Vivotek S Series IZ9361-EH 1080p Outdoor Network Bullet Camera with Heater User Manual

Page 72

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VIVOTEK

72 - User's Manual

■ Dynamic Intra frame period

High quality motion codecs, such as H.265, utilize the redundancies between video frames to

deliver video streams at a balance of quality and bit rate.

The encoding parameters are summarized and illustrated below. The

I-frames

are completely

self-referential and they are largest in size. The

P-frames

are predicted frames. The encoder

refers to the previous I- or P-frames for redundant image information.

P I P P P P P P P P P P P P P P P P P P P I

P I P P P P P P P I P P P P P P P I

Static scene

Activities

P P P

P I P P P P P P P I P P P P P P P I

By dynamically prolonging the intervals for I-frames insertion to up to 10 seconds, the bit rates

required for streaming a video can be tremendously reduced. When streaming a video of a

static scene, the Dynamic Intra frame feature can save up to 53% of bandwidth. The amount of

bandwidth thus saved is also determined by the activities in the field of view. If activities occur

in the scene, firmware automatically shortens the I-frame insertion intervals in order to maintain

image quality. In the low light or night conditions, the sizes of P-frames tend to be enlarged due

to the noises, and hence the bandwidth saving effect is also reduced.

Streaming a typical 2MP scene normally requires 3~4Mb/s of bandwidth. With the Dynamic Intra

frame function, the bandwidth for streaming a medium-traffic scene can be reduced to 2~3Mb/s,

and during the no-traffic period of time, down to 500kb/s.

H.264/265 Frame Types

Dynamic Intra Frame w/

static scenes

Dynamic Intra Frame w/

activities in scenes

Smart stream II

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