rgb565toyuv422.c

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

void split(uint8_t* r, uint8_t* g, uint8_t* b, uint16_t rgb16) {
	*r = (((rgb16 >> 11) & 0x1f) * 255 + 15) / 31;
	*g = (((rgb16 >> 5) & 0x3f) * 255 + 31) / 63;
	*b = (((rgb16 >> 0) & 0x1f) * 255 + 15) / 31;
}

uint8_t Y(uint8_t r, uint8_t g, uint8_t b) { return ((r *  66 + g * 129 + b *  25 + 128) >> 8) + 16; }
uint8_t U(uint8_t r, uint8_t g, uint8_t b) { return ((r * -38 + g * -74 + b * 112 + 128) >> 8) + 128; }
uint8_t V(uint8_t r, uint8_t g, uint8_t b) { return ((r * 112 + g * -94 + b * -18 + 128) >> 8) + 128; }

uint32_t ref(uint16_t left, uint16_t right) {
	uint8_t lr, lg, lb, rr, rg, rb;
	split(&lr, &lg, &lb, left);
	split(&rr, &rg, &rb, right);
	uint8_t b0 = Y(lr, lg, lb);
	uint8_t b1 = (U(lr, lg, lb) + U(rr, rg, rb)) >> 1;
	uint8_t b2 = Y(rr, rg, rb);
	uint8_t b3 = (V(lr, lg, lb) + U(rr, rg, rb)) >> 1;
	return (uint32_t)b3 << 24 | (uint32_t)b2 << 16 | (uint32_t)b1 << 8 | b0;
}

uint32_t t0[256], t1[256], t2[256], t3[256];

void dut_setup() {
	uint32_t base = ref(0,0);
	for (int i = 0; i < 256; ++i) {
		t0[i] = ref(0, i << 0) - base;
		t1[i] = ref(0, i << 8) - base;
		t2[i] = ref(i << 0, 0) - base;
		t3[i] = ref(i << 8, 0) - base;

		t0[i] += base;
	}
}

uint32_t dut(uint16_t left, uint16_t right) {
	return t0[right & 255] + t1[right >> 8] + t2[left & 255] + t3[left >> 8];
}

int main(void) {
	dut_setup();
	for (int i = 0; i < 65536; ++i) {
		for (int j = 0; j < 65536; ++j) {
			uint32_t r = ref(i, j);
			uint32_t d = dut(i, j);
			uint32_t map = 0;
			int e = 0;
			for (int k = 0; k < 32; k += 8) {
				int diff = abs((int)((r >> k) & 255) - (int)((d >> k) & 255));
				if (e < diff) e = diff;
				map |= diff << k;
			}
			if (e > 3) printf("%04x,%04x: %08x != %08x  %08x %08x\n", i, j, d, r, d ^ r, map);
		}
		if ((i & 255) == 0) printf("%d\n", i >> 8);
	}
	return 0;
}

rgb888toyuv422.c

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

uint8_t Y(uint8_t r, uint8_t g, uint8_t b) { return ((r *  66 + g * 129 + b *  25 + 128) >> 8) + 16; }
uint8_t U(uint8_t r, uint8_t g, uint8_t b) { return ((r * -38 + g * -74 + b * 112 + 128) >> 8) + 128; }
uint8_t V(uint8_t r, uint8_t g, uint8_t b) { return ((r * 112 + g * -94 + b * -18 + 128) >> 8) + 128; }

uint32_t ref(uint8_t const* p) {
	uint8_t lr = p[0], lg = p[1], lb = p[2], rr = p[3], rg = p[4], rb = p[5];
	uint8_t b0 = Y(lr, lg, lb);
	uint8_t b1 = (U(lr, lg, lb) + U(rr, rg, rb)) >> 1;
	uint8_t b2 = Y(rr, rg, rb);
	uint8_t b3 = (V(lr, lg, lb) + U(rr, rg, rb)) >> 1;
	return (uint32_t)b3 << 24 | (uint32_t)b2 << 16 | (uint32_t)b1 << 8 | b0;
}

uint32_t t0[256], t1[256], t2[256], t3[256], t4[256], t5[256];

void dut_setup() {
	uint8_t rgbrgb[11] = { 0 };
	uint32_t base = ref(rgbrgb);
	for (int i = 0; i < 256; ++i) {
		rgbrgb[5] = i;
		t0[i] = ref(rgbrgb + 5) - base;
		t1[i] = ref(rgbrgb + 4) - base;
		t2[i] = ref(rgbrgb + 3) - base;
		t3[i] = ref(rgbrgb + 2) - base;
		t4[i] = ref(rgbrgb + 1) - base;
		t5[i] = ref(rgbrgb + 0) - base;

		t0[i] += base;
	}
}

uint32_t dut(uint8_t const* p) {
	return t0[p[0]] + t1[p[1]] + t2[p[2]] + t3[p[3]] + t4[p[4]] + t5[p[5]];
}

uint64_t hash24(uint64_t x) {
	x = ((x ^ (x >> 12)) * 0x46e963) & 0xffffff;
	x = ((x ^ (x >> 10)) * 0x6da653) & 0xffffff;
	return x ^ (x >> 12);
}

int main(void) {
	dut_setup();
	for (int i = 0; i < 65536; ++i) {
		for (int j = 0; j < 65536; ++j) {
			int ii = hash24(i), jj = hash24(j);
			uint8_t test[6] = { ii & 255, (ii >> 8) & 255, (ii >> 16) & 255,
			                    jj & 255, (jj >> 8) & 255, (jj >> 16) & 255 };
			uint32_t r = ref(test);
			uint32_t d = dut(test);
			uint32_t map = 0;
			int e = 0;
			for (int k = 0; k < 32; k += 8) {
				int diff = abs((int)((r >> k) & 255) - (int)((d >> k) & 255));
				if (e < diff) e = diff;
				map |= diff << k;
			}
			if (e > 4) printf("%06x,%06x: %08x != %08x  %08x %08x\n", ii, jj, d, r, d ^ r, map);
		}
		if ((i & 255) == 0) printf("%d\n", i >> 8);
	}
	return 0;
}