struct timespec t1,t2;
clock_gettime(CLOCK_PROCESS_CPUTIME_ID,&t2);
printf("wait video time:%ld us\n", ((t2.tv_sec - t1.tv_sec) * 1000000000 - t1.tv_nsec + t2.tv_nsec)/1000);
struct timespec t1,t2;
clock_gettime(CLOCK_PROCESS_CPUTIME_ID,&t2);
printf("wait video time:%ld us\n", ((t2.tv_sec - t1.tv_sec) * 1000000000 - t1.tv_nsec + t2.tv_nsec)/1000);