HOLD! Don't do ANYTHING, Don't worry!
Currently investigating nomarch and patent 4,586,027 applies to hardware
RLE compression system for tape drives, even though the claims section
does not mention this, most of the claims are specific to a logic
assembly to implement algorithm where uncompressed sections have
preceding and trailing length counts, and compressed sections are datum
followed by count (basic RLE). There is also a threshold repeat value
built in to. From looking at it, the patent stands because of the other
features combined with basic RLE, and does not cover basic RLE by
itself.
Conlusion: US Patent 4,586,027 does not apply to nomarch, which RLE's by
identifying a repeat count of preceding byte with an escape code of
0x90, and the escape code in the input is represented by specially
encoding a repeat count of zero.
Going to look at US patents 4,872,009, and 4,988,998 (RLE followed by
LZ77).
On Fri, 2002-05-17 at 13:19, Daniel Burrows wrote:
On Fri, May 17, 2002 at 11:58:28AM +1200, Matthew Grant <grantma@debian.org> was heard to say:
> Could you please withdraw the nomarch package from the main upload queue.
> This thing belongs in non-free.
If it violates a patent, shouldn't it be removed entirely?
> Sorry about this. I have tried to be careful. Who would have thought that
> such an obvious compression technique (Run Length Encoding - count number
> of bytes in a row of same value, store count and byte value) is covered by
> a software patent?
Hm, don't SDL and OpenGL...errr, I mean, Mesa...both use RLE compression
to accelerate some blits? Should we remove them too?
I have to say that this patent is pretty despicable, even for a software
patent. For people who didn't bother following the URL:
"The first one covers run length encoding in its most primitive form: a
length byte followed by the repeated byte."
Daniel, who thinks he "invented" that one sometime in junior high
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