bt829bkrf ETC-unknow, bt829bkrf Datasheet - Page 30

• Manufacturer Part Number: bt829bkrf
• Description: Video Streamii Decoders
• Manufacturer: ETC-unknow

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1.0 Functional Description
1.7 Video Scaling, Cropping, and Temporal Decimation
1.7.1 Horizontal and Vertical Scaling
1.7.2 Luminance Scaling
Figure 1-7. Optional Horizontal Luma Low-Pass Filter Responses
ICON
QCIF
1.7 Video Scaling, Cropping, and Temporal
The Bt829B provides three mechanisms to reduce the amount of video pixel data
in its output stream: down-scaling, cropping, and temporal decimation. All three
can be controlled independently.
The Bt829B provides independent and arbitrary horizontal and vertical down-
scaling. The maximum scaling ratio is 16:1 in both X and Y dimensions. The
maximum vertical scaling ratio is reduced from 16:1 when using frames, and to
8:1 when using fields. The different methods utilized for scaling luminance and
chrominance are described in the following sections.
The first stage in horizontal luminance scaling is an optional pre-filter which pro-
vides the capability to reduce antialiasing artifacts. It is generally desirable to
limit the bandwidth of the luminance spectrum prior to performing horizontal
scaling because the scaling of high-frequency components may create image arti-
facts in the resized image.
frequency spectrum in the luminance signal. Figure 1-8 and Figure 1-9 illustrates
the combined results of the optional low-pass filters, and the luma notch and 2x
oversampling filter.
The optional low-pass filters shown in Figure 1-7 reduce the horizontal high-
CIF
Decimation
NTSC
D829BDSA
ICON
QCIF
VideoStream II Decoders
CIF
PAL/SECAM
Bt829B/827B