Planet ICA-650, Руководство пользователя

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Appendix C
Bandwidth Calculation
Appendix C: Bandwidth Calculation
The frame rate of video transmitted from the ICA-650 depends on connection
bandwidth between client and server and quality setting of server. Here is a guideline
to help you roughly estimate the bandwidth requirements form your ICA-650.
Image bandwidth is approximately equal to the average frame rate in frames per
second multiplied by the average frame data size in kilobits. Frame data size, or the
number of bits comprising a single video frame varies a great deal from depending on
scene complexity, lighting conditions, camera noise, etc. The table shown below is
reference figures. Actual results generated by the ICA-650 may be varying.
Image Resolution Average range of Data Sizes
176 x 144 (QCIF) 20 – 40k bit
320 x 240 (QVGA) 56– 92k bit
352 x 288 (CIF) 64 – 112k bit
640 x 480 (VGA) 160 – 320k bit
For example, streaming 2 fps of 320 x 240 video requires 112 to 184 kbps (kilobits per
second). Therefore, with a 128K upload connection; you will typically see 3 to 6
frames per second with 176 x 144 resolution and 1 to 2 frames per second with 320 x
240 resolution without audio stream.
Audio streaming also takes bandwidth around 32 kbps to
64kbps. Most ADSL/Cable modem upload speeds may not
even reach up to 128 kbps. Thus, you may not be able to
receive any video while streaming audio on a 128 kbps
or lower connection. Even though the upload speed is
more than 128kbps, for optimal video performance,
disabling audio streaming will get better video
performance.
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