const int totalFrames = 1000;
    const int sourceFps = 30;
    const int targetFps = 20;

    // 计算跳帧的间隔
    float frameSkip = float(sourceFps) / float(targetFps);
    
    int i = 0;
    float pre = 0;
    int flame_id = 0;
    for (int id = 0; id < 150; ++id)
    {
        if (pre == 0)
        {
            pre = id;
            std::cout << i << " " << id << std::endl;
            ++i;
            pre = float(id) + frameSkip;
        }
        if (int(pre) == id)
        {
            std::cout << i << " " << id << std::endl;
            ++i;
            pre = pre + frameSkip;
        }
    }