yuv420p 詳解_YUV（yuv422、yuv420p、yuv420sp） convert to RGB

void convert_yuv420p_to_rgb_buffer(unsigned char* yuv, unsigned char* rgb, unsigned int width, unsigned int height)

{

int y, u, v;

int r, g, b;

unsigned char* rgbPixel = rgb;

unsigned char* yuvPixel = yuv;

unsigned char* uHeader = yuv + width * height;

unsigned char* vHeader = yuv + width * height + (width * height) / 4;

int half_width = width / 2;

for (int j = 0; j < height; j++) {

for (int i = 0; i < width; i++) {

y = *yuvPixel;

yuvPixel++;

u = *(uHeader + (i / 2 + (j / 2 * half_width)));

v = *(vHeader + (i / 2 + (j / 2 * half_width)));

// yuv to rgb, 整數、移位， 減少計算量

r = y + ((360 * (v - 128)) >> 8);

r = r > 255 ? 255 : (r < 0 ? 0 : r);

*rgbPixel = r;

rgbPixel++;

g = y - (((88 * (u - 128) + 184 * (v - 128))) >> 8);

g = g > 255 ? 255 : (g < 0 ? 0 : g);

*rgbPixel = g;

rgbPixel++;

b = y + ((455 * (u - 128)) >> 8);

b = b > 255 ? 255 : (b < 0 ? 0 : b);

*rgbPixel = b;

rgbPixel++;

}

}

}void convert_yuv420sp_to_rgb_buffer(unsigned char* yuv, unsigned char* rgb, unsigned int width, unsigned int height)

{

int y, u, v;

int r, g, b;

unsigned char* rgbPixel = rgb;

unsigned char* yuvPixel = yuv;

unsigned char* uHeader = yuv + width * height;

//unsigned char* vHeader = yuv + width * height + (width * height) / 4;

int half_width = width / 2;

for (int j = 0; j < height; j++) {

for (int i = 0; i < width; i++) {

y = *yuvPixel;

yuvPixel++;

u = *(uHeader + (i / 2 + (j / 2 * half_width)) * 2); // 注意： 因為是整數乘除， 這裡 (i / 2 * 2) 不一定都等于 i, 不要簡化。

v = *(uHeader + (i / 2 + (j / 2 * half_width)) * 2+1);

// yuv to rgb, 整數、移位， 減少計算量

r = y + ((360 * (v - 128)) >> 8);

r = r > 255 ? 255 : (r < 0 ? 0 : r);

*rgbPixel = r;

rgbPixel++;

g = y - (((88 * (u - 128) + 184 * (v - 128))) >> 8);

g = g > 255 ? 255 : (g < 0 ? 0 : g);

*rgbPixel = g;

rgbPixel++;

b = y + ((455 * (u - 128)) >> 8);

b = b > 255 ? 255 : (b < 0 ? 0 : b);

*rgbPixel = b;

rgbPixel++;

}

}

}void convert_yuyv_to_rgb_buffer(unsigned char* yuv, unsigned char* rgb, unsigned int width, unsigned int height)

{

unsigned int i;

unsigned char* rgbPixel = rgb;

unsigned char* yuvPixel = yuv;

int y0, u, y1, v;

int r, g, b;

for (i = 0; i < width * height / 2; i++) {

y0 = *yuvPixel;

yuvPixel++;

u = *yuvPixel;

yuvPixel++;

y1 = *yuvPixel;

yuvPixel++;

v = *yuvPixel;

yuvPixel++;

// yuv to rgb, 整數、移位， 減少計算量

r = y0 + ((360 * (v - 128)) >> 8);

r = r > 255 ? 255 : (r < 0 ? 0 : r);

*rgbPixel = r;

rgbPixel++;

g = y0 - (((88 * (u - 128) + 184 * (v - 128))) >> 8);

g = g > 255 ? 255 : (g < 0 ? 0 : g);

*rgbPixel = g;

rgbPixel++;

b = y0 + ((455 * (u - 128)) >> 8);

b = b > 255 ? 255 : (b < 0 ? 0 : b);

*rgbPixel = b;

rgbPixel++;

// yuv to rgb, 整數、移位， 減少計算量

r = y1 + ((360 * (v - 128)) >> 8);

r = r > 255 ? 255 : (r < 0 ? 0 : r);

*rgbPixel = r;

rgbPixel++;

g = y1 - (((88 * (u - 128) + 184 * (v - 128))) >> 8);

g = g > 255 ? 255 : (g < 0 ? 0 : g);

*rgbPixel = g;

rgbPixel++;

b = y1 + ((455 * (u - 128)) >> 8);

b = b > 255 ? 255 : (b < 0 ? 0 : b);

*rgbPixel = b;

rgbPixel++;

}

}