From eea914cb888209811e6d8f4b58f4f1224f913594 Mon Sep 17 00:00:00 2001
From: Jean-Marc Valin <jean-marc.valin@usherbrooke.ca>
Date: Sun, 12 Sep 2010 20:11:32 -0400
Subject: [PATCH] Simplifies vector renormalisation (and using it less)
---
libcelt/bands.c | 14 +++++++++-----
libcelt/vq.c | 27 ++++++++++++++++++++-------
libcelt/vq.h | 4 +++-
3 files changed, 32 insertions(+), 13 deletions(-)
diff --git a/libcelt/bands.c b/libcelt/bands.c
index 396835ccf..df311f7e1 100644
--- a/libcelt/bands.c
+++ b/libcelt/bands.c
@@ -177,7 +177,7 @@ void renormalise_bands(const CELTMode *m, celt_norm * restrict X, int end, int _
for (c=0;c<C;c++)
{
i=0; do {
- renormalise_vector(X+M*eBands[i]+c*M*m->shortMdctSize, Q15ONE, M*eBands[i+1]-M*eBands[i], 1);
+ renormalise_vector(X+M*eBands[i]+c*M*m->shortMdctSize, M*eBands[i+1]-M*eBands[i]);
} while (++i<end);
}
}
@@ -563,8 +563,12 @@ static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_
if (stereo)
stereo_band_mix(m, X, Y, bandE, 0, i, 1, N);
- mid = renormalise_vector(X, Q15ONE, N, 1);
- side = renormalise_vector(Y, Q15ONE, N, 1);
+ mid = vector_norm(X, N);
+ side = vector_norm(Y, N);
+ /* TODO: Renormalising X and Y *may* help fixed-point a bit at very high rate.
+ Let's do that at higher complexity */
+ /*mid = renormalise_vector(X, Q15ONE, N, 1);
+ side = renormalise_vector(Y, Q15ONE, N, 1);*/
/* theta is the atan() of the ratio between the (normalized)
side and mid. With just that parameter, we can re-scale both
@@ -801,8 +805,8 @@ static void quant_band(int encode, const CELTMode *m, int i, celt_norm *X, celt_
stereo_band_mix(m, X, Y, bandE, 0, i, -1, N);
/* We only need to renormalize because quantization may not
have preserved orthogonality of mid and side */
- renormalise_vector(X, Q15ONE, N, 1);
- renormalise_vector(Y, Q15ONE, N, 1);
+ renormalise_vector(X, N);
+ renormalise_vector(Y, N);
}
}
}
diff --git a/libcelt/vq.c b/libcelt/vq.c
index 4876b5986..1b52ce19f 100644
--- a/libcelt/vq.c
+++ b/libcelt/vq.c
@@ -191,7 +191,7 @@ void alg_quant(celt_norm *X, int N, int K, int spread, int B, celt_norm *lowband
X[j] = (int)(*seed)>>20;
}
}
- renormalise_vector(X, Q15ONE, N, 1);
+ renormalise_vector(X, N);
return;
}
K = get_pulses(K);
@@ -368,7 +368,7 @@ void alg_unquant(celt_norm *X, int N, int K, int spread, int B, celt_norm *lowba
X[i] = (int)(*seed)>>20;
}
}
- renormalise_vector(X, Q15ONE, N, 1);
+ renormalise_vector(X, N);
return;
}
K = get_pulses(K);
@@ -384,7 +384,20 @@ void alg_unquant(celt_norm *X, int N, int K, int spread, int B, celt_norm *lowba
RESTORE_STACK;
}
-celt_word16 renormalise_vector(celt_norm *X, celt_word16 value, int N, int stride)
+celt_word16 vector_norm(const celt_norm *X, int N)
+{
+ int i;
+ celt_word32 E = EPSILON;
+ const celt_norm *xptr = X;
+ for (i=0;i<N;i++)
+ {
+ E = MAC16_16(E, *xptr, *xptr);
+ xptr++;
+ }
+ return celt_sqrt(E);
+}
+
+void renormalise_vector(celt_norm *X, int N)
{
int i;
#ifdef FIXED_POINT
@@ -397,20 +410,20 @@ celt_word16 renormalise_vector(celt_norm *X, celt_word16 value, int N, int strid
for (i=0;i<N;i++)
{
E = MAC16_16(E, *xptr, *xptr);
- xptr += stride;
+ xptr++;
}
#ifdef FIXED_POINT
k = celt_ilog2(E)>>1;
#endif
t = VSHR32(E, (k-7)<<1);
- g = MULT16_16_Q15(value, celt_rsqrt_norm(t));
+ g = celt_rsqrt_norm(t);
xptr = X;
for (i=0;i<N;i++)
{
*xptr = EXTRACT16(PSHR32(MULT16_16(g, *xptr), k+1));
- xptr += stride;
+ xptr++;
}
- return celt_sqrt(E);
+ /*return celt_sqrt(E);*/
}
diff --git a/libcelt/vq.h b/libcelt/vq.h
index 432c8e580..5bea13205 100644
--- a/libcelt/vq.h
+++ b/libcelt/vq.h
@@ -62,6 +62,8 @@ void alg_quant(celt_norm *X, int N, int K, int spread, int B, celt_norm *lowband
*/
void alg_unquant(celt_norm *X, int N, int K, int spread, int B, celt_norm *lowband, ec_dec *dec, celt_int32 *seed);
-celt_word16 renormalise_vector(celt_norm *X, celt_word16 value, int N, int stride);
+void renormalise_vector(celt_norm *X, int N);
+
+celt_word16 vector_norm(const celt_norm *X, int N);
#endif /* VQ_H */
--
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