c/c++ NV21转为YUV444格式代码

以下是将NV21格式转换为YUV444格式的C++代码示例：

#include <iostream>

// NV21 to YUV444 conversion
void nv21_to_yuv444(unsigned char* nv21, unsigned char* yuv444, int width, int height) {
    int frameSize = width * height;
    int i, j, yp, y, u, v;
    unsigned char* yptr = yuv444;
    unsigned char* uptr = yuv444 + frameSize;
    unsigned char* vptr = yuv444 + frameSize * 2;

    for (j = 0, yp = 0; j < height; j++) {
        u = 0; v = 0;
        for (i = 0; i < width; i++, yp++) {
            y = (int)(nv21[yp]) & 0xff;
            if ((i & 1) == 0) {
                v = (int)(nv21[frameSize + (yp >> 1)]) & 0xff;
                u = (int)(nv21[frameSize + (yp >> 1) + 1]) & 0xff;
            }
            yptr[yp] = y;
            uptr[yp] = u;
            vptr[yp] = v;
        }
    }
}

int main() {
    // Dimensions of input NV21 frame
    int width = 640;
    int height = 480;

    // Allocate memory for input NV21 frame
    unsigned char* nv21 = new unsigned char[width * height * 3 / 2];

    // Allocate memory for output YUV444 frame
    unsigned char* yuv444 = new unsigned char[width * height * 3];

    // Perform NV21 to YUV444 conversion
    nv21_to_yuv444(nv21, yuv444, width, height);

    // Clean up memory
    delete[] nv21;
    delete[] yuv444;

    return 0;
}

这段代码中的`nv21_to_yuv444`函数用于执行NV21到YUV444的转换。请注意，此代码仅提供了转换功能，您需要根据自己的需求进行适当的输入和输出处理。