Play rendered animation 1920_1080 issue

I have rendered an animation at 1920 * 1080 and when I activate Play Rendered Animation the rendered sequence plays back but I cant see the whole image in the render playback ( its too big ) and I cant for the life of me figure out how to resize the playback in the internal player so that I can resize the playback size of the rendered sequence.

I can resize the playback screen itself of course using the standard window controls at the top but not the size of the image within the playback window, with the result that the played back image is just cropped, if I resize the window down.

Are there image sizing controls for the internal player? Ive seen the list of playback controls in the wiki, but cant see anything about resizing other than ctrl+ / -

ctrl+ works to resize up but ctrl- wont resize down below the actual rendered size.

Im on 2.76b