Axis Communications AXIS 221 MPEG-4 protocols and communication methods, How to stream MPEG-4

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AXIS 221 - Video Streams 13

MPEG-4 protocols and communication methods

To deliver live streaming video over IP networks, various combinations of transport protocols and broadcast methods are employed.

RTP (Realtime Transport Protocol) is a protocol that allows programs to manage the real-time transmission of multimedia data, via unicast or multicast.

RTSP (Real Time Streaming Protocol) serves as a control protocol, to negotiate which transport protocol to use for the stream. RTSP is thus used by a viewing client to start a unicast session, see below.

UDP (User Datagram Protocol) is a communications protocol that offers limited service for exchanging data in a network that uses the Internet Protocol (IP). UDP is an alterna- tive 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 e.g. 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 net- work. This means that the video stream goes independently to each user, and each user gets their own stream. A benefit of unicasting is that if one stream fails, it only affects one user.

Multicast is bandwidth-conserving technology that reduces bandwidth usage by simul- taneously 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.

How to stream MPEG-4

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 the control applet for AMC, which is found in the Windows Control Panel. When this has been set, AMC will test all the selected methods in the specified order, until the first functioning one is found.

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 can be configured as multicast or unicast.

Multicasting provides the most efficient usage of bandwidth, especially when there are large numbers of clients viewing simultaneously. Note however, that a multicast broadcast cannot pass a network router unless the router is configured to allow this. It is thus not possible to multicast over e.g. the Internet.

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Contents Axis 221 Network Camera User’s Manual About this Document Contents Axis Product Features Rear panel OverviewNetwork LED indicatorsAccess from a browser Accessing the CameraAccessing the camera from the Internet Setting the root passwordFocusing Live View Axis 221 Accessing the Camera Video stream types Video StreamsMotion Jpeg MPEG-4 protocols and communication methods How to stream MPEG-4Axis Media Control Other methods of accessing the video streamRTP/RTSP/HTTP or RTP/RTSP/HTTPS Other MPEG-4 clients Accessing the setup tools from a browser Setup ToolsImage Settings Video and Image SettingsText Overlay Settings Image AppearanceVideo Stream Overlay/Mask SettingsTest Overlay/Mask TypeOverlay image requirements Upload and use an overlayCamera settings Advanced settingsMPEG-4 Settings Mjpeg Settings Use custom settings Live View ConfigOwn home Upload Own Web FilesUser-defined Links ExampleDefault Viewer Default Video FormatAction Buttons Output ButtonsViewer settings Sequence ModeHtml Examples External VideoEvent Servers Event ConfigurationDefinitions How to set up a triggered event Configuring Event TypesTriggered Event Click Add triggered... on the Event TypesScheduled Event Pre-trigger and Post-trigger buffersCamera Tampering SettingsMotion Detection History Sensitivity Port StatusSecurity Users System OptionsSecurity IP Address Filtering ReferralsSecurity Https Security CA servers Authentication processIP Address Configuration Network Basic TCP/IP SettingsDate & Time Services Network Advanced TCP/IP SettingsDNS Configuration NTP ConfigurationLink-Local IPv4 Address Host Name ConfigurationNAT Traversal Network Traffic Network SocksQoS Settings Network QoS Quality of ServiceNetwork Smtp email Network UPnP Network SnmpNetwork RTP Multicast/MPEG-4 Network BonjourMaintenance LED SettingsSupport Support OverviewLogs & Reports AdvancedUsing the Reset Button Resetting to the Factory Default SettingsAbout Terminal connector Unit ConnectorsTerminal connector schematic diagram Terminal connector pinout tablePower connector block Power connectionsSchematic Diagram Power terminal block and power connectors RS-232 connector Basic Configuration TroubleshootingChecking the Firmware Upgrading the FirmwareAxis Support Emergency Recovery ProcedureProblems setting the IP address Symptoms, Possible Causes and Remedial ActionsVideo/Image problems general Status and Network indicator LEDs are flashing red rapidly Removing and attaching the lens Replacing the lensFrame rate Technical SpecificationsCasing Applications Optimizing your system General performance considerationsBandwidth Frame rates Motion Jpeg and MPEG-4Glossary of Terms Page Axis 221 Index IndexRtsp