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Date:      Sun, 28 Jan 1996 14:29:24 -0700 (MST)
From:      Terry Lambert <terry@lambert.org>
To:        hasty@rah.star-gate.com (Amancio Hasty Jr.)
Cc:        jkh@time.cdrom.com, terry@lambert.org, luigi@labinfo.iet.unipi.it, james@miller.cs.uwm.edu, dufault@hda.com, hackers@freebsd.org, multimedia@rah.star-gate.com
Subject:   Re: Amancio's tv program with capture!
Message-ID:  <199601282129.OAA01511@phaeton.artisoft.com>
In-Reply-To: <199601280750.XAA00879@rah.star-gate.com> from "Amancio Hasty Jr." at Jan 27, 96 11:50:43 pm

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> 3. I can spot graphic cards which don't support a linear buffer or don't
>    have the linear buffer mmap and in such cases just exit out of tv
>    or resort to the shared memory method.

Resort to the shared memory method, please.  Makes it much more widely
available!

> The changes required to support wiring the graphic card's buffer
> to the meteor driver are minimal. 

How do you deal with bus-to-bus DMA cache effects?  It seems likely
that this type of usage is one that wasn't considered by the
motherboard manufacturers... considering how many of them have blown
simple bus-to-memory DMA cache update/invalidate.

> *First* phase at high speed video just raw dump on the screen.
> *Second phase port the xvideo extensions to XFree86 and 
> make necessary changes to the X server.

That's sexy -- a draggable video window -- resizable as well?  Are you
going to put scaling in the copy?

> Now, for the religious X cult fans if they don't like this approach
> they can always resort to a shared buffer access at the cost of 
> lower performance.

Or those of us with less than $10,000 in video hardware.  8-).


					Terry Lambert
					terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.



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