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implement Remap;
include "sys.m";
include "mpegio.m";
Mpegi, YCbCr: import Mpegio;
CLOFF: con 255;
width, height, w2, h2: int;
out: array of byte;
ered, egrn, eblu: array of int;
b0r1, b1, r0: array of int;
clamp := array[CLOFF + 256 + CLOFF] of int;
clamp16 := array[CLOFF + 256 + CLOFF] of int;
init(m: ref Mpegi)
{
width = m.width;
height = m.height;
w2 = width >> 1;
h2 = height >> 1;
out = array[width * height] of byte;
b0r1 = array[w2] of int;
b1 = array[w2] of int;
r0 = array[w2] of int;
ered = array[width + 1] of int;
egrn = array[width + 1] of int;
eblu = array[width + 1] of int;
for (i := 0; i < CLOFF; i++) {
clamp[i] = 0;
clamp16[i] = 0;
}
for (i = 0; i < 256; i++) {
clamp[i + CLOFF] = i;
clamp16[i + CLOFF] = i >> 4;
}
for (i = CLOFF + 256; i < CLOFF + 256 + CLOFF; i++) {
clamp[i] = 255;
clamp16[i] = 255 >> 4;
}
}
include "closest.m";
include "rgbvmap.m";
# rgb(y, cb, cr: int): (int, int, int)
# {
# Y := real y;
# Cb := real (cb - 128);
# Cr := real (cr - 128);
# r := int (Y+1.402*Cr);
# g := int (Y-0.34414*Cb-0.71414*Cr);
# b := int (Y+1.772*Cb);
# return (r, g, b);
# }
B: con 16;
M: con (1 << B);
B0: con int (-0.34414 * real M);
B1: con int (1.772 * real M);
R0: con int (1.402 * real M);
R1: con int (-0.71414 * real M);
remap(p: ref Mpegio->YCbCr): array of byte
{
Y := p.Y;
Cb := p.Cb;
Cr := p.Cr;
for (e := 0; e <= width; e++)
ered[e] = 0;
egrn[0:] = ered[0:];
eblu[0:] = ered[0:];
m := 0;
n := 0;
for (i := 0; i < h2; i++) {
for (j := 0; j < w2; j++) {
cb := int Cb[m] - 128;
cr := int Cr[m] - 128;
b0r1[j] = B0 * cb + R1 * cr;
b1[j] = B1 * cb;
r0[j] = R0 * cr;
m++;
}
j = 2;
do {
ex := 0;
er := 0;
eg := 0;
eb := 0;
for (k := 0; k < w2; k++) {
l := 2;
do {
y := int Y[n] << B;
r := clamp[((y + r0[k]) >> B) + CLOFF] + ered[ex];
g := clamp[((y + b0r1[k]) >> B) + CLOFF] + egrn[ex];
b := clamp[((y + b1[k]) >> B) + CLOFF] + eblu[ex];
rc := clamp16[r + CLOFF];
gc := clamp16[g + CLOFF];
bc := clamp16[b + CLOFF];
col := int closest[bc + 16 * (gc + 16 * rc)];
out[n++] = byte col;
col *= 3;
r -= int rgbvmap[col + 0];
t := (3 * r) >> 4;
ered[ex] = t + er;
ered[ex + 1] += t;
er = r - 3 * t;
g -= int rgbvmap[col + 1];
t = (3 * g) >> 4;
egrn[ex] = t + eg;
egrn[ex + 1] += t;
eg = g - 3 * t;
b -= int rgbvmap[col + 2];
t = (3 * b) >> 4;
eblu[ex] = t + eb;
eblu[ex + 1] += t;
eb = b - 3 * t;
ex++;
} while (--l > 0);
}
} while (--j > 0);
}
return out;
}
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