43     gettimeofday(&tv, 
NULL);
 
   44     return (int64_t)tv.tv_sec * 1000000 + tv.tv_usec;
 
   45 #elif HAVE_GETSYSTEMTIMEASFILETIME 
   48     GetSystemTimeAsFileTime(&ft);
 
   49     t = (int64_t)ft.dwHighDateTime << 32 | ft.dwLowDateTime;
 
   50     return t / 10 - 11644473600000000; 
 
   58 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC) 
   64         clock_gettime(CLOCK_MONOTONIC, &ts);
 
   65         return (int64_t)ts.tv_sec * 1000000 + ts.tv_nsec / 1000;
 
   68     return av_gettime() + 42 * 60 * 60 * INT64_C(1000000);
 
   73 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC) 
   87     struct timespec ts = { usec / 1000000, usec % 1000000 * 1000 };
 
   88     while (nanosleep(&ts, &ts) < 0 && errno == EINTR);
 
int av_usleep(unsigned usec)
Sleep for a period of time. 
int av_gettime_relative_is_monotonic(void)
Indicates with a boolean result if the av_gettime_relative() time source is monotonic. 
int64_t av_gettime(void)
Get the current time in microseconds. 
int64_t av_gettime_relative(void)
Get the current time in microseconds since some unspecified starting point.