如何从UWP运行ffmpeg

Question

我想在我的UWP应用程序中使用ffmpeg使用时间戳剪切视频。

我的应用程序是完全基础的。

我有一个选择文件的按钮时间戳字段

我可以使用cmd剪切视频。但是我在华盛顿大学该怎么做呢？

Answer 1

您应该考虑使用MediaComposition(Microsoft链接(。你想要实现的一些例子：

private void TrimClipBeforeCurrentPosition()
{
var currentClip = composition.Clips.FirstOrDefault(
mc => mc.StartTimeInComposition <= mediaPlayerElement.MediaPlayer.PlaybackSession.Position &&
mc.EndTimeInComposition >= mediaPlayerElement.MediaPlayer.PlaybackSession.Position);
TimeSpan positionFromStart = mediaPlayerElement.MediaPlayer.PlaybackSession.Position - currentClip.StartTimeInComposition;
currentClip.TrimTimeFromStart = positionFromStart;
} 
private async Task RenderCompositionToFile()
{
var picker = new Windows.Storage.Pickers.FileSavePicker();
picker.SuggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.VideosLibrary;
picker.FileTypeChoices.Add("MP4 files", new List<string>() { ".mp4" });
picker.SuggestedFileName = "RenderedComposition.mp4";
Windows.Storage.StorageFile file = await picker.PickSaveFileAsync();
if (file != null)
{
// Call RenderToFileAsync
var saveOperation = composition.RenderToFileAsync(file, MediaTrimmingPreference.Precise);
saveOperation.Progress = new AsyncOperationProgressHandler<TranscodeFailureReason, double>(async (info, progress) =>
{
await this.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, new DispatchedHandler(() =>
{
ShowErrorMessage(string.Format("Saving file... Progress: {0:F0}%", progress));
}));
});
saveOperation.Completed = new AsyncOperationWithProgressCompletedHandler<TranscodeFailureReason, double>(async (info, status) =>
{
await this.Dispatcher.RunAsync(CoreDispatcherPriority.Normal, new DispatchedHandler(() =>
{
try
{
var results = info.GetResults();
if (results != TranscodeFailureReason.None || status != AsyncStatus.Completed)
{
ShowErrorMessage("Saving was unsuccessful");
}
else
{
ShowErrorMessage("Trimmed clip saved to file");
}
}
finally
{
// Update UI whether the operation succeeded or not
}
}));
});
}
else
{
ShowErrorMessage("User cancelled the file selection");
}

}

Answer 2

mediaclip4trim.TrimTimeFromStart=_Starttime；mediaclip4trim.TrimTimeFromEnd=停止时间；

这将从合成中剪切您的剪辑并保存合成