I have an undying and unconditional love for VirtualDub.
The first reason I love the fact that Avery Lee wrote the program all on his own because he wanted to be able to compress anime videos of Sailor Moon.
The second reason why I love it is for me it was the most intuitive Windows open-source video capture and video processing utility for me.
Virtualdub is made for the linear processing of video clips so this means there is are some real major disadvantages in using it. Linear editors aren’t very flexible but using Avisynth with Virtualdub does help to give you a bit more flexibility. Another point against it the fact that it only works with AVI files. I use WinFF to convert AVI files into other files types easily.
The reason I use love VirtualDub is that you can compress a video file with itwhile still retaining the quality of the original video.
VirtualDub can split extract and join files without re-encoding. It can crop videos, it can make animated gifs, it can image sequence and with the many different filters that it has it can do hundreds of other useful things such as watermarking.
I’ve tried using other free video editors like Lightworks but the software is just way to far over my head still. I feel overwhelmed every time I try to use it.
That is not to say that VirtualDub doesn’t have a huge learning curve. It definitely does. Its documentation is also pretty sparse and so are tutorials for it but I still found it easier for me to learn then the other programs I found out there.