VirtualDub by Avery Lee is a great freeware video utility program that is an extremely useful all-round tool for working with videos. You can use it for trimming, cropping, re-sizing, re-saving and fixing problem AVI files.

The VirtualDub interface.

Two display windows are presented inside the main program window. The one on the left shows the original video, and the one on the right shows what the video looks like after manipulations such as cropping or adjusting the image. Controls along the bottom work like most multi-media players. If you hold your mouse cursor over a button in the program for a while, a description of the button's function will come up.

There is also a frame counter along the bottom of the frame that you can click and drag for quick access to any part of the video. An information box shows your location in the video by frame count and time.

There are many different functions that we can use VirtualDub for:

• Converting MOV to AVI

  VirtualDub does not normally open MOV files. However, it can be used with a plugin that will open MOV files. You can then simply save the video as an uncompressed AVI files for use in programs like AutoStakkert!, AviStack and RegiStax.

  You can download the plugin here: http://fcchandler.home.comcast.net/~fcchandler/Plugins/QuickTime/.

  After you install VirtualDub, unzip the plugin. There will be two versions of the plugin, one for 32-bit Windows operating systems, and one for 64-bit Windows operating systems.

  If you have a 32-bit operating system, create a folder named "Plugins32" (without the quotes) in VirtualDub's program folder, usually located on the C drive in a folder named "Program Files". Then copy the file "QuickTime.vdplugin" into the Plugins32 folder.

  If you have a 64-bit operating system, create a folder named "Plugins64" (without the quotes) in VirtualDub's program folder, usually located on the C drive in a folder named "Program Files". Then copy the file "QuickTime64.vdplugin" into the Plugins64 folder.

  • Open the MOV file with File > Open Video File.

  • Navigate to the folder with the MOV file that you want to convert and open the file.

  • Go to Audio and select No Audio.

  • Go to Video and select Compression and select (Uncompressed RGB/YCbCr).

  • Click OK to close the compression dialog box.

  • Go to File > Save As AVI and name the file and select the save location.

  • Double check the save location because VirtualDub defaults to the last directory used, not the directory that the MOV file is located in. You will have to specifically change the save location to the folder you want.

• Saving an Uncompressed AVI File

  For videos for use in planetary image processing programs like AutoStakkert!, AviStack and RegiStax, save the video as an uncompressed AVI file.

  • Go to Audio and select No Audio.

  • Go to Video > Compression and select (Uncompressed RGB/YCbCr).

  • Click OK to close the compression dialog box.

  • Go to File > Save As AVI and give the file a new name and select the save location.

• Fixing Problem Files

  Sometimes you will encounter an AVI file that won't open in a planetary image processing program like RegiStax, AviStack or AutoStakkert!. Sometimes opening the file in VirtualDub and re-saving it as a normal uncompressed AVI file will help fix any compatibility problems.

  Go to File > Save As AVI and name the file and select the save location.

• Saving a Video without Audio

  Go to Audio > No Audio.

  Go to File > Save As AVI and give the file a new name and select the save location.

• Trimming

  VirtualDub can be used to trim out bad parts of a video. These can sometimes occur at the beginning if you have to touch the camera to start the video. At the high magnifications used for planetary work, this can cause the image to move around wildly until the scope and mount stabilize a few seconds later. Some planetary image processing programs can have a problem with fast motion of the image like this. If you do have a problem, use VirtualDub to cut out, or trim, the bad part of the video.

  Move the location slider to the part of the video that you want to cut out or trim out. Click the Mark In button (second from right). Move the slider to the end of the section you want to cut out. Click the Mark Out button (farthest right button).

  The part of the time-line selected for editing will now be highlights in light blue. Now go to Edit > Cut.

  You can also select a part of the video with the Mark In and Mark Out buttons, and trim off the rest of the unselected part of the video before and after the marks. Go to Edit > Crop to Selection.

  Go to File > Save As AVI and give the file a new name and select the save location.

• Converting a Video to Still Frames

  VirtualDub can take an AVI video and output a series of sequentially numbers still images.

  Go to File > Export > Image Sequence and select the file type and name you want to use for the sequence.

• Converting a Sequence of Still Frames to a Video

  VirtualDub can also take a series of sequentially numbered still images and turn them into an AVI movie.

  Go to File > Open Video File and navigate to the folder where the still images are stored. They must be sequentially numbered with the same file name where only the number is incremented. Select the first file. VirtualDub will automatically load every file in the sequence into the time-line.

  Go to File > Save As AVI and give the file a new name and select the save location.

• Cropping a Video

  You may have a video of a planet with a lot of black sky around it. VirtualDub can be used to crop this out of a video.

  • Load the video you want to crop.

  • Go to Video > Filters.

  • Click the Add button. The Add Filters dialog box will come up. Select the Null Transform filter and ok the dialog box.

  • Now click the Cropping Button. The Filter Input Cropping dialog box will come up.

  • Click and drag the top and bottom or sides of the image box to change the crop, or directly input the number of pixels to be cropped into the X1, Y1, X2, Y2 boxes.

  • Click ok to that dialog box, and then ok to the filters dialog box.

  • You should now see the cropped version of the video on the right.

  • Go to File > Save As AVI and give the file a new name and select the save location.

• Filters

  There are other filters that can sometimes be useful in processing a video in VirtualDub, such as adjusting the contrast or brightness or color. These are all accessed under the Video > Filters menu.

  Click the Add button. The Add Filters dialog box will come up. Select the filter you want and ok the dialog box. When you click on a filter you should see a brief description of what the filter does.

  Additional filters are also available that can be added to the filter menu.

  Go to File > Save As AVI and give the file a new name and select the save location.

Resources

There is a good tutorial on how to use VirtualDub at divxland.

For help with VirtualDub, go to the VirtualDub support forums.

This tutorial was done with VirtualDub version 1.9.11.