Axis 01089-001 - About Media Streams; About H.264 Format; About MJPEG Format; About AXIS Media Control (AMC)

XF40-Q2901Explosion-ProtectedTemperatureAlarmCamera
Aboutmediastreams
Aboutmediastreams
TheAxisproductprovidesseveralvideostreamformats.Yourrequirementsandthepropertiesofyournetworkwilldeterminethe
typeyouuse.
TheliveviewwindowintheproductprovidesaccesstoH.264andMotionJPEGvideostreams,andtothelistofavailablestream
proles.Otherapplicationsandclientscanaccessvideostreamsdirectly,withoutgoingviatheliveviewwindow.
AboutH.264format
H.264can,withoutcompromisingimagequality,reducethesizeofadigitalvideolebymorethan80%comparedwiththeMotion
JPEGformatandasmuchas50%morethantheMPEG-4standard.Thismeansthatmuchlessnetworkbandwidthandstoragespace
arerequiredforavideole.Orseenanotherway,muchhighervideoqualitycanbeachievedforagivenbitrate.
Decidingwhichcombinationofprotocolsandmethodstousedependsonyourviewingrequirements,andonthepropertiesof
yournetwork.TheavailableoptionsinAXISMediaControlare:
UnicastRTP
Thisunicastmethod(RTPoverUDP)isused
forliveunicastvideo,especiallywhenitis
importanttohaveanup-to-datevideostream,
evenifsomeframesaredropped.
RTPoverRTSP
Thisunicastmethod(RTPtunneledoverRTSP)
isusefulasitisrelativelysimpletocongure
rewallstoallowRTSPtrafc.
RTPoverRTSPoverHTTP
Thisunicastmethodcanbeusedtotraverse
rewalls.Firewallsarecommonlyconguredto
allowtheHTTPprotocol,thusallowingRTPto
betunneled.
Unicastingisusedforvideo-on-demand
transmissionsothatthereisnovideotrafc
onthenetworkuntilaclientconnectsand
requeststhestream.
Notethatthereareamaximumof20
simultaneousunicastconnections.
MulticastRTP
Thismethod(RTPoverUDP)shouldbeusedforlivemulticastvideo.Thevideostreamisalways
up-to-date,evenifsomeframesaredropped.
Multicastingprovidesthemostefcientusageofbandwidthwhentherearelargenumbersof
clientsviewingsimultaneously.Amulticastcannothowever,passanetworkrouterunlessthe
routerisconguredtoallowthis.ItisnotpossibletomulticastovertheInternet,forexample.
Notealsothatallmulticastviewerscountasoneunicastviewerinthemaximumtotalof20
simultaneousconnections.
AXISMediaControlnegotiateswiththeAxisproducttodeterminethetransportprotocoltouse.Theorderofpriority,listedinthe
AMCControlPanel,canbechangedandtheoptionsdisabled,tosuitspecicrequirements.
Note
H.264islicensedtechnology.TheAxisproductincludesoneH.264viewingclientlicense.Installingadditionalunlicensed
copiesoftheclientisprohibited.Topurchaseadditionallicenses,contactyourAxisreseller.
AboutMJPEGformat
ThisformatusesstandardJPEGstillimagesforthevideostream.Theseimagesarethendisplayedandupdatedataratesufcient
tocreateastreamthatshowsconstantlyupdatedmotion.
TheMotionJPEGstreamusesconsiderableamountsofbandwidth,butprovidesexcellentimagequalityandaccesstoeveryimage
containedinthestream.TherecommendedmethodofaccessingMotionJPEGlivevideofromtheAxisproductistousetheAXIS
MediaControlinInternetExplorerinWindows.
AboutAXISMediaControl(AMC)
AXISMediaControl(AMC)inInternetExplorerinWindowsistherecommendedmethodofaccessinglivevideofromtheAxisproduct.
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