Date: Mon, 1 May 1995 10:44:46 -0600 (MDT) From: Jeremy Chatfield <jdc@crab.xinside.com> To: hasty@star-gate.com (Amancio Hasty) Cc: jdc@xinside.com, hackers@freefall.cdrom.com Subject: Re: Video stuff... Message-ID: <199505011644.KAA07182@crab.xinside.com> In-Reply-To: <199504301340.NAA01587@star-gate.com> from "Amancio Hasty" at Apr 30, 95 01:40:33 pm
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Amancio Hasty writes:
>
> >>> Jeremy Chatfield said:
> >
> > Hardware restrictions and the XVideo extension (or our interpretation
> > of the restrictions, at least), mean that we won't be supporting the
> > MPEG hardware initially. However, you will be able to take a live
>
> Are you aware of any existing extensions which are capable of supporting
> mpeg?
>
> I got hold of an mpeg board from OmniMedia which is capable of outputing
> to TV and/or vga works great under FreeBSD :)
We don't know of any X Consortium standards that cover MPEG control.
Strictly speaking the XVideo extension is much more for control of
the video stream, rather than any manipulation of it. For example,
you can change brightness, contrast and so on, but you can't specify
a source other than a channel. Connecting a channel to an MPEG
device is beyond the scope of the extension.
The Sun X Image Library offers something that is headed in the right
direction , but is much more general than solely video sinks and sources.
We suspect that it may be overkill for what most people want, but is
probably interesting to those wishing to do some serious video work.
It would also, we suspect, be a considerably licensing fee for us.
At the moment, we believe that we will have to create our own
extension, probably building an API that will be a compatible
extension of the X Video extension. We will also need a device
driver for each OS, because MPEG hardware works by filling a buffer
and then refilling it before the decompressor empties it again. The
signal to refill is typically sent via an interrupt.
The Matrox Marvel II permits both SuperVGA (up to 1280x1204x16bpp or
800x600x24bpp) and TV formatted (NTSC and PAL, I think) output.
However, when you engage the output, you lose the video input, so you
don;t seem to be able to do a video window in a video output, until
we get MPEG running on that board.
Cheers, JeremyC.
--
Jeremy Chatfield, +1(303)470-5302, FAX:+1(303)470-5513, email:jdc@xinside.com
X Inside Inc, P O Box 10774, Golden, CO 80401-0610, USA.
Commercial X Server - for more information please try these services
http://www.xinside.com info@xinside.com ftp.xinside.com
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