If you haven’t opened keynote for a while, you may not be aware that Apple recently added a Dynamic Backgrounds option. This allows you to add a background design to your keynote presentations that contain a subtle animation effect. Furthermore, when applying the effect, you also have the option of creating a custom colour scheme for the design. This feature can be used to add a video background to your blocs project, which you can then overlay with other content elements. This is a nice option for hero blocs where you want some movement but don’t want to use a traditional movie clip.
You can see an example of how this looks on this demo page
To create the video background, open a new keynote project and add a dynamic background of your choice to the first slide. Next, customise the colours for your background. Once it’s how you want it, add a piece of text to the slide. It can be a simple title, but it is important to add the text as it will determine the looping time of the animation.
With the text selected, set its opacity to “0” (so it won’t be seen in the final animation). Next, add a build In effect (choose any effect you like, but a simple fade in effect will usually be just fine). Set the duration of the effect to about 10 seconds. This will be the length of time the animation will run for before looping back to the beginning).
In the Document settings tab, set the presentation type to self-playing and check the boxes to automatically play upon open and loop slideshow. You’re now ready to export the slide to a video file.
Use the export option in keynote’s file menu and choose the movie option. Be sure to set the self playing option and then export to your chosen file name. This will create an m4v file. Open that file in handbrake and use the 720 fast preset. Be sure to select the web optimised and fast decode options, and export as an mp4 file. This file may now be used as a video background in your blocs project.
If you use a 10 second duration on the invisible text animation, your video will be under 3 mb. If you feel that the loop jump after 10 seconds is too quick, simply extend the transition time. This will add weight to the file size, but as long as you keep it below 10 mb it should be just fine for use in blocs.
You could, of course, add text or other elements in the keynote slide and make them visible as part of the video, but I prefer to keep things simple by adding other content as brics on top of the video background.
Give it a go - it’s simple and can add a little interest to your hero blocs.
EDIT: I’ve been playing with this a little more and discovered that you can set a delay on the slide transition to a number of seconds instead of adding a piece of animated text to the the slide. Using this option tends to reduce the file size even further.
