the URL of a GIF file
settings for the canvas used to render the GIF frames
OptionalprogressCallback: GIFProgressCallbackFunction[optional] callback for showing progress of decoding process (when GIF is interlaced calls after each pass (4x on the same frame))
OptionalavgAlpha: boolean[optional] if this is true then, when encountering a transparent pixel, it uses the average value of the pixels RGB channels to calculate the alpha channels value, otherwise alpha channel is either 0 or 1 - default false
the GIF with each frame decoded separately
decodes a GIF into its components for rendering on a canvas