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 1.8.0 :

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 1.7.8 to VirtualDub 1.8.0 :

• Build 29393 (1.8.0, stable): [February 24, 2008]
• [breaking changes]
- The old support for reading "striped AVIs" has been removed.
• [features added]
- Alternate audio streams in an AVI file can now be chosen.
- Added fallback audio decoders for mu-law, A-law, MP2, and MP3 formats.
- Video files with audio tracks can also be used for replacing existing audio.
- MP3 files without a WAV header can now be used as input.
- Added support for writing AVI files with VBR audio.
- The default frame rate for loaded image sequences can now be changed in Preferences.
- The time knob can be dragged during a preview.
- Mark-in and mark-out commands now work during preview.
- Added new "time stretch" audio filter.
- Increased precision of ratios for audio stretch filters.
- Added "zone plate" test video mode.
- Changes to the input color format are now reflected in the preview panes.
- Added support for non-standard 15fps MPEG-1 video streams.
- VBR warning for AVI audio streams can now be toggled in Preferences.
- Filters: Can now be toggled on and off in the filter list.
- Filters: Fast YCbCr cropping is now supported.
- Filters: Flip vertically, grayscale, and resize now support direct planar YCbCr processing.
- Filters: Added "convert format" video filter.
- Filters: Redesigned color popup; hold down SHIFT. Now works after stretching video window.
- Script: Implemented string+int, string+long, and string+double.
- Plugins: Input driver plugins can now delegate video decompression to VirtualDub.
- Capture: Added /capfilealloc switch to preallocate capture files from the command line.
- Hex editor: Now supports Unicode filenames.
• [bugs fixed]
- Cmdline: Ctrl+C/Break when a render is running also aborts a running script.
- If a particular input driver is forced when opening a video, that driver is remembered in a job.
- Video filter dialog didn't update the indicated frame sizes properly when deleting a filter.
- Fixed slight delay when a rendering job stops.
- Optimized AVI frame index code to avoid extreme delay when starting a direct stream mode operation on an AVI file with only one key frame.
- Progress bar is now lies less when reindexing large AVI files.
- Fixed issue in AVI aggressive recovery algorithm that could cause valid chunks to be missed.
- Selection was not properly saved in .vcf files, causing it to be invalid on load if edits had occurred.
- Fixed crash when dragging curve points with no video loaded.
- Video/audio error mode dialogs weren't properly disabling options not supported for the current input file.
- Capture: Video filter list now reflects active capture format.
- D3D: Fixed slowdown when bicubic mode is enabled.

Changes from VirtualDub 1.7.7 to VirtualDub 1.7.8 :

• Build 28346 (1.7.8, stable): [February 12, 2008]
• [bugs fixed]
- Capture: Fixed crash when starting capture from command line with filters and preview acceleration enabled.
- Capture: Fixed issues with custom DirectShow filters not reconnecting.
- Capture: Added workaround for audio source switching to "no audio" in UI due to DirectShow crossbar goofiness.
- Capture: Changing the audio source manually now asks to turn off auto-switching.
- Capture: Audio source now saves properly when set to "no audio."
- Fixed crash when previewing beyond end of selection with IVTC enabled.
- Added workaround for XviD decompression crashes.
• [regressions fixed]
- Filters receive distinct source frame numbers for null frames again.