I have a gallery setup with multiple videos. These play perfectly on every browser I'm targeting (chrome/ie/firefox), except safari; but only on Safari 7/OSX Mavericks (other versions of safari are working fine): It displays black boxes over the videos, even when they are shown to be playing/loaded (a finished video will trigger its videoended() function, as intended, behind its black background).
The black boxes occur on the videos even when they are pulled outside the gallery, with nothing else affecting them. Sometimes not all videos get a black cover when refreshing; rarely none will.
This is a sample of one of the video tags:
<video id="video-1a" width="958px" onended="videoEnded()">
<source src="/assets/video/product-1a.mp4" type="video/mp4" />
<source src="/assets/video/product-1a.webm" type="video/webm" />
</video>