Re: Any news on Compress::LZW?

[meredith]

Can't say I've heard any murmurs, sorry. This is an interesting thought, though. I did find a perl script implementing LZW from google... maybe I can modularize it and ready it for CPAN. Gotta ask the author though. Looking at the code, I can't believe someone could patent something so obvious... oh wait, yes I can :P What do you think, diotalevi?

Update: I just sent the email to the author... we'll see what he has to say :)

mhoward - at - hattmoward.org

[rcaputo]

This is that author speaking. Thanks for the e-mail! I'd be delighted if you used my code. It would be a wonderful way to commemorate the end of an error. :)

What you found on the web is probably hideously out of date, however. Here is the latest, self-testing version.

Read more... (3 kB)

[meredith]

Thanks for the response! I had assumed that you were no longer listening to that email address.

I had actually already used your code to understand the LZW method, but reworked some code from the CPAN module Compress::SelfExtracting to make the actual code. I'll be rewriting much of this code too, though, but your code was a great help at getting started. Check this thread: RFC: Compress::LZW for more info. Thanks again! I will keep this new script in my reference collection.

mhoward - at - hattmoward.org

[rcaputo]

Apologies for not responding sooner. I was at YAPC::NA and didn't have a laptop. Remind me never to do that again. :)

-- Rocco Caputo - [e-mail] - poe.perl.org

[diotalevi]

I'd have done this myself if I didn't already know that there might be good ways to cheat and get better performance on memory, cpu or on the API. I really wanted SomeGuru to pick it up. *shrug* Having the original paper around would be pretty handy as well.

[meredith]

SomeGuru, eh? Don't know him. :) Actually, I looked at the code (dont tell:) and it's just the LZW algorithm in perl... it doesn't output in any sort of data format, so there's work to be done there, and it doesn't have a decompressor (likely because there is no set data format :). I'm going to poke around some more on the subject... I'll also look at that Compress::SelfExtracting to see if the LZW can be isolated (and optimized, if it really is dog-slow).

Update: I've pulled the compression code out of Compress::SelfExtracting. It's working perfectly... got a 2.91:1 compression on a text file I had laying around :) We'll see if the author cares about his code being repackaged :)

mhoward - at - hattmoward.org