Axis 0643-001~EOL Axis P3915-R User Manual

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AXISP3915–RNetworkCamera

VideoandAudio

•Maximumframerate.Toavoidbandwidthproblems,theframerateallowedtoeachviewercanbeLimitedtoaxed

amount.Alternatively,theframeratecanbesetasUnlimited,whichmeanstheAxisproductalwaysdeliversthehighest

frameratepossibleunderthecurrentconditions.

•Overlaysettings.SeeOverlayonpage21.

ClickSavetoapplythenewsettings.

H.264

H.264,alsoknownasMPEG-4Part10/AVC,isavideocompressionstandardthatprovideshighqualityvideostreamsatlowbitrates.

AnH.264videostreamconsistsofdifferenttypesofframessuchasI-framesandP-frames.AnI-frameisacompleteimagewhereas

P-framesonlycontainthedifferencesfrompreviousframes.

TheGOVlengthisthenumberofframesbetweentwoconsecutiveI-frames.IncreasingtheGOVlengthmaysaveconsiderablyon

bandwidthrequirementsinsomecases,butmayalsohaveanadverseaffectonimagequality.

TheAxisproductsupportstwoH.264proles.TheMainproleprovideshighercompressionthantheBaselineprolewiththesame

videoquality,butrequiresmoreprocessingpowertodecode.

ThebitratecanbesetasVariablebitrate(VBR)orConstantbitrate(CBR).VBRadjuststhebitrateaccordingtotheimage

complexity,usingupmorebandwidthforincreasedactivityintheimage,andlessforlowerimageactivity.Whentheactivityin

thesceneincreases,thebitratewouldusuallyincreaseaswell.Ifthereisasurplusinbandwidth,thismaynotbeanissueand

selectingVariablebitrate(VBR)willbesufcient.Butifbandwidthislimited,itisrecommendedtocontrolthebitratebyselecting

Constantbitrate(CBR).Whentheactivityinthesceneincreases,VBRadjuststhebitrateaccordingtothecomplexity,usingup

morebandwidthforincreasedactivityinthescene,andlessforlowersceneactivity.CBRallowsyoutosetatargetbitratethat

limitsthebandwidthconsumption.

TheCBRtargetbitrateworksliketheceilingofatent.Itlimitsthebitrate,whilemaintainingsomeexibility.Thebitratemaybounce

upanddownwithinthesettargetbutwhenitnearsthesettargetvalue,thelimitationkicksin.However,becauseCBRwillalways

prioritizeacontinuousvideostream,itallowstemporaryovershootsfromthetargetbitrate.Becausesettingatargetvalueprevents

thebitratefromincreasing,framerateandimagequalityareaffectednegatively.Topartlycompensateforthis,selectwhichvariable

shallbeprioritized,framerateorimagequality.Notsettingaprioritymeansthatframerateandimagequalityareequallyaffected.

Thecurrentbitratecanbesettoappearastextoverlay.UnderOverlaySettings,selectIncludetextandenterthemodier

#bintheeld.

Toapplythesettings,clickSave.

MJPEG

Sometimestheimagesizeislargeduetolowlightorcomplexscenery.Adjustingthemaximumframesizehelpstocontrolthe

bandwidthandstorageusedbytheMotionJPEGvideostreaminthesesituations.SettingtheframesizetotheDefaultsetting

providesconsistentlygoodimagequalityattheexpenseofincreasedbandwidthandstorageusageinlowlight.Limitingtheframe

sizeoptimizesbandwidthandstorageusage,butmaygivepoorimagequality.Topreventincreasedbandwidthandstorageusage,

themaximumframesizeshouldbesettoanoptimalvalue.

StreamProles

Astreamproleisasetofpredenedstreamsettingsincludingresolution,compression,framerateandoverlaysettings.Stream

prolescanbeused:

•Whensettinguprecordingusingactionrules.SeeEventsonpage34.

•Whensettingupcontinuousrecording.SeeContinuousRecordingonpage39.

•IntheLiveViewpage–selectthestreamprolefromtheStreamproledrop-downlist.

Forquicksetup,useoneofthepredenedstreamproles.Eachpredenedprolehasadescriptivename,indicatingitspurpose.If

required,thepredenedstreamprolescanbemodiedandnewcustomizedstreamprolescanbecreated.

Tocreateanewproleormodifyanexistingprole,gotoSetup>Video&Audio>StreamProles.

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Axis 0643-001~EOL P3915-R 2MP Fixed Dome Network Camera 0643-001

Axis P3915-R User Manual - Page 18