MPMoviePlayerController showing black empty screen

问题:

I use MPMoviePlayerController to play a local file in my Application Document folder which have I have downloaded for a server URL:

itemMoviePlayerController = [[MPMoviePlayerController alloc] initWithContentURL:fileURL];
 [self.view addSubview:itemMoviePlayerController.view];
 itemMoviePlayerController.fullscreen = YES;
 itemMoviePlayerController.movieSourceType = MPMovieSourceTypeFile;
 itemMoviePlayerController.initialPlaybackTime = -1.0;
 [itemMoviePlayerController play];

When I play .mov file just after I downloaded it, It shows up a black empty screen & app UI is unusable. But if play same local file next time, it plays fine. I even verified playState & localState for MPMoviePlayerController they seems fine. What could be reason for black empty screen?

回答1:

You need to retain your instance of MPMoviePlayerController i.e. as a property or an instance variable. The reference to the movie player is lost if you do not retain it.

回答2:

You could try to put [itemMoviePlayerController prepareToPlay]; before the [itemMoviePlayerController play];

The way preferred by Apple to display an only full screen video is to present a modal MPMoviePlayerViewController (as Hollance said). To present it, you should use something like :

 moviePlayerViewController = [[MPMoviePlayerViewController alloc] initWithContentURL:fileURL];
 [self presentMoviePlayerViewControllerAnimated:moviePlayerViewController];
 [itemMoviePlayerController play];

This is documented by Apple here

You can read there that you should keep a reference to your MPMoviePlayerViewController in order to dismiss it later with

[self dismissMoviePlayerViewControllerAnimated:moviePlayerViewController].

回答3:

I fixed this by putting

@property (strong, nonatomic) MPMoviePlayerController *moviePlayer; 

in my .h file, and calling self.moviePlayer in all my code and it worked!

回答4:

You need to use MPMoviePlayerViewController instead. Notice the word "View" in there.

回答5:

I hope this will help. I solved this problem in my project

 -(void)startPlayingMovie
{
    NSLog(@"startPlayingMovie");
    NSURL *url = [NSURL fileURLWithPath:[[NSBundle mainBundle]
                                         pathForResource:@"Start_video" ofType:@"mov"]];
    moviePlayer =  [[MPMoviePlayerViewController alloc]
                    initWithContentURL:url];
    moviePlayer.view.frame = CGRectMake(0, 0, self.view.bounds.size.height, self.view.bounds.size.width);
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(moviePlayBackDidFinish:)
                                                 name:MPMoviePlayerPlaybackDidFinishNotification
                                               object:moviePlayer.moviePlayer];

moviePlayer.moviePlayer.controlStyle = MPMovieControlStyleNone;
moviePlayer.moviePlayer.shouldAutoplay = YES;
[self presentMoviePlayerViewControllerAnimated:moviePlayer];
[moviePlayer.moviePlayer setFullscreen:YES animated:NO];

NSLog(@"endPlayingMovie");

}

回答6:

Same thing happened to me. It turns out, I had tried to play the movie while the UIImagePicker wasn't dismissed yet.

In my UIImagePickerDelegate I had to first dismiss the UIImagePicker Popup and then open the ViewController managing the MPMediaPlayerController:

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)infoDict
{
    //the first thing to do: dismiss the media picker
    if ([ipPop isPopoverVisible])
    {
        [ipPop dismissPopoverAnimated:ANIMATION_SETTING];
    }

    myMediaPlayerViewController * playerVC = [[myMediaPlayerViewController alloc] initWithMediaDict:infoDict];
    [self.navigationController pushViewController:playerVC animated:ANIMATION_SETTING];
}

回答7:

I had this same problem and it made me crazy. It would work on one view controller fine (audio and video), but not work on another (black screen with just audio). In the end, all I did was CHANGE THE ORDER of the calls: I simply waited until I was done configuring the movie player before adding it to the view. In other words, I called "addSubview" on the line just before the call to "play".

回答8:

This is the code I'm using to play a file from URL:

MPMoviePlayerViewController *movieViewController = [[MPMoviePlayerViewController alloc] initWithContentURL:[NSURL URLWithString:contentUrl]];
movieViewController.moviePlayer.movieSourceType = MPMovieSourceTypeFile;
[self presentMoviePlayerViewControllerAnimated:movieViewController];
[movieViewController release];

It seems to work fine for me. Two notes:

• Some simulators (like the current iOS 5.0) crash when playing a movie, but it works on a real device
• If you leave out the movieSourceType part, a black screen is shown for about a second before the movie starts

回答9:

I had the same problem, solved it changing the extension of the file being played from .mpg to .mp4. apparently MPMoviePlayerController expects a correct extension, though from the documentation it is not clear to me that this is a requirement:

http://developer.apple.com/library/ios/#documentation/mediaplayer/reference/MPMoviePlayerController_Class/Reference/Reference.html

Supported Formats This class plays any movie or audio file supported in iOS. This includes both streamed content and fixed-length files. For movie files, this typically means files with the extensions .mov, .mp4, .mpv, and .3gp and using one of the following compression standards:

回答10:

This issue seems fixed after updating device iOS to 5.0.
Seems to iOS SDK issue for previous version

回答11:

you must do like that with CGRectMake(0, 0, 0, 0) in the finished callback!

-(void)playMovieAtURL:(NSURL*)theURL

{
    MPMoviePlayerController* theMovie=[[MPMoviePlayerController alloc] initWithContentURL:theURL];
    theMovie.scalingMode=MPMovieScalingModeAspectFill;

    theMovie.view.frame = CGRectMake(2, 246, 317, 70);
    [self.view addSubview:theMovie.view];

    // Register for the playback finished notification. 

    [[NSNotificationCenter defaultCenter] addObserver:self 
                                             selector:@selector(myMovieFinishedCallback:) 
                                                 name:MPMoviePlayerPlaybackDidFinishNotification 
                                               object:theMovie];

    // Movie playback is asynchronous, so this method returns immediately. 
    [theMovie play];
} 

// When the movie is done,release the controller. 
-(void)myMovieFinishedCallback:(NSNotification*)aNotification 
{
    MPMoviePlayerController* theMovie=[aNotification object]; 
    [[NSNotificationCenter defaultCenter] removeObserver:self 
                                                    name:MPMoviePlayerPlaybackDidFinishNotification 
                                                  object:theMovie];

    theMovie.view.frame = CGRectMake(0, 0, 0, 0);
    // Release the movie instance created in playMovieAtURL
    [theMovie release];

}

回答12:

I was having a similar issue. After playback there comes an empty screen, which prevents me to play video again. Well here is my work around. That way play button doesn't disappear.

[self.movieController stop]; 
[self.movieController prepareToPlay];
[self.movieController pause];

回答13:

Also, If you are using http URLs, make sure you disable App Transport Security in your projects *.plist file. It will also cause a black screen.

Add the following code:

<key>NSAppTransportSecurity</key>
<dict>
<key>NSAllowsArbitraryLoads</key><true/>
</dict>

Here:

   [INSERT CODE ABOVE HERE]
  </dict>
</plist>
----- BOTTOM OF PLIST FILE