Commit cbcba9e7 authored by Yaowu Xu's avatar Yaowu Xu
Browse files

scaled the threshold for 2nd order coefficient reset

extend_qrange introduces a different scaling factor, this commit takes
the scaling difference into account for reset 2nd order coefficients.

Change-Id: Ie58bca9f52698fa759e3f88da2aa4d82630fa91a
parent 8974daea
......@@ -615,33 +615,48 @@ static void optimize_b(MACROBLOCK *mb, int ib, int type,
*a = *l = (d->eob != !type);
}
#if CONFIG_EXTEND_QRANGE
/**************************************************************************
our inverse hadamard transform effectively is weighted sum of all 16 inputs
with weight either 1 or -1. It has a last stage scaling of (sum+1)>>2. And
dc only idct is (dc+16)>>5. So if all the sums are between -65 and 63 the
output after inverse wht and idct will be all zero. A sum of absolute value
smaller than 65 guarantees all 16 different (+1/-1) weighted sums in wht
fall between -65 and +65.
**************************************************************************/
#define SUM_2ND_COEFF_THRESH 65
#else
/**************************************************************************
our inverse hadamard transform effectively is weighted sum of all 16 inputs
with weight either 1 or -1. It has a last stage scaling of (sum+3)>>3. And
dc only idct is (dc+4)>>3. So if all the sums are between -35 and 29, the
output after inverse wht and idct will be all zero. A sum of absolute value
smaller than 35 guarantees all 16 different (+1/-1) weighted sums in wht
fall between -35 and +35.
**************************************************************************/
#define SUM_2ND_COEFF_THRESH 35
#endif
static void check_reset_2nd_coeffs(MACROBLOCKD *x, int type,
ENTROPY_CONTEXT *a, ENTROPY_CONTEXT *l)
{
int sum=0;
int i;
BLOCKD *bd = &x->block[24];
if(bd->dequant[0]>=35 && bd->dequant[1]>=35)
if(bd->dequant[0]>=SUM_2ND_COEFF_THRESH
&& bd->dequant[1]>=SUM_2ND_COEFF_THRESH)
return;
for(i=0;i<bd->eob;i++)
{
int coef = bd->dqcoeff[vp8_default_zig_zag1d[i]];
sum+= (coef>=0)?coef:-coef;
if(sum>=35)
if(sum>=SUM_2ND_COEFF_THRESH)
return;
}
/**************************************************************************
our inverse hadamard transform effectively is weighted sum of all 16 inputs
with weight either 1 or -1. It has a last stage scaling of (sum+3)>>3. And
dc only idct is (dc+4)>>3. So if all the sums are between -35 and 29, the
output after inverse wht and idct will be all zero. A sum of absolute value
smaller than 35 guarantees all 16 different (+1/-1) weighted sums in wht
fall between -35 and +35.
**************************************************************************/
if(sum < 35)
if(sum < SUM_2ND_COEFF_THRESH)
{
for(i=0;i<bd->eob;i++)
{
......
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