shithub: treason

ref: 66c086c68d190935c0113735278a99b100bf07da
dir: /yuv.c/

#include <u.h>

void yuv420_rgb24(
	u32int width, u32int height,
	const u8int *Y, const u8int *U, const u8int *V, u32int Y_stride, u32int UV_stride,
	u8int *RGB, u32int RGB_stride)
{
	u32int x, y;
	int yy1, cb1, cr1;
	int r, g, b, go;

	for(y = 0; y < height-1; y += 2){
		for(x = 0; x < width-1; x += 2){
			cb1 = *U - 0x80;
			cr1 = *V - 0x80;
			go = 22554*cb1 + 46802*cr1;

#define ONE do{ \
			yy1 = *Y * 0x10101; \
			b = yy1 + 116130*cb1; \
			RGB[0] = (b >> 24) ? ~(b >> 31) : (b>>16); \
			g = yy1 - go; \
			RGB[1] = (g >> 24) ? ~(g >> 31) : (g>>16); \
			r = yy1 + 91881*cr1; \
			RGB[2] = (r >> 24) ? ~(r >> 31) : (r>>16); \
}while(0)

			ONE; Y += 1;        RGB += 3;
			ONE; Y += Y_stride; RGB += RGB_stride;
			ONE; Y -= 1;        RGB -= 3;
			ONE; Y -= Y_stride; RGB -= RGB_stride - 6;

			Y += 2;
			U += 1;
			V += 1;
		}

		Y += Y_stride*2 - x;
		U += UV_stride - x/2;
		V += UV_stride - x/2;
		RGB += RGB_stride*2 - 3*x;
	}
}