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NXP Semiconductors
PNX15xx/952x Series
Volume 1 of 1
Chapter 11: QVCP
PNX15XX_PNX952X_SER_N_4
NXP B.V. 2007. All rights reserved.
Product data sheet
Rev. 4.0 — 03 December 2007
11-363
2.3.4
Chroma Upsample Filter (CUPS)
The chroma (chrominance) upsampling module allows conversion of YUV 4:2:2 data
streams to 4:4:4 data streams by interpolating the missing chrominance information.
There exist two forms of 4:2:2 co-sited and interspersed. It depends on how the U&V
data was down-sampled from 4:4:4 to 4:2:2. Since both co-sited and interspersed
4:2:2 formats (as shown in
Figure 4) are supported, the up-sampling method of
CUPS should be adapted accordingly. This feature is necessary for supporting RGB/
YUV outputs in full-color resolution.
2.3.5
Linear Interpolator (LINT)
The linear interpolator is used for horizontal up-scaling of graphics images. It is
specically used for graphics images because its nature makes it unsuitable for
quality scaling of video material. However, due to its small size, the block is present in
both layers of QVCP. This unit supports up-scaling only, and can handle both YUV
and RGB data streams. It also supports scaling of the alpha channel as well as any
potential previously-extracted color keys. The output samples are calculated from the
input samples via a piece-wise linear interpolator. All pixel components are treated
equally.
Remark: Layer Size (final)) register has to be updated to match the scaled width, if
LINT scaling is changed.
2.3.6
Video/Graphics Contrast Brightness Matrix (VCBM)
The rst purpose of VCBM is contrast (gain) and brightness (offset) control (in that
order). The contrast and brightness controls are for normalizing the amplitude (black
and white level) of all sources. They also permit balancing the visibility of all video
and graphics layers. An important benet of having separate controls for all video and
graphics layers is that the user interface never needs to disappear, even if the user
tries to make (the video part of) the picture invisible. This benet should be achieved
by control software: limit the control range for the user interface layers.
Figure 4:
4:2:2 and 4:4:4 Formats
chroma (U, V) samples
luma, alpha (Y, A) samples
Interspersed
Co-Sited
(U0, V0)
(U2, V2)
(U4, V4)
(U6, V6)
(U0, V0)
(U2, V2)
(U4, V4)
(U6, V6)
chroma (U, V) samples
luma (Y) samples
first luma, alpha samples in each line (Y0, A0)
(U0, V0)
(U2, V2)
(U4, V4)
(U6, V6)
(U1, V1)
(U3, V3)
(U5, V5)
(U7, V7)
4:4:4 Output
4:2:2 Input