ref: 387a20d740caa9cbe9893d468bcd679e0219ff7b
parent: e40a19cbe9c121444c28905b217275b21dee1c05
author: Jean-Marc Valin <[email protected]>
date: Wed Feb 27 08:49:54 EST 2008
fixed-point: exp_rotation() mostly converted (still need to convert the cos/sin)
--- a/libcelt/bands.c
+++ b/libcelt/bands.c
@@ -39,32 +39,32 @@
#include "vq.h"
#include "cwrs.h"
-/** Applies a series of rotations so that pulses are spread like a two-sided
-exponential. The effect of this is to reduce the tonal noise created by the
-sparse spectrum resulting from the pulse codebook */
-static void exp_rotation(celt_norm_t *X, int len, float theta, int dir, int stride, int iter)
+
+void exp_rotation(celt_norm_t *X, int len, float theta, int dir, int stride, int iter)
{int i, k;
- float c, s;
- c = cos(theta);
- s = dir*sin(theta);
+ celt_word16_t c, s;
+ c = Q15ONE*cos(theta);
+ s = dir*Q15ONE*sin(theta);
for (k=0;k<iter;k++)
{+ /* We could use MULT16_16_P15 instead of MULT16_16_Q15 for more accuracy,
+ but at this point, I really don't think it's necessary */
for (i=0;i<len-stride;i++)
{- float x1, x2;
+ celt_norm_t x1, x2;
x1 = X[i];
x2 = X[i+stride];
- X[i] = c*x1 - s*x2;
- X[i+stride] = c*x2 + s*x1;
+ X[i] = MULT16_16_Q15(c,x1) - MULT16_16_Q15(s,x2);
+ X[i+stride] = MULT16_16_Q15(c,x2) + MULT16_16_Q15(s,x1);
}
for (i=len-2*stride-1;i>=0;i--)
{- float x1, x2;
+ celt_norm_t x1, x2;
x1 = X[i];
x2 = X[i+stride];
- X[i] = c*x1 - s*x2;
- X[i+stride] = c*x2 + s*x1;
+ X[i] = MULT16_16_Q15(c,x1) - MULT16_16_Q15(s,x2);
+ X[i+stride] = MULT16_16_Q15(c,x2) + MULT16_16_Q15(s,x1);
}
}
}
--- a/libcelt/bands.h
+++ b/libcelt/bands.h
@@ -38,6 +38,11 @@
#include "entdec.h"
#include "rate.h"
+/** Applies a series of rotations so that pulses are spread like a two-sided
+exponential. The effect of this is to reduce the tonal noise created by the
+sparse spectrum resulting from the pulse codebook */
+void exp_rotation(celt_norm_t *X, int len, float theta, int dir, int stride, int iter);
+
/** Compute the amplitude (sqrt energy) in each of the bands
* @param m Mode data
* @param X Spectrum
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -1,9 +1,9 @@
INCLUDES = -I$(top_srcdir)/libcelt
METASOURCES = AUTO
-TESTS = type-test ectest cwrs32-test cwrs64-test real-fft-test dft-test laplace-test mdct-test
+TESTS = type-test ectest cwrs32-test cwrs64-test real-fft-test dft-test laplace-test mdct-test rotation-test
-noinst_PROGRAMS = type-test ectest cwrs32-test cwrs64-test real-fft-test dft-test laplace-test mdct-test
+noinst_PROGRAMS = type-test ectest cwrs32-test cwrs64-test real-fft-test dft-test laplace-test mdct-test rotation-test
type_test_SOURCES = type-test.c
ectest_SOURCES = ectest.c
@@ -13,5 +13,6 @@
dft_test_SOURCES = dft-test.c
laplace_test_SOURCES = laplace-test.c
mdct_test_SOURCES = mdct-test.c
+rotation_test_SOURCES = rotation-test.c
LDADD = $(top_builddir)/libcelt/libcelt.la
--- /dev/null
+++ b/tests/rotation-test.c
@@ -1,0 +1,43 @@
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "celt_types.h"
+#include "bands.h"
+#include <math.h>
+#define MAX_SIZE 100
+
+int ret=0;
+void test_rotation(int N, int K)
+{+ int i;
+ double err = 0, ener = 0, snr;
+ float theta = .007*N/K;
+ celt_word16_t x0[MAX_SIZE];
+ celt_word16_t x1[MAX_SIZE];
+ for (i=0;i<N;i++)
+ x1[i] = x0[i] = rand()%32767-16384;
+ exp_rotation(x1, N, theta, 1, 1, 8);
+ exp_rotation(x1, N, theta, -1, 1, 8);
+ for (i=0;i<N;i++)
+ {+ err += (x0[i]-(double)x1[i])*(x0[i]-(double)x1[i]);
+ ener += x0[i]*(double)x0[i];
+ }
+ snr = 20*log10(ener/err);
+ printf ("SNR for size %d (%d pulses) is %f\n", N, K, snr);+ if (snr < 60)
+ ret = 1;
+}
+
+int main()
+{+ test_rotation(4, 40);
+ test_rotation(7, 20);
+ test_rotation(10, 10);
+ test_rotation(23, 5);
+ test_rotation(50, 3);
+ return ret;
+}