test-triple-generators.swift

let asset = AVURLAsset(url: url)
let generator = AVAssetImageGenerator(asset: asset)
generator.requestedTimeToleranceBefore = CMTime(seconds: 0.05, preferredTimescale: 600)
generator.requestedTimeToleranceAfter = CMTime(seconds: 0.05, preferredTimescale: 600)
let sizeModifier: CGFloat = 0.1
generator.maximumSize = CGSize(width: 450.0 * sizeModifier, height: 563.0 * sizeModifier)

let asset2 = AVURLAsset(url: url)
let generator2 = AVAssetImageGenerator(asset: asset2)
generator2.requestedTimeToleranceBefore = CMTime(seconds: 0.05, preferredTimescale: 600)
generator2.requestedTimeToleranceAfter = CMTime(seconds: 0.05, preferredTimescale: 600)
generator2.maximumSize = CGSize(width: 450.0 * sizeModifier, height: 563.0 * sizeModifier)

let asset3 = AVURLAsset(url: url)
let generator3 = AVAssetImageGenerator(asset: asset3)
generator3.requestedTimeToleranceBefore = CMTime(seconds: 0.05, preferredTimescale: 600)
generator3.requestedTimeToleranceAfter = CMTime(seconds: 0.05, preferredTimescale: 600)
generator3.maximumSize = CGSize(width: 450.0 * sizeModifier, height: 563.0 * sizeModifier)

// I know there's around 200 frames, gross code though
let timeValues1 = Array(timeValues[0..<62])
let timeValues2 = Array(timeValues[62..<124])
let timeValues3 = Array(timeValues[124..<186])

let startTime = CFAbsoluteTimeGetCurrent()

var framesProcessed1 = 0

generator.generateCGImagesAsynchronously(forTimes: timeValues1) { (requestedTime, resultingImage, actualTime, result, error) in
    framesProcessed1 += 1
    
    if framesProcessed1 == timeValues1.count {
        let timeElapsed = CFAbsoluteTimeGetCurrent() - startTime
        print("[1] Time elapsed: \(timeElapsed) s.")
    }
}

var framesProcessed2 = 0

generator2.generateCGImagesAsynchronously(forTimes: timeValues2) { (requestedTime, resultingImage, actualTime, result, error) in
    framesProcessed2 += 1
    
    if framesProcessed2 == timeValues2.count {
        let timeElapsed = CFAbsoluteTimeGetCurrent() - startTime
        print("[2] Time elapsed: \(timeElapsed) s.")
    }
}

var framesProcessed3 = 0

generator2.generateCGImagesAsynchronously(forTimes: timeValues3) { (requestedTime, resultingImage, actualTime, result, error) in
    framesProcessed3 += 1
    
    if framesProcessed3 == timeValues3.count {
        let timeElapsed = CFAbsoluteTimeGetCurrent() - startTime
        print("[3] Time elapsed: \(timeElapsed) s.")
    }
}