快速计算fps

fps.c

    static int counter;
    static long counter_ms;
    struct timeval time;
    long now;
    if (counter == 0) {
        counter = 1;
        gettimeofday(&time, NULL);
        counter_ms = (time.tv_sec * 1000) + (time.tv_usec / 1000);
    } else if (counter > 100) {
        gettimeofday(&time, NULL);
        now = (time.tv_sec * 1000) + (time.tv_usec / 1000);
        printf("fps = %ld\n", counter * 1000 / (now - counter_ms));
        counter = 0;
    } else {
        counter++;
    }