Video strip coming in too large.

When I import a clip in the VSE, the clip is much larger than the actual video and audio. It’s very annoying having to tinker with every strip. Any reason why it’s happening, and what fixes there are? I think its to do with the program I’m editing the clips with before bringing it into the VSE? I’m using Avidemux; maybe I need to tinker with settings in that program?

Larger in what way (file size, length, resolution ?)
Does the render fps match the imported footage

If not a mismatched frame rate (between source and project settings) then it could be a funny codec that Blender doesn’t like. AVCHD gives problems due to frame segmented encoding.

The size of the clip on the UI is too big. fps on video and in Blender match yes.