Date: Tue, 05 Feb 2008 16:33:42 +0100 From: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= <des@des.no> To: Oliver Fromme <olli@lurza.secnetix.de> Cc: freebsd-chat@FreeBSD.ORG Subject: Re: why is it called /boot/beastie.4th ? Message-ID: <86myqfwh7t.fsf@ds4.des.no> In-Reply-To: <86zlufwi4o.fsf@ds4.des.no> ("Dag-Erling =?utf-8?Q?Sm=C3=B8rg?= =?utf-8?Q?rav=22's?= message of "Tue\, 05 Feb 2008 16\:13\:59 %2B0100") References: <200802051332.m15DW2WU020689@lurza.secnetix.de> <86zlufwi4o.fsf@ds4.des.no>
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Dag-Erling Sm=C3=B8rgrav <des@des.no> writes: > The kernel splash code supports both BMP (courtesy of Mike Smith, IIRC) > and PCX (courtesy of yours truly). I've written a number of PCX decoders over the years, BTW, and I remember that I once wrote a codec for a stripped-down version which supported only single-plane 8-bit color. It turns out that for that specific case, which was the most common at the time, you could achieve considerably better compression by dropping the padding at the end of each scan line, and allowing runs to cross from the end of one scan line to the beginning of the next (with due consideration given to not exceeding the width of the run length counter). Of course, RLE pales in comparison with most other lossless algorithms, even contemporary ones such as the LZ family. Considering that an LZ codec can be implemented with a fairly small amount of code and requires a fairly small amount of memory for the dictionary, and how poorly RLE performs with anything more complex than line drawings, it is surprising that ZSoft even considered it, much less used it in their finished product. DES --=20 Dag-Erling Sm=C3=B8rgrav - des@des.no
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