[Image-SIG] Distinguish single-frame from multi-frame GIF images?

[Fredrik Lundh]

skip at pobox.com wrote:

> Is there a way to determine I'm dealing with a single-frame vs. multi-frame
> GIF image without actually trying to seek?  For example, will the duration
> key in the info dict always be present in multi-frame images (and never be
> present in single-frame images)?

not sure; the duration value and the frames are in different blocks, so 
it's perfectly possible to create a GIF that has multiple frames but no 
information block.  not sure if it's valid, though; you'll have to check 
the specification for details.

</F>