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3.1 Video Stream Types
Motion JPEG
This format uses standard JPEG images in the video stream. These images are then
displayed and updated at a rate sufficient to create a stream that shows constantly updated
motion.
The Motion JPEG stream uses a considerable amount of bandwidth, but it also provides
excellent image quality and access to every individual image contained in the stream.
H.264 protocols and communication methods
•
RTP
(
R
eal-time
T
ransport
P
rotocol) is a protocol that allows programs to manage the real-
time transmission of multimedia data, via unicast or multicast.
•
RTSP
(
R
eal
T
ime
S
treaming
P
rotocol) serves as a control protocol, to negotiate the type of
transport protocol to use for the stream. RTSP is used by a viewing client to start a unicast
session.
•
UDP
(
U
ser
D
atagram
P
rotocol) is a communications protocol that offers limited service for
exchanging data in a network which uses the Internet Protocol (IP).
UDP is an alternative to the Transmission Control Protocol (TCP). The advantage of UDP is
that it is not required to deliver all data and may drop network packets when there is network
congestion. This is suitable for live video, as there is no point in re-transmitting old
information that will not be displayed anyway.
•
Unicasting
is communication between a single sender and a single receiver over a
network. This means that the video stream goes independently to each user, and each user
gets own stream. A benefit of unicasting is in case one stream fails, it only affects one user.
•
Multicasting
is bandwidth-conserving technology that reduces bandwidth usage by
simultaneously delivering a single stream of information to multiple network recipients. This
technology is used primarily on delimited networks (intranets), as each user needs an
uninterrupted data flow and should not rely on network routers. (Note that multicasting may
not be available with the firmware you received; check the Vicon website for updated
firmware.)
3.2 How to Stream H.264
Deciding on the combination of protocols and methods to use depends on your viewing
requirements, and on the properties of your network. Setting the preferred method(s) is done
in webpage.
RTP+RTSP
This method (actually RTP over UDP and RTSP over TCP) should be your first
consideration for live video, especially when it is important to always have an up-to-date
video stream, even if some images are lost due to network problems. This could be
configured as multicast or unicast.
RTP/RTSP/Unicasting
should be used for video-on-demand broadcasting, so that there is
no video traffic on the network until a client connects and requests the stream. However, as
more and more unicast clients get connected, the traffic on the network will increase and
