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?
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 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.
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 am working on iOS app which will be compatible with iOS 6/7 and stream audio .mp3 files from a website.
I have already gotten this to work using the following code:
-(NSString*)documentsFolder
{
NSString* dataPath = [NSHomeDirectory() stringByAppendingPathComponent:#"Documents"];
if (![[NSFileManager defaultManager] fileExistsAtPath:dataPath])
[[NSFileManager defaultManager] createDirectoryAtPath:dataPath withIntermediateDirectories:NO attributes:nil error:NULL];
return dataPath;
}
-(NSString*)createURLFile:(NSString*)songURL
{
NSString* M3U_FILE = #"song.m3u";
NSString* path = [NSString stringWithFormat:#"%#",[[self documentsFolder] stringByAppendingPathComponent:M3U_FILE]];
if([[NSFileManager defaultManager] createFileAtPath:path contents:nil attributes:nil])
{
NSFileHandle* outFile = [NSFileHandle fileHandleForWritingAtPath:path];
if(outFile != nil)
{
NSData* buffer = [songURL dataUsingEncoding:NSUTF8StringEncoding];
[outFile writeData:buffer];
return path;
}
}
return nil;
}
- (void)createStreamer
{
// Remove any previous references.
[[NSNotificationCenter defaultCenter] removeObserver:self];
// Create a new player.
NSString* fileURL = [self createURLFile:self.aSong.songpath];
self.songPlayer = [[AVPlayer alloc]initWithURL:[NSURL fileURLWithPath:fileURL]];
NSAssert(self.songPlayer != nil, #"NIL AVPlayer Created!!!");
// Observer for when the song ends...
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(playerItemDidReachEnd:)
name:AVPlayerItemDidPlayToEndTimeNotification
object:[self.songPlayer currentItem]];
[[UIApplication sharedApplication] setIdleTimerDisabled: YES];
}
I store the url for the .mp3 file in a local .m3u file and use that to load up the AVPlayer. In earlier versions of iOS, I was told that the AVPlayer would load the song first and then play it, not stream it immediately. While this does not appear to be true in iOS 6/7 (the song starts streaming almost immediately), the .m3u file was being created in case there were any problems created by not having it done this way.
With this, a loop is monitoring the status of the AVPlayer and after a few seconds, the audio starts to play out the phone without a problem.
For testing purposes, I set up an MPVolumeView on the page which plays songs:
MPVolumeView *volumeView = [[[MPVolumeView alloc] initWithFrame:CGRectMake(0, 0, 310, 20)] autorelease];
volumeView.center = CGPointMake(160,62);
[volumeView sizeToFit];
[self.view addSubview:volumeView];
The reason for this is that the volume slider will also show an indicator if the bluetooth is connected as an audio output source and allow me to change the audio route between the phone and the bluetooth device. So far, so good.
I connected my phone to my Jawbox Jambone via bluetooth, start the AVPlayer on a song, and the song comes out of the Jawbox as expected. The volume control has the small "rectangle with arrow" indicating that I can switch the audio output and indeed, while the song is playing, I can switch between the phone and the Jawbox. Happiness.
The problem occurs when I try to connect it to a car. I have two experiences with this:
The car is already paired with the phone for making/receiving calls. The phone even indicates it is paired when I get into the car. But when I use the same code to play the same audio files, they only come out of the phone. The volume slider does not show the "bluetooth route" indicator at all (like it does not recognize the car as a audio output route).
In another car, the audio was streaming from another app (some radio streaming app). The other app was stopped and this one started. The audio started playing for the same song tested above, but stopped after a second or two. Again, there was no indicator on the volume slider that the bluetooth was connected at this point.
Can somebody explain to me why the audio could stream fine out to one bluetooth device but not to another?
Have I missed something (an entitlement?) in the profile for my app that will allow it to stream audio via bluetooth to a car?
There is this project at GIT.
Play iOS project is a streaming client for Play that runs on your iPhone/iPad. It supports background audio as well as the media keys when backgrounded.
It supports:
Streams shoutcast stream
Displays currently playing track
Background audio
Lock screen album art & play controls
AirPlay (along with Bluetooth) streaming. Supports sending metadata
and album art
You can download the project here.
I have not tested this on CAR bluetooth audio player though. Hope it may be of any help to you.
In the first example, your car may simply be a remote player. You would need to register for remote events like this (consider using an AVAudioPlayer instead of an AVPlayer also)
Setup the AudioSession to recognize a bluetooth audio route:
- (BOOL)prepareAudioSession {
// deactivate existing session
NSError *setCategoryError = nil;
NSError *activationError = nil;
BOOL success = [[AVAudioSession sharedInstance] setActive:NO error: nil];
if (!success) {
NSLog(#"deactivationError");
}
// set audio session category AVAudioSessionCategoryPlayAndRecord options AVAudioSessionCategoryOptionAllowBluetooth
success = [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback withOptions:AVAudioSessionCategoryOptionAllowBluetooth error:&setCategoryError];
if (!success)
{
NSLog(#"setCategoryError %#",setCategoryError);
}
// activate audio session
success = [[AVAudioSession sharedInstance] setActive:YES error: &activationError];
if (!success) {
NSLog(#"activationError");
}
return success;
}
You can check the routes:
AVAudioSessionRouteDescription *mAVASRD = audioSession.currentRoute;
NSLog(#"the array is %#",mAVASRD.outputs);
for (int ctr = 0; ctr < [mAVASRD.outputs count]; ctr++)
{
AVAudioSessionPortDescription *myPortDescription = [mAVASRD.outputs objectAtIndex:ctr];
NSLog(#"the type is %#",myPortDescription.portType);
NSLog(#"the name is %#",myPortDescription.portName);
NSLog(#"the UID is %#",myPortDescription.UID);
NSLog(#"the data sources are %#",myPortDescription.dataSources);
}
Then initialize your AVAudioPlayer and turn on RemoteControlEvents (you can use the console in your car to send play/pause/etc)
[[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
then implement something like the delegate method for AVAudioPlayer in this stack overflow question to capture the received events and react accordingly in your code:
AVAudioPlayer on Lock Screen
In the scenario 2, when you moved one app to the background (the radio streaming app) and started your app, the likely culprit for the issue is the same cause - your app has to recognize the bluetooth route for audio.
By the way for phone calls and Siri, the iOS uses a different Bluetooth channel that the default for remote control (which is the one I am describing for your car).
When you setup this route and remote control events, you also get a bonus byproduct - your app will be controllable from the lock screen. Check out this technical note from Apple to configure your app to play in the background as well if that is also something you need to do when the screen locks: Technical QA document QA1668
Finally, for added integration via your bluetooth route, look at MPNowPlayingInfoCenter - put the title artist artwork and other good stuff on the lock screen and on most bluetooth screens in the car that are displaying that information.
I'm pretty sure MPVolumeView can only address Bluetooth devices which conform to the newer low power consumption Bluetooth spec... (Bluetooth Low Energy or BLE)...
I know the phone app doesn't use MPVolumeView, probably this other audio player doesn't either.. You may need to look into CoreBluetooth and implement your own :( good luck. There may be a solution on github
A bluetooth speaker designed as a speaker will be no problem.
However, a car will usually be a "phone" bluetooth speaker and will only accept a "phone" type of communications.
My guess would be that you would have to trick it by setting up a "phone audio" connection and having the incoming audio transfer into the void, and the outgoing music stream as a phone signal.
Mind you, signal quality might degrade and there probaly won't be a fix for that.
I have the following code that no longer works in iOS 7 for changing the sessionPreset of a capture session while it is still running (but not capturing video). This worked on iOS 6.x, but on 7 the video preview freezes.
I've tried removing begin/commit configuration, as well as locking the input device and unlocking after. I've also tried calling beginSession again after the commitConfiguration, but this causes the device to start capturing video.
Is this a bug or am I doing something wrong?
- (void)setVideoCaptureSessionPreset:(NSString *)videoCaptureSessionPreset
{
if (_captureSession.sessionPreset == videoCaptureSessionPreset) return;
if (![_captureSession canSetSessionPreset:videoCaptureSessionPreset])
{
TFLog(#"%s Device cannot set preset to: %#", __PRETTY_FUNCTION__, videoCaptureSessionPreset);
return;
}
[_captureSession beginConfiguration];
_captureSession.sessionPreset = videoCaptureSessionPreset;
[_captureSession commitConfiguration];
}
Edit: Not only does this cause the video preview to freeze, it causes the entire phone lock up (background no longer displayed on home screen, app cannot restart, and eventually the entire phone has to be hard-reset).
In iOS 7 and up, the solution is to use the new AVCaptureDevice activeFormat API and set the session preset to AVCaptureSessionPresetInputPriority. When you change the active format, you have to wrap your startRunning in the lockForConfiguration like so:
if ([_videoCaptureDevice lockForConfiguration:nil])
{
_videoCaptureDevice.activeFormat = format
[_captureSession startRunning];
[_videoCaptureDevice unlockForConfiguration];
}