JVC V.NETWORKS VN-C30U Instructions Manual page 23

6-1 Setting the Image Compression Method
VN-C30U allows selection of either the MPEG1 compression or the JPEG
compression. (Hereafter, MPEG1 will be referred to as MPEG in this
manual.) On the V.NETWORKS Setup Tool screen, select MPEG or JPEG
in the "Image Compression" area, and then click the Details button to set
the details for the compression method.
When MPEG is selected
This is to select the data structure for the intra-frame compression of the
image data.Group of Pictures (GOP) denotes a group that contains at least
one frame of the image (I picture) frames of the data of the in-frame com-
pression that becomes the source of the intra-frame compression. Press
the Details button and select GOP.If the bit rate is the same, the image
quality will be higher when there are more B frames and as the delay time
becomes large for the composition of the final lines of the frame, this set-
ting is recommended for recording.
GOP consists of three types of pic-
tures, namely I, P and B.
I picture: Image composed only by
the in-frame compression data.
(Data size: Large)
P picture: Image compressed by ref-
erencing past picture data.
(Data size: Medium)
B picture: Image with data com-
pressed by using past and future I or
P pictures. (Data size: Small)
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