diff --git a/celt/bands.c b/celt/bands.c
index 412e37f7599f4ea949d26f38d343489cee524a07..ef5fb44939017d781726df22a496119bc44c6aff 100644
--- a/celt/bands.c
+++ b/celt/bands.c
@@ -648,6 +648,175 @@ static int compute_qn(int N, int b, int offset, int pulse_cap, int stereo)
return qn;
}
+struct split_ctx {
+ int inv;
+ int imid;
+ int iside;
+ int delta;
+ int itheta;
+ int qalloc;
+};
+
+static void compute_theta(struct split_ctx *ctx, int encode, const CELTMode *m,
+ int i, celt_norm *X, celt_norm *Y, int N, int *b, int B, int B0,
+ int intensity, ec_ctx *ec, opus_int32 *remaining_bits, int LM,
+ const celt_ener *bandE, 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;
+
+ /* 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 && *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));
+ }
+
+ ctx->inv = inv;
+ ctx->imid = imid;
+ ctx->iside = iside;
+ ctx->delta = delta;
+ ctx->itheta = itheta;
+ ctx->qalloc = qalloc;
+}
static unsigned quant_band_n1(int encode, celt_norm *X, celt_norm *Y, int b,
opus_int32 *remaining_bits, ec_ctx *ec, celt_norm *lowband_out)
{
@@ -796,154 +965,22 @@ static unsigned quant_band(int encode, const CELTMode *m, int i, celt_norm *X, c
if (split)
{
- int qn;
- int itheta=0;
int mbits, sbits, delta;
+ int itheta;
int qalloc;
- int pulse_cap;
- int offset;
+ struct split_ctx ctx;
int orig_fill;
- opus_int32 tell;
-
- /* 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 && *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;
orig_fill = fill;
- 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));
- }
+ compute_theta(&ctx, encode, m, i, X, Y, N, &b, B, B0, intensity, ec,
+ remaining_bits, LM, bandE, stereo, &fill);
+ inv = ctx.inv;
+ imid = ctx.imid;
+ iside = ctx.iside;
+ delta = ctx.delta;
+ itheta = ctx.itheta;
+ qalloc = ctx.qalloc;
#ifdef FIXED_POINT
mid = imid;
side = iside;