YUVtoRGB

#include <stdio.h>
#include <stdlib.h>
#define W 384
#define H 288
#define Bytes 3
#define SIZE (W*H*Bytes)

// YUV444 -> RGB888
// write new img to a file
// get green value for X = 60, Y = 257
// both have 3 Bpp
//|R0|R1|R2|R3|G0|G1|G2|G3|B0|B1|B2|B3|

FILE* openRead(char *path)
{

    FILE *f;

    if( (f = fopen(path, "rb")) == NULL)
    {
        perror("can't open read file");
        exit(-2);
    }
    return f;
}
FILE* openWrite(char *path)
{

    FILE *g;

    if((g = fopen(path, "wb")) == NULL)
    {
        perror("can't open write file");
        exit(-2);
    }

    return g;
}

int clamp(double x, int min, int max)
{
    if(x < min)
        x = min;
    else
        if(x > max)
            x = max;
    return x;
}


void scan_image(int x, int y, char *path, char *newPath)
{
    FILE *f = openRead(path);
    FILE *g = openWrite(newPath);

    int c, d, e, R, G, B;
    int Y, U, V;

    char newCharBuffer[W*H*3] = {0};
    fread(newCharBuffer, (W*H*3), 1, f);

    for(int i = 0; i < (W*H*3) ; i = i + 3) //cate 3 bytes Y, U, V
    {

       Y = newCharBuffer[i];
       U = newCharBuffer[i+1];
       V = newCharBuffer[i+2];
       if(i >= 0 && i <= 15)
       {
           printf("\nY = %d\n", Y);
           printf("U = %d\n", U);
           printf("V = %d\n", V);
       }

       c = Y - 16;
       d = U - 128;
       e = V - 128;

       R = clamp(((298*c + 409*e + 128) >> 8), 0, 255);
       G = clamp(((298*c - 100*d - 208*e + 128) >> 8), 0, 255);
       B = clamp(((298*c + 516*d + 128) >> 8), 0, 255);
        if(i >= 0 && i <= 15)
       {
           printf("\nR = %d\n", R);
           printf("G = %d\n", G);
           printf("B = %d\n", B);
       }

        newCharBuffer[i] = R;
        newCharBuffer[i+1] = G;
        newCharBuffer[i+2] = B;

    }

    fwrite(newCharBuffer, (W*H*3), 1, g); // bun

    fclose(f); fclose(g);
}


int main()
{
    int x = 60;
    int y = 257;
    char path[] = "img2.raw";
    char newPath[] = "newImg.raw";
    scan_image(x, y, path, newPath);

    return 0;
}