Welcome to the developer page for dvd-slideshow. Here, we can discuss upcoming changes and progress toward the next version(s) of the dvd-slideshow tools.
Several people have been thinking about extending dvd-slideshow and/or writing new transitions, etc... I've recently transitioned to a different system of rendering the transitions and effects like the kenburns effect, and this restricts how new transitions are written.
Transitions get applied on top of existing frames or effects, so 1. If previous effect is a kenburns or scroll effect, render those frames now. This duration is 1/2 of the transition duration for crossfade and wipe, and the complete duration for fadein and fadeout. 2. Render the "static" frames that are not kenburns or scroll frames. 3. If the next effect is a kenburns or scroll effect, render those frames now.