41
TANDBERG
FieldView Administrator Guide
D14098.02 June 2008
segment with the least bandwidth which will limit the overall bandwidth.
You should also consider what fraction of the available bandwidth you wish to
use so as to leave a margin for other users and other traffic.
Table 6-2 shows the bandwidth required if FieldView is configured to operate
at its maximum limits. If the network has insufficient bandwidth to support
the streams, defects will be evident in the image and audio, and it will be
necessary to drop to a lower stream rate.
Table 6-2 Maximum FieldView Bandwidth Requirement
Stream
To TANDBERG
FieldView
Application
To TANDBERG
FieldView Device
Notes
Video
Up to 2.5 Mbps
(TANDBERG
FieldView Device
video streaming –
live or playback)
Up to 2.5 Mbps
(playback from
TANDBERG
FieldView
Application)
MPEG-4
Operator voice
64 kbps
G.711
Expert voice
64 kbps
G.711
Subject audio
64 kbps
64 kbps (playback
from TANDBERG
FieldView
Application)
G.711
Data/Control
Up to 64 kbps
Up to 64 kbps
Total
Up to 2.7 Mbps
Up to 2.7 Mbps
Note:
if low bandwidth audio is negotiated the voice and subject audio are
reduced to 13 kbps from 64 kbps.
Video Size
The TANDBERG FieldView Device is designed to transmit a range of image
sizes from 320
!
240 (76,800 pixels) to 720
!
480 (345,600 pixels) for the NTSC
model and to 720
!
576 (414,720 pixels) for the PAL model.
Some video sizes may result in cropping of the video that is streamed or
recorded as compared to that shown on the viewfinder. Use the Show Actual
Video Boundary feature at the TANDBERG FieldView Device to view the
cropped area on the TANDBERG FieldView Device.
Frame Rate
Higher frame rates provide better motion capture, although this will generally
require a higher bit rate to maintain image quality. The available frame rates
are based on camera type:
NTSC: 3 5 10 15 30
PAL:
3.1 5 8.3 12.5 25
MPEG-4 Frame Types
MPEG-4 works by processing the successive pictures of a video into
compressed frames. There are two types of frames which may be produced:
I-Frames are independent of any other frame and may be decompressed to
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Chapter 6
