使用AVAssetExportSession全屏導出視頻

Question

我正在嘗試對視頻進行一些動畫（錄製後），然後將其導出。 但在任何動畫之前，我已經成爲風景的方向問題（沒有出口它是肖像），它是解決不了，但現在我有問題，使其全屏。在iPhone 6,7加上其全屏如何它不是。

這裏是我的方法：

func export(_ url : URL) { 
    let composition = AVMutableComposition() 
    let asset = AVURLAsset(url: url, options: nil) 

    let track = asset.tracks(withMediaType : AVMediaTypeVideo) 
    let videoTrack:AVAssetTrack = track[0] as AVAssetTrack 
    let timerange = CMTimeRangeMake(kCMTimeZero, asset.duration) 

    let compositionVideoTrack:AVMutableCompositionTrack = composition.addMutableTrack(withMediaType: AVMediaTypeVideo, preferredTrackID: CMPersistentTrackID()) 

    do { 
     try compositionVideoTrack.insertTimeRange(timerange, of: videoTrack, at: kCMTimeZero) 
    } catch { 
     print(error) 
    } 

    let compositionAudioTrack:AVMutableCompositionTrack = composition.addMutableTrack(withMediaType: AVMediaTypeAudio, preferredTrackID: CMPersistentTrackID()) 

    for audioTrack in asset.tracks(withMediaType: AVMediaTypeAudio) { 
     do { 
      try compositionAudioTrack.insertTimeRange(audioTrack.timeRange, of: audioTrack, at: kCMTimeZero) 
     } catch { 
      print(error) 
     } 

    } 

    let size = self.view.bounds.size 

    let videolayer = CALayer() 
    videolayer.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height) 

    let parentlayer = CALayer() 
    parentlayer.frame = CGRect(x: 0, y: 0, width: size.width, height: size.height) 
    parentlayer.addSublayer(videolayer) 

    let layercomposition = AVMutableVideoComposition() 
    layercomposition.frameDuration = CMTimeMake(1, 30) 
    layercomposition.renderSize = self.view.bounds.size 
    layercomposition.animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayer: videolayer, in: parentlayer) 

    let instruction = AVMutableVideoCompositionInstruction() 

    instruction.timeRange = CMTimeRangeMake(kCMTimeZero, asset.duration) 

    let videotrack = composition.tracks(withMediaType: AVMediaTypeVideo)[0] as AVAssetTrack 
    let layerinstruction = AVMutableVideoCompositionLayerInstruction(assetTrack: videotrack) 


    let ratio = size.height/videoTrack.naturalSize.width 

    composition.naturalSize = videoTrack.naturalSize 

    layerinstruction.setTransform(videoTrack.preferredTransform.scaledBy(x: 0.645 , y: ratio).translatedBy(x: self.view.bounds.height, y: 0), at: kCMTimeZero) 

    instruction.layerInstructions = [layerinstruction] 
    layercomposition.instructions = [instruction] 

    let filePath = self.fileName() 
    let movieUrl = URL(fileURLWithPath: filePath) 

    guard let assetExport = AVAssetExportSession(asset: composition, presetName:AVAssetExportPresetHighestQuality) else {return} 
    assetExport.videoComposition = layercomposition 
    assetExport.outputFileType = AVFileTypeMPEG4 
    assetExport.outputURL = movieUrl 
    assetExport.exportAsynchronously(completionHandler: { 
     switch assetExport.status { 
     case .completed: 
      print("success") 
      let player = AVPlayer(url: movieUrl) 
      let playerViewController = AVPlayerViewController() 
      playerViewController.player = player 
      self.present(playerViewController, animated: true) { 
       playerViewController.player!.play() 
      } 
      break 
     case .cancelled: 
      print("cancelled") 
      break 
     case .exporting: 
      print("exporting") 
      break 
     case .failed: 
      print("failed: \(String(describing: assetExport.error))") 
      break 
     case .unknown: 
      print("unknown") 
      break 
     case .waiting: 
      print("waiting") 
      break 
     } 
    }) 
} 

Answer 1

什麼固定我的問題是改變比例因子和轉化量。這裏是下面的代碼：

let size = self.view.bounds.size 
    let trackTransform = videoTrack.preferredTransform 
    let xScale = size.height/videoTrack.naturalSize.width 
    let yScale = size.width/videoTrack.naturalSize.height 


    let exportTransform = videoTrack.preferredTransform.translatedBy(x: trackTransform.ty * -1 , y: 0).scaledBy(x: xScale , y: yScale)