VirtualDub is a video capture/processing utility for Windows platforms (95/98/ME/NT4/Win2k/Windows XP/Vista), licensed under the GNU General Public License (GPL). It lacks the editing power of a general-purpose editor such as Adobe Premiere, but is streamlined for fast linear operations over video.

It has batch-processing capabilities for processing large numbers of files and can be extended with third-party video filters. VirtualDub is mainly geared toward processing AVI files, although it can read (not write) MPEG-1 and also handle sets of BMP images.

Features of VirtualDub 1.8.5 :

Sure, you've probably played a few video clips on your monitor. But have you ever made one yourself? Used a video capture device? Wrestled with the software that comes with it? Felt like the software is a few leagues above or below your level? Time to try something else.
• VirtualDub helps you get video into your computer.
If your capture device is Video for Windows compatible, then VirtualDub can capture video with it. But VirtualDub isn't your average capture program:
- Fractional frame rates. Don't settle for 29 or 30 when you want 29.97.
- Optimized disk access for more consistent hard disk usage.
- Create AVI2 (OpenDML) files to break the AVI 2GB barrier and multiple files to break the FAT32 4GB limit.
- Integrated volume meter and histogram for input level monitoring.
- Real-time downsizing, noise reduction, and field swapping.
- Verbose monitoring, including compression levels, CPU usage, and free disk space.
- Access hidden video formats your capture card may support but not have a setting for, such as 352x480.
- Keyboard and mouse shortcuts for faster operation. To capture, just hit F6.
- Clean interface layout: caption, menu bar, info panel, status bar.
• VirtualDub lets you clean up video on your computer.
There are lots of programs that let you "edit" video. And yet, they're frustratingly complex for some of the simplest tasks. VirtualDub isn't an editor application; it's a pre- and post-processor that works as a valuable companion to one:
- Reads and writes AVI2 (OpenDML) and multi-segment AVI clips.
- Integrated MPEG-1 and Motion-JPEG decoders.
- Remove and replace audio tracks without touching the video.
- Extensive video filter set, including blur, sharpen, emboss, smooth, 3x3 convolution, flip, resize rotate, brightness/contrast, levels, deinterlace, and threshold.
- Bilinear and bicubic resampling -- no blocky resizes or rotates here.
- Decompress and recompress both audio and video.
- Remove segments of a video clip and save the rest, without recompressing.
- Adjust frame rate, decimate frames, and 3:2 pulldown removal.
- Preview the results, with live audio.
You can take a captured clip, trim the ends, clean up some of the noise, convert it to the proper frame size, and write out a better one. Don't see a video filter you want? Write your own, with the filter SDK.
• VirtualDub is fast.
The author of VirtualDub is very impatient. That means his program is designed for speed, both in the interface and in the processing pipeline. Converting a compressed, 320x240 MPEG-1 file to an uncompressed, 24-bit AVI requires only these two steps in VirtualDub:
- Open video file (Ctrl-O).
- Save AVI (F7).
How fast is this operation? On a C450, 40 frames per second (1.3x real-time speed). With a little tweaking, the speed rises to 55 fps (1.8x), with the CPU hardly breaking a sweat at 40%.
• VirtualDub is cheap.
To be exact, it costs nothing. VirtualDub is licensed under the GNU General Public License, meaning you can use it for free. No risk involved, and the whole source code is available if you want it.

Changes from VirtualDub 1.8.4 to VirtualDub 1.8.5 :

• Build 29963 (1.8.4, stable): [August 18, 2008]
• [features added]
- Export > Raw Audio defaults to .mp3 extension when the audio track is in MPEG layer III format.
- Capture: Optimized display code slightly when main window is minimized.
• [bugs fixed]
- Capture: Fixed a possible crash when loading device settings.
- Fixed another crash with uncompressed paletted video.
- Fixed several dialogs that had placeholder icons.
- "Open shared job list" dialog now shows the correct title.
- Fixed shared job list sync errors when using a job file originally saved from non-shared mode.
- Image sequence export jobs didn't reload properly.
- Perspective filter no longer shows garbage preview frame before a frame is sampled.
- Capture: The "track active window client area" setting of the screencap driver is now saved properly.
- Capture: Fixed crash when exiting Set Custom Format dialog with no width or height selected.
- DV: Fixed noise when audio switches between 12-bit and 16-bit encoding.
- D3D: Fixed wrong-boxing of video when source frame is YCbCr and larger than screen.
• [regressions fixed]
- Video filters which used GDI rendering in in-place mode but only requested a DC for one buffer now work.
- Video > Select Range dialog now works again. It now sets the selection.