Axis P1425–LE - Stream Profiles; H.264; Mjpeg

AXISP1425–LENetworkCamera
Video
•Overlaysettings.SeeOverlayonpage20.
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.SeeEventsonpage33.
•Whensettingupcontinuousrecording.SeeContinuousRecordingonpage38.
•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>StreamProles.
ToselectadefaultstreamprolefortheLiveViewpage,gotoSetup>LiveViewCong.
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