Aspect ratio not preserved. Foreground images. Fits the screen. frame=320x240 px
Image-container = 320x21120 px = 1x88 frames: File size = 2 Meg;
This possibly reaches processing limits on our Acer Aspire 5532, Ubuntu 10.04, FF 25.0.1. Sluggisheness.
But works fine in Chrome on the same PC:
Because of bigger frame, quality of picture is noticeably better but animation is "choppier".
Image-container: ~25Megapixels = 5120 x 5280 px = 8x11frames, 3.7 Mb, 88 frames.
Previous version 56.
( ... reluctant to lose interesting landing page animation transitions ... )