My app takes a video (using a custom overlay, in case that's relevant) where I have the cameraDevice set to front facing camera. 3 videos need to be taken, though the cameraDevice alternates between front and rear each time the UIImpagePickerController is called to take the video. On each occasion the
picker.cameraDevice = UIImagePickerControllerCameraDeviceFront;
is used within the code, though as mentioned the app ignores this command every other time.
I see this problem has been asked before, though I am using ARC so the previously suggested solutions of releasing the UIImagePickerController is not an option for me.
Thanks in advance, Jim.
You cannot release the picker in ARC but you can still create a brand new one like this:
picker = nil;
picker = [[UIImagePickerController alloc] init];
// configure picker
Notice that in Apple's sample code "Using UIImagePickerController to Select Pictures and Take Photos" they call a method each time which does exactly this.
Related
I'm running into a strange issue, I hope someone can help.
In my iOS app I create a video with a custom soundtrack using MutableComposition by combining a video from the user's photo library and an audio file from the app bundle. I then use an AVPlayer and AVPlayerItem to play the video back to the user using a custom video player I made.
Each time a new composition is created, the assets, the player and the composition are cleared, released and it basically starts from a clean, init state.
All works fine, until after exactly 4 successful videos created this way every other attempt to create the player fails with error Cannot Decode. It does not matter if its the same video I'm recreating, has no relation to the size/length of the video or the audio file it simply always fails exactly on the fifth attempt, like clockwork. Once it fails, it will then always fail!
This is weird, because it just decoded the same video four times with no problem, so all of a sudden it fails? So, if anyone has a clue, please let me know.
Ok everyone, I have the answer to this straight from Apple. I used one of my developer TSI lifelines to ask the question, and I'll summarize the response.
There is a limit on the number of concurrent video players that AVFoundation will allow. It is due to the limitations of iOS hardware. The limit for current devices is 4 players. If you create a 5th player, you will get the "cannot decode" error. It is not a limit on the number of instances of AVPlayer, or AVPlayerItem. Rather,it is the association of AVPlayerItem with an AVPlayer which creates a "render pipeline", and you are limited to 4 of these. For example, this causes a new render pipeline:
AVPlayer *player = [AVPlayer playerWithPlayerItem:somePlayerItem];
// assuming the AVPlayerItem is ready to go with an AVAsset that has been loaded
I was also warned that you cannot assume that you will have 4 pipelines available to you. Another App may be using one or more. Indeed, I have seen this happen on an iPad, but it was not clear which app was using a pipeline.
So, there you go, it was totally undocumented, but that is the story.
I ran into the same error message after creating 4 AVPlayer instances, the fix in my case wasn't exactly the same though. Perhaps this will help anyone else who comes across this problem.
What I eventually found is that the AVPlayers were not being released when I had thought they were. In my case I was pushing my AVPlayer View Controller onto a Navigation Controller. Even though I was only creating one AVPlayer instance at a time, when the View Controllers are popped off a nav controller they were not being released immediately. It was then very easy for me to reach 4 AVPlayer instances before the old View Controllers were cleaned up.
It wasn't until I made sure that the previous players were released that this problem went away. To be complete I released the AVPlayerItem, AVPlayer and set the player on the AVPlayerLayer to nil before releasing.
I have to wonder if there is some limit on AVPlayer instances, unintentional or not. A related bit of info from the docs:
https://developer.apple.com/library/ios/#documentation/AudioVideo/Conceptual/AVFoundationPG/Articles/02_Playback.html
"Multiple player layers: You can create arbitrarily many AVPlayerLayer objects from a single AVPlayer instance, but only the most-recently-created such layer will display any video content on-screen."
This one was absolutely killing me until I figured it out, picking up clues from this thread and a few others. The biggest single problem in my code was that I was instantiating my video player controller every time I wanted to play a video. Now, it gets instantiated once in the primary controller (in this case, my DetailViewContoller):
#interface DetailViewController () {
VideoPlayerViewController *videoPlayerViewController;
}
- (void) viewDidLoad
{
[super viewDidLoad];
videoPlayerViewController = [[VideoPlayerViewController alloc] initWithNibName: nil bundle: nil];
}
When I want to show a video, I call my DetailViewController's startVideoPlayback method:
- (void) startVideoPlayback: (NSString *)videoUID
{
videoPlayerViewController.videoUID = videoUID;
[self presentModalViewController: videoPlayerViewController animated: YES];
}
(NOTE: I'm passing it 'videoUID' -- a unique identified that was used to create the video in another part of the app.)
In the VideoPlayerViewController (which is largely cribbed from Apple's AVPlayerDemo sample), the one-time screen setup (initializing the AVPlayer, setting up the toolbar, etc.) is done in viewDidLoad -- which now only get's called once, and all per-video setup gets done within viewWillAppear, which then calls prepareToPlay:
- (void) prepareToPlay
{
[self initScrubberTimer];
[self syncPlayPauseButtons];
[self syncScrubber];
NSString *documentsDirectory = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
//*** Retrieve and play video at associated with this videoUID
NSString *destinationPath = [documentsDirectory stringByAppendingFormat: #"/%#.mov", videoUID];
if ([self fileExists: destinationPath]) {
//*** Show the activity indicator spinny thing
[pleaseWait startAnimating];
[self setURL: [NSURL fileURLWithPath: destinationPath]];
//*** Get things going with the first video in this session
if (isFirst) {
isFirst = NO;
//*** Subseqeunt videos replace the first one
} else {
[self.mPlayer replaceCurrentItemWithPlayerItem: [AVPlayerItem playerItemWithURL: [NSURL fileURLWithPath: destinationPath]]];
}
}
}
OK, I figured out a solution, I hope this is helpful to anyone who may stumble on something similar to this problem.
The solution in my case was to initialize the asset for the AVPlayer and the AVPlayerItem on the main thread and make sure I don't create the actual AVPlayerLayer before the playerItem and the player objects return with status "ReadyToPlay".
This proved to be tricky to isolate and I still don't know why it worked the first 4 times and then failed consistently on the 5th time.
Till, I couldn't really include the code, it wasn't a matter of one line or even a few functions. It was a complex problem that I couldn't isolate to begin with. Thanks for the comments though.
It seems like that issue can be caused by any decoding tasks, not only actual players.
I randomly had this problem when I implemented a background task to extract frames from currently playing videos with generateCGImagesAsynchronously
I need to display 4 videos on screen and a race condition would sometime cause the frame extraction to start before the video started playing and I would wait for isReadyForDisplay forever.
Not sure what a good recover strategy is if you can't avoid the condition in the first place, I would probably try to replaceCurrentItem
I'm programming an application for the hearing-impaired. I'm hoping to take tracks from the iTunes library, and in my app have a slider for panning. I don't want to use OpenAL (this isn't a game - I repeat this is a media player). So since AVAudioPlayer has the easy pan method, can I take selections from the MPMediaPicker and feed them into the AVAudioPlayer so I can pan them?
I dont do a lot of iOS development, but I believe there are two ways.
Method #1
You need to add /System/Library/Frameworks/AVFoundation.framework to your target in Xcode and #import AVAudioPlayer.h as well as You need to add MediaPlayer.framework to your target in Xcode and #import .
For this operation, you need MPMediaPicker to pass the song data to AVAMedia Player. That can be accomplished like this:
#interface MusicPlayerDemoViewController : UIViewController <MPMediaPickerControllerDelegate> {
...
}
...
// This action should open the media picker
- (IBAction)openMediaPicker:(id)sender;
#end
// MusicPlayerDemoViewController.m
- (IBAction)openMediaPicker:(id)sender {
MPMediaPickerController *mediaPicker = [[MPMediaPickerController alloc] initWithMediaTypes:MPMediaTypeMusic];
mediaPicker.delegate = self;
mediaPicker.allowsPickingMultipleItems = NO; // this is the default
[self presentModalViewController:mediaPicker animated:YES];
[mediaPicker release];
}
// Media picker delegate methods
- (void)mediaPicker: (MPMediaPickerController *)mediaPicker didPickMediaItems:(MPMediaItemCollection *)mediaItemCollection {
// We need to dismiss the picker
[self dismissModalViewControllerAnimated:YES];
(Code Continues Below, the blanks are for you to fill in)
AT THIS POINT, CALL THE AVAAUDIOPLAYER CLASS AND TELL IT TO PLAY mediaItemCollection . REMEMBER TO STOP AUDIO BEFORE PLAYING, AS IT WILL PLAY MULTIPLE SONGS AT ONCE.
}
- (void)mediaPickerDidCancel:(MPMediaPickerController *)mediaPicker {
// User did not select anything
// We need to dismiss the picker
[self dismissModalViewControllerAnimated:YES];
}
NOW, ONCE THIS IS DONE THE USER NEEDS TO SELECT A NEW SONG. YOU COULD EITHER CREATE A WHILE LOOP AROUND THE WHOLE THING, WHERE THE CONDITIONAL IS CURRENT TIME >= DURATION (FROM AVAAUDIO PLAYER),
ALTERNATIVELY, YOU COULD CREATE A BUTTON TO OPEN THE PICKER
For more questions checkout:
http://oleb.net/blog/2009/07/the-music-player-framework-in-the-iphone-sdk/ (I used much of their code)
http://developer.apple.com/library/ios/#DOCUMENTATION/AVFoundation/Reference/AVAudioPlayerClassReference/Reference/Reference.html
Good Luck!
Derek
Try having AVAMediaPlayer play the variable mediaItemCollection. This was assigned by the picker to be the song location by the code above. If this does not work make sure that AVAMediaPlayer uses the same input variable type (format, like an ID or a folder location) as MpMediaPicker.
That error message sounds like a technical issue. The only thing I can think of is that AVAAudio player or MPmedia player is looking for a Volume variable (it is required?) and can't find one. I can't really answer this one as I don't do iPhone Development, try there forums or website for some help.
Sounds like you are doing a good job! If you are interested, (I don't know if you are staying at DA) Mr. Cochran (the dean of students at the Upper School) is teaching a iPhone Development Class and a AP Computer Science Class (I am in). If you want to take it further, or you want to just ask questions I know he is more than happy too!
Good Luck! Tell me when it is finished so I can test the results!
Is it a known issue that if you try to test your UIImagePickerController using the Camera as a source type then the simulator will crash?
I have the following code:
self.imgPicker = [[UIImagePickerController alloc] init];
self.imgPicker.allowsEditing = NO;
self.imgPicker.delegate = self;
[self.imgPicker setSourceType:UIImagePickerControllerSourceTypeCamera];
[self presentModalViewController:self.imgPicker animated:YES];
[imgPicker release];
Running this in simulator, I get an objc-exception-throw error on the stack # -[UIImagePickerController setSourceType:].
Now if I set the source type to the Photo Library though, everything runs smoothly and fine? What's the deal?
Simulator doesn't have the camera and can't simulate to take a picture (it would have been nice to use the isight but Apple has not been so kindly). However Your code is not safe because, for example, old ipod touch doesn't have a camera and in this case your app will crash on this device.
As Apple suggest in UIImagePickerController documentation:
To use an image picker controller
containing its default controls,
perform these steps:
1.Verify that the device is capable of picking content from the
desired source. Do this calling the
isSourceTypeAvailable: class method,
providing a constant from the
“UIImagePickerControllerSourceType”
enum.
2.Check which media types are available, for the source type you’re
using, by calling the
availableMediaTypesForSourceType:
class method. This lets you
distinguish between a camera that can
be used for video recording and one
that can be used only for still
images.
3.Tell the image picker controller to adjust the UI according to the
media types you want to make
available—still images, movies, or
both—by setting the mediaTypes
property.
4.Present the user interface by calling the
presentModalViewController:animated:
method of the currently active view
controller, passing your configured
image picker controller as the new
view controller.
5.When the user taps a button to pick a newly-captured or saved image
or movie, or cancels the operation,
dismiss the image picker using your
delegate object. For newly-captured
media, your delegate can then save it
to the Camera Roll on the device. For
previously-saved media, your delegate
can then use the image data according
to the purpose of your app.
So you have to call isSourceTypeAvailable and set your sourceType consistently.
I am streaming an MP3 file using MPMoviePlayer, and I would like to have an image displayed instead of the default Quicktime logo in the background.
I found out a way to have an image overlay the player, but the problem with that, is you have to tap outside the image to get the player controls to appear. And when they do appear, they are underneath the image.
Does someone know how to do this?
Thanks,
John
backgroundColor is deprecated, and diving into private View structures is dangerous. This worked fine for me:
UIImageView *coverImageView = [[UIImageView alloc] initWithImage:coverImage];
coverImageView.contentMode = UIViewContentModeScaleAspectFit;
coverImageView.autoresizingMask = UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
coverImageView.frame = moviePlayerController.view.bounds;
[moviePlayerController.view addSubview:coverImageView];
Most every app on the iPhone is made of a hierarchy of views. You could go up to the top root node of the movie player and walk down the child views recursively and set the hidden value to YES until you find the right item, then insert your UIImageView below that item. That way, the controls stay on top and still respond to user inputs.
The risk you run is if Apple changes the MPMoviePlayer UI and shuffles the view hierarchy, but you'll probably have lots of advance notice and can patch your app to allow for the new layout.
There is a question as to whether this is kosher for appstore apps, but many current apps (especially camera/picture-taking ones) are doing it to get rid of standard window elements.
Use AVAudioPlayer and implement your own player UI.
it will work check this
MPMoviePlayerController *moviePlayerController=[[MPMoviePlayerController alloc] initWithContentURL:theURL];
moviePlayerController.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"Default.png"]];
I'm trying to use the UIImagePickerController interface from OS 3.1, with the cameraOverlayView and takePicture, but I've clearly failed to understand how this works, and so I'm not getting the behaviour I want.
What I want to do is open the camera and take a picture automatically without having to having the user interact with the picker or edit the image. So I subclass UIImagePickerController (similar to the example in http://github.com/pmark/Helpful-iPhone-Utilities/tree/master/BTL%20Utilities/) and turn off all of the controls:
- (void)displayModalWithController:(UIViewController*)controller animated:(BOOL)animated {
self.sourceType = UIImagePickerControllerSourceTypeCamera;
self.showsCameraControls = NO;
self.navigationBarHidden = YES;
self.toolbarHidden = YES;
// Setting the overlay view up programmatically.
ipView = [[ImagePickerView alloc] init];
self.cameraOverlayView = ipView;
[controller presentModalViewController:self animated:NO];
}
In the overlayView, I've managed to force the takePicture method of UIImagePickerController to fire (I know this, because I can NSLog it, and I hear the sound of the camera taking a picture). The overlayView shows up just fine. However, the delegate method didFinishPickingMediaWithInfo: never gets called, and imagePickerControllerDidCancel doesn't get called either.
So, how do I either get the delegate methods to get called, or save the picture by overriding the takePicture method? (I have no idea how to capture the picture data here, and Google seems to have failed me). I can't help feeling that I've failed to understand how the guts of UIImagePickerController works, but the docs aren't overly helpful:
e.g.:
"You can provide a custom overlay view to display a custom picture-taking interface and you can initiate the taking of pictures from your code. Your custom overlay view can be displayed in addition to, or instead of, the default controls provided by the image picker interface."
or from showCameraControls:
"If you set this property to NO and provide your own custom controls, you can take multiple pictures before dismissing the image picker interface." - How do I dismiss the picker interface?
Note: the delegate is set properly in IB, so that's not the problem.
Thanks for any help you can provide!
I've found that you just have to wait "long enough" before calling takePicture, or it just silently fails. I don't have a good answer for how to determine the minimum value of "long enough" that will always work, but if you set a timer and wait five or ten seconds you should be okay. It would be nice if it returned some kind of an "I'm not ready to take a picture yet, sorry" error either directly from takePicture or through the delegate, but as far as I know it doesn't.
As an update to my own question: It turns out that I was trying to use takePicture too early. When I moved the action to a button on the overlay and sent takePicture from that button (once the picker was presented modally), the delegate methods fired as they should. I don't know if what I wanted is achievable - taking the image without having to press that button, automatically - but if it is, it will probably have to be done by sending takePicture sometime after I was trying to use it.
-(void)imageMethod:(id)sender{
imagePickerController = [[UIImagePickerController alloc]init];
imagePickerController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
imagePopover=[[UIPopoverController alloc]initWithContentViewController:imagePickerController];
[imagePopover presentPopoverFromRect:importButton.frame inView:self.view permittedArrowDirections:UIPopoverArrowDirectionLeft animated:YES];
}