4.4 Streaming conguration
There is a relation between the camera image, the resolution (the number of pixels),
the amount of motion in the image and the video bitrate. The more colorful and
the more varied the image is that the camera delivers, the higher the bitrate that is
required to transmit the image with sucient quality. The more motion there is in
the image, the more bits (higher bitrate) are needed to display that motion right.
With a given resolution and bitrate combination it is always possible to calculate the
number of bits per pixel. The more bits per pixel, the better the image (as long as the
network connection can handle it). At some point `saturation' occurs, where a higher
bit rate does not help, because there are enough bits to display each pixel correctly.
The more pixels, more details can be passed in the picture, but only if the bitrate is
sucient to transmit the details with sucient quality. More pixels (higher resolution)
with the same bit rate gives a lower quality and not necessarily a better viewing
experience. An exception to this is the situation where the bitrate is more than
sucient for the chosen resolution. In that case the image can become better by just
increasing the resolution.
If you have a good image quality at (for example) 3 bits per pixel and you increase
the resolution, you will need a higher resolution of 3 to the power of 0.75 bits per
pixel for the same quality. For example:
Current resolution
Higher resolution
Pixels
352 x 288
768 x 576
Bitrate
300
to be determined
Bits/pixel
2.96
2
.
96
0
.
75
= 2
.
26
Then the required bitrate for the same quality is
768(
hor
)
·
576(
ver
)
·
2
.
26(
bitperpix
)
1000
= 998
Kbps
It is important to vary these parameters when conguring the Maven to tune optimally
to the local situation.
Version v8.0
Nov 2012
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