Created attachment 593337 [details] screenshot Platforms: all Mozilla/5.0 (Windows NT 6.1; rv:11.0a2) Gecko/20120129 Firefox/11.0a2 When scalling videos width smaller window, video doesn't scale under some value (328px), unless height is also reduced. Steps to reproduce: 1. Go to http://download.blender.org/peach/trailer/trailer_1080p.ogg 2. Reduce the window width to under 300 px (by dragging only horizontaly) Expected result: Video should resize to match the window size at any dimension Actual result: Video doesn't scale to fit the window when width is minimized under 328 px unless window height is also reduced (to less than video height). Still, the video does not center anymore. Note: reproducible also in Nighly(12.0a1), but at width under 250 px. Mozilla/5.0 (Windows NT 6.1; rv:12.0a1) Gecko/20120131 Firefox/12.0a1
This is because the browser doesn't shrink the size of tabbed browser below a value near 328 pixels. You can see this when resizing the browser how the navigation toolbar will flex the size of the address bar to a certain point and then any smaller and the navigation toolbar items are clipped.
Yep. If you need to test resizing behavior, use an iframe whose size you set. And please do file a Firefox front-end bug on the not-shrinking-below-328px behavior.