User's Manual

AXISM3007–PV

Video

Thisoptionisonlyavailableforthefollowingviewmodes:

•Panorama

•DoublePanorama

•QuadView

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