Matrox RT.X2 User Manual page 50

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3 Under GOP Structure , you can customize the GOP structure for the
MPEG-2 IBP compression as follows:
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Under Profile , the 4:2:0 profile is selected, which uses 4:2:0
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luminance/chrominance sampling and is suitable for broadcast transmission
and distribution on DVD.
Under Motion Estimation , drag the slider to adjust the quality of the
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motion estimation used for the video compression. The default setting gives
good results for most video. However, if you have a lot of fast motion in your
video, such as fast-paced sports footage, you can get better results by
dragging the slider to the right (towards Slow/High quality ). This improves
the quality of the motion estimation, but decreases the speed of the video
compression. Alternately, if you have mostly slow-paced video, you may
want to drag the slider to the left (towards Fast/Low quality ) to decrease
the quality of the motion estimation and speed up the video compression.
Click OK to save your settings.
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Chapter 3, Defining Your Adobe Premiere Pro Settings
Variable bit rate (VBR)
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based on the complexity of the video. The target data rate you select is
used as the average data rate for the compression.
Min , Target , and Max sliders Use these sliders to select your desired data
rate. The higher the target data rate you select, the better the video quality
will be. Only the Target slider will be available if you selected Constant
bit rate (CBR) . If you selected Variable bit rate (VBR) , all three sliders
will be available so that you can set the minimum, target, and maximum
data rates for the video compression.
Determines the number of frames in the GOP (Group of
GOP length
Pictures).
Subgroup length
P-frames in the GOP, after the initial I-frame. For example, a subgroup of
3 appears as "BBP," and a subgroup of 2 appears as "BP." The available
subgroup lengths depend on your selected GOP length.
Video is compressed at varying data rates
Determines the subgroup length of B-frames and