Changing resolution
 

When i try to change the resolution of a playing 1080p movie to smaller, i get an error. Why?

Would playing it in smaller resolution result in less system load?

Yes, it may result in less resources usage, but it will be just a little improvement.. but if you have problems when changing resolution I think it's a video driver issue.. update your video card drivers, and if you are now using Microsoft default drivers you'll probably notice a huge increase in performances just by installing the proper drivers ;)

I've got the latest catalyst drivers for my graphic card.

So post here the error message..or we can't help you further..
Have you tried to change rendering mode? (CTRL+P -> Video -> Video renderer)

And the filters used by BSplayer to decode that video (with video playing -> right-click on movie window -> Options -> Filters -> Advanced)

Do we talk about x264, VC1 or MPEG2 ?

Re: Changing resolution
 

No, it would not. All data must still be decoded before downsampling.

Yes, all data have to be decoded, but on low end PCs you have to deal also with 2D video rendering and a less amount of pixels to display will result in a minor resources consumption :roll:

The best performance and quality will be achieved if you play without resizing. This is however impossible with BS.Player if the video is larger or equal than the width of the desktop (playback window has borders).