ref: f276b23415bad8a5197133b87aa1a1d1b4b74a1d
parent: ac1da4f42b36e08e2cda9793b50818cfad1ec437
author: Jean-Marc Valin <[email protected]>
date: Sat Jul 24 13:13:17 EDT 2010
Using random noise in upper bands when signal is "normal"
--- a/libcelt/bands.c
+++ b/libcelt/bands.c
@@ -485,7 +485,7 @@
can be called recursively so bands can end up being split in 8 parts. */
static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_norm *Y,
int N, int b, int spread, int tf_change, celt_norm *lowband, int resynth, void *ec,
- celt_int32 *remaining_bits, int LM, celt_norm *lowband_out, const celt_ener *bandE, int level)
+ celt_int32 *remaining_bits, int LM, celt_norm *lowband_out, const celt_ener *bandE, int level, celt_int32 *seed)
{int q;
int curr_bits;
@@ -754,7 +754,7 @@
else
sign = -1;
}
- quant_band(encode, m, i, v, NULL, N, mbits, spread, tf_change, lowband, resynth, ec, remaining_bits, LM, lowband_out, NULL, level+1);
+ quant_band(encode, m, i, v, NULL, N, mbits, spread, tf_change, lowband, resynth, ec, remaining_bits, LM, lowband_out, NULL, level+1, seed);
if (sbits)
{if (encode)
@@ -806,8 +806,8 @@
else
next_level = level+1;
- quant_band(encode, m, i, X, NULL, N, mbits, spread, tf_change, lowband, resynth, ec, remaining_bits, LM, next_lowband_out1, NULL, next_level);
- quant_band(encode, m, i, Y, NULL, N, sbits, spread, tf_change, next_lowband2, resynth, ec, remaining_bits, LM, NULL, NULL, level);
+ quant_band(encode, m, i, X, NULL, N, mbits, spread, tf_change, lowband, resynth, ec, remaining_bits, LM, next_lowband_out1, NULL, next_level, seed);
+ quant_band(encode, m, i, Y, NULL, N, sbits, spread, tf_change, next_lowband2, resynth, ec, remaining_bits, LM, NULL, NULL, level, seed);
}
} else {@@ -826,9 +826,9 @@
}
if (encode)
- alg_quant(X, N, q, spread, lowband, resynth, (ec_enc*)ec);
+ alg_quant(X, N, q, spread, lowband, resynth, (ec_enc*)ec, seed);
else
- alg_unquant(X, N, q, spread, lowband, (ec_dec*)ec);
+ alg_unquant(X, N, q, spread, lowband, (ec_dec*)ec, seed);
}
/* This code is used by the decoder and by the resynthesis-enabled encoder */
@@ -909,6 +909,7 @@
int B;
int M;
int spread;
+ celt_int32 seed;
celt_norm *lowband;
int update_lowband = 1;
int C = _Y != NULL ? 2 : 1;
@@ -920,6 +921,10 @@
ALLOC(_norm, M*eBands[m->nbEBands], celt_norm);
norm = _norm;
+ if (encode)
+ seed = ((ec_enc*)ec)->rng;
+ else
+ seed = ((ec_dec*)ec)->rng;
balance = 0;
lowband = NULL;
for (i=start;i<end;i++)
@@ -930,6 +935,7 @@
int curr_balance;
celt_norm * restrict X, * restrict Y;
int tf_change=0;
+ celt_norm *effective_lowband;
X = _X+M*eBands[i];
if (_Y!=NULL)
@@ -956,12 +962,8 @@
if (b > C*16*N<<BITRES)
b = C*16*N<<BITRES;
- if (M*eBands[i]-N >= M*eBands[start])
- {- if (update_lowband || lowband==NULL)
+ if (M*eBands[i]-N >= M*eBands[start] && (update_lowband || lowband==NULL))
lowband = norm+M*eBands[i]-N;
- } else
- lowband = NULL;
tf_change = tf_res[i];
if (i>=m->effEBands)
@@ -970,7 +972,12 @@
if (_Y!=NULL)
Y = norm;
}
- quant_band(encode, m, i, X, Y, N, b, spread, tf_change, lowband, resynth, ec, &remaining_bits, LM, norm+M*eBands[i], bandE, 0);
+
+ if (tf_change==0 && !shortBlocks && fold)
+ effective_lowband = NULL;
+ else
+ effective_lowband = lowband;
+ quant_band(encode, m, i, X, Y, N, b, spread, tf_change, effective_lowband, resynth, ec, &remaining_bits, LM, norm+M*eBands[i], bandE, 0, &seed);
balance += pulses[i] + tell;
--- a/libcelt/vq.c
+++ b/libcelt/vq.c
@@ -45,6 +45,10 @@
#define M_PI 3.141592653
#endif
+static celt_uint32 lcg_rand(celt_uint32 seed)
+{+ return 1664525 * seed + 1013904223;
+}
static void exp_rotation1(celt_norm *X, int len, int dir, int stride, celt_word16 c, celt_word16 s)
{@@ -150,7 +154,7 @@
while (++i < N);
}
-void alg_quant(celt_norm *X, int N, int K, int spread, celt_norm *lowband, int resynth, ec_enc *enc)
+void alg_quant(celt_norm *X, int N, int K, int spread, celt_norm *lowband, int resynth, ec_enc *enc, celt_int32 *seed)
{VARDECL(celt_norm, y);
VARDECL(int, iy);
@@ -172,12 +176,15 @@
{for (j=0;j<N;j++)
X[j] = lowband[j];
- renormalise_vector(X, Q15ONE, N, 1);
} else {/* This is important for encoding the side in stereo mode */
for (j=0;j<N;j++)
- X[j] = 0;
+ {+ *seed = lcg_rand(*seed);
+ X[j] = (int)(*seed)>>20;
+ }
}
+ renormalise_vector(X, Q15ONE, N, 1);
return;
}
K = get_pulses(K);
@@ -333,7 +340,7 @@
/** Decode pulse vector and combine the result with the pitch vector to produce
the final normalised signal in the current band. */
-void alg_unquant(celt_norm *X, int N, int K, int spread, celt_norm *lowband, ec_dec *dec)
+void alg_unquant(celt_norm *X, int N, int K, int spread, celt_norm *lowband, ec_dec *dec, celt_int32 *seed)
{int i;
celt_word32 Ryy;
@@ -345,12 +352,15 @@
{for (i=0;i<N;i++)
X[i] = lowband[i];
- renormalise_vector(X, Q15ONE, N, 1);
} else {/* This is important for encoding the side in stereo mode */
for (i=0;i<N;i++)
- X[i] = 0;
+ {+ *seed = lcg_rand(*seed);
+ X[i] = (int)(*seed)>>20;
+ }
}
+ renormalise_vector(X, Q15ONE, N, 1);
return;
}
K = get_pulses(K);
--- a/libcelt/vq.h
+++ b/libcelt/vq.h
@@ -51,7 +51,7 @@
* @param p Pitch vector (it is assumed that p+x is a unit vector)
* @param enc Entropy encoder state
*/
-void alg_quant(celt_norm *X, int N, int K, int spread, celt_norm *lowband, int resynth, ec_enc *enc);
+void alg_quant(celt_norm *X, int N, int K, int spread, celt_norm *lowband, int resynth, ec_enc *enc, celt_int32 *seed);
/** Algebraic pulse decoder
* @param x Decoded normalised spectrum (returned)
@@ -60,7 +60,7 @@
* @param p Pitch vector (automatically added to x)
* @param dec Entropy decoder state
*/
-void alg_unquant(celt_norm *X, int N, int K, int spread, celt_norm *lowband, ec_dec *dec);
+void alg_unquant(celt_norm *X, int N, int K, int spread, celt_norm *lowband, ec_dec *dec, celt_int32 *seed);
celt_word16 renormalise_vector(celt_norm *X, celt_word16 value, int N, int stride);