /* Finally do the actual quantization */
+ if (encode)
+ {
+ cm = alg_quant(X, N, K, spread, B, ec
+#ifdef RESYNTH
+ , gain
+#endif
+ );
+ } else {
+ cm = alg_unquant(X, N, K, spread, B, ec, gain);
+ }
+ } else {
+ /* If there's no pulse, fill the band anyway */
+ int j;
+ if (resynth)
+ {
+ unsigned cm_mask;
+ /* B can be as large as 16, so this shift might overflow an int on a
+ 16-bit platform; use a long to get defined behavior.*/
+ cm_mask = (unsigned)(1UL<<B)-1;
+ fill &= cm_mask;
+ if (!fill)
+ {
+ for (j=0;j<N;j++)
+ X[j] = 0;
+ } else {
+ if (lowband == NULL)
+ {
+ /* Noise */
+ for (j=0;j<N;j++)
+ {
+ ctx->seed = celt_lcg_rand(ctx->seed);
+ X[j] = (celt_norm)((opus_int32)ctx->seed>>20);
+ }
+ cm = cm_mask;
+ } else {
+ /* Folded spectrum */
+ for (j=0;j<N;j++)
+ {
+ opus_val16 tmp;
+ ctx->seed = celt_lcg_rand(ctx->seed);
+ /* About 48 dB below the "normal" folding level */
+ tmp = QCONST16(1.0f/256, 10);
+ tmp = (ctx->seed)&0x8000 ? tmp : -tmp;
+ X[j] = lowband[j]+tmp;
+ }
+ cm = fill;
+ }
+ renormalise_vector(X, N, gain);
+ }
+ }
+ }
+ }
+
+ return cm;
+}
+
+
+/* This function is responsible for encoding and decoding a band for the mono case. */
+static unsigned quant_band(struct band_ctx *ctx, celt_norm *X,
+ int N, int b, int B, celt_norm *lowband,
+ int LM, celt_norm *lowband_out,
+ opus_val16 gain, celt_norm *lowband_scratch, int fill)
+{
+ int N0=N;
+ int N_B=N;
+ int N_B0;
+ int B0=B;
+ int time_divide=0;
+ int recombine=0;
+ int longBlocks;
+ unsigned cm=0;
+#ifdef RESYNTH
+ int resynth = 1;
+#else
+ int resynth = !ctx->encode;
+#endif
+ int k;
+ int encode;
+ int tf_change;
+
+ encode = ctx->encode;
+ tf_change = ctx->tf_change;
+
+ longBlocks = B0==1;
+
+ N_B /= B;
+
+ /* Special case for one sample */
+ if (N==1)
+ {
+ return quant_band_n1(ctx, X, NULL, b, lowband_out);
+ }
+
+ if (tf_change>0)
+ recombine = tf_change;
+ /* Band recombining to increase frequency resolution */
+
+ if (lowband_scratch && 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++)
+ {
+ static const unsigned char bit_interleave_table[16]={
+ 0,1,1,1,2,3,3,3,2,3,3,3,2,3,3,3
+ };
+ if (encode)
+ haar1(X, N>>k, 1<<k);
+ if (lowband)
+ haar1(lowband, N>>k, 1<<k);
+ fill = bit_interleave_table[fill&0xF]|bit_interleave_table[fill>>4]<<2;
+ }
+ B>>=recombine;
+ N_B<<=recombine;
+
+ /* Increasing the time resolution */
+ while ((N_B&1) == 0 && tf_change<0)
+ {
+ if (encode)
+ haar1(X, N_B, B);
+ if (lowband)
+ haar1(lowband, N_B, B);
+ fill |= fill<<B;
+ B <<= 1;
+ N_B >>= 1;
+ time_divide++;
+ tf_change++;
+ }
+ B0=B;
+ N_B0 = N_B;
+
+ /* Reorganize the samples in time order instead of frequency order */
+ if (B0>1)
+ {
+ if (encode)
+ deinterleave_hadamard(X, N_B>>recombine, B0<<recombine, longBlocks);
+ if (lowband)
+ deinterleave_hadamard(lowband, N_B>>recombine, B0<<recombine, longBlocks);
+ }
+
+ cm = quant_partition(ctx, X, N, b, B, lowband,
+ LM, gain, fill);
+
+ /* This code is used by the decoder and by the resynthesis-enabled encoder */
+ if (resynth)
+ {
+ /* Undo the sample reorganization going from time order to frequency order */
+ if (B0>1)
+ interleave_hadamard(X, N_B>>recombine, B0<<recombine, longBlocks);
+
+ /* Undo time-freq changes that we did earlier */
+ N_B = N_B0;
+ B = B0;
+ for (k=0;k<time_divide;k++)
+ {
+ B >>= 1;
+ N_B <<= 1;
+ cm |= cm>>B;
+ haar1(X, N_B, B);
+ }
+
+ for (k=0;k<recombine;k++)
+ {
+ static const unsigned char bit_deinterleave_table[16]={
+ 0x00,0x03,0x0C,0x0F,0x30,0x33,0x3C,0x3F,
+ 0xC0,0xC3,0xCC,0xCF,0xF0,0xF3,0xFC,0xFF
+ };
+ cm = bit_deinterleave_table[cm];
+ haar1(X, N0>>k, 1<<k);
+ }
+ B<<=recombine;
+
+ /* Scale output for later folding */
+ if (lowband_out)
+ {
+ int j;
+ opus_val16 n;
+ n = celt_sqrt(SHL32(EXTEND32(N0),22));
+ for (j=0;j<N0;j++)
+ lowband_out[j] = MULT16_16_Q15(n,X[j]);
+ }
+ cm &= (1<<B)-1;
+ }
+ return cm;
+}
+
+
+/* This function is responsible for encoding and decoding a band for the stereo case. */
+static unsigned quant_band_stereo(struct band_ctx *ctx, celt_norm *X, celt_norm *Y,
+ int N, int b, int B, celt_norm *lowband,
+ int LM, celt_norm *lowband_out,
+ celt_norm *lowband_scratch, int fill)
+{
+ int imid=0, iside=0;
+ int inv = 0;
+ opus_val16 mid=0, side=0;
+ unsigned cm=0;
+#ifdef RESYNTH
+ int resynth = 1;
+#else
+ int resynth = !ctx->encode;
+#endif
+ int mbits, sbits, delta;
+ int itheta;
+ int qalloc;
+ struct split_ctx sctx;
+ int orig_fill;
+ int encode;
+ ec_ctx *ec;
+
+ encode = ctx->encode;
+ ec = ctx->ec;
+
+ /* Special case for one sample */
+ if (N==1)
+ {
+ return quant_band_n1(ctx, X, Y, b, lowband_out);
+ }
+
+ orig_fill = fill;
+
+ compute_theta(ctx, &sctx, X, Y, N, &b, B, B,
+ LM, 1, &fill);
+ inv = sctx.inv;
+ imid = sctx.imid;
+ iside = sctx.iside;
+ delta = sctx.delta;
+ itheta = sctx.itheta;
+ qalloc = sctx.qalloc;
+#ifdef FIXED_POINT
+ mid = imid;
+ side = iside;
+#else
+ mid = (1.f/32768)*imid;
+ side = (1.f/32768)*iside;
+#endif
+
+ /* 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)
+ {
+ int c;
+ int sign=0;
+ celt_norm *x2, *y2;
+ mbits = b;
+ sbits = 0;
+ /* Only need one bit for the side. */
+ if (itheta != 0 && itheta != 16384)
+ sbits = 1<<BITRES;
+ mbits -= sbits;
+ c = itheta > 8192;
+ ctx->remaining_bits -= qalloc+sbits;
+
+ x2 = c ? Y : X;
+ y2 = c ? X : Y;
+ if (sbits)
+ {
+ if (encode)
+ {
+ /* Here we only need to encode a sign for the side. */
+ sign = x2[0]*y2[1] - x2[1]*y2[0] < 0;
+ ec_enc_bits(ec, sign, 1);
+ } else {
+ sign = ec_dec_bits(ec, 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 = quant_band(ctx, x2, N, mbits, B, lowband,
+ LM, lowband_out, Q15ONE, 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];
+ if (resynth)
+ {
+ celt_norm tmp;
+ X[0] = MULT16_16_Q15(mid, X[0]);
+ X[1] = MULT16_16_Q15(mid, X[1]);
+ Y[0] = MULT16_16_Q15(side, Y[0]);
+ Y[1] = MULT16_16_Q15(side, Y[1]);
+ tmp = X[0];
+ X[0] = SUB16(tmp,Y[0]);
+ Y[0] = ADD16(tmp,Y[0]);
+ tmp = X[1];
+ X[1] = SUB16(tmp,Y[1]);
+ Y[1] = ADD16(tmp,Y[1]);
+ }
+ } else {
+ /* "Normal" split code */
+ opus_int32 rebalance;
+
+ mbits = IMAX(0, IMIN(b, (b-delta)/2));
+ sbits = b-mbits;
+ ctx->remaining_bits -= qalloc;
+
+ rebalance = ctx->remaining_bits;
+ 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 = quant_band(ctx, X, N, mbits, B,
+ lowband, LM, lowband_out,
+ Q15ONE, lowband_scratch, fill);
+ rebalance = mbits - (rebalance-ctx->remaining_bits);
+ if (rebalance > 3<<BITRES && itheta!=0)
+ sbits += rebalance - (3<<BITRES);
+
+ /* For a stereo split, the high bits of fill are always zero, so no
+ folding will be done to the side. */
+ cm |= quant_band(ctx, Y, N, sbits, B,
+ NULL, LM, NULL,
+ side, NULL, fill>>B);
+ } else {
+ /* For a stereo split, the high bits of fill are always zero, so no
+ folding will be done to the side. */
+ cm = quant_band(ctx, Y, N, sbits, B,
+ NULL, LM, NULL,
+ side, NULL, fill>>B);
+ rebalance = sbits - (rebalance-ctx->remaining_bits);
+ if (rebalance > 3<<BITRES && itheta!=16384)
+ mbits += rebalance - (3<<BITRES);
+ /* In stereo mode, we do not apply a scaling to the mid because we need the normalized
+ mid for folding later. */
+ cm |= quant_band(ctx, X, N, mbits, B,
+ lowband, LM, lowband_out,
+ Q15ONE, lowband_scratch, fill);
+ }
+ }
+
+
+ /* This code is used by the decoder and by the resynthesis-enabled encoder */
+ if (resynth)
+ {
+ if (N!=2)
+ stereo_merge(X, Y, mid, N);
+ if (inv)
+ {
+ int j;
+ for (j=0;j<N;j++)
+ Y[j] = -Y[j];
+ }
+ }
+ return cm;
+}
+
+
+void quant_all_bands(int encode, const CELTMode *m, int start, int end,
+ celt_norm *X_, celt_norm *Y_, unsigned char *collapse_masks, const celt_ener *bandE, int *pulses,
+ int shortBlocks, int spread, int dual_stereo, int intensity, int *tf_res,
+ opus_int32 total_bits, opus_int32 balance, ec_ctx *ec, int LM, int codedBands, opus_uint32 *seed)
+{
+ int i;
+ opus_int32 remaining_bits;
+ const opus_int16 * OPUS_RESTRICT eBands = m->eBands;
+ celt_norm * OPUS_RESTRICT norm, * OPUS_RESTRICT norm2;
+ VARDECL(celt_norm, _norm);
+ celt_norm *lowband_scratch;
+ int B;
+ int M;
+ int lowband_offset;
+ int update_lowband = 1;
+ int C = Y_ != NULL ? 2 : 1;
+ int norm_offset;
+#ifdef RESYNTH
+ int resynth = 1;
+#else
+ int resynth = !encode;
+#endif
+ struct band_ctx ctx;
+ SAVE_STACK;
+
+ M = 1<<LM;
+ B = shortBlocks ? M : 1;
+ norm_offset = M*eBands[start];
+ /* No need to allocate norm for the last band because we don't need an
+ output in that band. */
+ ALLOC(_norm, C*(M*eBands[m->nbEBands-1]-norm_offset), celt_norm);
+ norm = _norm;
+ norm2 = norm + M*eBands[m->nbEBands-1]-norm_offset;
+ /* We can use the last band as scratch space because we don't need that
+ scratch space for the last band. */
+ lowband_scratch = X_+M*eBands[m->nbEBands-1];
+
+ lowband_offset = 0;
+ ctx.bandE = bandE;
+ ctx.ec = ec;
+ ctx.encode = encode;
+ ctx.intensity = intensity;
+ ctx.m = m;
+ ctx.seed = *seed;
+ ctx.spread = spread;
+ for (i=start;i<end;i++)
+ {
+ opus_int32 tell;
+ int b;
+ int N;
+ opus_int32 curr_balance;
+ int effective_lowband=-1;
+ celt_norm * OPUS_RESTRICT X, * OPUS_RESTRICT Y;
+ int tf_change=0;
+ unsigned x_cm;
+ unsigned y_cm;
+ int last;
+
+ ctx.i = i;
+ last = (i==end-1);
+
+ X = X_+M*eBands[i];
+ if (Y_!=NULL)
+ Y = Y_+M*eBands[i];
+ else
+ Y = NULL;
+ N = M*eBands[i+1]-M*eBands[i];
+ tell = ec_tell_frac(ec);
+
+ /* Compute how many bits we want to allocate to this band */
+ if (i != start)
+ balance -= tell;
+ remaining_bits = total_bits-tell-1;
+ ctx.remaining_bits = remaining_bits;
+ if (i <= codedBands-1)
+ {
+ curr_balance = balance / IMIN(3, codedBands-i);
+ b = IMAX(0, IMIN(16383, IMIN(remaining_bits+1,pulses[i]+curr_balance)));
+ } else {
+ b = 0;
+ }
+
+ if (resynth && M*eBands[i]-N >= M*eBands[start] && (update_lowband || lowband_offset==0))
+ lowband_offset = i;
+
+ tf_change = tf_res[i];
+ ctx.tf_change = tf_change;
+ if (i>=m->effEBands)
+ {
+ X=norm;
+ if (Y_!=NULL)
+ Y = norm;
+ lowband_scratch = NULL;
+ }
+ if (i==end-1)
+ lowband_scratch = NULL;
+
+ /* Get a conservative estimate of the collapse_mask's for the bands we're
+ going to be folding from. */
+ if (lowband_offset != 0 && (spread!=SPREAD_AGGRESSIVE || B>1 || tf_change<0))
+ {
+ int fold_start;
+ int fold_end;
+ int fold_i;
+ /* This ensures we never repeat spectral content within one band */
+ effective_lowband = IMAX(0, M*eBands[lowband_offset]-norm_offset-N);
+ fold_start = lowband_offset;
+ while(M*eBands[--fold_start] > effective_lowband+norm_offset);
+ fold_end = lowband_offset-1;
+ while(M*eBands[++fold_end] < effective_lowband+norm_offset+N);
+ x_cm = y_cm = 0;
+ fold_i = fold_start; do {
+ x_cm |= collapse_masks[fold_i*C+0];
+ y_cm |= collapse_masks[fold_i*C+C-1];
+ } while (++fold_i<fold_end);
+ }
+ /* Otherwise, we'll be using the LCG to fold, so all blocks will (almost
+ always) be non-zero. */
+ else
+ x_cm = y_cm = (1<<B)-1;
+
+ if (dual_stereo && i==intensity)
+ {
+ int j;
+
+ /* Switch off dual stereo to do intensity. */
+ dual_stereo = 0;
+ if (resynth)
+ for (j=0;j<M*eBands[i]-norm_offset;j++)
+ norm[j] = HALF32(norm[j]+norm2[j]);
+ }
+ if (dual_stereo)
+ {
+ x_cm = quant_band(&ctx, X, N, b/2, B,
+ effective_lowband != -1 ? norm+effective_lowband : NULL, LM,
+ last?NULL:norm+M*eBands[i]-norm_offset, Q15ONE, lowband_scratch, x_cm);
+ y_cm = quant_band(&ctx, Y, N, b/2, B,
+ effective_lowband != -1 ? norm2+effective_lowband : NULL, LM,
+ last?NULL:norm2+M*eBands[i]-norm_offset, Q15ONE, lowband_scratch, y_cm);
+ } else {
+ if (Y!=NULL)
+ {
+ x_cm = quant_band_stereo(&ctx, X, Y, N, b, B,
+ effective_lowband != -1 ? norm+effective_lowband : NULL, LM,
+ last?NULL:norm+M*eBands[i]-norm_offset, lowband_scratch, x_cm|y_cm);
+ } else {
+ x_cm = quant_band(&ctx, X, N, b, B,
+ effective_lowband != -1 ? norm+effective_lowband : NULL, LM,
+ last?NULL:norm+M*eBands[i]-norm_offset, Q15ONE, lowband_scratch, x_cm|y_cm);
+ }
+ y_cm = x_cm;
+ }
+ collapse_masks[i*C+0] = (unsigned char)x_cm;
+ collapse_masks[i*C+C-1] = (unsigned char)y_cm;
+ balance += pulses[i] + tell;
+
+ /* Update the folding position only as long as we have 1 bit/sample depth. */
+ update_lowband = b>(N<<BITRES);
+ }
+ *seed = ctx.seed;
+
+ RESTORE_STACK;
+}
+