📸 iOS Media Capture – features touch-to-record video, slow motion, and photography

Hey @piemonte I have a use case where i need to grab a frame from the live preview buffer in order to do some animation that doesn't require changing PBJVision modes. For example, lets say the user is in PBJCameraModePhoto and the user performs a gesture that requires immediate feedback/animation, in order to make animation smooth i basically need a freeze frame as a UIImage of the preview to make the animation fluid.

I hacked my way into the project to get this working on my own fork, but i was wondering if you had any suggestions on how to clean this up, or if there is an easier route to take. https://github.com/rromanchuk/PBJVision/pull/3/files

I tried changing the fps to 60, permissible by iPhone 5 and I see that I cannot set the below since lockForConfiguration always returns 0.

Therefore, the below attributes cannot be set - _currentDevice.activeVideoMinFrameDuration = fps; _currentDevice.activeVideoMaxFrameDuration = fps; _videoFrameRate = videoFrameRate;

Calling lockForConfiguration, is not returning any errors. It always returns 0 or no for whether the lock was acquired or not. I don't know why it won't grant the lock. [device lockForConfiguration:nil];

I manually set the camera orientation to begin with:

[vision setCameraOrientation:PBJCameraOrientationPortrait];

But I would like the orientation to change if the device rotates (regardless wether the rotation lock is active or not on the device)

I tried getting orientation changes (which only works if the orientation lock is off):

- (void)rotateCameraToInterfaceOrientation:(UIDeviceOrientation)orientation {
    switch (orientation) {
        case UIDeviceOrientationPortrait:
            [[PBJVision sharedInstance] setCameraOrientation:PBJCameraOrientationPortrait];
            break;
        case UIDeviceOrientationPortraitUpsideDown:
            [[PBJVision sharedInstance] setCameraOrientation:PBJCameraOrientationPortraitUpsideDown];
            break;
        case UIDeviceOrientationLandscapeLeft:
            [[PBJVision sharedInstance] setCameraOrientation:PBJCameraOrientationLandscapeLeft];
            break;
        case UIDeviceOrientationLandscapeRight:
            [[PBJVision sharedInstance] setCameraOrientation:PBJCameraOrientationLandscapeRight];
            break;
        default:
            [[PBJVision sharedInstance] setCameraOrientation:PBJCameraOrientationPortrait];
            break;
    }
}

But the preview layer rotates when I change the orientation. What I want is the metadata to update the orientation value, so when you put the image in the camera roll it ends up in the correct direction.

How do I achieve this?

I'm trying to write a photo to the photo album and my front facing photos are always vertically flipped (until it is slightly zoomed). A GIF to help:

I've tried saving the UIImage with the orientation set to image.imageOrientation like so:

[assetsLibrary writeImageToSavedPhotosAlbum:currentImage.CGImage orientation:(ALAssetOrientation)currentImage.imageOrientation completionBlock:nil];

I've also tried to save the PBJVisionPhotoJPEGKey data with the PBJVisionPhotoMetadataKey dictionary and am getting the same results:

NSDictionary *currentMediaMetadata = currentMediaDict[PBJVisionPhotoMetadataKey];
NSData *currentMediaData = currentMediaDict[PBJVisionPhotoJPEGKey];

[assetsLibrary writeImageDataToSavedPhotosAlbum:currentMediaData metadata: currentMediaMetadata completionBlock:nil];

vision.cameraOrientation is set to 0 and vision.mirroringMode is set to PBJMirroringAuto at the time if that helps.

Any help would be appreciated!

The above error gets called in endCaptureVideo if the audio session is manually set to ambient (i do this to replay the video immediately after capture via: [[AVAudioSession sharedInstance] setCategory: AVAudioSessionCategoryAmbient error:nil] )

So I was in the process of implementing subjectAreaChangeMonitoringEnabled and found the _setFocusLocked method - but I can't figure out where/when it's called?

Also, the way it's set - wouldn't you want to set subjectAreaChangeMonitoringEnabled to the opposite value of focusLocked? Or am I completely misunderstanding what focusLocked means?

Once I set captureSessionPreset with a value different from AVCaptureSessionPresetMedium, it is impossible to record.

I made many tests, and even when changing the default value of _captureSessionPreset in PBJVision::init, the problem remains.

@piemonte, would you have an idea of a quickfix I could use for this ?

Thanks by advance

In PBJVision.m, I added an if statement to handle situations where the method capturedVideoSeconds was returning a negative value. This situation had prevented my multi-view application from recognizing that new video was being captured on a return visit to a view that recorded video.

Hey - so a bit new to video on iOS - I'm trying to update a UIProgressView when recording but finding that it's stealing the main thread from the capture session. The shorter the update interval of the UIProgressView (either using NSTimer or GCD), the choppier the video is.

Is AVCaptureSession not thread safe by default, or just this particular implementation? I notice other apps like Vine have no problem updating the UI while video is recording so either they're using something like CADisplayLink to update the UI or there's a way to record video off the main thread?

In the sample project when you press for a very short time (more like a tap than a long press) the capturedVideoSeconds is calculated incorrectly.

Part of the fix would be to not initiate _audioTimestamp and _videoTimestamp to kCMTimeZero but to the current value of _startTimestamp. This however does not fix the problem entirely. It seems that for a very short record time _videoTimestamp is not updated correctly but set to nan.

Thanks for sharing your amazing camera engine!

While running on a 64-bit device, we've discovered that -[PBJVision captureOutput:didOuputSampleBuffer:fromConnection:] is not always called.

In our app, by default, we always have the camera mode set to PBJCameraModePhoto. When the user goes to record a video, we change the camera mode to PBJCameraModeVideo. When the user is done recording a video, we reset the camera mode back to PBJCameraModePhoto to restore its default state. If the user quickly goes to record a video again, then the delegate method mentioned previously (-[PBJVision captureOutput:didOuputSampleBuffer:fromConnection:]) is not called.

The way we came across this was by discovering that in this specific scenario, the PBJMediaWriter's _assetWriter had a status of AVAssetWriterStatusUnknown inside the method -[PBJMediaWriter finishWritingWithCompletionHandler:]. Further, we realized that the _assetWriter did not have any inputs. We realized both of these issues were because the method that sets up the inputs (-[PBJVision captureOutput:didOuputSampleBuffer:fromConnection:]) was not being called the second time recording a video.

We noticed that this issue does _not_ occur when delaying several seconds between stopping recording, and beginning to record video again; and does _not_ occur on 32-bit devices. We verified this by testing on an iPhone 5, iPod Touch (5th gen), iPhone 5S, and iPad Air.