Matrox Electronic Systems M.Key/100 - Manual (Page 13)

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Using Matrox M.Key/100 with VFW programs
Using Matrox M.Key/100 with VFW programs
When using VFW programs to render material to an .avi file, such as in the case
of a completed video production or an animation, you can use a Matrox codec to
create a Matrox .avi file. For example, you may want to render an animation to
Matrox DV/DVCAM format so that you can record it onto DV tape. You could
also use your VFW program to render video to a Matrox .avi file so that you can
import the file as a realtime clip into your Adobe Premiere Pro projects on
Matrox Axio.
When rendering compositions or animations that have an alpha channel, you can
select a “+ Alpha” Matrox VFW codec to render to a Matrox uncompressed or
MPEG-2 .avi file that includes the alpha-key information. This .avi file will play
back in real time on your Axio system, and will be automatically keyed when you
place the clip in your Adobe Premiere Pro sequence.
¦ Note Although Matrox has tested many VFW programs, there may be certain
operational limitations when using Matrox M.Key/100 with some of these
programs (as well as with untested programs).
Before you start rendering
Before you start rendering material to a Matrox .avi file, make the following
settings in your Video for Windows program:
• Set the appropriate frame rate for the video format to which you are
rendering. For example, if you are rendering to PAL format, set the frame
rate to 25 fps.
• Set the frame size of your rendered material to full-screen:
$
720 × 480 if you are rendering to NTSC or 486p @ 23.98 fps format using
the DV/DVCAM, DVCPRO, DVCPRO50, or MPEG-2 I-frame codec (with
or without alpha).
$
720 × 576 if you are rendering to PAL format using the DV/DVCAM,
DVCPRO, DVCPRO50, or MPEG-2 I-frame codec (with or without alpha).
$
720 × 486 or 720 × 576 if you are rendering to Matrox uncompressed SD or
Matrox M-JPEG format.
$
1920 ×1080 or 1280× 720 if you are rendering to uncompressed HD or
DVCPRO HD format.
$
1440 Ч1080, 1920Ч 1080, or 1280× 720 if you are rendering to MPEG-2
I-frame HD format.
$
480 × 270 or 320× 180 if you are rendering to offline HD format. If you’re
rendering clips for use in an Adobe Premiere Pro project on Matrox Axio,
set the frame size to 480× 270 for an HDV 1080i, 1080i, or 1080p project,
or 320× 180 for a 720p project. For more information, see “Using the