如何将 AVMutableVideoComposition 转换为 AVAsset

Question

我正在做一些视频编辑，我需要将我正在操作的 AVMutableVideoComposition 放回播放器项目中。要进入播放器项目，它需要是 AVAsset。如何做到这一点？

Answer 1

您可以将AVMutableComposition 用作AVPlayerItem 的资产，因为AVMutableComposition 是AVAsset 的子类。

AVMutableVideoComposition 不是AVAsset 的子类，而是一种在AVMutableComposition 中显示您插入AVAssetTracks 的视频的方式。

（如果没有AVMutableVideoComposition，您的所有视频都按照您想要的方式定位，那么您可能不需要设置播放器项目的videoComposition 属性）

对象：

AVMutableComposition *composition = ...
AVMutableVideoComposition *videoComposition = ...
AVPlayerItem *item = [AVPlayerItem playerItemWithAsset:composition];
item.videoComposition = videoComposition;

斯威夫特：

let composition = AVMutableComposition(...
let videoComposition = AVMutableVideoComposition(...
let item = AVPlayerItem(asset: composition)
item.videoComposition = videoComposition

Answer 2

勾选此项 - exportPath 可以是任何用于保存视频的临时路径。

    func ConvertAvcompositionToAvasset(avComp: AVComposition, completion:@escaping (_ avasset: AVAsset) -> Void){
        let exporter = AVAssetExportSession(asset: avComp, presetName: AVAssetExportPresetHighestQuality)
        let randNum:Int = Int(arc4random())
        //Generating Export Path
        let exportPath: NSString = NSTemporaryDirectory().appendingFormat("\(randNum)"+"video.mov") as NSString
        let exportUrl: NSURL = NSURL.fileURL(withPath: exportPath as String) as NSURL
        //SettingUp Export Path as URL
        exporter?.outputURL = exportUrl as URL
        exporter?.outputFileType = AVFileTypeQuickTimeMovie
        exporter?.shouldOptimizeForNetworkUse = true
        exporter?.exportAsynchronously(completionHandler: {() -> Void in
            DispatchQueue.main.async(execute: {() -> Void in
                if exporter?.status == .completed {
                    let URL: URL? = exporter?.outputURL
                    let Avasset:AVAsset = AVAsset(url: URL!)
                    completion(Avasset)
                }
                else if exporter?.status == .failed{
                    print("Failed")

                }
            })
        }) }