Matrox Electronic Systems Matrox RT.X2 - Manual (Page 165)

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Rendering material to a Matrox VFW .avi file
Configuring the Matrox MPEG-2 I-frame codecs
When you click your program’s Configure button to configure a Matrox
MPEG-2 I-frame codec (SD or HD resolution, with or without alpha), a dialog
box similar to the following appears:
¡ Important Unless you have the Matrox RT.X2 hardware, you can use the
Matrox MPEG-2 I-frame HD codec to render to a 1440× 1080i/p file only. The
“+ Alpha” Matrox MPEG-2 I-frame codecs are available only on a system that
has RT.X2 hardware.
1 Drag the Data Rate slider until your desired data rate is displayed. The
higher the data rate you select, the better the video quality will be.
Depending on the capabilities of your system, however, you may not be able
to smoothly play back video at a high quality using your VFW program.
2 Beside Frame Rate , select a frame rate from the list. Make sure the frame
rate you select is appropriate for the format to which you are rendering.
¦ Note The Frame Rate setting is not available if you’re rendering to
MPEG-2 I-frame SD format without alpha.
3 To apply advanced settings to your MPEG-2 I-frame file, click the
Advanced button.
¦ Note The Advanced button will be available only on a system that has the
Matrox RT.X2 hardware, and is not available if you’re rendering to MPEG-2
I-frame SD format without alpha. The default advanced settings should
provide good results for most applications. We recommend that you change
these settings only when needed for special purposes.
4 Beside DC Precision , select the bit-depth precision of the DC intra block.
The higher the DC precision value that’s used to render your video, the more
likely that the DC content will be increased at the expense of the AC content
in the encoded stream. This may result in lowering the overall quality of the
compressed stream at a specified data rate.