VPX3220A Datasheet, PDF (12/80 Pages) List of Unclassifed Manufacturers – Video Pixel Decoders

VPX 3220 A, VPX 3216 B, VPX 3214 C
PRELIMINARY DATA SHEET
2.3.1. Horizontal Resizer
The horizontal resizer alters the sampling raster of the
video signal, thereby varying the number of pixels in the
active portion of the video line. The number of pixels per
line is selectable within the range from 1056 to 32 in in-
crements of 2 pixels. In the digital domain, this is done
by lowpass filtering (VPX 3220 A only), followed by a
programmable phase shift with an allpass filter.
The VPX 3220 A is equipped with a battery of 32 FIR fil-
ters to cover the four octave operating range of the resiz-
er. Fig. 2–13 shows the magnitude response of the en-
tire filter set. All filters exhibit a minimum stop band
attenuation of at least 35 dB. Figures 2–11 and 2–12
illustrate the performance of the filters in detail.
Filter selection is performed by an internal processor
based on the selected resizing factor. This automated
selection is optimized for best visual performance but
can be fine tuned to satisfy different needs. It is also pos-
sible to override the internal selection completely. In that
case, filters are selected over I²C bus.
The Resize and Skew block performs programmable
phase shifting with subpixel accuracy. In the luminance
path, a linear interpolation filter provides a phase shift
between 0 and 31/32 in steps of 1/32. This corresponds
to an accuracy of 1.6 ns. The chrominance signal can be
shifted between 0 and 3/4 in steps of 1/4. Figs. 2–14
through 2–17 show the the transfer function of the two
skew filters.
Fig. 2–11: Resizer filters for the upper octave
Fig. 2–12: Resizer filters for the lower three octaves
Fig. 2–13: Magnitude response of resizer filter bank (VPX 3220 A only)
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MICRONAS INTERMETALL