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Simplify the texture evaluation Disto4x4()

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We don't need to use the exact forward transform,
since it's only a rough evaluation.
-> Removed some shifts and rounding constants.

Change-Id: I3fdf8b4fe9720473894155e1ad0345f4d1fd9a33
This commit is contained in:
skal
2012-11-14 07:49:31 +01:00
parent a7305c2ef0
commit e5c3b3f554
2 changed files with 21 additions and 39 deletions
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30
src/dsp/enc.c
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@ -569,30 +569,30 @@ static int TTransform(const uint8_t* in, const uint16_t* w) {
int i;
// horizontal pass
for (i = 0; i < 4; ++i, in += BPS) {
const int a0 = (in[0] + in[2]) << 2;
const int a1 = (in[1] + in[3]) << 2;
const int a2 = (in[1] - in[3]) << 2;
const int a3 = (in[0] - in[2]) << 2;
tmp[0 + i * 4] = a0 + a1 + (a0 != 0);
const int a0 = in[0] + in[2];
const int a1 = in[1] + in[3];
const int a2 = in[1] - in[3];
const int a3 = in[0] - in[2];
tmp[0 + i * 4] = a0 + a1;
tmp[1 + i * 4] = a3 + a2;
tmp[2 + i * 4] = a3 - a2;
tmp[3 + i * 4] = a0 - a1;
}
// vertical pass
for (i = 0; i < 4; ++i, ++w) {
const int a0 = (tmp[0 + i] + tmp[8 + i]);
const int a1 = (tmp[4 + i] + tmp[12+ i]);
const int a2 = (tmp[4 + i] - tmp[12+ i]);
const int a3 = (tmp[0 + i] - tmp[8 + i]);
const int a0 = tmp[0 + i] + tmp[8 + i];
const int a1 = tmp[4 + i] + tmp[12+ i];
const int a2 = tmp[4 + i] - tmp[12+ i];
const int a3 = tmp[0 + i] - tmp[8 + i];
const int b0 = a0 + a1;
const int b1 = a3 + a2;
const int b2 = a3 - a2;
const int b3 = a0 - a1;
// abs((b + (b<0) + 3) >> 3) = (abs(b) + 3) >> 3
sum += w[ 0] * ((abs(b0) + 3) >> 3);
sum += w[ 4] * ((abs(b1) + 3) >> 3);
sum += w[ 8] * ((abs(b2) + 3) >> 3);
sum += w[12] * ((abs(b3) + 3) >> 3);
sum += w[ 0] * abs(b0);
sum += w[ 4] * abs(b1);
sum += w[ 8] * abs(b2);
sum += w[12] * abs(b3);
}
return sum;
}
@ -601,7 +601,7 @@ static int Disto4x4(const uint8_t* const a, const uint8_t* const b,
const uint16_t* const w) {
const int sum1 = TTransform(a, w);
const int sum2 = TTransform(b, w);
return (abs(sum2 - sum1) + 8) >> 4;
return abs(sum2 - sum1) >> 5;
}
static int Disto16x16(const uint8_t* const a, const uint8_t* const b,