rgb转yuv420源代码(C语言)

/* * packed and tested by Peter.Xu @ 2009.8 */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include "lm_rgb2yuv.h" //转换矩阵 #define MY(a,b,c) (( a* 0.2989 + b* 0.5866 + c* 0.1145)) #define MU(a,b,c) (( a*(-0.1688) + b*(-0.3312) + c* 0.5000 + 128)) #define MV(a,b,c) (( a* 0.5000 + b*(-0.4184) + c*(-0.0816) + 128)) //大小判断 #define DY(a,b,c) (MY(a,b,c) > 255 ? 255 : (MY(a,b,c) < 0 ? 0 : MY(a,b,c))) #define DU(a,b,c) (MU(a,b,c) > 255 ? 255 : (MU(a,b,c) < 0 ? 0 : MU(a,b,c))) #define DV(a,b,c) (MV(a,b,c) > 255 ? 255 : (MV(a,b,c) < 0 ? 0 : MV(a,b,c))) void rgb2yuv_convert(unsigned char *YUV, unsigned char *RGB_RAW, unsigned int width, unsigned int height) { //变量声明 unsigned int i,x,y,j; unsigned char *Y = NULL; unsigned char *U = NULL; unsigned char *V = NULL; char temp; unsigned char *RGB = RGB_RAW + 54; unsigned char *tmp_buf; int line_width = width * 3; tmp_buf = malloc(line_width); for(i = 0, j = height - 1; i < j; i++, j--){ memcpy(tmp_buf, RGB + i * line_width, line_width); memcpy(RGB + i * line_width, RGB + j * line_width, line_width); memcpy(RGB + j * line_width, tmp_buf, line_width); } //顺序调整 for(i=0; (unsigned int)i < width*height*3; i+=3) { temp = RGB[i]; RGB[i] = RGB[i+2]; RGB[i+2] = temp; } i = j = 0; Y = YUV; U = YUV + width*height; V = U + ((width*height)>>2); for(y=0; y < height; y++) for(x=0; x < width; x++) { j = y*width + x; i = j*3; Y[j] = (unsigned char)(DY(RGB[i], RGB[i+1], RGB[i+2])); if(x%2 == 1 && y%2 == 1) { j = (width>>1) * (y>>1) + (x>>1); //上面i仍有效 U[j] = (unsigned char) ((DU(RGB[i ], RGB[i+1], RGB[i+2]) + DU(RGB[i-3], RGB[i-2], RGB[i-1]) + DU(RGB[i -width*3], RGB[i+1-width*3], RGB[i+2-width*3]) + DU(RGB[i-3-width*3], RGB[i-2-width*3], RGB[i-1-width*3]))/4); V[j] = (unsigned char) ((DV(RGB[i ], RGB[i+1], RGB[i+2]) + DV(RGB[i-3], RGB[i-2], RGB[i-1]) + DV(RGB[i -width*3], RGB[i+1-width*3], RGB[i+2-width*3]) + DV(RGB[i-3-width*3], RGB[i-2-width*3], RGB[i-1-width*3]))/4); } } free(tmp_buf); }