...please try my program...

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  1. #1
    Guest Sebastiani's Avatar
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    Exclamation ...please try my program...

    Will someone try my file-compression program? It's free! You can even call it from another program, making it easy to incorperate into GUI downloads. Anyway, please try it!
    To compress files, simply drag and drop as many as necessary onto the .exe's icon. Decompressing works the same way. The compressed files will have a ".pkt" extension and both the decompressed and compressed files recieve a "(PK)" stamp at the beginning of the filename to allow them to coexist with the originals.
    The most remarkable compressions will result from bitmaps. The exceptions are bitmaps of photographic images, since these have more random fluctuations in their byte patterns.
    Interestingly, I used the above scenario (calling from another program) to "unpack" a windows program. It originally required the download of about 130MB of graphics files. These were compressed down to about 0.75MB. My uncle downloaded the entire program from a 56K modem in under 2 minutes! This saved several hours of downloading!
    Attached Files Attached Files



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  2. #2
    Registered User toaster's Avatar
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    what compression algorithm are you using?
    think only with code.
    write only with source.

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    you think i believe hat crap?

  4. #4
    Guest Sebastiani's Avatar
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    The algorithm is my own and, admittedly, simple. Basically, the program starts at the first byte and checks to see if the adjacent byte is identical. The process continues on like this, gradually widening the comparing buffer till a match is found. If not, the buffer falls back to one-byte's width and the comparison starts at byte two! After the compression is complete, the size of the new buffer is double-checked with the original to guarantee the former is smaller than the latter.
    I am no math genius, so it was the most logical way to do it.

  5. #5
    Refugee face_master's Avatar
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    I could only get it to work on some bitmap files that I made so heaps of the adjacent pixels were here same. I used 3 different colours all lined up and it more than halved the 14k bitmap.

  6. #6
    Guest Sebastiani's Avatar
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    A good benchmark is the WinZip program. Side by side, mine doesn't do too bad. But of course, Winzip usually outdoes me a bit! Still, like I said you can call it in other programs, a nice feature that Winzip doesn't do.



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  7. #7
    _B-L-U-E_ Betazep's Avatar
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    It is a very nice application. I am impressed.
    Blue

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    Talking

    Am I the only one that finds it ironic that your compression program is downloaded as a zip? Not trying to make fun, I think it's awesome that you wrote this. Just thought it was a little humorous.

  9. #9
    Guest Sebastiani's Avatar
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    Hey thanks for the comment, Beta But honesty comes first

    And yes, I did notice that little bootstrap irony too

    Please let me know if you have any problems with it.



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  10. #10
    Linguistic Engineer... doubleanti's Avatar
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    sounds like RLE to me... try it with other data as input... eg, random data... or at least more random than what i assume you are using [blank or bytewise repeatative bitmaps]...
    hasafraggin shizigishin oppashigger...

  11. #11
    Guest Sebastiani's Avatar
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    That's just the thing. In essence the function looks at things rather flatly, and due to this, the compression is weak on photos, complex bitmaps, etc. I will experiment on some "deeper" analysis techniques soon though. I won't be satisfied till I beat Winzip! Oh, and how might I make the process run faster? I am using register variables (well, ASKING for them, that is ) and running as efficiently as possible. For instance: at first I would iterate through an entire chunk to see if it was identical with the comparing chunk. Then I tripled the speed by comparing the first and last bytes of the two FIRST. Still, when processing huge photos, several seconds are needed and then I find I couldn't make it smaller. ( note: there is an overhead of 12 bytes for each "sub-compress").



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    I dont

    >It originally required the download of about 130MB of graphics files. These were compressed down to about 0.75MB

    i dont believe this part

  13. #13
    Registered User Dual-Catfish's Avatar
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    Code:
    |Packet.exe - Application Error                        |x| 
    |                                                        |
    |     The instruction at "0x00405930" refrenced memory   |
    |     at 0x02BA0000". The memory could not be "read".    |
    |                                                        |
    |     Click on OK to terminate the program	         |
    |     Click on CANCEL to debug the program	         |
    |                				         |
    | 	+---------+   +---------+	                 |     
    |  	|    Ok   |   | Cancel  |                        |
    |  	+---------+   +---------+	                 |
    +--------------------------------------------------------+
    Last edited by Dual-Catfish; 07-20-2002 at 11:09 PM.

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