swift - 视频本地文件URL与保存的相册不兼容

Question

我正在将单个图像转换为视频，然后尝试将视频保存到相机胶卷中，但 UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(url.path) 始终为 false。

从相机胶卷中选择图像:

if UIImagePickerController.isSourceTypeAvailable(.photoLibrary){
      let imagePicker = UIImagePickerController()
      imagePicker.delegate = self
      imagePicker.sourceType = .photoLibrary
      imagePicker.allowsEditing = false

      present(imagePicker, animated: true, completion: nil)
    }

func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
    dismiss(animated: true, completion: nil)

    var message = ""
    if let img = info[UIImagePickerController.InfoKey.originalImage] as? UIImage {
      self.img = img
      message = "image chosen"
    } else { print("FAILED IN PICKER"); return }

    let alert = UIAlertController(title: "Asset Loaded", message: message, preferredStyle: .alert)
    alert.addAction(UIAlertAction(title: "OK", style: UIAlertAction.Style.cancel, handler: nil))
    present(alert, animated: true, completion: nil)
  }

按下按钮时，尝试转换为视频并保存到相机胶卷

guard let img = img else { return }
    let images = [img]

    VideoCreator.buildVideoFromImageArray(with: images) { (url) in
      print("PATH: " + url.path)
      if UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(url.path) {
        print("PATHHHHH")
        UISaveVideoAtPathToSavedPhotosAlbum(
          url.path,
          self,
          #selector(self.video(_:didFinishSavingWithError:contextInfo:)),
          nil)
      }
    }

视频创建者:(忽略重构和粗代码的缺乏)

import UIKit
import AVFoundation

class VideoCreator {
  static private var outputSize = CGSize(width: 1920, height: 1280) // placeholder
  static private let imagesPerSecond: TimeInterval = 10 //each image will be stay for 3 secs
  static private var selectedPhotosArray = [UIImage]()
  static private var imageArrayToVideoURL = NSURL()
  static private let audioIsEnabled: Bool = false //if your video has no sound
  static private var asset: AVAsset!

  static func buildVideoFromImageArray(with images: [UIImage], completionHandler: @escaping (_ url: URL) -> Void) {
    outputSize = images[0].size

    for image in images {
      selectedPhotosArray.append(image)
    }

   guard let documentDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first else { return }

    imageArrayToVideoURL = NSURL(fileURLWithPath: documentDirectory.path + "/video.mov")
    removeFileAtURLIfExists(url: imageArrayToVideoURL)
      guard let videoWriter = try? AVAssetWriter(outputURL: imageArrayToVideoURL as URL, fileType: AVFileType.mov) else {
      fatalError("AVAssetWriter error")
    }
    let outputSettings = [AVVideoCodecKey : AVVideoCodecType.h264, AVVideoWidthKey : NSNumber(value: Float(outputSize.width)), AVVideoHeightKey : NSNumber(value: Float(outputSize.height))] as [String : Any]
      guard videoWriter.canApply(outputSettings: outputSettings, forMediaType: AVMediaType.video) else {
      fatalError("Negative : Can't apply the Output settings...")
    }
    let videoWriterInput = AVAssetWriterInput(mediaType: AVMediaType.video, outputSettings: outputSettings)
    let sourcePixelBufferAttributesDictionary = [kCVPixelBufferPixelFormatTypeKey as String : NSNumber(value: kCVPixelFormatType_32ARGB), kCVPixelBufferWidthKey as String: NSNumber(value: Float(outputSize.width)), kCVPixelBufferHeightKey as String: NSNumber(value: Float(outputSize.height))]
    let pixelBufferAdaptor = AVAssetWriterInputPixelBufferAdaptor(assetWriterInput: videoWriterInput, sourcePixelBufferAttributes: sourcePixelBufferAttributesDictionary)
    if videoWriter.canAdd(videoWriterInput) {
      videoWriter.add(videoWriterInput)
    }
    if videoWriter.startWriting() {
      let zeroTime = CMTimeMake(value: Int64(imagesPerSecond),timescale: Int32(1))
      videoWriter.startSession(atSourceTime: zeroTime)

      assert(pixelBufferAdaptor.pixelBufferPool != nil)
      let media_queue = DispatchQueue(label: "mediaInputQueue")
      videoWriterInput.requestMediaDataWhenReady(on: media_queue, using: { () -> Void in
        let fps: Int32 = 1
        let framePerSecond: Int64 = Int64(self.imagesPerSecond)
        let frameDuration = CMTimeMake(value: Int64(self.imagesPerSecond), timescale: fps)
        var frameCount: Int64 = 0
        var appendSucceeded = true
        while (!self.selectedPhotosArray.isEmpty) {
          if (videoWriterInput.isReadyForMoreMediaData) {
            let nextPhoto = self.selectedPhotosArray.remove(at: 0)
            let lastFrameTime = CMTimeMake(value: frameCount * framePerSecond, timescale: 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, status == 0 {
              let managedPixelBuffer = pixelBuffer
              CVPixelBufferLockBaseAddress(managedPixelBuffer, CVPixelBufferLockFlags(rawValue: CVOptionFlags(0)))
              let data = CVPixelBufferGetBaseAddress(managedPixelBuffer)
              let rgbColorSpace = CGColorSpaceCreateDeviceRGB()
              let context = CGContext(data: data, width: Int(self.outputSize.width), height: Int(self.outputSize.height), bitsPerComponent: 8, bytesPerRow: CVPixelBufferGetBytesPerRow(managedPixelBuffer), space: rgbColorSpace, bitmapInfo: CGImageAlphaInfo.premultipliedFirst.rawValue)
              context!.clear(CGRect(x: 0, y: 0, width: CGFloat(self.outputSize.width), height: CGFloat(self.outputSize.height)))
              let horizontalRatio = CGFloat(self.outputSize.width) / nextPhoto.size.width
              let verticalRatio = CGFloat(self.outputSize.height) / nextPhoto.size.height
              //let aspectRatio = max(horizontalRatio, verticalRatio) // ScaleAspectFill
              let aspectRatio = min(horizontalRatio, verticalRatio) // ScaleAspectFit
              let newSize: CGSize = CGSize(width: nextPhoto.size.width * aspectRatio, height: 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
              context?.draw(nextPhoto.cgImage!, in: CGRect(x: x, y: y, width: newSize.width, height: newSize.height))
              CVPixelBufferUnlockBaseAddress(managedPixelBuffer, CVPixelBufferLockFlags(rawValue: CVOptionFlags(0)))
              appendSucceeded = pixelBufferAdaptor.append(pixelBuffer, withPresentationTime: presentationTime)
            } else {
              print("Failed to allocate pixel buffer")
              appendSucceeded = false
            }
          }
          if !appendSucceeded {
            break
          }
          frameCount += 1
        }
        videoWriterInput.markAsFinished()
        videoWriter.finishWriting { () -> Void in
          print("-----video1 url = \(self.imageArrayToVideoURL)")
          completionHandler(self.imageArrayToVideoURL as URL)
        }
      })
    }
  }

  private static func removeFileAtURLIfExists(url: NSURL) {
    if let filePath = url.path {
      let fileManager = FileManager.default
      if fileManager.fileExists(atPath: filePath) {
        do{
          try fileManager.removeItem(atPath: filePath)
        } catch let error as NSError {
          print("Couldn't remove existing destination file: \(error)")
        }
      }
    }
  }
}

Answer 1

您可以随时保存文件并检查它是否已成功保存到照片中，使用:

 PHPhotoLibrary.shared().performChanges({
            PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: tempUrl)
                })

UISaveVideoAtPathToSavedPhotosAlbum(::::) 对某些人不起作用。