#include <stdio.h>
#include <stdlib.h>
#include "libavcodec/colorspace.h"

int clip_uint8(int v)
{
    if (v < 0) return 0;
    if (v > 255) return 255;
    return v;
}

int main()
{
    int r, g, b, y, u, v, i = 0;
    int y1, u1, v1, y2, u2, v2;
    int y0, r0, g0, b0, r1, g1, b1;
    int r2, g2, b2;
    int step = 8;
    for (r = 0; r <= 256; r += step) {
        if (r == 256) r = 255;
        for (g = 0; g <= 256; g += step) {
            if (g == 256) g = 255;
            for (b = 0; b <= 256; b += step) {
               if (b == 256) b = 255;
               y = (257 * r + 504 * g + 98 * b + 16500) / 1000;
               u = (-148 * r - 291 * g + 439 * b + 128500) / 1000;
               v = (439 * r - 368 * g - 71 * b + 128500) / 1000;
               y1 = RGB_TO_Y_CCIR(r, g, b);
               u1 = RGB_TO_U_CCIR(r, g, b, 0);
               v1 = RGB_TO_V_CCIR(r, g, b, 0);
               y0 = (y-16)*255/219;
               r0 = y0 + 1.4022*(u-128);
               g0 = y0 - 0.3456*(u-128) - 0.7145*(v-128);
               b0 = y0 + 1.7710*(v-128);
               r2 = y0 + 1.403*(v-128);
               g2 = y0 - 0.344*(u-128) - 0.714*(v-128);
               b2 = y0 + 1.770*(u-128);
               if (y < 16 || y > 235)
                   printf("\n outbound y: %d\n", y);
               if (y1 < 16 || y1 > 235)
                   printf("\n outbound y1: %d\n", y1);
               if (r0 < 0 || r0 > 255) {
                   printf("\n outbound r0: %d\n", r0);
                   if (r0 < 0) r0 = 0;
                   else r0 = 255;
               }
               if (g0 < 0 || g0 > 255) {
                   printf("\n outbound g0: %d\n", g0);
                   if (g0 < 0) g0 = 0;
                   else g0 = 255;
               }
               if (b0 < 0 || b0 > 255) {
                   printf("\n outbound b0: %d\n", b0);
                   if (b0 < 0) b0 = 0;
                   else b0 = 255;
               }
	y2 = clip_uint8( 0.1494  * r0 + 0.6061 * g0 + 0.2445 * b0);
	u2 = clip_uint8( 0.6066  * r0 - 0.4322 * g0 - 0.1744 * b0 + 128);
	v2 = clip_uint8(-0.08435 * r0 - 0.3422 * g0 + 0.4266 * b0 + 128);
	y2 = y2*219/255.0+16;
	if (abs(y - y2) >= 8 || abs(u - u2) >= 8 || abs(v - v2) >= 8)
                   printf("\n far range between original and reverted yuv\n");
               if (y2 < 16 || y2 > 235)
                   printf("\n y2y2y2y2y2y2y2y2y2outbound y2: %d\n", y2);
               y2 = (y2 - 16) * 255 / 219;
               r1 = y2 + 1.403*(v2-128);
               g1 = y2 - 0.344*(u2-128) - 0.714*(v2-128);
               b1 = y2 + 1.770*(u2-128);

//               if (y != y1 || u != u1 || v != v1) {
               printf("%02x%02x%02x => %02x%02x%02x ", r, g, b, y, u, v);
               printf("%02x%02x%02x => %02x%02x%02x ", y1, u1, v1, r0, g0, b0);
               printf("%02x%02x%02x ", r2, g2, b2);
               printf("=> %02x%02x%02x => %02x%02x%02x", y2, u2, v2, r1, g1, b1);
//               if (++i % 2 == 0)
                   printf("\n");
 //              }
            }
        }
    }
    printf("\n");
    return 0;
}