optimize fast_quantizer c version
As the zbin and rounding constants are normalized, rounding effectively
does the zbinning, therefore the zbin operation can be removed. In
addition, the memset on the two arrays are no longer necessary.
Change-Id: If39c353c42d7e052296cb65322e5218810b5cc4c
diff --git a/vp8/encoder/quantize.c b/vp8/encoder/quantize.c
index 20ec9d1..d06b048 100644
--- a/vp8/encoder/quantize.c
+++ b/vp8/encoder/quantize.c
@@ -125,38 +125,29 @@
int zbin;
int x, y, z, sz;
short *coeff_ptr = &b->coeff[0];
- short *zbin_ptr = &b->zbin[0][0];
short *round_ptr = &b->round[0][0];
short *quant_ptr = &b->quant[0][0];
short *qcoeff_ptr = d->qcoeff;
short *dqcoeff_ptr = d->dqcoeff;
short *dequant_ptr = &d->dequant[0][0];
- vpx_memset(qcoeff_ptr, 0, 32);
- vpx_memset(dqcoeff_ptr, 0, 32);
-
eob = -1;
-
for (i = 0; i < 16; i++)
{
rc = vp8_default_zig_zag1d[i];
z = coeff_ptr[rc];
- zbin = zbin_ptr[rc] ;
sz = (z >> 31); // sign of z
x = (z ^ sz) - sz; // x = abs(z)
- if (x >= zbin)
- {
- y = ((x + round_ptr[rc]) * quant_ptr[rc]) >> 16; // quantize (x)
- x = (y ^ sz) - sz; // get the sign back
- qcoeff_ptr[rc] = x; // write to destination
- dqcoeff_ptr[rc] = x * dequant_ptr[rc]; // dequantized value
+ y = ((x + round_ptr[rc]) * quant_ptr[rc]) >> 16; // quantize (x)
+ x = (y ^ sz) - sz; // get the sign back
+ qcoeff_ptr[rc] = x; // write to destination
+ dqcoeff_ptr[rc] = x * dequant_ptr[rc]; // dequantized value
- if (y)
- {
- eob = i; // last nonzero coeffs
- }
+ if (y)
+ {
+ eob = i; // last nonzero coeffs
}
}
d->eob = eob + 1;
