I have quite a long video to go through and the default playback speed is very inadequate and I need it to be 4-8 X faster. Another viewing method that--may--be adequate--if--tweaked would be by the "wheel", the horizontal grey bar with a red vertical bar at its center an it becoming darker the further from it (center), that should take the largest space in the attached screenshot.
Avidemux-2.8.1-wheel.png
The default "wheel" sensitivity with the default interface is absolutely inadequate for this purpose, I have to move the mouse quite slightly to set it to my need and by the time I set it properly I've either skipped a part I should have stopped at or almost so (skipped). If I'm to use the "wheel", I need it to be either a--lot--wider (so that its effect is spread) or that its sensitivity is seriously decreased, 4-10 X.
Thank you kindly for your help
Fast seek (keyframe-based seek) granularity is given by keyframe density in the source video. Anything else is in most cases orders of magnitude slower.
In the future, some sort of sped-up playback might be added by this pull request (https://github.com/mean00/avidemux2/pull/453) if it gets accepted (obviously, it cannot fullfill its promise if hardware is not fast enough to decode the video stream faster than in real time).