DATA SHEET
VSP 94x2A
segment 0 segment 1
segment 2 segment 3
segment 4 segment 5 segment 6 segment 7
Ky/Kc
15
14
13
12
11
10
9
TNRSSY,
TNRSSC
8
7
6
5
4
3
2
1
0
TNRSY
,
TNRSC
0001
1111
1111
0100
0100
0100
0000
0000
0
4
8
12
20
28
36
48
64 motion
Fig. 2–25: Predefined Curve Characteristics for LUT
2.3.3. Noise Measurement
black bars at the top and bottom exist. With the help of
an expansion algorithm it is possible to expand the let-
terbox picture vertically and horizontally in such a way,
that the letterbox picture will fill the complete screen
without loosing information. To do so, the information
about the active part of the letterbox picture is neces-
sary. Active part means the information about the first
active line and the last active line of the letterbox pic-
ture. The figure below shows the principle of this idea.
The noise measurement algorithm can be used to
change the parameters of the temporal noise reduction
processing depending on the actual noise level of the
input signal. This is done by the TV- microcontroller
which reads the noise level (NOISEME), and sends
different parameter sets to the temporal noise reduc-
tion registers of the VSP 94x2A depending on this
value (0 = no noise, 126 = strong noise). Value 127
indicates an overflow status which means that the
measurement failed. The value is determined by aver-
aging over several fields. The line taken for noise mea-
surement is selected by NMLINE. When NOISEME
contains updated data which were not read so far,
NMSTATUS is set. NMSTATUS is reset when read.
The measurement position can be adjusted (NMPOS)
as well as the sensitivity (NMSENSE).
The WSS (Wide Screen Signal) signal contains some
information about the picture format (4:3 or 14:9 or
16:9), but not all existing formats are covered and not
all signals contain WSS. Therefore a separate algo-
rithm is necessary which delivers the necessary infor-
mation. The figure below shows the concept of the let-
terbox detection algorithm. One part of the algorithm is
dedicated hardware and located in the VSP 94x2A
another part is software and located in the RAM of the
TV microcontroller. The part located in VSP 94x2A is
called measurement part. The measurement part
delivers 5 signals to the controller part.Based on the
delivered information the controller part calculates an
expansion and a vertical pan factor and sends these
values back to the VSP 94x2A for manipulation of the
video signal.
2.3.4. Letterbox Detection
A drawback of wide screen 16:9 TV sets are the black
bars at the left and the right side on the screen, if dis-
playing a 4:3 source on a 16:9 screen with correct
aspect ratio. In case of letterbox source material also
4:3 Letterbox Picture
Expanded Letterbox Picture
Fig. 2–26: Handling of Letterbox Pictures on 16:9 Tubes
Micronas
Aug. 16, 2004; 6251-552-1DS
19
MICRONAS [ MICRONAS ]
