iOS基于AVFoundation制作用于剪辑视频项目

 //选择视频
       @objc func selectVideo() {
           if UIImagePickerController.isSourceTypeAvailable(.photoLibrary) {
               //初始化图片控制器
               let imagePicker = UIImagePickerController()
               //设置代理
               imagePicker.delegate = self
               //指定图片控制器类型
               imagePicker.sourceType = .photoLibrary
               //只显示视频类型的文件
               imagePicker.mediaTypes = [kUTTypeMovie as String]
               //弹出控制器，显示界面
               self.present(imagePicker, animated: true, completion: nil)
           }
           else {
               print("读取相册错误")
           }
       }

    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
        //获取视频路径（选择后视频会自动复制到app临时文件夹下）
        guard let videoURL = info[UIImagePickerController.InfoKey.mediaURL] as? URL else {
            return
        }
        let pathString = videoURL.relativePath
        print("视频地址：\(pathString)")

        //图片控制器退出
        self.dismiss(animated: true, completion: {
            let editorVC = EditorVideoViewController.init(with: videoURL)

            editorVC.modalPresentationStyle = UIModalPresentationStyle.fullScreen
            self.present(editorVC, animated: true) {

            }
        })
    }

 
    open func generateCGImagesAsynchronously(forTimes requestedTimes: [NSValue], completionHandler handler: @escaping AVAssetImageGeneratorCompletionHandler)

func splitVideoFileUrlFps(splitFileUrl:URL, fps:Float, splitCompleteClosure:@escaping (Bool, [UIImage]) -> Void) {
        var splitImages = [UIImage]()
		
		//初始化 Asset
        let optDict = NSDictionary(object: NSNumber(value: false), forKey: AVURLAssetPreferPreciseDurationAndTimingKey as NSCopying)
        let urlAsset = AVURLAsset(url: splitFileUrl, options: optDict as? [String : Any])

        let cmTime = urlAsset.duration
        let durationSeconds: Float64 = CMTimeGetSeconds(cmTime)

        var times = [NSValue]()
        let totalFrames: Float64 = durationSeconds * Float64(fps)
        var timeFrame: CMTime

		//定义 CMTime 即请求缩略图的时间间隔
        for i in 0...Int(totalFrames) {
            timeFrame = CMTimeMake(value: Int64(i), timescale: Int32(fps))
            let timeValue = NSValue(time: timeFrame)

            times.append(timeValue)
        }

        let imageGenerator = AVAssetImageGenerator(asset: urlAsset)
        imageGenerator.requestedTimeToleranceBefore = CMTime.zero
        imageGenerator.requestedTimeToleranceAfter = CMTime.zero

        let timesCount = times.count
		
		//调用获取缩略图的方法
        imageGenerator.generateCGImagesAsynchronously(forTimes: times) { (requestedTime, image, actualTime, result, error) in

        var isSuccess = false
        switch (result) {
        case AVAssetImageGenerator.Result.cancelled:
            print("cancelled------")

        case AVAssetImageGenerator.Result.failed:
            print("failed++++++")

        case AVAssetImageGenerator.Result.succeeded:

            let framImg = UIImage(cgImage: image!)

            splitImages.append(self.flipImage(image: framImg, orientaion: 1))
            if (Int(requestedTime.value) == (timesCount-1)) { //最后一帧时 回调赋值
                isSuccess = true
                splitCompleteClosure(isSuccess, splitImages)
                print("completed")
            }
        }
        }
    }

				//调用时利用回调更新 UI
self.splitVideoFileUrlFps(splitFileUrl: url, fps: 1) { [weak self](isSuccess, splitImgs) in
            if isSuccess {
                //由于方法是异步的，所以需要回主线程更新 UI
                DispatchQueue.main.async {
                
                    }
                print("图片总数目imGCount:\(String(describing: self?.imageArr.count))")
            }
        }

 
    open func seek(to time: CMTime, toleranceBefore: CMTime, toleranceAfter: CMTime)

	let totalTime = self.avPlayer.currentItem?.duration
	let scale = self.avPlayer.currentItem?.duration.timescale
	
	//width：跳转到的视频轨长度 videoWidth：视频轨总长度
 	let process = width / videoWidth
 	
      //快进函数
 	self.avPlayer.seek(to: CMTimeMake(value: Int64(totalTime * process * scale!), timescale: scale!), toleranceBefore: CMTime.zero, toleranceAfter: CMTime.zero)

    open func addPeriodicTimeObserver(forInterval interval: CMTime, queue: DispatchQueue?, using block: @escaping (CMTime) -> Void) -> Any

//player的监听
        self.avPlayer.addPeriodicTimeObserver(forInterval: CMTimeMake(value: 1, timescale: 120), queue: DispatchQueue.main) { [weak self](time) in
                //与轨道的联动操作
        }

 
    open func insertTimeRange(_ timeRange: CMTimeRange, of track: AVAssetTrack, at startTime: CMTime) throws

	let composition = AVMutableComposition()
            //合并视频、音频轨道
    let videoTrack = composition.addMutableTrack(
                        withMediaType: AVMediaType.video, preferredTrackID: CMPersistentTrackID())
  	let audioTrack = composition.addMutableTrack(
                        withMediaType: AVMediaType.audio, preferredTrackID: CMPersistentTrackID())


 	let asset = AVAsset.init(url: self.url)

	var insertTime: CMTime = CMTime.zero

 	let timeScale = self.avPlayer.currentItem?.duration.timescale

			//循环每个片段的信息
	for clipsInfo in self.clipsInfoArr {
            
            //片段的总时间
		let clipsDuration = Double(Float(clipsInfo.width) / self.videoWidth) * self.totalTime
            
            //片段的开始时间
		let startDuration = -Float(clipsInfo.offset) / self.perSecondLength

      	do {
           	try videoTrack?.insertTimeRange(CMTimeRangeMake(start: CMTimeMake(value: Int64(startDuration * Float(timeScale!)), timescale: timeScale!), duration:CMTimeMake(value: Int64(clipsDuration * Double(timeScale!)), timescale: timeScale!)), of: asset.tracks(withMediaType: AVMediaType.video)[0], at: insertTime)
                } catch _ {}

		do {
         	try audioTrack?.insertTimeRange(CMTimeRangeMake(start: CMTimeMake(value: Int64(startDuration * Float(timeScale!)), timescale: timeScale!), duration:CMTimeMake(value: Int64(clipsDuration * Double(timeScale!)), timescale: timeScale!)), of: asset.tracks(withMediaType: AVMediaType.audio)[0], at: insertTime)
      		 } catch _ {}
   		insertTime = CMTimeAdd(insertTime, CMTimeMake(value: Int64(clipsDuration * Double(timeScale!)), timescale: timeScale!))
            }

  		videoTrack?.preferredTransfORM = CGAffineTransform(rotationAngle: CGFloat.pi / 2)

            //获取合并后的视频路径
  		let documentsPath = NSSearchPathForDirectoriesInDomains(.documentDirectory,.userDomainMask,true)[0]

  		let destinationPath = documentsPath + "/mergeVideo-\(arc4random()%1000).mov"
     	print("合并后的视频：\(destinationPath)")