Question

I want to turn on torch mode AVCaptureTorchModeOn in my app while doing video recording.

I m using below code.

-(void)set_TorchMode:(BOOL)turnOn
{
 AVCaptureDevice *theDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    if ([theDevice hasTorch]) {
        [theDevice lockForConfiguration: nil];
        AVCaptureTorchMode currentMode = [theDevice torchMode];
        BOOL isAlreadyTurnedOn = (AVCaptureTorchModeOn == currentMode);
        if (isAlreadyTurnedOn != turnOn) {
            [theDevice setTorchMode: turnOn? AVCaptureTorchModeOn: AVCaptureTorchModeOff];
        }

        [theDevice unlockForConfiguration];
    }    
}

I m calling this method while start recording to turn ON and while stop recording to turn it OFF.

Its working fine for me first time when i record, but while start recording second time, its turn on but immediately turns OFF.Its not keeping ON while recording is running.

Thanks for any help.

Answer 1

Following code is implemented for the turn on and off back light .

May this helping to you,

- (void) setTorchOn:(BOOL)isOn
{
    AVCaptureDevice* device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    [device lockForConfiguration:nil]; //you must lock before setting torch mode
    [device setTorchMode:isOn ? AVCaptureTorchModeOn : AVCaptureTorchModeOff];
    [device unlockForConfiguration];
}

- (IBAction)changedState:(id)sender {
    UISwitch *switchValue = (UISwitch*)sender;
    [self setTorchOn:[switchValue isOn]];
}

please test this code into the devices.