Date: Wed, 26 May 1999 02:56:21 +0200 From: Eivind Eklund <eivind@FreeBSD.org> To: Robert Nordier <rnordier@nordier.com> Cc: "Daniel C. Sobral" <dcs@newsguy.com>, cvs-all@FreeBSD.org, cvs-committers@FreeBSD.org Subject: Re: cvs commit: src/sys/i386/boot/biosboot table.c Message-ID: <19990526025621.I22354@bitbox.follo.net> In-Reply-To: <199905252223.AAA17260@ceia.nordier.com>; from Robert Nordier on Wed, May 26, 1999 at 12:23:00AM %2B0200 References: <374B1422.79F6707@newsguy.com> <199905252223.AAA17260@ceia.nordier.com>
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On Wed, May 26, 1999 at 12:23:00AM +0200, Robert Nordier wrote: > Daniel C. Sobral wrote: > > > Robert Nordier wrote: > > > > > > I'm just not up on the legal side of things: how does "Adaptive > > > Huffman Coding" stand in the patent world? > > > > Interestingly, that's my concern too. Huffman encoding is poor > > though. It is used to pre or post-compress a dictionary algorithm in > > almost any decent compression algorithm. The exception (which I > > think is used by bzip) requires too much memory to uncompress. > > He calls it "Adaptive Huffman", though I think the emphasis is > strongly on the "adaptive" part. <DISCLAIMER: I last messed around much with this stuff in 1988/1989, and everybody knows I am not a lawyer and wouldn't be an american lawyer no matter what> lharc uses a Lempel-Ziv-77 compressor with an adaptive huffman encoder. Huffman codes are from the 50s; if they ever were patented (and I don't think they were), it would be expired. LZ77 is from 1977; I am pretty sure this was never patented, and if it was, it would be expired around now. I believe the only LZ function patented was Welch' (sp?) Lempel-Ziv-Welch compression (which is a really beatuiful concept, as opposed to LZ77/LZ78, which are obvious). Eivind. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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