Undo edit

[jfx]

This patch adds undo operation. I've been using it for a week with no problems.

[kolpotoru]

If you have avidemux 2.5 compiled with this patch please give the download link. I am using avidemux 2.5 because avidemux 2.6 dose not have the smart copy feature.

[ZeodyScott]

I've run into similar behavior before. One thing that helped was testing with the latest Avidemux build and trying a different output container or codec just to rule out compatibility issues. If you can share the media info for the source file, that might also give a clue about what's causing it.