Version 1.0 of the "External Video for Everybody" WordPress plugin addresses two issues relating to poster images for HTML5 videos:
- First-time activations will now use poster images by default. This is a reversal of the previous initial setting. Existing activations will retain their current settings, but existing users who are not using posters might want to start. (See rationale below.)
- The plugin now includes a simple and optional built-in style sheet to help posterless videos establish a visual presence in FireFox 4.
The HTML5 <video> tag can take a poster attribute, but setting a poster previously (in iOS3) caused the video to fail on iPhones and iPads, so the default for the External Video for Everybody plugin had been not to set a poster. The iPhone/iPad problem has been corrected in iOS4 so that viewers with an up-to-date iOS should not have difficulty with posters. But there is an even more compelling reason to start using poster images: Unlike FireFox 3, FireFox 4 does not automatically display the first frame of a video. Unless you preload or set a poster, viewers may well see nothing but a blank space (with controls at the bottom) where the video should be. The video will play when you click to start it, but the white space can make for an awkward layout.
If you've been uploading poster files all along in anticipation of the day when they would work across devices, you might want to throw the switch on the Media > External VfE options page. Of course, you can still override site-wide settings in your individual shortcodes.
In case you haven't been using posters and don't plan to start, the plugin's optional built-in style sheet will somewhat alleviate the blank spaces in FireFox 4 by adding a drop shadow and a background gradient. A posterless video in FireFox 4 will then look like this: