Digital Watchdog MEGApix DWC-MHS5W37T User Manual page 18

Set up - Video & Audio Set up
Video Configuration
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GOP (Group of Pictures) Size - Set up the number of frames (P-frame) that contain only changed
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information based on the basic frame (I-frame). Regarding videos with lots of movement, if you set the GOP
size bigger, only the number of P-frames is bigger.
As a result, the video resolution will be low, but 'File size' and 'Bitrate can be decreased.
GOP (Group of Pictures) Size -
I-frame and P-frame creation for MPEG4, H.264, and H.265 (HEVC) video compression. 'I-frame,' also known
as 'key-frame,' refers to the complete image data for a specific video frame. 'P-frame' refers to the changes
in the image compared to the previous video frame. As a result, the GOP consists of one I-frame and
several P-frames. For improved video quality, use a lower number of P-frames for this setting.
Profile - The profile defines the subset of bitstream features in H.264, H.265 (HEVC) stream, including color
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reproduction and additional video compression.
H.264: Main, High / H.265 (HEVC): Main
Main - An intermediate profile with a medium compression ratio. Supports I-frames, P-frames, and B-frames.
High - A complex profile with a high compression ratio. Supports I-frames, P-frames, and B-frames.
Bitrate Mode - Select the bitrate control scheme of video compression from CBR (Constant Bitrate) or VBR
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(Variable Bitrate).
CBR - To guarantee the designated constant bit rate, the video quality is controlled in this mode. Therefore, the
video quality will likely vary when network traffic changes.
VBR - To guarantee the designated quality, the bit rate of the video stream is changed in this mode. Therefore,
the video's frame rate will likely vary when network traffic changes.
This category will not appear if you select the MJPEG codec.
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