Decompiling animated GIF file within an app

I would like to download a animated GIF file (more specifically, a weather radar loop), decompile it in frames and play the contents via AnimationDrawable.

The latter part and down开发者_运维知识库loading the image is not a problem, but the middle part is puzzling me: how on earth can I extract the separate frames from the GIF within an app?

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I found an easy to use GifDecoder that did the trick for me.