Making new PLC code work in fixed-point even though it's still using float
arithmetic.
diff --git a/libcelt/plc.c b/libcelt/plc.c
index 8f5100c..8eb12d5 100644
--- a/libcelt/plc.c
+++ b/libcelt/plc.c
@@ -1,16 +1,17 @@
+#ifndef NEW_PLC
+#define NEW_PLC
+#endif
-
-
-celt_word32 _celt_lpc(
-celt_word16 *lpc, /* out: [0...p-1] LPC coefficients */
-const celt_word16 *ac, /* in: [0...p] autocorrelation values */
+float _celt_lpc(
+ float *lpc, /* out: [0...p-1] LPC coefficients */
+const float *ac, /* in: [0...p] autocorrelation values */
int p
)
{
int i, j;
- celt_word16 r;
- celt_word16 error = ac[0];
+ float r;
+ float error = ac[0];
if (ac[0] == 0)
{
@@ -22,38 +23,34 @@
for (i = 0; i < p; i++) {
/* Sum up this iteration's reflection coefficient */
- celt_word32 rr = NEG32(SHL32(EXTEND32(ac[i + 1]),13));
+ float rr = -ac[i + 1];
for (j = 0; j < i; j++)
- rr = SUB32(rr,MULT16_16(lpc[j],ac[i - j]));
-#ifdef FIXED_POINT
- r = DIV32_16(rr+PSHR32(error,1),ADD16(error,1));
-#else
+ rr = rr - lpc[j]*ac[i - j];
r = rr/(error+1e-15);
-#endif
/* Update LPC coefficients and total error */
lpc[i] = r;
for (j = 0; j < i>>1; j++)
{
- celt_word16 tmp = lpc[j];
- lpc[j] = MAC16_16_P13(lpc[j],r,lpc[i-1-j]);
- lpc[i-1-j] = MAC16_16_P13(lpc[i-1-j],r,tmp);
+ float tmp = lpc[j];
+ lpc[j] = lpc[j ] + r*lpc[i-1-j];
+ lpc[i-1-j] = lpc[i-1-j] + r*tmp;
}
if (i & 1)
- lpc[j] = MAC16_16_P13(lpc[j],lpc[j],r);
+ lpc[j] = lpc[j] + lpc[j]*r;
- error = SUB16(error,MULT16_16_Q13(r,MULT16_16_Q13(error,r)));
+ error = error - r*r*error;
if (error<.00001*ac[0])
break;
}
return error;
}
-void fir(const celt_word16 *x,
- const celt_word16 *num,
- celt_word16 *y,
+void fir(const float *x,
+ const float *num,
+ float *y,
int N,
int ord,
- celt_word32 *mem)
+ float *mem)
{
int i,j;
@@ -73,12 +70,12 @@
}
}
-void iir(const celt_word16 *x,
- const celt_word16 *den,
- celt_word16 *y,
+void iir(const celt_word32 *x,
+ const float *den,
+ celt_word32 *y,
int N,
int ord,
- celt_word32 *mem)
+ float *mem)
{
int i,j;
for (i=0;i<N;i++)
@@ -98,9 +95,9 @@
}
void _celt_autocorr(
- const celt_word16 *x, /* in: [0...n-1] samples x */
+ const float *x, /* in: [0...n-1] samples x */
float *ac, /* out: [0...lag-1] ac values */
- const float *window,
+ const celt_word16 *window,
int overlap,
int lag,
int n
@@ -115,8 +112,8 @@
xx[i] = x[i];
for (i=0;i<overlap;i++)
{
- xx[i] *= window[i];
- xx[n-i-1] *= window[i];
+ xx[i] *= (1./Q15ONE)*window[i];
+ xx[n-i-1] *= (1./Q15ONE)*window[i];
}
while (lag>=0)
{