Axis M3046-V - Image, Stream, and Profile Settings Relation; Bitrate Control

AXISM30NetworkCameraSeries
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MotionJPEG,orMJPEG,isadigitalvideosequencethatismadeupofaseriesofindividualJPEGimages.Theseimagesarethen
displayedandupdatedataratesufcienttocreateastreamthatshowsconstantlyupdatedmotion.Fortheviewertoperceivemotion
videotheratemustbeatleast16imageframespersecond.Fullmotionvideoisperceivedat30(NTSC)or25(PAL)framespersecond.
TheMotionJPEGstreamusesconsiderableamountsofbandwidth,butprovidesexcellentimagequalityandaccesstoeveryimage
containedinthestream.
H.264orMPEG-4Part10/AVC
Note
H.264isalicensedtechnology.TheAxisproductincludesoneH.264viewingclientlicense.Toinstalladditionalunlicensed
copiesoftheclientisprohibited.Topurchaseadditionallicenses,contactyourAxisreseller.
H.264can,withoutcompromisingimagequality,reducethesizeofadigitalvideolebymorethan80%comparedtotheMotion
JPEGformatandbyasmuchas50%comparedtotheMPEG-4standard.Thismeansthatlessnetworkbandwidthandstoragespace
arerequiredforavideole.Orseenanotherway,highervideoqualitycanbeachievedforagivenbitrate.
HowdoImage,Stream,andStreamprolesettingsrelatetoeachother?
TheImagetabcontainscamerasettingsthataffectallvideostreamsfromtheproduct.Ifyouchangesomethinginthistab,it
immediatelyaffectsallvideostreamsandrecordings.
TheStreamtabcontainssettingsforvideostreams.Yougetthesesettingsifyourequestavideostreamfromtheproductanddon’t
specifyforexampleresolution,orframerate.WhenyouchangethesettingsintheStreamtab,itdoesn’taffectongoingstreams,but
itwilltakeeffectwhenyoustartanewstream.
TheStreamprolessettingsoverridethesettingsfromtheStreamtab.Ifyourequestastreamwithaspecicstreamprole,the
streamcontainsthesettingsofthatprole.Ifyourequestastreamwithoutspecifyingastreamprole,orrequestastreamprole
thatdoesn'texistintheproduct,thestreamcontainsthesettingsfromtheStreamtab.
Bitratecontrol
Withbitratecontrol,youcanmanagethebandwidthconsumptionofyourvideostream.
Variablebitrate(VBR)
Withvariablebitrate,thebandwidthconsumptionvariesbasedonthelevelofactivityinthescene.Themoreactivityinthescene,
themorebandwidthyouneed.Youareguaranteedconstantimagequalitybutitrequiresstoragemargins.
kbit/s
s
Maximumbitrate(MBR)
Withmaximumbitrate,youcansetatargetbitratetohandlebitratelimitationsinyoursystem.Youmayseeadeclineinimage
qualityorframeratewhentheinstantaneousbitrateiskeptbelowthespeciedtargetbitrate.Youcanchoosetoeitherprioritize
imagequalityorframerate.Werecommendthatyoucongurethetargetbitratetoahighervaluethantheexpectedbitrate.This
givesyouamarginforadditionalcomplexitythatneedstobecaptured.
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