我目前正在制作一个小型应用程序,该程序可以使Mac上的网络摄像头延时播放,将捕获的帧保存为png,并且正在考虑将捕获的帧导出为单个视频。
我使用CGImage处理原始图像,并将它们设置在数组中,但是我不确定从那里开始。根据我自己的研究,我不得不以某种方式使用AVAssetWriter和AVAssetWriterInput。
我在这里浏览了一下,阅读了苹果文档并搜索了谷歌。但是所有指南等都在obj-c中,而不是快捷的,这使得它真的很难理解(因为我没有Obj-C的经验)。
任何帮助将不胜感激。
非常感谢,卢克。
我在Swift中解决了同样的问题。从UIImage数组开始,尝试一下(有点长:-),但是可以):
var choosenPhotos: [UIImage] = [] *** your array of UIImages *** var outputSize = CGSizeMake(1280, 720) func build(outputSize outputSize: CGSize) { let fileManager = NSFileManager.defaultManager() let urls = fileManager.URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask) guard let documentDirectory: NSURL = urls.first else { fatalError("documentDir Error") } let videoOutputURL = documentDirectory.URLByAppendingPathComponent("OutputVideo.mp4") if NSFileManager.defaultManager().fileExistsAtPath(videoOutputURL.path!) { do { try NSFileManager.defaultManager().removeItemAtPath(videoOutputURL.path!) } catch { fatalError("Unable to delete file: \(error) : \(__FUNCTION__).") } } guard let videoWriter = try? AVAssetWriter(URL: videoOutputURL, fileType: AVFileTypeMPEG4) else { fatalError("AVAssetWriter error") } let outputSettings = [AVVideoCodecKey : AVVideoCodecH264, AVVideoWidthKey : NSNumber(float: Float(outputSize.width)), AVVideoHeightKey : NSNumber(float: Float(outputSize.height))] guard videoWriter.canApplyOutputSettings(outputSettings, forMediaType: AVMediaTypeVideo) else { fatalError("Negative : Can't apply the Output settings...") } let videoWriterInput = AVAssetWriterInput(mediaType: AVMediaTypeVideo, outputSettings: outputSettings) let sourcePixelBufferAttributesDictionary = [kCVPixelBufferPixelFormatTypeKey as String : NSNumber(unsignedInt: kCVPixelFormatType_32ARGB), kCVPixelBufferWidthKey as String: NSNumber(float: Float(outputSize.width)), kCVPixelBufferHeightKey as String: NSNumber(float: Float(outputSize.height))] let pixelBufferAdaptor = AVAssetWriterInputPixelBufferAdaptor(assetWriterInput: videoWriterInput, sourcePixelBufferAttributes: sourcePixelBufferAttributesDictionary) if videoWriter.canAddInput(videoWriterInput) { videoWriter.addInput(videoWriterInput) } if videoWriter.startWriting() { videoWriter.startSessionAtSourceTime(kCMTimeZero) assert(pixelBufferAdaptor.pixelBufferPool != nil) let media_queue = dispatch_queue_create("mediaInputQueue", nil) videoWriterInput.requestMediaDataWhenReadyOnQueue(media_queue, usingBlock: { () -> Void in let fps: Int32 = 1 let frameDuration = CMTimeMake(1, fps) var frameCount: Int64 = 0 var appendSucceeded = true while (!self.choosenPhotos.isEmpty) { if (videoWriterInput.readyForMoreMediaData) { let nextPhoto = self.choosenPhotos.removeAtIndex(0) let lastFrameTime = CMTimeMake(frameCount, fps) let presentationTime = frameCount == 0 ? lastFrameTime : CMTimeAdd(lastFrameTime, frameDuration) var pixelBuffer: CVPixelBuffer? = nil let status: CVReturn = CVPixelBufferPoolCreatePixelBuffer(kCFAllocatorDefault, pixelBufferAdaptor.pixelBufferPool!, &pixelBuffer) if let pixelBuffer = pixelBuffer where status == 0 { let managedPixelBuffer = pixelBuffer CVPixelBufferLockBaseAddress(managedPixelBuffer, 0) let data = CVPixelBufferGetBaseAddress(managedPixelBuffer) let rgbColorSpace = CGColorSpaceCreateDeviceRGB() let context = CGBitmapContextCreate(data, Int(self.outputSize.width), Int(self.outputSize.height), 8, CVPixelBufferGetBytesPerRow(managedPixelBuffer), rgbColorSpace, CGImageAlphaInfo.PremultipliedFirst.rawValue) CGContextClearRect(context, CGRectMake(0, 0, CGFloat(self.outputSize.width), CGFloat(self.outputSize.height))) let horizontalRatio = CGFloat(self.outputSize.width) / nextPhoto.size.width let verticalRatio = CGFloat(self.outputSize.height) / nextPhoto.size.height //aspectRatio = max(horizontalRatio, verticalRatio) // ScaleAspectFill let aspectRatio = min(horizontalRatio, verticalRatio) // ScaleAspectFit let newSize:CGSize = CGSizeMake(nextPhoto.size.width * aspectRatio, nextPhoto.size.height * aspectRatio) let x = newSize.width < self.outputSize.width ? (self.outputSize.width - newSize.width) / 2 : 0 let y = newSize.height < self.outputSize.height ? (self.outputSize.height - newSize.height) / 2 : 0 CGContextDrawImage(context, CGRectMake(x, y, newSize.width, newSize.height), nextPhoto.CGImage) CVPixelBufferUnlockBaseAddress(managedPixelBuffer, 0) appendSucceeded = pixelBufferAdaptor.appendPixelBuffer(pixelBuffer, withPresentationTime: presentationTime) } else { print("Failed to allocate pixel buffer") appendSucceeded = false } } if !appendSucceeded { break } frameCount++ } videoWriterInput.markAsFinished() videoWriter.finishWritingWithCompletionHandler { () -> Void in print("FINISHED!!!!!") } }) } }