Display HDR video in EDR with AVFoundation and Metal

6:58 - Playing media using AVPlayerViewController

// Playing media using AVPlayerViewController
let player = AVPlayer(URL: videoURL)

// Creating a player view controller
var playerViewController = AVPlayerViewController()

playerViewController.player = player

self.presentViewController(playerViewController, animated: true) {
   playerViewController.player!.play()
}

7:38 - Playing media using AVPlayer and AVPlayerLayer

// Playing media using AVPlayer and AVPlayerLayer
let player = AVPlayer(URL: videoURL)

var playerLayer = AVPlayerLayer(player: player)

playerLayer.frame = self.view.bounds

self.view.layer.addSublayer(playerLayer)

player.play()

9:28 - CAMetalLayer Properties

// Opt into using EDR
let layer: CAMetalLayer
layer.wantsExtendedDynamicRangeContent = true

// Use half-float pixel format
layer.pixelFormat = MTLPixelFormatRGBA16Float

// Use extended linear display P3 color space
layer.colorspace = kCGColorSpaceExtendedLinearDisplayP3

11:33 - Create an AVPlayerItemVideoOutput

let videoColorProperties = [
    AVVideoColorPrimariesKey: AVVideoColorPrimaries_P3_D65,
    AVVideoTransferFunctionKey: AVVideoTransferFunction_Linear,
    AVVideoYCbCrMatrixKey: AVVideoYCbCrMatrix_ITU_R_2020
]

let outputVideoSettings = [
    AVVideoAllowWideColorKey: true,
    AVVideoColorPropertiesKey: videoColorProperties,
    kCVPixelBufferPixelFormatTypeKey as String: NSNumber(value: kCVPixelFormatType_64RGBAHalf)
] as [String : Any]
   
// Create a player item video output
let videoPlayerItemOutput 
= AVPlayerItemVideoOutput(outputSettings: outputVideoSettings)

13:02 - Create a display link

// Create a display link
lazy var displayLink: CADisplayLink 
= CADisplayLink(target: self, 
                selector: #selector(displayLinkCopyPixelBuffers(link:)))

var statusObserver: NSKeyValueObservation?

statusObserver = videoPlayerItem.observe(\.status,
      options: [.new, .old],
      changeHandler: { playerItem, change in
        if playerItem.status == .readyToPlay {
          playerItem.add(videoPlayerItemOutput)
          displayLink.add(to: .main, forMode: .common)
          videoPlayer?.play()
        }
     })
}

14:16 - Run DisplayLink to get pixel buffers

@objc func displayLinkCopyPixelBuffers(link: CADisplayLink) 
{
  let currentTime = videoPlayerItemOutput.itemTime(forHostTime: CACurrentMediaTime())
	
  if videoPlayerItemOutput.hasNewPixelBuffer(forItemTime: currentTime)
  {
      if let buffer 
      = videoPlayerItemOutput.copyPixelBuffer(forItemTime: currentTime, 
	                                          itemTimeForDisplay: nil) 
	  {
        let image = CIImage(cvPixelBuffer: buffer!)

        let filter = CIFilter.sepiaTone()
        filter.inputImage = image
        output = filter.outputImage ?? CIImage.empty()
    
        // use context to render to you CIRenderDestination
     }
 }
}

15:53 - Integrate Core Image

@objc func displayLinkCopyPixelBuffers(link: CADisplayLink) 
{
  let currentTime = videoPlayerItemOutput.itemTime(forHostTime: CACurrentMediaTime())
	
  if videoPlayerItemOutput.hasNewPixelBuffer(forItemTime: currentTime)
  {
      if let buffer 
      = videoPlayerItemOutput.copyPixelBuffer(forItemTime: currentTime, 
	                                          itemTimeForDisplay: nil) 
	  {
        let image = CIImage(cvPixelBuffer: buffer)

        let filter = CIFilter.sepiaTone()
        filter.inputImage = image
        output = filter.outputImage ?? CIImage.empty()
    
        // use context to render to your CIRenderDestination
     }
  }
}

19:13 - Using CVMetalTextureCache

// Create a CVMetalTextureCacheRef

let mtlDevice = MTLCreateSystemDefaultDevice()

var mtlTextureCache: CVMetalTextureCache? = nil

CVMetalTextureCacheCreate(allocator: kCFAllocatorDefault, 
                          cacheAttributes: nil, 
                          metalDevice: mtlDevice, 
                          textureAttributes: nil, 
                          cacheOut: &mtlTextureCache)

// Create a CVMetalTextureRef using metalTextureCache and our pixelBuffer
let width  = CVPixelBufferGetWidth(pixelBuffer)
let height = CVPixelBufferGetHeight(pixelBuffer)

var cvTexture : CVMetalTexture? = nil

CVMetalTextureCacheCreateTextureFromImage(allocator: kCFAllocatorDefault, 
                                          textureCache: mtlTextureCache, 
                                          sourceImage: pixelBuffer, 
                                          textureAttributes: nil, 
                                          pixelFormat: MTLPixelFormatRGBA16Float, 
                                          width: width, 
                                          height: height, 
                                          planeIndex: 0, 
                                          textureOut: &cvTexture)

let texture = CVMetalTextureGetTexture(cvTexture)

// In Obj-C, release CVMetalTextureRef in Metal command buffer completion handlers