Current branch of multimedia/avidemux is 2.7 with version 2.7.4 from 2019-08-15.
There is 2.6.11 in ports from 2016-02-07. Last version in the branch 2.6 was 2.6.21 from 2017-05-01. Both are old, deprecated and unsupported.
I started working on an update.
Created attachment 209953 [details]
Attached is the first rough update... let me know what I missed, as I have no clue what avidemux should do or not :D
(In reply to Tobias C. Berner from comment #2)
Thanks so much for helping at this. First, if builds cleanly on 12.1, though you likely knew that.
avidemux is a video editor, though it can still demux an avi or even an mp4. The name is obsolete as it now supports most common codecs and muxers. The most important part of the tool is the extremely easy to use GUI editor, formerly avidemux-qt4, which has been deleted with the removal of qt4. As of avidemux-2.7 it defaults to qt5 and getting that part to work is really the key. The old qt4 port can be recovered from svn as r476029.
It is quite possible that it will just build. I will need to be sure that I have a safety copy of the 2.6 version before I can try it as I still actively use it and would hate to lose it before 2.7 is working. I will try soon, though.