Scrubber (UISlider) in AVPlayer? - ios

Question

When you play remote video via AVPlayer and start rewinding, the scrubber is buggy.
I'm doing a player based on this Apple example.
How to implement it smoothly?
Code from my project follows - https://github.com/nullproduction/Player
- (void)initScrubberTimer
{
double interval = .1f;
CMTime playerDuration = [self playerItemDuration];
if (CMTIME_IS_INVALID(playerDuration))
{
return;
}
double duration = CMTimeGetSeconds(playerDuration);
if (isfinite(duration))
{
CGFloat width = CGRectGetWidth([scrubberSlider bounds]);
interval = 0.5f * duration / width;
}
__weak id weakSelf = self;
CMTime intervalSeconds = CMTimeMakeWithSeconds(interval, NSEC_PER_SEC);
mTimeObserver = [self.player addPeriodicTimeObserverForInterval:intervalSeconds
queue:dispatch_get_main_queue()
usingBlock:^(CMTime time) {
[weakSelf syncScrubber];
}];
}
- (void)syncScrubber
{
CMTime playerDuration = [self playerItemDuration];
if (CMTIME_IS_INVALID(playerDuration))
{
scrubberSlider.minimumValue = 0.0;
return;
}
double duration = CMTimeGetSeconds(playerDuration);
if (isfinite(duration))
{
float minValue = [scrubberSlider minimumValue];
float maxValue = [scrubberSlider maximumValue];
double time = CMTimeGetSeconds([self.player currentTime]);
[scrubberSlider setValue:(maxValue - minValue) * time / duration + minValue];
}
}
- (IBAction)beginScrubbing:(id)sender
{
mRestoreAfterScrubbingRate = [self.player rate];
[self.player setRate:0.f];
[self removePlayerTimeObserver];
}
- (IBAction)scrub:(id)sender
{
if ([sender isKindOfClass:[UISlider class]])
{
UISlider* slider = sender;
CMTime playerDuration = [self playerItemDuration];
if (CMTIME_IS_INVALID(playerDuration))
{
return;
}
double duration = CMTimeGetSeconds(playerDuration);
if (isfinite(duration))
{
float minValue = [slider minimumValue];
float maxValue = [slider maximumValue];
float value = [slider value];
double time = duration * (value - minValue) / (maxValue - minValue);
[self.player seekToTime:CMTimeMakeWithSeconds(time, NSEC_PER_SEC)];
}
}
}
- (IBAction)endScrubbing:(id)sender
{
if (!mTimeObserver)
{
CMTime playerDuration = [self playerItemDuration];
if (CMTIME_IS_INVALID(playerDuration))
{
return;
}
double duration = CMTimeGetSeconds(playerDuration);
if (isfinite(duration))
{
CGFloat width = CGRectGetWidth([scrubberSlider bounds]);
double tolerance = 0.5f * duration / width;
__weak id weakSelf = self;
CMTime intervalSeconds = CMTimeMakeWithSeconds(tolerance, NSEC_PER_SEC);
mTimeObserver = [self.player addPeriodicTimeObserverForInterval:intervalSeconds
queue:dispatch_get_main_queue()
usingBlock: ^(CMTime time) {
[weakSelf syncScrubber];
}];
}
}
if (mRestoreAfterScrubbingRate)
{
[self.player setRate:mRestoreAfterScrubbingRate];
mRestoreAfterScrubbingRate = 0.f;
}
}

Answer 1

I guess the problem is, that your scrubber is still updating from the video, while you are using the seekbar. Implement it in a way, that you pause the player during the scrubbing, and you won't have this bug anymore. Checkout my solution:
The function to update your player:
- (IBAction)seekbarAction:(UISlider *)sender {
CMTime videoLength = playerItem1.duration; //gets the video duration
float videoLengthInSeconds = videoLength.value/videoLength.timescale; //transfers the CMTime duration into seconds
[player1 seekToTime:CMTimeMakeWithSeconds(videoLengthInSeconds*sender.value, 1)];
}
And another seekbar action with "Touch down" in order to pause the video:
- (IBAction)pauseSeek:(id)sender {
[player1 pause];
}
And another seekbar action with "Touch up" in order to resume the video when you release the scrubber. Hope this helps.