When you use "Link to Embedded Player with Image" feature in FreeVideoCoding.com, your image will automatically be resized to fit your selected video display size (ie: 320x240). See three examples below - they all use the same image and wmv video file, but each one appears to be a different size to your web visitors.
NOTE: Using FreeVideoCoding.com will NOT reduce (or encrease) any file size, it will only increase or decrease the size you post it as - it's display size.