AVPlayer - Fast Backward / Forward Stream

In Swift,

fileprivate let seekDuration: Float64 = 5


@IBAction func doForwardJump(_ sender: Any) {
    guard let duration  = player.currentItem?.duration else{
        return
    }
    let playerCurrentTime = CMTimeGetSeconds(player.currentTime())
    let newTime = playerCurrentTime + seekDuration

    if newTime < CMTimeGetSeconds(duration) {

        let time2: CMTime = CMTimeMake(Int64(newTime * 1000 as Float64), 1000)
        player.seek(to: time2)
    }
}
@IBAction func doBackwardJump(_ sender: Any) {

    let playerCurrentTime = CMTimeGetSeconds(player.currentTime())
    var newTime = playerCurrentTime - seekDuration

    if newTime < 0 {
        newTime = 0
    }
    let time2: CMTime = CMTimeMake(Int64(newTime * 1000 as Float64), 1000)
    player.seek(to: time2)

}

In Objective-C,

#define seekDuration (float)5

- (IBAction)backwardButtonAction:(UIButton *)sender {
    float playerCurrentTime = [self getCurrentTime];
    float newTime = playerCurrentTime - seekDuration;

    if (newTime < 0) {
        newTime = 0;
    }
    CMTime time = CMTimeMake(newTime*1000, 1000);
    [self.player seekToTime:time completionHandler:^(BOOL finished) {
        dispatch_async(dispatch_get_main_queue(), ^{
            playerSliderisScrubbing = NO;
        });
    }];
}
- (IBAction)forwardButtonAction:(UIButton *)sender {
    float duration = [self getPlayerDuration];
    float playerCurrentTime = [self getCurrentTime];
    float newTime = playerCurrentTime + seekDuration;

    if (newTime < duration) {
        CMTime time = CMTimeMake(newTime*1000, 1000);
        [self.player seekToTime:time completionHandler:^(BOOL finished) {
            dispatch_async(dispatch_get_main_queue(), ^{
                playerSliderisScrubbing = NO;
            });
        }];

    }
}
- (float)getCurrentTime {
    float seconds = 0;
    if (_player) {
        seconds = CMTimeGetSeconds([_player currentTime]);
    }
    return seconds;
}
- (float)getPlayerDuration {
    float seconds = 0;
    if (_player) {
        seconds = CMTimeGetSeconds([[_player currentItem] duration]);
    }
    return seconds;
}

Swift 4, 4.2 & 5

var player : AVPlayer!

@IBAction func fastForwardBtn(_ sender: UIButton) {
        let moveForword : Float64 = 5

        if player == nil { return }
        if let duration  = player!.currentItem?.duration {
        let playerCurrentTime = CMTimeGetSeconds(player!.currentTime())
        let newTime = playerCurrentTime + moveForword
        if newTime < CMTimeGetSeconds(duration)
        {
            let selectedTime: CMTime = CMTimeMake(value: Int64(newTime * 1000 as Float64), timescale: 1000)
            player!.seek(to: selectedTime)
        }
        player?.pause()
        player?.play()
        }

    }

@IBAction func rewindBtn(_ sender: UIButton) {
            let moveBackword: Float64 = 5
            if player == nil
            {
                return
            }
            let playerCurrenTime = CMTimeGetSeconds(player!.currentTime())
            var newTime = playerCurrenTime - moveBackword
            if newTime < 0
            {
                newTime = 0
            }
            player?.pause()
            let selectedTime: CMTime = CMTimeMake(value: Int64(newTime * 1000 as Float64), timescale: 1000)
            player?.seek(to: selectedTime)
            player?.play()
        }

Use AVPlayer method seekToTime

AVPlayer *player=..;
 [player seekToTime:time toleranceBefore:kCMTimeZero toleranceAfter:kCMTimeZero];

here is a reference

Hope it helps