Observing currentPlaybackTime and showing an overlay at intervals

问题

I’m making a video that shows overlays at certain intervals of a video. I’ve managed to get the video to play. Now my objective is to watch/observe the currentPlaybackTime value and pause the video when it hits 2 seconds.

After some research found that currentPlaybackTime does not support KOV. So I need to implement this solution but I have no idea where to put the code - I’m very new to Objective C. I keep trying to put it in the ViewController (My only view) but the way its written hints to it being placed somewhere else…

Should I create a new controller for it? Or do I override methods from the MediaPlayer framework?

Here's my code:

#import <UIKit/UIKit.h>
#import <MediaPlayer/MediaPlayer.h>

@interface ViewController : UIViewController

@property (strong, nonatomic) MPMoviePlayerController *movieController;

@property(nonatomic) NSTimeInterval currentPlaybackTime;

@end



#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}


- (void)viewDidAppear:(BOOL)animated {

    self.movieController = [[MPMoviePlayerController alloc] init];


    NSString *moviePath = [[NSBundle mainBundle] pathForResource:@"Movie" ofType:@"m4v"];
    NSURL *movieURL = [NSURL fileURLWithPath:moviePath];
    self.movieController = [[MPMoviePlayerController alloc] initWithContentURL:movieURL];

    [self.movieController.view setFrame:CGRectMake (0, 0, 480, 326)];
    [self.view addSubview:self.movieController.view];


    [self.movieController play];
    [self.movieController currentPlaybackTime];




}



@end

回答1:

You can implement following method in your found solution in this same view controller.

Right after

[self.movieController play];

call following method

[self BeginPlayerPolling];

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(movieFinishedCallback:)
                                             name:MPMoviePlayerPlaybackDidFinishNotification
                                           object: self.movieController];
self.movieController = [[MPMoviePlayerController alloc] init];

and implement this notification observer's method

- (void)movieFinishedCallback:(NSNotification*)aNotification
{
    // Remove the movie player view controller from the "playback did finish" notification observers
    [[NSNotificationCenter defaultCenter] removeObserver: self
                                                name:MPMoviePlayerPlaybackDidFinishNotification
                                              object: self.movieController];
    [self EndPlayerPolling];
}

来源：https://stackoverflow.com/questions/20807914/observing-currentplaybacktime-and-showing-an-overlay-at-intervals

标签

ios

objective-c

cocoa

media-player

mpmediaplayercontroller