I use iPhone camera to capture images in my iOS APP.
AVCaptureVideoDataOutputSampleBufferDelegate is used to get images from iPhone camera.
A part of the program is shown below.
AVCaptureDevice *videoDevice = [AVCamViewController deviceWithMediaType:AVMediaTypeVideo preferringPosition:AVCaptureDevicePositionBack];
AVCaptureDeviceInput *videoDeviceInput = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:&error];
if (error)
{
NSLog(#"%#", error);
}
if ([session canAddInput:videoDeviceInput])
{
[session addInput:videoDeviceInput];
[self setVideoDeviceInput:videoDeviceInput];
dispatch_async(dispatch_get_main_queue(), ^{
// Why are we dispatching this to the main queue?
// Because AVCaptureVideoPreviewLayer is the backing layer for AVCamPreviewView and UIView can only be manipulated on main thread.
// Note: As an exception to the above rule, it is not necessary to serialize video orientation changes on the AVCaptureVideoPreviewLayer’s connection with other session manipulation.
//[self previewView] layer
[[(AVCaptureVideoPreviewLayer *)[[self previewView] layer] connection] setVideoOrientation:(AVCaptureVideoOrientation)[self interfaceOrientation]];
});
}
Sometimes, the environment is dark a bit. In the iPhone camera app, it can brighten the image by tapping the iPhone screen on the darker part. But I don't like such suer's involvement.
I check RGB intensity, once I realise the brightness is not enough, I like to brighten the image by adjusting the camera parameters (such as camera exposure, etc) in my program. Is it possible in iPhone programming?
Thanks
I haven't work on AVFoundation much but you can find more details here.
I hope this will be useful for you.
Related
I have created a camera using AVCaptureSession. I have configured that for both Photo and Video recording modes.
Camera and App is running fine. Also I allowed background music play (If user play song using Music App in iPhone) while open camera or recording video. It is also working fine. (Attached image 2)
I allowed background Music play with the help of this code
AVAudioSession *session1 = [AVAudioSession sharedInstance];
[session1 setCategory:AVAudioSessionCategoryPlayAndRecord withOptions:AVAudioSessionCategoryOptionMixWithOthers|AVAudioSessionCategoryOptionDefaultToSpeaker|AVAudioSessionCategoryOptionAllowBluetooth error:nil];
[session1 setActive:YES error:nil];
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
Now if i receive a call, minimize phone call screen by tapping on Home button and open app and want to open camera screen to capture image / record video, It opens but freeze with a image (Attached image(1)).
Now my requirement is, i want to capture image / record video while on phone call. I looked for another apps, and Snapchat is doing same, and i am able to record video while i am on call.
please help me, how can i achieve this.
You need to use the AVCaptureSessionWasInterruptedNotification and AVCaptureSessionInterruptionEndedNotification callbacks and disconnect the audio capture while the session is interrupted:
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(sessionWasInterrupted:) name:AVCaptureSessionWasInterruptedNotification object:self.session];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(sessionInterruptionEnded:) name:AVCaptureSessionInterruptionEndedNotification object:self.session];
// note that self.session is an AVCaptureSession
-
- (void)sessionWasInterrupted:(NSNotification *)notification {
NSLog(#"session was interrupted");
AVCaptureDevice *device = [[self audioInput] device];
if ([device hasMediaType:AVMediaTypeAudio]) {
[[self session] removeInput:[self audioInput]];
[self setAudioInput:nil];
}
}
- (void)sessionInterruptionEnded:(NSNotification *)notification {
NSLog(#"session interuption ended");
}
// note that [self audioInput] is a getter for an AVCaptureDeviceInput
This will allow the camera to continue running and allows it to capture stills / silent video
Now as for how to reconnect the audio after the call ends.. let me know if you figure it out, seemed impossible as of iOS 10: Callback when phone call ends? (to resume AVCaptureSession)
I'm running a session with AVCaptureSessionPresetMediumto process the frames, when I find what I need I want to capture a stills image with AVCaptureSessionPresetPhoto. I'm changing the sessionPreset with the code
dispatch_async(_captureSessionQueue, ^{
[_captureSession beginConfiguration];
if ([_captureSession canSetSessionPreset:AVCaptureSessionPresetPhoto])
{
_captureSession.sessionPreset = AVCaptureSessionPresetPhoto;
}
[_captureSession commitConfiguration];
});
When this code is called the screen(AVCaptureVideoPreviewLayer) "blinks".
I can't use highResolutionStillImageOutputEnabled because I need to support iOS 7 and devices lower than iPhone 6. Does any one have an idea why this blink happens?
I have the following code:
-(void) startCameraCapture {
// start capturing frames
// Create the AVCapture Session
session = [[AVCaptureSession alloc] init];
// create a preview layer to show the output from the camera
AVCaptureVideoPreviewLayer *previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:session];
// Specify that the video should be stretched to fill the layer’s bounds.
previewLayer.videoGravity = AVLayerVideoGravityResize;
//previewView.frame = CGRectMake(126.0, 164.0, 64.0, 75.0);
previewLayer.frame = previewView.frame;
[previewView.layer addSublayer:previewLayer];
// Get the default camera device
AVCaptureDevice* camera = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
// get the current settings
[appDelegate loadSettings];
[session startRunning];
}
Is there a way I can lock the exposure of a camera device to only allow the screen to adjust to a certain brightness?
Sorry if I am not asking this right.
Thank you.
EDIT:
I tried adding:
[camera setExposureModeCustomWithDuration:CMTimeMake(1,1) ISO:100 completionHandler:nil];
but that only results in the app crashing at that line.
According to Apple's doc:
An NSGenericException exception is thrown if this method is invoked without first obtaining exclusive access to the receiver using lockForConfiguration:.
So add this line in front:
[camera lockForConfiguration:nil];
I'm developing a camera app that has a video function. I want the button that the user presses to begin recording, which it does, and stop recording. This works properly. But, I want to raise the alpha of the recordButton to 1.0 when the button is pressed. This works properly, but when it is pressed again to stop recording the alpha remains at 1.0. The if...else statement that stops recording should trigger [self.recordButton setAlpha:0.50], but for some reason nothing happens, aside from recording stopping properly. Any clarification would be greatly appreciated.
- (IBAction)toggleMovieRecording:(id)sender
{
[[self recordButton] setEnabled:NO];
dispatch_async([self sessionQueue], ^{
if (![[self movieFileOutput] isRecording])
{
[self setLockInterfaceRotation:YES];
[self.recordButton setAlpha:1.0];
if ([[UIDevice currentDevice] isMultitaskingSupported])
{
// Setup background task. This is needed because the captureOutput:didFinishRecordingToOutputFileAtURL: callback is not received until the app returns to the foreground unless you request background execution time. This also ensures that there will be time to write the file to the assets library when the app is backgrounded. To conclude this background execution, -endBackgroundTask is called in -recorder:recordingDidFinishToOutputFileURL:error: after the recorded file has been saved.
[self setBackgroundRecordingID:[[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:nil]];
}
// Update the orientation on the movie file output video connection before starting recording.
[[[self movieFileOutput] connectionWithMediaType:AVMediaTypeVideo] setVideoOrientation:[[(AVCaptureVideoPreviewLayer *)[[self previewView] layer] connection] videoOrientation]];
// Turn OFF flash for video recording
[AAPLCameraViewController setFlashMode:AVCaptureFlashModeOff forDevice:[self videoDevice]];
// Start recording to a temporary file.
NSString *outputFilePath = [NSTemporaryDirectory() stringByAppendingPathComponent:[#"movie" stringByAppendingPathExtension:#"mov"]];
[[self movieFileOutput] startRecordingToOutputFileURL:[NSURL fileURLWithPath:outputFilePath] recordingDelegate:self];
}
else
{
[[self movieFileOutput] stopRecording];
[self.recordButton setAlpha:0.50];
}
});
}
You have to make sure that anything related to UI have to be done on the main queue. Check this answer
iPhone - Grand Central Dispatch main thread
To make sure add this block around setting alpha.
dispatch_async(dispatch_get_main_queue(), ^{
[self.recordButton setAlpha:0.50];
});
Let me know if that worked.
How can I set the orientation of AVCaptureFileOutput? I mean the final output, it must be landscape.
When you setup camera, you have a AVCaptureVideoDataOutput videoDataOutput, and a AVCaptureVideoPreviewLayer previewLayer. You can configure them in the following way.
//set the orientation of previewlayer, which is presented to user
AVCaptureConnection *conncetion = self.previewLayer.connection;
conncetion.videoOrientation = AVCaptureVideoOrientationLandscapeRight;
//set the output frame orientation
AVCaptureConnection *conn = [self.videoDataOutput connectionWithMediaType:AVMediaTypeVideo];
conn.videoOrientation = AVCaptureVideoOrientationLandscapeRight;
In AVCam sample code, when recording and saving as a file. The above two are set to the same orientation, which is viewcontroller's interfaceOrientation:
[[[self movieFileOutput] connectionWithMediaType:AVMediaTypeVideo] setVideoOrientation:[[(AVCaptureVideoPreviewLayer *)[[self previewView] layer] connection] videoOrientation]];
And it observes device orientation, which is nice.