媒体转码uwp

Question

我想创建使用Windows.Media.Transcoding转换视频的UWP应用。下面的代码。运行该应用程序后-崩溃，并显示（0xc0000005）“访问冲突”代码。 我尝试在清单中添加权限，但无济于事。 此代码有什么问题？

var openPicker = new Windows.Storage.Pickers.FileOpenPicker();

        openPicker.SuggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.VideosLibrary;
        openPicker.FileTypeFilter.Add(".wmv");

        StorageFile source = await openPicker.PickSingleFileAsync();
        StorageFile destination = await KnownFolders.VideosLibrary.CreateFileAsync("nowy.mp4", CreationCollisionOption.ReplaceExisting);

        if (source != null)
        {
            MediaEncodingProfile profile = MediaEncodingProfile.CreateMp4(VideoEncodingQuality.HD720p);
            MediaTranscoder transcoder = new MediaTranscoder();

            var prepareOp = await transcoder.PrepareFileTranscodeAsync(source, destination, profile);

            if (prepareOp.CanTranscode)
            {
                var transcodeOp = prepareOp.TranscodeAsync();

                transcodeOp.Progress +=
                    new AsyncActionProgressHandler<double>(TranscodeProgress);
                transcodeOp.Completed +=
                    new AsyncActionWithProgressCompletedHandler<double>(TranscodeComplete);
            }
            else
            {
                switch (prepareOp.FailureReason)
                {
                    case TranscodeFailureReason.CodecNotFound:
                        System.Diagnostics.Debug.WriteLine("Codec not found.");
                        break;

                    case TranscodeFailureReason.InvalidProfile:
                        System.Diagnostics.Debug.WriteLine("Invalid profile.");
                        break;

                    default:
                        System.Diagnostics.Debug.WriteLine("Unknown failure.");
                        break;
                }
            }
        }

编辑，我在使用GitHub

中的Windows示例时遇到了同样的问题