Gadspot N600E User Manual page 19

Resolution -
The resolution here describes an image size counted by width and height, e.g. 640x480, referring to pixel
st
resolution. The 1 stream can be set from more options of resolution; 1600x1200 (2 megapixels), 1280x720(HD),
800x600(SVGA), 640x480(VGA), 320x240(QVGA). While Stream2 has the options of VGA and QVGA, stream3 is
in a fixed resolution, the QVGA.
Video Mode -
This option allows the selection of two bit rate modes, the Constant Bit Rate (CBR) or Variable Bit Rate (VBR).
CBR refers to the setting of a fixed Target Bit Rate (configuration in the rage of 64Kbps to 6Mbps) that would apply
in the case of limited bandwidth or/and storage requirement. While CBR concerns a fixed data rate transmitting, the
video quality is of high priority for VBR mode selected. VBR therefore is configured with the Quality Level
(Standard, Good, Best). In general, CBR predicts the provided condition; if image activity requires higher bit rates
than configured, the frame rate and quality would be affected as not likely to increase bandwidth (bit rate). In spite
of the required recording storage estimation, VBR is by way of compensation that adjustable bit rate fits the actual
image activity.
Image Format -
H.264 and MJPEG are available for image format selection. The term, "image format", is referring to compression /
encoding technique. The selection of image format decides the performance of bandwidth and storage requirement.
In the request of same video quality, H.264 contributes to less bandwidth and storage requirement, which is more
efficient than MJPEG.
GOP -
In H.264 video coding, GOP (group of pictures) describes how the different types of frames are arranged. The
frame types implemented here are I-frame (full image information) and P-frame (motion-compensated difference
information). This setting configures the GOP length which is the number of frames before next I-frame appears.
Having more I-frames usually increases the stream size, and therefore more bandwidth and storage are required.
Frame Rates -
The Frame Rates defines the number of frames that will be displayed per second. The frame rate setting can affect
the target bit rate (bandwidth requirement) and storage requirement.
Note:
While multiple streaming is possible, each stream has its limitation and dependency to other stream. See "Video
Stream Specification".
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