对于YUV422的格式，网上有一大堆资料，这里就不说了。直奔主题，给出如何转换的函数，一如既往，只用代码说事。
YUV422有打包格式(Packed)，一如前文所述。同时还有平面格式(Planar)，即Y、U、V是分开存储的，每个分量占一块地方，其中Y为width*height，而U、V合占width*height，该种格式每个像素占16比特。根据U、V的顺序，分出2种格式，U前V后即YUV422P，也叫I422，V前U后，叫YV16(YV表示Y后面跟着V，16表示16bit)。另外，还有一种变态的半平面格式(Semi-planar)，即Y单独占一块地方，但其后U、V又紧挨着排在一起，根据U、V的顺序，又有2种，U前V后叫NV16，在国内好像很多人叫它为YUV422SP格式；V前U后叫NV61。不过这种格式似乎不太受VLC欢迎(具体可去看看VLC的wiki)。
先给出YUV422平面格式的转换函数，如下：
/**内存分布w+--------------------+|Y0Y1Y2Y3... ||... | h|... |||+--------------------+|U0U1||... | h|... |||+----------+|V0V1||... | h|... |||+----------+w/2*/void yuv422p_to_rgb24(YUV_TYPE type, unsigned char* yuv422p, unsigned char* rgb, int width, int height){int y, cb, cr;int r, g, b;int i = 0;unsigned char* p_y;unsigned char* p_u;unsigned char* p_v;unsigned char* p_rgb;p_y = yuv422p;p_u = p_y + width * height;p_v = p_u + width * height / 2;if (type == FMT_YV16){p_v = p_y + width * height;p_u = p_u + width * height / 2;}p_rgb = rgb;init_yuv422p_table();for (i = 0; i < width * height / 2; i++){y = p_y[0];cb = p_u[0];cr = p_v[0];r = MAX (0, MIN (255, (V[cr] + Y1[y])/10000)); //R valueb = MAX (0, MIN (255, (U[cb] + Y1[y])/10000)); //B valueg = MAX (0, MIN (255, (Y2[y] - 5094*(r) - 1942*(b))/10000)); //G value// 此处可调整RGB排序，BMP图片排序为BGR// 默认排序为：RGBp_rgb[0] = r;p_rgb[1] = g;p_rgb[2] = b;y = p_y[1];cb = p_u[0];cr = p_v[0];r = MAX (0, MIN (255, (V[cr] + Y1[y])/10000)); //R valueb = MAX (0, MIN (255, (U[cb] + Y1[y])/10000)); //B valueg = MAX (0, MIN (255, (Y2[y] - 5094*(r) - 1942*(b))/10000)); //G valuep_rgb[3] = r;p_rgb[4] = g;p_rgb[5] = b;p_y += 2;p_u += 1;p_v += 1;p_rgb += 6;}}
接着给出NV16、NV61转换成RGB的函数，如下：
/**内存分布w+--------------------+|Y0Y1Y2Y3... ||... | h|... |||+--------------------+|U0V0U1V1 ||... | h|... |||+--------------------+w/2UV交织为NV16，VU交织为NV61可以与上一函数合并，但方便查看，还是不合并*/void yuv422sp_to_rgb24(YUV_TYPE type, unsigned char* yuv422sp, unsigned char* rgb, int width, int height){int y, cb, cr;int r, g, b;int i = 0;unsigned char* p_y;unsigned char* p_uv;unsigned char* p_rgb;p_y = yuv422sp;p_uv = p_y + width * height; // uv分量在Y后面p_rgb = rgb;init_yuv422p_table();for (i = 0; i < width * height / 2; i++){y = p_y[0];if (type == FMT_NV16){cb = p_uv[0];cr = p_uv[1]; // v紧跟u，在u的下一个位置}if (type == FMT_NV61){cr = p_uv[0];cb = p_uv[1]; // u紧跟v，在v的下一个位置}r = MAX (0, MIN (255, (V[cr] + Y1[y])/10000)); //R valueb = MAX (0, MIN (255, (U[cb] + Y1[y])/10000)); //B valueg = MAX (0, MIN (255, (Y2[y] - 5094*(r) - 1942*(b))/10000)); //G value// 此处可调整RGB排序，BMP图片排序为BGR// 默认排序为：RGBp_rgb[0] = r;p_rgb[1] = g;p_rgb[2] = b;y = p_y[1];if (type == FMT_NV16){cb = p_uv[0];cr = p_uv[1];}if (type == FMT_NV61){cr = p_uv[0];cb = p_uv[1];}r = MAX (0, MIN (255, (V[cr] + Y1[y])/10000)); //R valueb = MAX (0, MIN (255, (U[cb] + Y1[y])/10000)); //B valueg = MAX (0, MIN (255, (Y2[y] - 5094*(r) - 1942*(b))/10000)); //G valuep_rgb[3] = r;p_rgb[4] = g;p_rgb[5] = b;p_y += 2;p_uv += 2;p_rgb += 6;}}
参考资料：
/yuv.php
/YUV/
李迟 .8.5 晚上
