int YUV422To420(unsigned char yuv422[], unsigned char yuv420[], int width, int height)
{int ynum = width * height;int i, j, k = 0;//得到Y分量for (i = 0; i < ynum; i++) {yuv420[i] = yuv422[i * 2];}//得到U分量for (i = 0; i < height; i++) {if ((i % 2) != 0)continue;for (j = 0; j < (width / 2); j++) {if ((4 * j + 1) > (2 * width))break;yuv420[ynum + k * 2 * width / 4 + j] = yuv422[i * 2 * width + 4 * j + 1];}k++;}k = 0;//得到V分量for (i = 0; i < height; i++) {if ((i % 2) == 0)continue;for (j = 0; j < (width / 2); j++) {if ((4 * j + 3) > (2 * width))break;yuv420[ynum + ynum / 4 + k * 2 * width / 4 + j] = yuv422[i * 2 * width + 4 * j + 3];}k++;}return 1;
}

亲测有效

代码完全复制于：

论YUV422(YUYV)与YUV420相互转换 - CodeAntenna