Is this possible with xcode ?

lf2 · Mar 13, 2012

I am making an iphone camera app.

I would like to know if this is possible:

When you push the camera button, it starts a recording but also makes a file with the exact time (maybe a php file that requests actual server time ?)

does anyone know if this is possible ?

Mark FX · Mar 14, 2012

Yes this is possable.

The first and easiest way to use the camera on your iOS device, is with the
UIImagePickerController class, you can find the documentation fro this class at this link.

https://developer.apple.com/library/ios/#documentation/UIKit/Reference/UIImagePickerController_Class/UIImagePickerController/UIImagePickerController.html#//apple_ref/doc/uid/TP40007070

https://developer.apple.com/library/ios/#documentation/UIKit/Reference/UIImagePickerControllerDelegate_Protocol/UIImagePickerControllerDelegate/UIImagePickerControllerDelegate.html#//apple_ref/doc/uid/TP40007069

Also there is Apple developer documentation related to using the devices camera, this is
also worth reading, you can find it at this link.

https://developer.apple.com/library/ios/#documentation/AudioVideo/Conceptual/CameraAndPhotoLib_TopicsForIOS/Introduction/Introduction.html#//apple_ref/doc/uid/TP40010400

Regards Mark

lf2 · Mar 16, 2012

is there a way to export the exact time when someone pushes the button to a text file

Mark FX · Mar 16, 2012

Yes you can do that, but you would not use the UIImagePickerController to create the time,
but would use a NSDate and NSDateFormatter to create an NSString that could be saved to
a file.

You would properbly create these other classes and NSString in one of the UIImagePickerController's delegate methiods, possably the

UIImagePickerController : didFinishPickingMediaWithInfo :

method would be a good choice.

Hope this gives you some ideas and guidance.

Regards Mark

xstep · Mar 18, 2012

You can actually write meta data to the QuickTime file. Well, at least using AV Foundation.

And of course you can create an independent file with what ever you want. You'll want to set sharing of your Documents folder so that iTunes can see the files for transferring. That I believe is just a plist entry.

lf2 · Mar 28, 2012

hmm i came up with another idea

lets i make a record app

so someone opens the app and he can use the app to record with the camera but i want to make sure that when he starts recording (he pushes the button to record) he gets the server time (from my server) not the iPhone time.. and that time should be stored somewhere (or in the meta data of the video file !)

what is the best way to to this...any heads up ?

xstep · Apr 21, 2012

I haven't been here for a while and just saw your response.

You'll have to figure out how to get the server timestamp, but what if the server ins't available. I think I'd have the app sync to the server and keep track of the time offset from UTC.

As far as the meta data, look into AVMutableMetadataItem. Here is a bit of sample code.

Code:

NSMutableArray * myMetadata = [[NSMutableArray new] autorelease];
AVMutableMetadataItem * metadataItem;

metadataItem = [AVMutableMetadataItem metadataItem];
metadataItem.keySpace = AVMetadataKeySpaceCommon;		
metadataItem.key = AVMetadataCommonKeySoftware;
metadataItem.value = @"CameraTime 1.1";
[myMetadata addObject: metadataItem];		

outputWriter = [AVAssetWriter assetWriterWithURL: [projectPaths movieURLPath] fileType: AVFileTypeQuickTimeMovie error: &error];
[outputWriter retain];

<A a bunch of setup here for outputWriter>

// [COLOR="Red"]You must do this before starting the outputWriter.[/COLOR]
outputWriter.metadata = myMetadata;
		
[outputWriter startWriting];

The key you're looking for may be AVMetadataCommonKeyCreationDate or AVMetadataCommonKeyLastModifiedDate.