Frames Per Second
Specifies the frame rate of the generated image, so you can change the playback speed.
Frames per second (FPS) works a bit differently for animated GIFs than it does for video. Instead of maintaining a constant rate of speed like video, animated GIFs place a pause between frames to mimic it (represented by the
UnclampedDelayTime values in the metadata.
fps parameter takes a positive integer and overrides these values (including any manual settings in the GIF file) to output the video at the frame rate requested.
See the API specification for more information about this parameter's value ranges and format.