DDF4010HDV
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Bitrate mode
The bit rate mode allows configuring a constant or a variable bit rate for the video encoding.
The “variable” mode changes the bit rate in accordance with the activity (changes) in the
image. The allowed bit rate variations can be limited by the according percentage value.
Example:
With a set bit rate of 4 Mbps and a bit rate mode of “variable 50 %”, the bit rate can vary
from 6 to 2 Mbps.
Variable bit rates make better use of the available hard disk space.
GoP-size
The GOP-size (Group Of Pictures) specifies how images are used to generate the H.264
data stream.
The higher the GOP-size is, the better the image quality. However, a higher GOP-size will
also result in an increase in the delay.
A GOP-size between 6 and 15 generally provides a good image quality with high compres-
sion.
A GOP-size of 1 denotes a low compression factor and should only be used for special ap-
plications (e.g. in multiplex mode).
GOP-sizes greater than 15 belong to the extended GOPs.
Reverse playback has limited quality (frame drops) with extended GOPs (GOP-size > 15).
Deinterlacing
Deinterlacing is not supported in this software version.
The aim of this function is to enhance the image quality by computationally eliminating the
so-called interlace effect, which may occur after merging two fields into a frame, from the
frame.
However, whether a higher quality can be achieved depends on many factors such as the
speed of the motions in the image or the type of output device on the decoder side (digital
or analogue monitor).
It is therefore not possible to provide a general recommendation to activate or deactivate
this function. Therefore, we do recommend that you test the output on the monitor/decoder
after the function has been configured.
For this purpose, select a playback scene typical for the camera concerned. If the interlace
effect can be detected with moving objects i.e. if moving edges are slightly displaced be-
tween two fields, this effect can be reduced by enabling “Deinterlacing”.
However, the playback thus may be jumpy. In this case disabling this function may, in cer-
tain circumstances, result in a smoother playback.
