iPhone：基于计时器的录像？

Question

I have implemented the code to do video recording feature. It works fine on 3GS device. I want to restrict the video recording based on some timer setting. Lets say, i want to allow user to do video recording only upto 20 seconds or 35 seconds like that. How can i do that? Can i show the timer kind of control on top of media player while recording the video?

Please suggest me.

Here is my code for video recording:

    UIImagePickerController *pickerController = 
                       [[[UIImagePickerController alloc] init] autorelease];
    pickerController.delegate = self;
    pickerController.sourceType = UIImagePickerControllerSourceTypeCamera;
    pickerController.showsCameraControls = YES;
    pickerController.mediaTypes = [NSArray arrayWithObject:(id)kUTTypeMovie];
    [self presentModalViewController:pickerController animated:YES];

Answer 1

videoMaximumDuration expects an NSTimeInterval , which is a tpyedef for a float value. So you should pass it a float value. Try it like this:

UIImagePickerController *pickerController = [[UIImagePickerController alloc] init];
pickerController.delegate = self;
pickerController.sourceType = UIImagePickerControllerSourceTypeCamera;
pickerController.showsCameraControls = YES;
pickerController.mediaTypes = [NSArray arrayWithObject:(NSString *)kUTTypeMovie]; // kUTTypeMovie is actually an NSString.
pickerController.videoMaximumDuration = 30.0f; // limits video length to 30 seconds.
[self presentModalViewController:pickerController animated:YES];
[pickerController release];

Answer 2

UIImagePickerController class has property videoMaximumDuration which works for NSTimeInterval .

By default it's value is set for 10 minutes but you can change it's float value according to your need.

So if you make object of UIImagePickerController class named videoPickerController then you can set timer for capturing video like-

videoPickerController.videoMaximumDuration = 25.0f;