Matrox MXO2 PCIe Host Adapter - Manual (Page 105)

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Selecting your MPEG-2 I-frame settings
Selecting your MPEG-2 I-frame settings
When using the Matrox MPEG-2 I-frame or Matrox MPEG-2 I-frame HD codec
to capture or render video, you can specify various settings for the MPEG-2
I-frame compression.
° To select your MPEG-2 I-frame settings:
1 Click the Configure button. This displays a dialog box similar to the
following:
2 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. The range
of available data rates depends on whether you’re using the Matrox MPEG-2
I-frame HD or SD format.
¡ Important Depending on the capabilities of your system, you may drop
frames if you select a data rate higher than 125 Mb/sec.
3 To apply advanced settings to your MPEG-2 I-frame file, click the
Advanced button.
¦ Note 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 Under Rounding Type , select one of the following:
$
MPEG-2 Rounds the AC coefficients up to the nearest whole number
when calculating the quantization coefficient.
$
Matrox Custom Truncates the AC coefficients to the lowest whole
number when calculating the quantization coefficient. In some cases, this
setting may yield less artifacts in graphics.
5 Under DC Precision , select the bit-depth precision of the DC intra block.