Axis P5624-E - H.264; MJPEG; Stream Profiles

AXISP5624–EPTZDomeNetworkCamera
Video
H.264
H.264,alsoknownasMPEG-4Part10/AVC,isavideocompressionstandardthatprovideshighqualityvideostreamsatlowbitrates.
AnH.264videostreamconsistsofdifferenttypesofframessuchasI-framesandP-frames.AnI-frameisacompleteimagewhereas
P-framesonlycontainthedifferencesfrompreviousframes.
TheH.264streamsettingscanbeconguredfromtheVideo>VideoStreampage.SelecttheH.264tab.Thesettingsdenedinthis
pagewillapplytoallH.264streamsthatdonotuseastreamprole.
TheGOVlengthisthenumberofframesbetweentwoconsecutiveI-frames.IncreasingtheGOVlengthmaysaveconsiderablyon
bandwidthrequirementsinsomecases,butmayalsohaveanadverseaffectonimagequality.
TheAxisproductsupportsthefollowingH.264prole(s):
•Baseline.TheBaselineproleisrecommendedforclientsthatdon’tsupportCABACentropycoding.
•Main.TheMainproleprovideshighercompressionwithmaintainedvideoqualitycomparedtotheBaselineprolebut
requiresmoreprocessingpowertodecode.
•High.TheHighproleprovidesreducedbitrateandhighercompressionwithmaintainedvideoqualitycomparedtothe
Mainprolebutrequiresmoreprocessingpowertodecode.
ThebitratecanbesetasVariablebitrate(VBR)orMaximumbitrate(MBR).VBRadjuststhebitrateaccordingtotheimage
complexity,usingupmorebandwidthforincreasedactivityintheimage,andlessforlowerimageactivity.Whentheactivityin
thesceneincreases,thebitratewouldusuallyincreaseaswell.Ifthereisasurplusinbandwidth,thismaynotbeanissueand
selectingVariablebitrate(VBR)willbesufcient.Butifbandwidthislimited,itisrecommendedtocontrolthebitratebyselecting
Maximumbitrate(MBR).Whentheactivityinthesceneincreases,VBRadjuststhebitrateaccordingtothecomplexity,usingup
morebandwidthforincreasedactivityinthescene,andlessforlowersceneactivity.MBRallowsyoutosetatargetbitratethat
limitsthebandwidthconsumption.
TheMBRtargetbitrateworksliketheceilingofatent.Itlimitsthebitrate,whilemaintainingsomeexibility.Thebitrate
maybounceupanddownwithinthesettargetbutwhenitnearsthesettargetvalue,thelimitationkicksin.However,because
MBRwillalwaysprioritizeacontinuousvideostream,itallowstemporaryovershootsfromthetargetbitrate.Becausesettinga
targetvaluepreventsthebitratefromincreasing,framerateandimagequalityareaffectednegatively.Topartlycompensatefor
this,selectwhichvariableshallbeprioritized,framerateorimagequality.Notsettingaprioritymeansthatframerateand
imagequalityareequallyaffected.
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.SeeContinuousRecordingonpage40.
•IntheLiveViewpage–selectthestreamprolefromtheStreamproledrop-downlist.
Forquicksetup,useoneofthepredenedstreamproles.Eachpredenedprolehasadescriptivename,indicatingitspurpose.If
required,thepredenedstreamprolescanbemodiedandnewcustomizedstreamprolescanbecreated.
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