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Groups > comp.sys.apple2.programmer > #980
| From | Mark P M Lim <marklim@macgui.com> |
|---|---|
| Newsgroups | comp.sys.apple2.programmer |
| Subject | RE: LZW decompressor |
| Date | 2013-11-23 02:31 +0000 |
| Organization | Mac GUI |
| Message-ID | <marklim-1385173911@macgui.com> (permalink) |
| References | <marklim-1383903408@macgui.com> <dog_cow-1384022046@macgui.com> <marklim-1384051053@macgui.com> |
Hi,
After spending sometime looking at the various LZW programs on the Internet,
I think I have located the bug that prevents the ShrinkIt decompressor
method UnpackLZW() from decoding correctly.
Right at the top of the method DecompressorError
DecompressorShrinkIt::UnpackLZW() is the following code snippet:
................
while (! putByteErr)
{
if (GotClearCode())
{
SetGotClearCode(false);
SetAtBit(0);
SetCurrentEntry(0x0101);
................
Commenting out the statement SetAtBit(0) allows an entire archived text file
to be decoded correctly.
However, the CRC of the uncompressed data (fCRC16.CRCword.crc) does not
tally with fOriginalCRC.
Regards.
Mark
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RE: LZW decompressor Mark P M Lim <marklim@macgui.com> - 2013-11-08 09:36 +0000
RE: LZW decompressor D Finnigan <dog_cow@macgui.com> - 2013-11-09 18:34 +0000
RE: LZW decompressor Mark P M Lim <marklim@macgui.com> - 2013-11-10 02:37 +0000
RE: LZW decompressor Mark P M Lim <marklim@macgui.com> - 2013-11-23 02:31 +0000
Re: LZW decompressor markpmlim@yahoo.com.sg - 2013-12-24 18:51 -0800
Re: LZW decompressor Mark P M Lim <marklim@macgui.com> - 2013-12-28 01:51 +0000
Re: LZW decompressor denisbytezone@gmail.com - 2014-03-20 00:37 -0700
Re: LZW decompressor Mark P M Lim <markpmlim@yahoo.com.sg> - 2014-03-20 22:28 +0000
Re: LZW decompressor Denis Molony <denisbytezone@gmail.com> - 2014-03-21 16:26 -0700
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