Access the camera flash?

Whitehk · June 2010

Hi. I can't figure out how to access the camera flash on the iPhone 4 for my app. Is anyone able to figure this out? I looked through the developer documentation and still can't figure it out. Thanks.

EDIT:When I try to import the <AVFoundation/AVFoundation.h, it's almost as if it doesn't detect it. For instance, I will type AVCaptureDevice in the .h file and it won't recognize it and give me an error. It detects that I've imported some classes (such as the ones that were in 3.0) but not the ones that are new to 4.0 (which one I need).

JasonR · June 2010

HAve you tried the AVCaptureDevice class? I don't have an iPhone4, so I can't try it, but it looks like the way to go.

Whitehk · June 2010

JasonR;215942 said:
HAve you tried the AVCaptureDevice class? I don't have an iPhone4, so I can't try it, but it looks like the way to go.

Yeah. That's the one I was looking at. I'm kind of a newbie and I'm trying to learn how to use the developer documentation. I just couldn't figure out how to implement it.

JasonR · June 2010

Since you are doing something that's not standard, there's not going to be sample code. So your choice is either try it yourself, or wait until someone else does and posts it. (If you can wait 3-4 weeks, that's when I get my iPhone 4).

If I were you, I would play with the devices array, taking each element and setting flashMode until one of them turned on the flash. IT might look something like this:

NSArray *devices = [AVCaptureDevice devices];
for (AVCaptureDevice *device in devices) {
     device.flashMode = AVCaptureFlashModeOn;
}

Keep in mind, I'm guessing since I don't have the hardware, but see if that gets you started.

Whitehk · June 2010

JasonR;215974 said:
Since you are doing something that's not standard, there's not going to be sample code. So your choice is either try it yourself, or wait until someone else does and posts it. (If you can wait 3-4 weeks, that's when I get my iPhone 4).

If I were you, I would play with the devices array, taking each element and setting flashMode until one of them turned on the flash. IT might look something like this:
NSArray *devices = [AVCaptureDevice devices];
for (AVCaptureDevice *device in devices) {
     device.flashMode = AVCaptureFlashModeOn;
}
Keep in mind, I'm guessing since I don't have the hardware, but see if that gets you started.

Ok. I will look at it and see if I can get it working. Thanks for your help.

ioiiooo · June 2010

Whitehk;215977 said:
Ok. I will look at it and see if I can get it working. Thanks for your help.

Did you end up figuring it out?

harrytheshark · June 2010

You need to take a look at AVCaptureSession, AVCaptureDevice, AVCaptureDeviceInput and AVCaptureVideoDataOutput in the documentation.

Everything you need is in there ;)

Whitehk · June 2010

ioiiooo;216162 said:
Did you end up figuring it out?

Yes, I found that there was a WWDC session on iTunes over this, so I'm on my way to figuring it out.

harrytheshark said:
You need to take a look at AVCaptureSession, AVCaptureDevice, AVCaptureDeviceInput and AVCaptureVideoDataOutput in the documentation.

Everything you need is in there

Thanks. Like I said above, I figured this out when I watched the WWDC session.

thecyberduck · June 2010

tell us if you find something interesting

mire3212 · July 2010

I'm having a very similar problem with trying to access the AVCaptureDevice class. I've imported the AVFoundation.framework into my project and also did an import statement of the AVFoundation/AVFoundation.h, but XCode just keeps saying AVCaptureDevice is undeclared. Also if I look at the header files within the framework itself, it's missing half of the 4.0 specific AVFoundation classes found within the documentation. Any ideas?

Andrew

Tentoxa · July 2010

I have the same problem. Who can help us?

I found a free version of a iP4 flashlight:
LED-Light

Works perfect!

mikevh · July 2010

Whitehk;216453 said:
Yes, I found that there was a WWDC session on iTunes over this, so I'm on my way to figuring it out.

Thanks. Like I said above, I figured this out when I watched the WWDC session.

Which session?

tavobartientos · July 2010

You try your codde on the real iphone 4?

I have one, and my code doesnt work in simulator, but in the iphone4, works....

Tentoxa · July 2010

@tavobartientos Could you show us your code, please? I have the same problem adding the AVFoundation.framework. (AVCaptureDevice is undeclared)

darkangelbhv · July 2010

Before we can use the flashMode we must use lockForConfiguration.

My Code:

NSArray* devices = [AVCaptureDevice devices];
AVCaptureDevice* captDevice = nil;
NSLog(@\"%d devices found\", [devices count]);

for(AVCaptureDevice* device in devices)
{
	if([device hasFlash])
	{
		NSLog(@\"device has flash\");
		
		
		if ([device isFlashModeSupported:AVCaptureFlashModeOn]) {

			if([device lockForConfiguration:&error])
			{
				device.flashMode = AVCaptureFlashModeOn;
			}
			
		}
	}
}

}

But the flashlight is off :/ What´s wrong ?

I have the same problem adding the AVFoundation.framework. (AVCaptureDevice is undeclared)

Test your Code on a iPhone 4. If you run this Code in Simulator it shows this error. If you use a Device it show´s no error ;)

MacBuddy · July 2010

I too am having difficulties. I have tried the above methods and just get 2 errors. I came up with this but can't seem to get it to work.

	AVCaptureSession *captureSession = [[AVCaptureSession alloc] init];
	AVCaptureDevice *videoCaptureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
	NSError *error = nil;
	AVCaptureDeviceInput *videoInput = [AVCaptureDeviceInput deviceInputWithDevice:videoCaptureDevice error:&error];
	
	if (videoInput) {
		[captureSession addInput:videoInput];
		
		AVCaptureVideoDataOutput* videoOutput = [[AVCaptureVideoDataOutput alloc] init];
		[videoOutput setSampleBufferDelegate:self queue:dispatch_get_current_queue()];
		
		[captureSession addOutput:videoOutput];
		
		[captureSession startRunning];
		
		videoCaptureDevice.torchMode = AVCaptureTorchModeOn;
	}

Any ideas?

EDIT:
It wont compile when building for the sim but builds and runs on my iPhone 4. When I tap the button with this action it returns SIGBART on it. telling me

videoCaptureDevice.torchMode = AVCaptureTorchModeOn;

this failed.

harrytheshark · July 2010

You have to set an output as well as an input for this to work.

MacBuddy · July 2010

harrytheshark;219990 said:
You have to set an output as well as an input for this to work.

what do you mean set an output and input?

harrytheshark · July 2010

Look in the documentation at AVCaptureSession, you should see an addOutput: method. Follow that through and you'll find what needs to be done :)

MacBuddy · July 2010

harrytheshark;220005 said:
Look in the documentation at AVCaptureSession, you should see an addOutput: method. Follow that through and you'll find what needs to be done :)

Kay Thanks!

MacBuddy · July 2010

harrytheshark;220005 said:
Look in the documentation at AVCaptureSession, you should see an addOutput: method. Follow that through and you'll find what needs to be done :)

		AVCaptureSession *captureSession = [[AVCaptureSession alloc] init];
		AVCaptureDevice *videoCaptureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
		NSError *error = nil;
		AVCaptureDeviceInput *videoInput = [AVCaptureDeviceInput deviceInputWithDevice:videoCaptureDevice error:&error];
		if (videoInput) {
			[captureSession addInput:videoInput];
			
			AVCaptureVideoDataOutput* videoOutput = [[AVCaptureVideoDataOutput alloc] init];
			[videoOutput setSampleBufferDelegate:self queue:dispatch_get_current_queue()];
			
			[captureSession addOutput:videoOutput];
			
			[captureSession startRunning];
			
			videoCaptureDevice.torchMode = AVCaptureTorchModeOn;
		}

Output and Input are their

harrytheshark · July 2010

Sorry, I was talking more generally, in regards to your code, you need to run lockForConfiguration and unlockForConfiguration before and after changing device properties.


[videoCaptureDevice lockForConfiguration:nil];
videoCaptureDevice.torchMode = AVCaptureTorchModeOn;
[videoCaptureDevice unlockForConfiguration];

crivoli · July 2010

Anyone get the LED flash to turn on yet?

I have tried all of these suggestions and got nothing to turn on. All of the calls work without errors and the flash modes are tuned on but nothing happens.

Any success for anyone?

agentBangla · July 2010

A question which is a little out of topic; do anyone know how can I set the video encoding format as H264 when recording video using AVCaptureSession, AVCaptureInput and AVCaptureOutput?

harrytheshark · July 2010

crivoli;220318 said:
Anyone get the LED flash to turn on yet?

I have tried all of these suggestions and got nothing to turn on. All of the calls work without errors and the flash modes are tuned on but nothing happens.

Any success for anyone?

Yeah, I've managed it.

crivoli · July 2010

Can you share any of the code you used to make it successful? I looped through all the AVCapture devices and locked them and set the flash and torch on but to no avail. This seems much trickier than I expected. All I want is a app I can customize to my liking but it's almost more effort than it is worth.

Do you have to bring up the video cam for recording mode before it will work?

Any code examples would be greatly appreciated.

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