So I had this bug for a while, and to make sure it's not my fault, I made a clean installation of Avidemux 2.6.19 on Win7x64, everything by default.
I'm trying to encode an average 4k video (a 2160p output from Adobe Premiere Pro) to Mpeg4 AVC (x264), and what I have - if I use an "ultrafast" preset, everything works fine, but if I use any other preset or my custom settings - an error occurs (either "Cannot setup codec. Bitrate too low?" or "Video too short"). If I encode video of a smaller framesize, like 1080p - everything works fine.
Same stuff happens with Nvidia H264, Nvidia HEVC and HEVC (x265) codecs, didn't try others. I read somewhere that some codecs have issues with framesize bigger than 2000 pixels (dunno, just guessing).
Anybody had anything like this, guys?