There seems to be a distinct lack of standards when it comes to spritesheet animations, hence REtroAnimator uses its own. Some sample code explaining how to parse the file format is included, alternatively you can get it here. (free for all uses)
Some sample files, demonstrating the file format are here:
^ copyright of the images are by nintendoIf you have any questions or suggestions, feel free to contact me at clemens.unterkofler@gmail.com