EVS XTnano User Manual

4.3.2. Maximum bitrates
These maximum values are valid for XTnano servers running Multicam version 11.00 or
11.01. They guarantee a smooth play and a browse at 100% speed on all channels
simultaneously.
Codec Format 2 ch 4 ch
DVCPro 50 PAL 50 50
NTSC 50 50
DVCPro HD PAL 100 100
NTSC 100 100
4.3.3. Interpolation
Introduction
The playing back of smooth slow motion pictures carries specific issues: since some
fields must be repeated at regular interval to provide the video at the playback speed
required by the operator, parity violation appears regularly on the output video signal. This
issue is specific to interlaced formats (525i, 625i and 1080i) and does not concern
progressive formats (720p).
If O and E represent respectively the odd and even fields of a standard video signal
(50/60Hz), we have:
The original video signal:
◦ O E O E O E O E O E O E O E O E
The output video signal at 50% speed:
◦ O O E E O O E E O O E E O O E E
The output video signal at 33% speed:
◦ O O O E E E O O O E E E O O O E
The output video signal at 25% speed :
◦ O O O O E E E E O O O O E E E E
Fields with parity violation are shown in bold, underlined letters. As it appears from the
above table, whatever the playback speed (with the exception of the normal 100%
playback speed), a number of fields violate the normal parity of the output signal. This
parity violation induces a 1-line shift of the field, resulting in a vertical jitter of the picture.
The jitter frequency depends upon the chosen playback speed.
To avoid this phenomenon and provide a stable output picture, EVS developed 2 types of
line interpolator: 2-line and 4-line interpolators. The interpolation process can be enabled or
disabled by the operator on all EVS slow motion systems.
XTnano Server- Version 11.01- Hardware Technical Reference Manual
4. Software Specifications 13

EVS XTnano Specifications

General

Brand	EVS
Model	XTnano
Category	Server
Language	English