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One_Fast_Kid
Advanced Newbie
Joined: 18 Sep 2005
Posts: 63
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 Posted: 19 Sep 2005 05:16:36 pm Post subject: |
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I'm not sure if its possible, but after I finish my unit converter program I want to make a compression program for lists and strings. I know there is already an assembly version out; this is more of a learning expierence for me (and hopefully others for that matter). I will probably not include a GUI with it unless requested as I intend it to be more for programmer's use.
Does anyone have any expierence with compression? I've look at howthingswork.com many months back and I remember images branching off a tree. It wasn't very helpful in terms of how to compress in a high-level language.  |
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Rezek
Better Than You
Calc Guru
Joined: 24 Apr 2005
Posts: 1229
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| Posted: 19 Sep 2005 05:20:24 pm Post subject: |
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| Try looking up RLE or Run Lenth Encoding. |
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DigiTan
Unregistered HyperCam 2
Super Elite (Last Title)
Joined: 10 Nov 2003
Posts: 4468
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| Posted: 19 Sep 2005 05:29:26 pm Post subject: |
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| A list compressor might be doable. Strings might be another story because you can't exploit repetitive patters in text quite like you can with other data. But to second Rezek's post, RLE is the best method to start any research on. |
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DarkerLine
ceci n'est pas une |
Super Elite (Last Title)
Joined: 04 Nov 2003
Posts: 8328
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| Posted: 19 Sep 2005 05:35:59 pm Post subject: |
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| this is something to read over as well. It's not exactly what you're going to do, but there is compression involved. |
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Jutt
Advanced Newbie
Joined: 27 Jun 2004
Posts: 94
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| Posted: 20 Sep 2005 11:05:47 am Post subject: |
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On string compressiong:
I had the idea to make a program that could save a string more efficiently making it 1/3rd smaller. The only restriction is that the string contains no more that 36 different characters (Pobably A-Z and some punctuation marks).
The prog changes 3 tokens into 2. There are 36^3 combinations of three tokens. Also there are more than 216 one byte tokens available - that makes over 216^2 combinations. 36^3=216^2, thus 3 tokens can be replaced by 2. |
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aforsy
the leaping penguin
Active Member
Joined: 13 Jul 2004
Posts: 653
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| Posted: 20 Sep 2005 06:01:42 pm Post subject: |
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| A through Z + 0 through 9 + punctuation, math, etc. = more than 36. more like 50 |
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DarkerLine
ceci n'est pas une |
Super Elite (Last Title)
Joined: 04 Nov 2003
Posts: 8328
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| Posted: 20 Sep 2005 06:06:49 pm Post subject: |
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| Supposing you only used 36. I don't think you're likely to unless you write in all uppercase. |
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One_Fast_Kid
Advanced Newbie
Joined: 18 Sep 2005
Posts: 63
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| Posted: 20 Sep 2005 06:14:37 pm Post subject: |
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Yeah, its defentely going to support both upper and lower cases, numberical and mathematical numbers, and probably finance vars for compatibility for some programs that acctually use them.
Thanks for the great links and help, should be starting the project in a few days. |
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Rezek
Better Than You
Calc Guru
Joined: 24 Apr 2005
Posts: 1229
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| Posted: 20 Sep 2005 09:02:36 pm Post subject: |
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Note that RLE doesn't work well for strings of text, unless you post like this:
Elseeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
Weeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
Subtlety-eeeeeeeeeeeeeeeeeeeeeeeeeee! (inside joke to 3FG)
It does work well for level maps etc, sometimes. Check out Vertical RLE as well; does great for pics. |
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