AviSynth is available free from its homepage at http://www.avisynth.org/, where you can also find the full documentation and additional filters!
To set up AviSynth:
Follow the download link at its homepage to SourceForge.
Locate the AviSynth 2.5 download group and click on the most recent entry with the
.exe
(executable) extension. That will redirect you to a list of mirrors from which you can select one near you. Be careful not to download an alpha version as those are only available for testing purposes and are likely to be unstable.Once the download is done, double-click on the file and follow the simple instructions to install it. That’s it!
Before we serve frames with AviSynth, we need to familiarize ourselves with the scripting language it employs. No previous experience with scripting is required, but if you have any you will find it trivial.