6.3 Capturing using VirtualVCR

If you own a capture card that is based on WDM (=Windows Driver Model) drivers, problems when capturing with VirtualDub occur frequently. There are several capture programs that utilize WDM though, and one of them is VirtualVCR, which has some unique features, one of them and probably one of the most important is that it is freeware.

After starting VirtualVCR you'll first get this sparse window:

The toolbar includes the following options:

  1. Opens the settings dialog.
  2. Saves the current settings as the standard profile.
  3. Opens another profile.
  4. Saves the current settings to a new profile.
  5. Starts the capture process.
  6. Activates the preview.
  7. Opens the statistics window.
  8. Displays a list of dropped frames.
Now click on the first symbol to open the settings dialog. It is recommended to the adjust the settings in the following order:
  1. Path and filename of the capture file.
  2. If you check this checkbox a time stamp is automatically inserted into the filename. Recommended to prevent the overwriting of files!
  3. Adds a compatibility index to the avi file; only needed for old applications.
  4. If you check this box a log file is created containing the most important statistics of the process like dropped frames, etc.
With the stop option you can set conditions that tell VirtualVCR when to stop the capture process:
  1. Here you can specify a max duration of the capture process.
  2. Quite self explanatory. VirtualVCR automatically quits after the capture process stops.
  3. Set a threshold for minimum free space.
  4. Minimum free space in MB.
In order to not have to specify these settings every time you can start VirtualVCR with special parameters!

The next important tab is 'Devices':

Here we first choose our Audio and Video capture device and then hit 'Select'. Due to a bug in VirtualVCR those settings aren't taken into account immediately. Therefore we close the settings dialog box by hitting 'Ok' and then immediately reopen it again.

In Video source we specify the appropriate input (Video Tuner, Composite or S-Video).

In Device Settings we now choose 'Video Capture Pin' and hit 'Prop'. This opens the settings dialog for your capture card, which is similar as this one:

  1. Frames per Second.
  2. Colorspace. If YUY2 doesn't work, try other settings. This depends on the hardware you are using.
  3. The resolution, for PAL 7** x 576, for NTSC 7** x 480. It is recommended that you choose the largest resolution.
If your card supports hardware based preview, you can now choose Video Preview Pin in the Device Settings and adjust the settings to your preference there. My card theoretically supports hardware preview, but effectively it doesn't work as expected. Anyway in this case you can always use Smart Tee Filter for the job. More on that later on.

Next tab is 'Audio':

  1. If you also want to capture audio (who doesn't?), tick the checkbox!
  2. In the 'Format' area you can choose Resolution, Frequency and the amount of channels.
  3. After clicking 'Input Settings' you can choose the input type (e.g. Line-In)
  4. Under 'TV audio' you can adjust special audio settings for direct TV capture. Some transmissions can contain more than one audio channel or special commentary for visually-disabled persons.
  5. If you want to compress the audio while capturing you have to check 'Compress Audio' (not recommended)
  6. Choose the audio codec if compression is switched on.
  7. Settings for the audio codec.
In most cases you capture audio and video streams utilize different hardware (e.g. TV-card for video, sound card for audio). These cards might work with different system frequencies and therefore sync issues can arise during the capture process. VirtualVCR has a feature that almost no other capture application has: it can resample the audio stream dynamically. To do so the time difference between audio and video is calculated and then the audio is resampled to keep the whole thing synced. In the 'AV Sync'-tab you can adjust these settings:
  1. Here you can enable/disable this function.
  2. Here you can toggle the dynamic resampling.
  3. If the difference between audio and video frequency is constant you should choose this option.
  4. The relative difference between audio and video frequency.
  5. If the offset between audio and video is constant you can sync audio and video here.
  6. Sync the audio using the DirectShow-Interface values.
  7. Manual syncing.
  8. Video - Audio offset in milliseconds.
  9. If one of the streams should 'act' as a Master Stream enable this option. (Only possible if Resample Audio (1.) is disabled).
  10. Enable the logging of the offset values. This file can get fairly big, therefore it's only recommended for testing purposes (short clips).
Next you have to adjust the tuner settings. If you are capturing from another video source you can skip this step:

When opened the Tuner- dialog is empty, but we are going to make the TV Tuner device search for channels in a minute. First we have to set the country code and the input type though. Therefore we hit the button TV Tuner Device. The following dialog box opens:

  1. Here you can set the country code, for germany it is 49.
  2. The input signal of your Tv-card.
  3. Tuner mode: TV.
  4. PAL, NTSC or Secam.
If you are done with the settings hit 'Ok' to get back to VirtualVCR. Now hit the button 'Scan'. After the alert that the scan-process will overwrite all prior settings the following dialog box will appear:

Activating 'Aggressive Channel Scan' will result in more channels being found, including those with a weaker signal. If you want to use those channels you can decide later on, therefore I'd recommend activating the checkbox. After the scan is done a list with all channels will pop up:

I recommend that you also name the channels appropriately! To do so, just choose the channel in question and enter the name in the 'Name' field. Afterwards you have to hit 'Update' or the new name will not be saved!

This work is rather straining, but don't worry, you'll only have to do it once! After everything is done, we are going to close the dialog box by hitting 'OK' and then saving our Settings as the default ones. You can do this by hitting the button with the 'Floppy' - symbol in the main window of VirtualVCR.

VirtualVCR can already apply filters during the capture process, which is not recommended though. It is way better to capture the unfiltered movie first and then do some post-processing in VirtualDub or AviSynth. For completeness sake I'm going to explain the filters tab too:

  1. Activate filtering during the capture process.
  2. In this list in the beginning only filters are shown which have been installed with VirtualVCR.
  3. To show all Direct-Show filters, you have to check this box. It will add all available filters to the list (2).
  4. By hitting the 'ADD' button you can add a previously selected filter to the process!
  5. This list shows all activated filters. The filters are applied in the shown order.
  6. By hitting one of these buttons you can (re)move the filters or change their properties!
Remember to again save your settings as standard settings if you desire to do so!

Now we can first try to start the preview window. To do so we are going to hit the monitor-symbol (# 6) in the main window . If you do not see a picture now, VirtualVCR can't handle the Preview-Pin of you card. In this case Smart Tee Filter helps.

Attention! Always close the preview window before changing settings in VirtualVCR!

To activate the Preview mode go to the settings dialog again and navigate to the View tab.

  1. Use Smart Tee Filter for Preview
    The Smart Tee Filter parts the Capture-Signal into a capture-stream and a preview-stream.This should always be activated if VirtualVCR cannot handle the preview pin right or it doesn't work correctly.
  2. Dock Capture Stats Window
    As it says, this docks the capture statistics window to the main window of VirtualVCR
  3. Show Capture Stats on Stop
  4. Show Color Histogram
    displays a color histogram during the capture process
  5. Show Audio Scope
    By looking at the audio scope (during capture, or testing) you can find out the fitting audio settings.
  6. Always on Top
  7. Hide Tool/Status Bar
After hitting 'OK' again and showing the preview you should hopefully see the picture in the appropriate resolution:

If everything worked fine it's once again time to save our settings as standard settings.

The Capture
If all settings are correct and Audio and Video sound/look ok, it's time to finally proceed to the actual capture process!

Manual Capture
With a simple click onto the capture button (# 5) VirtualVCR starts the capture process. You can always see the current status in the statistics window, which you can activate by hitting the stats button (# 7)

During capture the toolbar is reduced to these three buttons. The very left one stops the capture:

Manual capture with time limit:
If you cannot be here (or do not want to have to watch the time) you can set a specific time period after which VirtualVCR stops the process automatically. The setting can be found in the 'Stop' tab of the settings dialog.

Timer-based capture
This is not a built in function but a separate freeware program. You can find the download link at the end of this page. VirtualVCR Scheduler starts and stops the capture process at a time you specify in advance.

VirtualVCR Hotkeys
VirtualVCR can be accessed by a number of Hotkeys:
Key Function
F5 start capture process
Esc stop capture process
P toggle Preview
S toggle Stats window
F toggle fullscreen mode
H toggle tool and statusbar
T toggle 'Always on top'
C calls the settings dialog
Page Up Next higher channel
Page Down Next lower channel

Commandline parameters for VirtualVCR
You can also call and set VirtualVCR via commandline:
Parameter Function
-capture immediately start capturing after start
-channel "X" channel number
-profile "configfile" Choose another configuration than the default one. "configfile" must be with a full local path (c:\yourdir\yourconfig).
-runfor "seconds" length of the capture in seconds
-output "capturefile" name for the output file. 

VirtualVCR Scheduler

Next: Postprocessing: using VirtualDub or using AviSynth

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Last edited on: 06/10/2004 | First release: 05/07/2002 | Author: zisoft | Translator: killingspree | Content by Doom9.org