adv7189b Analog Devices, Inc., adv7189b Datasheet - Page 20

• Manufacturer Part Number: adv7189b
• Description: Multiformat Sdtv Video Decoder
• Manufacturer: Analog Devices, Inc.

ADV7189B
STANDARD DEFINITION PROCESSOR (SDP)
A block diagram of the ADV7189B’s standard definition
processor (SDP) is shown in
The ADV7189B block can handle standard definition video in
CVBS, YC, and YPrPb formats. It can be divided into a lumi-
nance and chrominance path. If the input video is of a composite
type (CVBS), both processing paths are fed with the CVBS input.
SD LUMA PATH
The input signal is processed by the following blocks:
x
x
x
x
x
x
DIGITIZED C (YC)
Digital Fine Clamp. This block uses a high precision
algorithm to clamp the video signal.
Luma Filter Block. This block contains a luma decimation
filter (YAA) with a fixed response, and some shaping filters
(YSH) that have selectable responses.
Luma Gain Control. The automatic gain control (AGC)
can operate on a variety of different modes, including gain
based on the depth of the horizontal sync pulse, peak white
mode, and fixed manual gain.
Luma Resample. To correct for line-length errors and
dynamic line-length changes, the data is digitally resampled.
Luma 2D Comb. The two-dimensional comb filter
provides YC separation.
AV Code Insertion. At this point, the decoded luma (Y)
signal is merged with the retrieved chroma values. AV
codes (as per ITU-R. BT-656) can be inserted.
DIGITIZED Y (YC)
DIGITIZED CVBS
DIGITIZED CVBS
CHROMA
DIGITAL
STANDARD DEFINITION PROCESSOR
DIGITAL
CLAMP
CLAMP
MACROVISION
LUMA
FINE
FINE
DETECTION
F igure 8.
1 6 7 H
RECOVERY
CHROMA
DEMOD
F
SC
Figure 8. Block Diagram of the Standard Definition Processor
RECOVERY
VBI DATA
EXTRACT
CHROMA
FILTER
FILTER
LUMA
SYNC
AUTODETECTION
Rev. B | Page 20 of 104
STANDARD
PREDICTOR
CONTROL
CONTROL
LENGTH
GAIN
GAIN
LINE
SD CHROMA PATH
The input signal is processed by the following blocks:
x
x
x
x
x
x
x
RESAMPLE
RESAMPLE
RESAMPLE
CONTROL
CHROMA
LUMA
Digital Fine Clamp. This block uses a high precision
algorithm to clamp the video signal.
Chroma Demodulation. This block employs a color sub-
carrier (F
for any modulated chroma scheme. The demodulation
block then performs an AM demodulation for PAL and
NTSC and an FM demodulation for SECAM.
Chroma Filter Block. This block contains a chroma
decimation filter (CAA) with a fixed response, and some
shaping filters (CSH) that have selectable responses.
Gain Control. Automatic gain control (AGC) can operate
on several different modes, including gain based on the
color subcarrier’s amplitude, gain based on the depth of
the horizontal sync pulse on the luma channel, or fixed
manual gain.
Chroma Resample. The chroma data is digitally resampled
to keep it perfectly aligned with the luma data. The
resampling is done to correct for static and dynamic line-
length errors of the incoming video signal.
Chroma 2D Comb. The two-dimensional, 5-line,
superadaptive comb filter provides high quality YC
separation in case the input signal is CVBS.
AV Code Insertion. At this point, the demodulated chroma
(Cr and Cb) signal is merged with the retrieved luma
values. AV codes (as per ITU-R. BT-656) can be inserted.
SC
CONTROL
2D COMB
2D COMB
CHROMA
) recovery unit to regenerate the color subcarrier
LUMA
SLLC
INSERTION
CODE
AV
VIDEO DATA
OUTPUT
MEASUREMENT
BLOCK (= >I
VIDEO DATA
PROCESSING
BLOCK
2
C)