And if a movie is 14mb at 320x240 can you work out how big it will be at 640x480 and the next size up?

 

Not sure I understand that question.

If you play a 320x240 movie whilst the screen resolution is 640x480 then it will fill quarter of the screen (half size vertically and horizontally).

As for the next size up, that all depends on what resolutions your video card supports, but it's simple maths...

 

1280x960..........i'm thick !!!!!!!!!!!!!!!

Its just double the previous size.
Is there a way of working out the file size?

 

Well, the best way to think of it is to put the movie in the top left corner of the screen. If you do this, then the movie will take up 320 pixels from left to right, and 240 from top to bottom. At 1280x960 this equates to a quarter of the width, and a quarter the height, and so in fact will only fill an eighth of the screen.

No way to accurately predict the file sizes. It all depends on how the video compression algorithms are set up.

 

Okay thanks.