AVPlayer seekToTime:toleranceBefore:toleranceAfter hangs Intermittently

Question

I am calling AVPlayer seekToTime:toleranceBefore:toleranceAfter which hangs intermittently, doesn't get complete (completion block not even called). I looked at other stackoverflow but no success.

[AVPlayer seekToTime:CMTimeMakeWithSeconds (19,1) toleranceBefore:kCMTimeZero toleranceAfter:kCMTimeZero completionHandler:^(BOOL finished) {}];

Has anyone come across this issue?

Answer 1

Technical Q&A QA1820 How do I achieve smooth video scrubbing with AVPlayer seekToTime:?

Q: My app allows the user to scrub video files using a slider control in combination with AVPlayer seekToTime: but there is a considerable lag in the display of the video frames. How can I achieve smoother scrubbing?

A: Avoid making calls to AVPlayer seekToTime: in rapid succession. This will cancel the seeks in progress, resulting in a lot of seeking and not a lot of displaying of the target frames. Instead, use the completion handler variant of AVPlayer seekToTime: and wait for a seek in progress to complete first before issuing another. Listing 1 and Listing 2 give examples of this technique (Note: these examples assume a valid player object has been created and the player's current item status is being maintained via key-value observing. See the AV Foundation Programming Guide for more information).

Using the completion handler variant of AVPlayer seekToTime: for smoother scrubbing (Objective-C).

@import AVFoundation;

@interface MyClass ()
{
    AVPlayer player;
    BOOL isSeekInProgress;
    CMTime chaseTime;
    AVPlayerStatus playerCurrentItemStatus; // your player.currentItem.status
    ...
}

@implementation MyClass

...

- (void)stopPlayingAndSeekSmoothlyToTime:(CMTime)newChaseTime
{
    [self->player pause];

    if (CMTIME_COMPARE_INLINE(newChaseTime, !=, self->chaseTime))
    {
        self->chaseTime = newChaseTime;

        if (!self->isSeekInProgress)
            [self trySeekToChaseTime];
    }
}

- (void)trySeekToChaseTime
{
    if (playerCurrentItemStatus == AVPlayerItemStatusUnknown)
    {
        // wait until item becomes ready (KVO player.currentItem.status)
    }
    else if (playerCurrentItemStatus == AVPlayerItemStatusReadyToPlay)
    {
        [self actuallySeekToTime];
    }
}

- (void)actuallySeekToTime
{
    self->isSeekInProgress = YES;
    CMTime seekTimeInProgress = self->chaseTime;
    [self->player seekToTime:seekTimeInProgress toleranceBefore:kCMTimeZero
    toleranceAfter:kCMTimeZero completionHandler:
     ^(BOOL isFinished)
     {
         if (CMTIME_COMPARE_INLINE(seekTimeInProgress, ==, self->chaseTime))
             self->isSeekInProgress = NO;
         else
             [self trySeekToChaseTime];
     }];
}

@end

Answer 2

Try -seekToDate:completionHandler: method . It's same as toleranceBefore:toleranceAfter with kCMTimeZero. If it doesn't help provide more details.