AVPlayer - Fast Backward / Forward Stream

Question

This is my code in the viewDidLoad :

AVPlayerItem* playerItem = [AVPlayerItem playerItemWithURL:[NSURL URLWithString:@"http://groove.wavestreamer.com:7321/listen.pls?sid=1"]];

[playerItem addObserver:self forKeyPath:@"timedMetadata" options:NSKeyValueObservingOptionNew context:nil];

music = [[AVPlayer playerWithPlayerItem:playerItem] retain];
[music play];

My question:
How can I create a button, that fast-forwards / fast-backwards the stream 5 seconds, when it´s pressed?

Thank you for your answers... :)

EDIT: How can I add to my current time...

CMTime currentTime = music.currentTime;

...the 5 seconds?

Answer 1

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;
}