swift - 使用 AVFoundation 在 Swift 中录制视频时如何删除临时文件？

Question

我在 objective-c 中有这个，但我不知道如何将它转换为 Swift。当我尝试这个翻译时，我在 library.removeItemAtPath 中遇到了崩溃。我不知道是什么:^{ ...还有其他形式可以保存然后删除它以避免获取冲突？？

   dispatch_async(_captureQueue, ^{
            [_encoder finishWithCompletionHandler:^{
                self.isCapturing = NO;
                _encoder = nil;
                ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
                [library writeVideoAtPathToSavedPhotosAlbum:url completionBlock:^(NSURL *assetURL, NSError *error){
                    NSLog(@"save completed");
                    [[NSFileManager defaultManager] removeItemAtPath:path error:nil];
                }];
            }];
        });

谢谢!!

Answer 1

我认为您需要在每次录制的开始和结束时删除您的临时文件，以防用户在录制期间退出应用程序或应用程序崩溃留下一段视频 block ，这会让作者在下一次写作 session 中感到不安

可以在这里找到一个完整的 swift 视频编写器示例:

https://github.com/OhioVR/CineVid/blob/master/CineVid/ViewController.swift

虽然它没有在 2015 年 4 月 30 日完成规定的任务，但可以轻松修改它以消除尝试的 iso 翻转效果，并且您可以使用它来保存设备支持的任何帧速率和分辨率的视频。您将获得一个完整的图像处理管道。

以下是与您的案例相关的 swift 部分:

func startRecording () {

     ///stuff you'd do to start the recording including deleting
     ///your temp file if it exists from the last recording session
     ////SET OUTPUT URL AND PATH. DELETE ANY FILE THAT EXISTS THERE
     var tmpdir = NSTemporaryDirectory()
     outputPath = "\(tmpdir)output.mov"
     outputURL = NSURL(fileURLWithPath:outputPath as String)!
     let filemgr = NSFileManager.defaultManager()
     if filemgr.fileExistsAtPath(outputPath) {
        filemgr.removeItemAtPath(outputPath, error: nil)
     }

}


func stopRecording() {

    ////FINISH WRITING AND TRANSFER RESULTS TO THE CAMERA ROLL
    assetWriterVideoInput.markAsFinished()
    assetWriterAudioInput.markAsFinished()
    self.videoWriter.finishWritingWithCompletionHandler({ () -> Void in
        if self.videoWriter.status == AVAssetWriterStatus.Failed {
            println("VIDEO WRITER ERROR: \(self.videoWriter.error.description)")
        } else {
            let fileManager = NSFileManager.defaultManager()
            if fileManager.fileExistsAtPath(self.outputPath as String) {
                dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), {
                    if UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(self.outputPath) {  ///(fileURL) {
                        var complete : ALAssetsLibraryWriteVideoCompletionBlock = {reason in println("reason \(reason)")}
                        UISaveVideoAtPathToSavedPhotosAlbum(self.outputPath as String, self, "savingCallBack:didFinishSavingWithError:contextInfo:", nil)
                    } else {
                        println("the file must be bad!")
                    }
                });
            } else {
                println("there is no file")
            }
        }
    });


}

func savingCallBack(video: NSString, didFinishSavingWithError error:NSError, contextInfo:UnsafeMutablePointer<Void>){
    println("the file has been saved sucessfully to the camera roll")
    //you could delete the temp file here if you like

}