Date: Wed, 30 Apr 1997 18:54:31 -0400 From: Randall Hopper <rhh@ct.picker.com> To: Amancio Hasty <hasty@rah.star-gate.com> Cc: multimedia@freebsd.org Subject: Re: The "BT848 RISC Challenge" Message-ID: <19970430185431.16765@ct.picker.com> In-Reply-To: <199704252248.PAA10046@rah.star-gate.com>; from Amancio Hasty on Fri, Apr 25, 1997 at 03:48:24PM -0700 References: <19970425120134.00918@ct.picker.com> <199704252248.PAA10046@rah.star-gate.com>
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Amancio Hasty:
|First of in PC Land we do refer to BGR to RGB.
? sorry, no clue what you meant there
|Not sure if we can support what you want. Heck get an S3 card.
Re the last part, I feel a bit differently about it. I've got an S3V,
but there's nothing sacred about its byte order. If the capture card can
support both orderings, the driver probably should so joe-user that has a
card with the opposite byte order from mine isn't left out needlessly.
Useful for joe if he wants to do 1280x1024@24bpp if he's only got 4Meg
(3Bpp flies, but not 4 -- insuff mem). But it doesn't help the 2Meg folks,
unless their card won't do 800x600x4Bpp, just 800x600x3Bpp.
Given no current customers for this feature, its probably not worth
any more brain cells now.
|Not sure that the a Risc program is the way to do the pixel reordering
|that is if a risc program can doit at all. The PCI latency will probably
|kill the risc program.
Yeah, I was joking. :-) 2.5Meg for a RISC program is kind'of amusing.
Thanks for the reply.
Randall
|From The Desk Of Randall Hopper :
|> THE CHALLENGE: Figure out how to get the BT848 to DMA pixels in
|> RGBRGB packed 24bpp (3Bpp) format to the frame
|> buffer or memory.
|>
|>
|> It'd be cool if we could do this to support those of us whose
|> Xservers config the card for this format. For now, the driver
|> limits direct video in 24bpp to those folks that have BGRBGR packed
|> 24bpp organization.
|>
|> SOME OPTIONS:
|>
|> 1. Put the chip in RGB32 pixel FIFO mode with byte and short
|> swapping enabled (ARGBARGB). For each pixel, write 2 RISC
|> instructions: a SKIP to skip the Alpha, and a WRITE to blast
|> the RGB.
|>
|> Hmmmmmm, let's see....that's only 2.5 Megs for a 640x480
|> image. :-)
|>
|> 2. Rotate the HUE 90 deg. (I'm not kidding. It works.
|> It's ugly but it works!)
|>
|> Anybody know a kindler, gentler way to do this on the chip? :-)
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