Gif support

[nudded]

I created a haskell gif parser and writer a while back: https://bitbucket.org/nudded/gif-parser/

I thought you might be interested. It should be able to read any GIF87a file (and most of the GIF89a files). But the lzw code is there (it is quite hard to cover all the edge cases).

I'm having exams atm, so i will be looking into this after them.

[Twinside]

Hi,

Thanks for the information, I tried your decoder, but there is a HUGE problem of performance, I tried it with this huge Gif image and ran into a stack overflow and when launching with more stack space (./gif-parser +RTS -K30000000 -RTS huge.gif), it consumed 3.5 GB of memory while running, I had to kill it from then.

For a direct inclusion in the library, a partial rewrite to handle huge loads is needed, but don't worry, it's doable, and having a reference implementation is always good to have.

[nudded]

Yes this is mostly a problem with the lzw implementation since it uses a very inefficient Map. If you look into it, you will see why (it maps List on Int. so the key is a List which makes for very bad performance).

Also, my example main does load the same gif in memory 6 times (and i didn't test if it was garbage collected)

[Twinside]

Reimplemented