private async void ButtonExtractSrt_Click(object sender, RoutedEventArgs e) { this.InputFile = SelectFile(this.InputFile); if (string.IsNullOrWhiteSpace(this.InputFile)) { return; } using (var ffmpeg = new FFmpeg(FFmpegFileName)) { ffmpeg.OnProgress += OnProgressEvent; ffmpeg.OnCompleted += OnCompletedEvent; ffmpeg.OnData += (s, args) => { OutputText(args.Data); }; OutputText("***Start extract srt"); try { await Task.Run(() => ffmpeg.ExtractSubtitle(this.InputFile, Path.ChangeExtension(InputFile, "srt"), 0)); } catch (Exception ex) { OutputText("!!!! Exception: " + ex.Message); } OutputText("***Ready extract srt"); } }