YUV格式学习：NV12和YUV420P格式互换

来源：互联网发布：python try except 编辑：程序博客网时间：2024/06/04 17:53

NV12和YUV420的转换是在相同采样空间的转换，只是个别分量位置的调整，只要明白了Y、U、V分量的布置，就很容易写出来。

代码如下：

/**yyyy yyyyuv    uv->yyyy yyyyuuvv*/void yuv420sp_to_yuv420p(unsigned char* yuv420sp, unsigned char* yuv420p, int width, int height){    int i, j;    int y_size = width * height;    unsigned char* y = yuv420sp;    unsigned char* uv = yuv420sp + y_size;    unsigned char* y_tmp = yuv420p;    unsigned char* u_tmp = yuv420p + y_size;    unsigned char* v_tmp = yuv420p + y_size * 5 / 4;    // y    memcpy(y_tmp, y, y_size);    // u    for (j = 0, i = 0; j < y_size/2; j+=2, i++)    {        u_tmp[i] = uv[j];        v_tmp[i] = uv[j+1];    }}/**yyyy yyyyuuvv->yyyy yyyyuv    uv*/void yuv420p_to_yuv420sp(unsigned char* yuv420p, unsigned char* yuv420sp, int width, int height){    int i, j;    int y_size = width * height;    unsigned char* y = yuv420p;    unsigned char* u = yuv420p + y_size;    unsigned char* v = yuv420p + y_size * 5 / 4;    unsigned char* y_tmp = yuv420sp;    unsigned char* uv_tmp = yuv420sp + y_size;    // y    memcpy(y_tmp, y, y_size);    // u    for (j = 0, i = 0; j < y_size/2; j+=2, i++)    {// 此处可调整U、V的位置，变成NV12或NV21#if 01        uv_tmp[j] = u[i];        uv_tmp[j+1] = v[i];#else        uv_tmp[j] = v[i];        uv_tmp[j+1] = u[i];#endif    }}

后记：

一口气把自己研究很久的东西写出来，好像都没写到点子上。以前也尝试过写技术性很强的文章，到处找资料，找出处，但后来发觉自己不是那块料，于是就直接贴代码，理论的东西反而不说——因为说不清，也怕说错。

关于YUV，初步听说是在6、7年前的大学，开始接触是在4、5年前，而真正了解其原理，却是近些年。学习进度不可谓不慢。写出来，也算有个交待。也为自己准备实现的YUV播放器做些准备。

迟 2015.8.5 晚上

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