24
Item
Option
Description
Video Codec
MJPEG
H.264
MJPEG:
Each video frame is individually compressed as single jpeg image
with full-scale contents itself and can be retouched freely with ease.
However, due to completeness of each frame, it brings about larger file size
and thus easily tends to lose frames under limited network bandwidth.
H.264:
The latest best-renowned video compression format, it adopts
intelligent technology to record variation in each frame rather than record
each full frame. As a result, less network bandwidth it requires and file size
is prone to be smaller compared with MJPEG.
Resolution
2048×1536, 1920×1080, 1280×960,
1280×720, 800×600, 640×480,
640x360, 320x240, 320x176
2048×1536 is the highest resolution
320x176 is the lowest resolution.
Frame Rate
(fps)
NTSC: 1~30
PAL: 1~25
The utmost fps settings for 2 systems varies as the following:
NTSC:
H.264/MJPEG single stream: 2048×1536@15fps; H.264/MJPEG single
stream: 1920×1080 to 320x176@30fps
PAL:
H.264/MJPEG single stream: 2048×1536@15fps; H.264/MJPEG single
stream: 1920×1080 to 320x176@25fps
GOP (Group
Of Pictures)
Length
NTSC: 1~60
PAL: 1~50
Select an applicable GOP length number for your environment. Less
number means the distance between 2 I-frames is smaller, which needs
more network bandwidth with better image. By contrast, larger number
consumes less bandwidth but is hard to be recovered. The default GOP
Length is 20
.
QoS (DSCP)
Codepoint
0 ~ 63
To classify and manage network traffic and provide quality of service (QoS)
on modern IP networks, Differentiated Services Code Point (DSCP) is a
computer networking architecture that specifies a resource allocation to
each device on a priority-based pattern for ideal bandwidth management.
The bigger value, the higher priority it will be.
H264 Profile
Main
High
There’re 2 kinds of profiles for H.264 codec and the compression ratio with
protocol for each type are different. Users may choose a proper one for
desired applications or contact IT personnel for more information.
Rate Control
CBR: Constant Bit Rate
VBR: Variable Bit Rate
Choose the Rate Control selection based on user requirements. Higher
bit rate values will result in better quality with bigger file size. CBR stands
for constant mode with a fixed bit rate value by user definition, while VBR
means variable mode in which users can set a range of upper and lower
limits respectively for bit rate control.
M-JPEG Quality
Level
Low/Mid/High
While “Low” produces the highest image quality, it increases the file size; on
the other hand, “High”, the lowest image quality, decreases the file size.
Table 4 - 3: Edit Profile Options