Microsoft Expression Encoder. ScreenCapture

I noticed that Exression Encoder 4 screen recordings are sometimes shorter than specified. E.g. a 5 minute recording yields only 15 seconds of video. This seems to be related to the audio being captured at the same time as the video. Initially I was using my headset speakers as the audio profile. When I removed captuing audio from my recording, the problems stopped. When I changed the audio profile to my standard speakers, it stopped as well. However I can easily repr开发者_如何学编程oduce it by rapidly changing volume when the recording starts. The result is that recording freezes... It still takes the 5 minutes to record; but the result is onlt 15 seconds (or so) of video.

The code snippet is shown below.

        try
        {
            _screenCaptureJob = new ScreenCaptureJob();
            _screenCaptureJob.CaptureRectangle = _screenRectangle;
            _screenCaptureJob.ShowFlashingBoundary = true;
            _screenCaptureJob.ScreenCaptureVideoProfile.FrameRate = 20;
            _screenCaptureJob.CaptureMouseCursor = false;

            _screenCaptureJob.ScreenCaptureCommandFinished += new EventHandler<ScreenCaptureCommandFinishedEventArgs>(_screenCaptureJob_ScreenCaptureCommandFinished);
            _screenCaptureJob.ScreenCaptureFinished += new EventHandler<ScreenCaptureEventArgs>(_screenCaptureJob_ScreenCaptureFinished);

            Collection<EncoderDevice> audioDevices = EncoderDevices.FindDevices(EncoderDeviceType.Audio);
            try
            {
                EncoderDevice foundDevice = audioDevices.First(delegate(EncoderDevice item) { return item.Name.StartsWith(@"Speakers"); });
                _screenCaptureJob.AddAudioDeviceSource(foundDevice);
            }
            catch (Exception ex)
            {
                _appLogger.Error(string.Format("RecordNextSegment. Cannot find prefered audio device using {0} !", audioDevices[0].Name), ex);
                _screenCaptureJob.AddAudioDeviceSource(audioDevices[0]);
            }
            _currentDurationInSeconds = (_recordDurationInSeconds < _maxSegmentDurationInSeconds) ? _recordDurationInSeconds : _maxSegmentDurationInSeconds;

            _screenCaptureJob.Duration = DateTimeUtilities.DurationToTimeSpan(_currentDurationInSeconds);
            _screenCaptureJob.OutputScreenCaptureFileName = string.Format(@"{0}\{1}.wmv", _tvaConfiguration.TVAVideoDirectoryRawVideo, FileNameFromSegment(_segmentNumber ));
             _screenCaptureJob.Start();
            LogInfo(string.Format("Remaining time (seconds): {0}. Current time: {1}. File: {2}", _recordDurationInSeconds, _currentDurationInSeconds, _screenCaptureJob.OutputScreenCaptureFileName));

Not sure, about the way to fix your problem but wanted to give you some input on the audio problem. On the couple machines, I tested my application, the screen capture and as well the audio worked perfectly. So from that, I could only conclude, that it might be something related to your hardware or a problem with your code...(maybe debug through it ?)

Also, your solution might be the same as this.