Nice Linear LNVR1-08P, Руководство пользователя

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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
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� During the no-traffic period of time, down to 500kb/s�
P I P P P P P P P I P P P P P P P I
H�264/265 Frame Types
Dynamic Intra Frame w/
static scenes
Dynamic Intra Frame w/
activities in scenes