What compression is this?

Discussion in 'NDS - ROM Hacking and Translations' started by Naxito, Feb 27, 2011.

  1. Naxito

    Naxito Advanced Member

    May 14, 2008
  2. Kaleid

    Kaleid Advanced Member

    Jan 22, 2011
    United States
  3. Zorua

    Zorua Newbie

    Try opening it using WinRAR.
  4. FAST6191

    FAST6191 Techromancer

    pip Reporter
    Nov 21, 2005
    United Kingdom
    I managed to grab the other day it but could not get anything done with it- I poked it around and while it apparently could decompress I only got garbage (I would expect a ncgr to give me some form of image- it decompressed to random little lines everywhere in all the things I tried- not noise that it was before but lines). This being said it did not error out the decompression tool which is what usually happens with a bad file.
    Crystaltile2 seems to think it is compressed (I stuck it in rom and had a look then), that it does not compress much and once "decompressed" decompresses back again to a similar size as the original file would support such an assessment as well.
    In the hex I did not look hard but nothing that usually gives LZ away (flags and the like) jumped out at me. I did not see any RLE type arrangements and 1bpp did not do much so that pretty much leaves huffman (which I also tried to see) but if it is custom huffman (even if it is just the "probability table" stashed somewhere unusual) that makes life difficult.

    All this is very odd.
    I think this might be an ASM hack- if there are files like it loaded earlier in the game do a bit of replacement and see if you can not hook things there.

    If someone else wants to try their hand and that link does not work then
  5. Dark315055Vash

    Dark315055Vash Member

    Jul 28, 2007
    it should be Huffman (0x20) with a 8 bit pattern. there is the 0x24 too which is a Huffman with a 4 bit pattern.
  6. Naxito

    Naxito Advanced Member

    May 14, 2008
    Thanks all

    Ok but, what i do? I don't know how work Huffman. Any idea?