GitHub - NextLevel/NextLevel: ⬆️ Rad Media Capture in Swift

README.md

NextLevel is a Swift camera system designed for easy integration, customized media capture, and image streaming for iOS.

It enables fast integration and customization leveraging AVFoundation or optionally ARKit.

Features ? “Vine-like” video clip recording and editing ? photo capture (raw, jpeg, and video frame) ? customizable gestural interaction and interface ? ARKit integration (beta) ? dual, wide angle, telephoto, & true depth support ? adjustable frame rate on supported hardware (ie fast/slow motion capture) ? depth data capture support ? video zoom ⚖ white balance, focus, and exposure adjustment ? flash and torch support ? mirroring support ☀ low light boost ? smooth auto-focus ⚙ configurable encoding and compression settings ? simple media capture and editing API ? extensible API for image processing and CV ? Swift 4

Need a different version of Swift?

• 4.2 - Target your Podfile to the swift4.2 branch
• 4.0 - Target your Podfile to the latest release or master
• 3.2 - Target your Podfile to release 0.6.3 or the swift3.2 branch

Quick Start

# CocoaPods
swift_version = "4.0"
pod "NextLevel", "~> 0.9.5"

# Carthage
github "nextlevel/NextLevel" ~> 0.9.5

# Swift PM
let package = Package(
    dependencies: [
        .Package(url: "https://github.com/nextlevel/NextLevel", majorVersion: 0)
    ]
)

Alternatively, drop the NextLevel source files or project file into your Xcode project.

ARKit Capture

Starting with release 0.8.0, NextLevel provides a mode for ARKit capture in addition to AVFoundation. This enables a variety of new camera features while leveraging the existing recording capabilities and media management of NextLevel.

The ARKit mode is in beta, so please help out if you encounter an issue or by contributing ideas for improvement. It is not compiled by default without the inclusion of the Swift compiler flag USE_ARKIT, since Apple will reject apps that link ARKit and do not use it. To try it out, setup the AppDelegate to load the MixedRealityViewController class and include the xcode build settings flag.

If you use Cocoapods, you can include -DUSE_ARKIT with the following podfile addition or by adding it to your Xcode build settings.

  installer.pods_project.targets.each do |target|
    # setup NextLevel for ARKit use
    if target.name == 'NextLevel'
      target.build_configurations.each do |config|
        config.build_settings['OTHER_SWIFT_FLAGS'] = '-DUSE_ARKIT'
      end
    end
  end

Overview

Before starting, ensure that permission keys have been added to your app's Info.plist.

<key>NSCameraUsageDescription</key>
    <string>Allowing access to the camera lets you take photos and videos.</string>
<key>NSMicrophoneUsageDescription</key>
    <string>Allowing access to the microphone lets you record audio.</string>

Recording Video Clips

Import the library.

import NextLevel

Setup the camera preview.

let screenBounds = UIScreen.main.bounds
self.previewView = UIView(frame: screenBounds)
if let previewView = self.previewView {
    previewView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
    previewView.backgroundColor = UIColor.black
    NextLevel.shared.previewLayer.frame = previewView.bounds
    previewView.layer.addSublayer(NextLevel.shared.previewLayer)
    self.view.addSubview(previewView)
}

Configure the capture session.

override func viewDidLoad() {
    NextLevel.shared.delegate = self
    NextLevel.shared.deviceDelegate = self
    NextLevel.shared.videoDelegate = self
    NextLevel.shared.photoDelegate = self
    
    // modify .videoConfiguration, .audioConfiguration, .photoConfiguration properties
    // Compression, resolution, and maximum recording time options are available
    NextLevel.shared.videoConfiguration.maximumCaptureDuration = CMTimeMakeWithSeconds(5, 600)
    NextLevel.shared.audioConfiguration.bitRate = 44000
 }

Start/stop the session when appropriate. These methods create a new "session" instance for 'NextLevel.shared.session' when called.

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)     
    NextLevel.shared.start()
    // …
}

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)        
    NextLevel.shared.stop()
    // …
}

Video record/pause.

// record
NextLevel.shared.record()

// pause
NextLevel.shared.pause()

Editing Recorded Clips

Editing and finalizing the recorded session.

if let session = NextLevel.shared.session {

    //..

    // undo
    session.removeLastClip()

    // various editing operations can be done using the NextLevelSession methods

    // export
    session.mergeClips(usingPreset: AVAssetExportPresetHighestQuality, completionHandler: { (url: URL?, error: Error?) in
        if let _ = url {
            //
        } else if let _ = error {
            //
        }
     })

    //..

}

Videos can also be processed using the NextLevelSessionExporter, a media transcoding library in Swift.

Custom Buffer Rendering

‘NextLevel’ was designed for sample buffer analysis and custom modification in real-time along side a rich set of camera features.

Just to note, modifications performed on a buffer and provided back to NextLevel may potentially effect frame rate.

Enable custom rendering.

NextLevel.shared.isVideoCustomContextRenderingEnabled = true

Optional hook that allows reading sampleBuffer for analysis.

extension CameraViewController: NextLevelVideoDelegate {
    
    // ...

    // video frame processing
    public func nextLevel(_ nextLevel: NextLevel, willProcessRawVideoSampleBuffer sampleBuffer: CMSampleBuffer) {
        // Use the sampleBuffer parameter in your system for continual analysis
    }

Another optional hook for reading buffers for modification, imageBuffer. This is also the recommended place to provide the buffer back to NextLevel for recording.

extension CameraViewController: NextLevelVideoDelegate {

    // ...

    // enabled by isCustomContextVideoRenderingEnabled
    public func nextLevel(_ nextLevel: NextLevel, renderToCustomContextWithImageBuffer imageBuffer: CVPixelBuffer, onQueue queue: DispatchQueue) {
		    // provide the frame back to NextLevel for recording
        if let frame = self._availableFrameBuffer {
            nextLevel.videoCustomContextImageBuffer = frame
        }
    }

NextLevel will check this property when writing buffers to a destination file. This works for both video and photos with capturePhotoFromVideo.

nextLevel.videoCustomContextImageBuffer = modifiedFrame

About

NextLevel was initally just a weekend project but has grown into a open community of camera enthusists. The software provides foundational components for managing media recording, camera interface customization, gestural interaction customization, and image streaming for iOS. The same capabilities can also be found in apps such as Snapchat, Instagram, and Vine.

The goal is to continue to provide a good foundation for quick integration (enabling projects to be taken to the next level) – allowing focus to placed on functionality that matters most whether it's realtime image processing, computer vision methods, augmented reality, or even new cinematographic recording techniques.

Documentation

You can find the docs here. Documentation is generated with jazzy and hosted on GitHub-Pages.

Stickers

If you found this project to be helpful, check out the Next Level stickers.

Project

NextLevel is a community – contributions and discussions are welcome!

• Feature idea? Open an issue.
• Found a bug? Open an issue.
• Need help? Use Stack Overflow with the tag ’nextlevel’.
• Questions? Use Stack Overflow with the tag 'nextlevel'.
• Want to contribute? Submit a pull request.

Related Projects

• Player (Swift), video player in Swift
• PBJVideoPlayer (obj-c), video player in obj-c
• GPUImage2, image processing library
• SCRecorder, obj-c capture library
• PBJVision, obj-c capture library
• NextLevelSessionExporter, media transcoding in Swift

Resources

• iOS Device Camera Summary
• AV Foundation Programming Guide
• AV Foundation Framework Reference
• Swift Evolution
• objc.io Camera and Photos
• objc.io Video
• objc.io Core Image and Video
• Cameras, ecommerce and machine learning
• Again, iPhone is the default camera

License

NextLevel is available under the MIT license, see the LICENSE file for more information.