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Background blur #72

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9a4047a
Consume bg blur from the SDK, remove legacy example
pblazej Apr 23, 2025
dfdd127
Old iOS
pblazej Apr 30, 2025
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97 changes: 11 additions & 86 deletions Multiplatform/Controllers/RoomContext.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -83,11 +83,19 @@ final class RoomContext: ObservableObject {
@Published var isVideoProcessingEnabled: Bool = false {
didSet {
if let track = room.localParticipant.firstCameraVideoTrack as? LocalVideoTrack {
track.capturer.processor = isVideoProcessingEnabled ? self : nil
track.capturer.processor = isVideoProcessingEnabled ? backgroundBlurProcessor : nil
}
}
}


private lazy var backgroundBlurProcessor: BackgroundBlurVideoProcessor? = {
if #available(iOS 15.0, *) {
BackgroundBlurVideoProcessor()
} else {
nil
}
}()

var _connectTask: Task<Void, Error>?

public init(store: ValueStore<Preferences>) {
Expand Down Expand Up @@ -305,90 +313,7 @@ extension RoomContext: RoomDelegate {
guard let localVideoTrack = publication.track as? LocalVideoTrack, localVideoTrack.source == .camera else { return }

Task { @MainActor in
localVideoTrack.capturer.processor = isVideoProcessingEnabled ? self : nil
localVideoTrack.capturer.processor = isVideoProcessingEnabled ? backgroundBlurProcessor : nil
}
}
}

extension RoomContext: VideoProcessor {
nonisolated func process(frame: VideoFrame) -> VideoFrame? {
guard let pixelBuffer = frame.toCVPixelBuffer() else {
print("Failed to get pixel buffer")
return nil
}

// Do something with pixel buffer.
guard let newPixelBuffer = processPixelBuffer(pixelBuffer) else {
print("Failed to proces the pixel buffer")
return nil
}

// Re-construct a VideoFrame
return VideoFrame(dimensions: frame.dimensions,
rotation: frame.rotation,
timeStampNs: frame.timeStampNs,
buffer: CVPixelVideoBuffer(pixelBuffer: newPixelBuffer))
}
}

// Processing example
func processPixelBuffer(_ pixelBuffer: CVPixelBuffer) -> CVPixelBuffer? {
// Lock the buffer for reading
CVPixelBufferLockBaseAddress(pixelBuffer, .readOnly)

// Create CIImage from the pixel buffer
let ciImage = CIImage(cvPixelBuffer: pixelBuffer)

// Create Core Image context
let device = MTLCreateSystemDefaultDevice()!
let context = CIContext(mtlDevice: device, options: nil)

// Apply dramatic filters

// 1. Gaussian blur effect
let blurFilter = CIFilter(name: "CIGaussianBlur")!
blurFilter.setValue(ciImage, forKey: kCIInputImageKey)
blurFilter.setValue(8.0, forKey: kCIInputRadiusKey) // Larger radius = more blur

// 2. Color inversion
// let colorInvertFilter = CIFilter(name: "CIColorInvert")!
// colorInvertFilter.setValue(blurFilter.outputImage, forKey: kCIInputImageKey)

// 3. Add a sepia tone effect
// let sepiaFilter = CIFilter(name: "CISepiaTone")!
// sepiaFilter.setValue(ciImage, forKey: kCIInputImageKey)
// sepiaFilter.setValue(0.8, forKey: kCIInputIntensityKey)

let pixelBufferAttributes: [String: Any] = [
kCVPixelBufferMetalCompatibilityKey as String: true,
]

// Create output pixel buffer
var outputPixelBuffer: CVPixelBuffer?
let status = CVPixelBufferCreate(
kCFAllocatorDefault,
CVPixelBufferGetWidth(pixelBuffer),
CVPixelBufferGetHeight(pixelBuffer),
CVPixelBufferGetPixelFormatType(pixelBuffer),
pixelBufferAttributes as CFDictionary,
&outputPixelBuffer
)

guard status == kCVReturnSuccess, let outputBuffer = outputPixelBuffer else {
CVPixelBufferUnlockBaseAddress(pixelBuffer, .readOnly)
return nil
}

// Render the processed image to the output buffer
context.render(
blurFilter.outputImage!,
to: outputBuffer,
bounds: ciImage.extent,
colorSpace: CGColorSpaceCreateDeviceRGB()
)

// Unlock the original buffer
CVPixelBufferUnlockBaseAddress(pixelBuffer, .readOnly)

return outputBuffer
}
2 changes: 1 addition & 1 deletion Multiplatform/Views/RoomView.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -497,7 +497,7 @@ struct RoomView: View {
}

Group {
Toggle("Video processing", isOn: $roomCtx.isVideoProcessingEnabled)
Toggle("Background blur", isOn: $roomCtx.isVideoProcessingEnabled)
}

#if os(macOS)
Expand Down