ios - addPeriodicTimeObserverForInterval called extra time -

i have avplayer 4 sec video (nstimeinterval duration = cmtimegetseconds(self.playeritem.asset.duration) = 4).

i'd update ui changes:

self.periodictimeobserver = [self.player addperiodictimeobserverforinterval:cmtimemake(1, 1) queue:dispatch_get_main_queue() usingblock:^(cmtime time) {      [weakself currenttimedidchange:cmtimegetseconds(time)];  }]; 

but reasons calls ui:

- (void)currenttimedidchange:(nstimeinterval)currenttime {     nslog(@"timepassed %f, total: %f", currenttime, self.duration); } 

logs:

2015-07-23 13:47:07.412   timepassed 0.000000, total: 4.000000 2015-07-23 13:47:07.448   timepassed 0.002814, total: 4.000000 2015-07-23 13:47:07.450   timepassed 0.005481, total: 4.000000 2015-07-23 13:47:08.447   timepassed 1.001473, total: 4.000000 2015-07-23 13:47:09.446   timepassed 2.001612, total: 4.000000 2015-07-23 13:47:10.446   timepassed 3.002021, total: 4.000000 2015-07-23 13:47:11.446   timepassed 4.002139, total: 4.000000 2015-07-23 13:47:12.445   timepassed 5.001977, total: 4.000000 2015-07-23 13:47:12.492   timepassed 5.046618, total: 4.000000 

any appreciated

you need sure not calling periodictimeobserver many time write code

if (self.periodictimeobserver == nil){ self.periodictimeobserver = [self.player addperiodictimeobserverforinterval:cmtimemake(1, 1) queue:dispatch_get_main_queue() usingblock:^(cmtime time) {      [weakself currenttimedidchange:cmtimegetseconds(time)];  }]; } 

then video finishes playing remove observer

[player removetimeobserver:self.periodictimeobserver]; self.periodictimeobserver = nil;