It took a bit longer than I anticipated to get R17 done but it’s finally done enough. The highlights are:

• User contributions! – this is the first release where several fixes and parts were contributed by other people
• The new Expr filter (similar to mt_lutxyz) which can evaluate expressions per pixels during run-time
• A subtitle filter based on libass (inappropriately named assvapour)
• Lots of bugfixes, for example AVISource should now be usable with all formats and alpha output
• Even stricter checks for filters – the ongoing work to detect common coding and API usage errors continues

With this release a few more popular scripts can be implemented using only VapourSynth filters, however the work will continue to recreate the missing common filters from masktools. I would appreciate some help in implementing equivalents to mt_edge, mt_inpand, mt_expand, mt_inflate and mt_deflate. It’s a simple project and good for someone who wants to get started writing filters and help out, I just happen to want to start with the challenging stuff. MVTools. The core part of several of the most powerful Avisynth scripts and a something that could certainly use a rewrite.