如何将UIImage数组导出为电影？

注：这是一个SWIFT 2.1解决方案(iOS 8+，XCode 7.2).上周，我开始编写iOS代码，从图像生成视频。我有一点AVFoundation的经验，但从未听说过CVPixelBuffer。我在这页上看到了答案这里..花了几天的时间来解剖所有的东西，然后用斯威夫特的方法把它们重新组合在一起，这对我的大脑是有意义的。下面是我想出来的。注意：如果您将下面的所有代码复制/粘贴到一个SWIFT文件中，它应该会编译。你只需要调整一下loadImages()而RenderSettings价值。第1部分：设置在这里，我将所有与导出相关的设置分组为一个RenderSettings结构。import AVFoundationimport UIKitimport Photosstruct RenderSettings {     var width: CGFloat = 1280     var height: CGFloat = 720     var fps: Int32 = 2   // 2 frames per second     var avCodecKey = AVVideoCodecH264     var videoFilename = "render"     var videoFilenameExt = "mp4"     var size: CGSize {         return CGSize(width: width, height: height)     }     var outputURL: NSURL {         // Use the CachesDirectory so the rendered video file sticks around as long as we need it to.         // Using the CachesDirectory ensures the file won't be included in a backup of the app.         let fileManager = NSFileManager.defaultManager()         if let tmpDirURL = try? fileManager.URLForDirectory(.CachesDirectory, inDomain: .UserDomainMask, appropriateForURL:          nil, create: true) {             return tmpDirURL.URLByAppendingPathComponent(videoFilename).URLByAppendingPathExtension(videoFilenameExt)         }         fatalError("URLForDirectory() failed")     }}第二部分：图像动画这个ImageAnimator类知道您的图像，并使用VideoWriter类来执行呈现。其想法是将视频内容代码与低级AVFoundation代码分开。我还补充说saveToLibrary()这里是一个类函数，它在链的末尾被调用，以便将视频保存到照片库。class ImageAnimator {     // Apple suggests a timescale of 600 because it's a multiple of standard video rates 24, 25, 30, 60 fps etc.     static let kTimescale: Int32 = 600     let settings: RenderSettings     let videoWriter: VideoWriter     var images: [UIImage]!     var frameNum = 0     class func saveToLibrary(videoURL: NSURL) {         PHPhotoLibrary.requestAuthorization { status in             guard status == .Authorized else { return }             PHPhotoLibrary.sharedPhotoLibrary().performChanges({                 PHAssetChangeRequest.creationRequestForAssetFromVideoAtFileURL(videoURL)                 }) { success, error in                     if !success {                         print("Could not save video to photo library:", error)                     }             }         }     }     class func removeFileAtURL(fileURL: NSURL) {         do {             try NSFileManager.defaultManager().removeItemAtPath(fileURL.path!)         }         catch _ as NSError {             // Assume file doesn't exist.         }     }     init(renderSettings: RenderSettings) {         settings = renderSettings         videoWriter = VideoWriter(renderSettings: settings)         images = loadImages()     }     func render(completion: ()->Void) {         // The VideoWriter will fail if a file exists at the URL, so clear it out first.         ImageAnimator.removeFileAtURL(settings.outputURL)         videoWriter.start()         videoWriter.render(appendPixelBuffers) {             ImageAnimator.saveToLibrary(self.settings.outputURL)             completion()         }     }     // Replace this logic with your own.     func loadImages() -> [UIImage] {         var images = [UIImage]()         for index in 1...10 {             let filename = "\(index).jpg"             images.append(UIImage(named: filename)!)         }         return images    }     // This is the callback function for VideoWriter.render()     func appendPixelBuffers(writer: VideoWriter) -> Bool {         let frameDuration = CMTimeMake(Int64(ImageAnimator.kTimescale / settings.fps), ImageAnimator.kTimescale)         while !images.isEmpty {             if writer.isReadyForData == false {                 // Inform writer we have more buffers to write.                 return false             }             let image = images.removeFirst()             let presentationTime = CMTimeMultiply(frameDuration, Int32(frameNum))             let success = videoWriter.addImage(image, withPresentationTime: presentationTime)             if success == false {                 fatalError("addImage() failed")             }             frameNum++         }         // Inform writer all buffers have been written.         return true     }}第3部分：录影作家这个VideoWriter全班做所有AVFoundation重举。它主要是一个包装器AVAssetWriter和AVAssetWriterInput..它还包含一些花哨的代码，不是我编写的，它知道如何将图像转换为CVPixelBuffer.class VideoWriter {     let renderSettings: RenderSettings     var videoWriter: AVAssetWriter!     var videoWriterInput: AVAssetWriterInput!     var pixelBufferAdaptor: AVAssetWriterInputPixelBufferAdaptor!     var isReadyForData: Bool {         return videoWriterInput?.readyForMoreMediaData ?? false     }     class func pixelBufferFromImage(image: UIImage, pixelBufferPool: CVPixelBufferPool, size: CGSize) -> CVPixelBuffer {         var pixelBufferOut: CVPixelBuffer?         let status = CVPixelBufferPoolCreatePixelBuffer(kCFAllocatorDefault, pixelBufferPool, &pixelBufferOut)         if status != kCVReturnSuccess {             fatalError("CVPixelBufferPoolCreatePixelBuffer() failed")         }         let pixelBuffer = pixelBufferOut!         CVPixelBufferLockBaseAddress(pixelBuffer, 0)         let data = CVPixelBufferGetBaseAddress(pixelBuffer)         let rgbColorSpace = CGColorSpaceCreateDeviceRGB()         let context = CGBitmapContextCreate(data, Int(size.width), Int(size.height),             8, CVPixelBufferGetBytesPerRow(pixelBuffer), rgbColorSpace, CGImageAlphaInfo.PremultipliedFirst.rawValue)         CGContextClearRect(context, CGRectMake(0, 0, size.width, size.height))         let horizontalRatio = size.width / image.size.width        let verticalRatio = size.height / image.size.height                 //aspectRatio = max(horizontalRatio, verticalRatio) // ScaleAspectFill         let aspectRatio = min(horizontalRatio, verticalRatio) // ScaleAspectFit         let newSize = CGSize(width: image.size.width * aspectRatio, height: image.size.height * aspectRatio)         let x = newSize.width < size.width ? (size.width - newSize.width) / 2 : 0         let y = newSize.height < size.height ? (size.height - newSize.height) / 2 : 0         CGContextDrawImage(context, CGRectMake(x, y, newSize.width, newSize.height), image.CGImage)         CVPixelBufferUnlockBaseAddress(pixelBuffer, 0)         return pixelBuffer    }     init(renderSettings: RenderSettings) {         self.renderSettings = renderSettings    }     func start() {         let avOutputSettings: [String: AnyObject] = [             AVVideoCodecKey: renderSettings.avCodecKey,             AVVideoWidthKey: NSNumber(float: Float(renderSettings.width)),             AVVideoHeightKey: NSNumber(float: Float(renderSettings.height))         ]         func createPixelBufferAdaptor() {             let sourcePixelBufferAttributesDictionary = [                 kCVPixelBufferPixelFormatTypeKey as String: NSNumber(unsignedInt: kCVPixelFormatType_32ARGB),                 kCVPixelBufferWidthKey as String: NSNumber(float: Float(renderSettings.width)),                 kCVPixelBufferHeightKey as String: NSNumber(float: Float(renderSettings.height))             ]             pixelBufferAdaptor = AVAssetWriterInputPixelBufferAdaptor(assetWriterInput: videoWriterInput,                 sourcePixelBufferAttributes: sourcePixelBufferAttributesDictionary)         }         func createAssetWriter(outputURL: NSURL) -> AVAssetWriter {             guard let assetWriter = try? AVAssetWriter(URL: outputURL, fileType: AVFileTypeMPEG4) else {                 fatalError("AVAssetWriter() failed")             }             guard assetWriter.canApplyOutputSettings(avOutputSettings, forMediaType: AVMediaTypeVideo) else {                 fatalError("canApplyOutputSettings() failed")             }             return assetWriter        }         videoWriter = createAssetWriter(renderSettings.outputURL)         videoWriterInput = AVAssetWriterInput(mediaType: AVMediaTypeVideo, outputSettings: avOutputSettings)         if videoWriter.canAddInput(videoWriterInput) {             videoWriter.addInput(videoWriterInput)         }         else {             fatalError("canAddInput() returned false")         }         // The pixel buffer adaptor must be created before we start writing.         createPixelBufferAdaptor()         if videoWriter.startWriting() == false {             fatalError("startWriting() failed")         }         videoWriter.startSessionAtSourceTime(kCMTimeZero)         precondition(pixelBufferAdaptor.pixelBufferPool != nil, "nil pixelBufferPool")     }     func render(appendPixelBuffers: (VideoWriter)->Bool, completion: ()->Void) {         precondition(videoWriter != nil, "Call start() to initialze the writer")         let queue = dispatch_queue_create("mediaInputQueue", nil)         videoWriterInput.requestMediaDataWhenReadyOnQueue(queue) {             let isFinished = appendPixelBuffers(self)             if isFinished {                 self.videoWriterInput.markAsFinished()                 self.videoWriter.finishWritingWithCompletionHandler() {                     dispatch_async(dispatch_get_main_queue()) {                         completion()                     }                 }             }             else {                 // Fall through. The closure will be called again when the writer is ready.             }         }     }     func addImage(image: UIImage, withPresentationTime presentationTime: CMTime) -> Bool {         precondition(pixelBufferAdaptor != nil, "Call start() to initialze the writer")         let pixelBuffer = VideoWriter.pixelBufferFromImage(image, pixelBufferPool: pixelBufferAdaptor.pixelBufferPool!, size:          renderSettings.size)         return pixelBufferAdaptor.appendPixelBuffer(pixelBuffer, withPresentationTime: presentationTime)     }}第4部分：使之成为现实一旦一切就绪，以下是你的三条魔法线：let settings = RenderSettings()let imageAnimator = ImageAnimator(renderSettings: settings)imageAnimator.render() {     print("yes")}

如何将UIImage数组导出为电影？

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