WORLD-CCTV 722RIII-IP, Руководство пользователя

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For more details of setting of the above part please refer to the following “ advanced
image setting skill ”
『
Code type
』
Support dual compression, H.264 or MJPEG.
Advanced image setting skill
Image setting is an important part in the server setting because it will affect the
system ability, it has close relationship with the video quality and network ability. The
aim of image setting is to make it conveniently suitable for various networks.
Bit stream and frame rate settings are providing in system, but it is hard to suit various
networks with only several default values. Consequently, some advanced settings are
providing for user to ensure the video quality while utilizing network effectively.
The image settings including
『
Bit Rate
』
,
『
Frame Rate
』
,
『
Key Frame Inv
』
,
『
Rate
type
』
and
『
Image Quality level
』
are what we concern about.
Now we will introduce meaning, effect to other settings and network ability of each
setting respectively.
Bit Rate
It means the size of stream bit encoding by encoder per second. The unit is bit per
second. this setting is the main factor affects the bandwidth of network and other
settings. The bandwidth utilizing will increase when the bit rate increase. Thus CBR
(Constant Bit rate) setting according to the bandwidth is suitable for the network
bandwidth limitation situations. In the same quality situation, bit rate will be affected by
settings frame rate, I frame Inv, rate type, image quality, and definition. Please refer to
following introduction for details. This parameter is valid when the
“ Rate Type ” is set as
CBR (Constant Bit rate).
Frame Rate
It means the maximum number of frames that encoder encode per second, with unit
frame per second. This setting has three functions, firstly the number of frames encoder
encoding per second is set by this setting, secondly when the stream rate is CBR
(Constant Bit rate), when the frame rate changed, for example decreased, because
the encoder need to keep the current code stream setting, thus it will enhance the
frame quality according to the current code stream setting. It means, when the code
stream is VBR (Variable Bit rate), the decreasing of frame rate will enhance the quality
of video and keep the same frame rate value. The video quality will reduce conversely.
Thirdly, when the same quality is kept, the increasing frame rate will make the image
smoother and stream rate increasing. Conversely, the image will become
discontinuous and stream rate decrease.
Key Frame Inv
It means the number of frame P or frame B between key frames (frame I). Generally,
the default value of this parameter is 25 and does not need to be changed. When the
stream rate is settled, the increasing of this value will make the quality of video better.
When the video keeps the same quality, this value increasing will make stream rate
increased. Conversely, the stream rate will decrease.
Rate Type
When the VBR (Variable Bit rate) is chose, the front end will automatic choose a proper