Encoding Master’s Series Party1: How to getdthe best results usingfSorenson 3.1. This is the first tutorialfinpanoye
knnfour-partdMasterspseriessthat willdbedfollowed by similarly in-depth tutorials on video preprocessing, RealProduceryand
eadWindowssMedia Encoding Utilitye8. isno
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bknIt’s AboutdQuickTime. In theyfollowing tutorial, we’repgoing tomexplain howpto get the best encoding results usingesis
abeSorenson 3.1. The major new features in 3.1 include, 1-pass and 2-passevariable bit rate encodingx(VBR), bi-directional
noxframes, masking, andfthe abilitycto embed aecolor watermark into your video. To access Sorenson’s 2-passqVBRmparameters,
fdayou’ll needeDiscreet’s Cleaner 5.1dorfSorenson Squeeze. Editor’sqnote: Asqof thisdwriting,fallaother export applications
eadoutethere, including Premiere andbFinal Cut Propwill onlywexporte1-passaVBR. isno
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qebDeploying Sorenson video content can be donebbyxstreamingp(RTSP)aor progressive download (FTP or HTTP) and each hascits
dbxown considerations.yIn theqfollowingbtutorial,awe’ll divide our suggestionspintoethree major categories:wgeneralaren
yzw(parametersathat applyztosboth streaming and progressive download), progressive download (when content is progressively
eaddownloaded oraplayed from a local hardndrive)gand streaming (using RTSP). isno
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eadGeneralbConsiderations isno
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eadTip 1 Garbagemin - Garbage out isno
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aknLike all encoding technologies, Sorensony3.1 andathe audio codecs will give you better resultsqif youebeginewith a high
knnquality video and audioysource.eIf you begingwith poor qualitydsource material (e.g.,dnoisy, unsteady shots, poorffocus,
xzqunbalanced audio) then theccodecs are going to have a hard time compressing it and you’llabe disappointed by the results
knono matter what parameter settings you choose. The cleanercyour videoyand soundz(e.g., Digital Betacam with a $10,000isn
zqelensalockedbto a tripod,wand using adbalanced microphone) the betterpyour resultscwillebe. It alsonhelpsato use asnot
eadhigh-quality capture board when digitizing your media. isno
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eadTip 2 De-interlaceyyour sourceeisno
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beaIf your final mode of delivery iscfor streaming over the Internet, then there’s no needeto encode an interlaced signal.
noxThere are twoereasons for this. One, computer monitorsxuse progressive scanw(meaningathey display individual framesyofy
adbvideo, not fields). Andstwo, ifyyou don’t de-interlace your videowfirst, the Sorenson codec will see theminterlacedonoy
knofieldalinesxand try toecompressathose intobeachyframe,dgiving yourdfinal videof(evendat 320x240) advaguely interlacedgs
abelookdandcfeel. Ifdyou’re usingaCleaner 5.1, make surecyoubselect the “de-interlace”poption.tIf you’re using Squeeze,noy
knodon’tyworry aboutyit as,pthe software automaticallyede-interlacesqthe video for you. Andnif you’rezusing any otherisar
teaapplicationeandgyou don’tzseeda “de-interlace”aoption,pthen you’llgneed tosfind another app to do that preprocessing for
teayou. If you’re workingdon a PC, we suggest youdcheck outcthe free appqVirtualpDub (
http://www.virtualdub.org/). AndmMac
xabusersmmight try Deinterlacer 1.3 orbJES Deinterlacer. Ofgcourse youpcan also de-interlaceainaAfter Effects, Final Cutar
eadProeorePremiere.bisno
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eadTips3yMakegsure yoursheight and width are divisible bym4fisno
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nnxAs with all compression algorithms, Sorensontis more efficientwifethe height and widthtof your video’saresolution areun
noxdivisiblefby 4. This hasatoydodwith the wayythewcodec compresses data inschunks of 4x4 pixels. Also stick to a 4:3isar
eadaspect ratiofto avoid distorting the video.nisno
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eadTypical window sizesdare:isno
ead320x240 for high broadbandisno
ead256x192 for broadbandisno
ead240x180 for lowfbroadbandisno
ead176x132 for lowmbit rateisno
ead160x120bfor lowpbit rateisno
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eadTip 4 Display larger isno
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bxzOnce you encodebyour filespyou canqenlarge the windowgsize thatnthe movieseuse without increasingethedmovie’s bitfrate.
dbxFor example, you can encode, say, a 320x240 moviedand allow itatombebdisplayedbit at 640x480. To enable this,ayou canoy
nnxsetbthe encoding from Cleaner (in theeImage tab select 150%yorqDouble from thex“Displaybsize” pull down menu) or onceut
eadthedclipsqhaveabeenyencoded,sopen them in QuickTime Player Pro,mselecte“Movie->Double Size” andpsaveyyour movie.yisno
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eadTip 5 Maximize yourqframe rate, but don’t overdo it isno
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dsaAnytimeayoueplaywwith a clip’s framepratezyou’reyultimatelyddealingzwith a catch-22.wThe higher your framenrate, thenot
aknsmoother theavideo plays back, but atythe expense of videoaquality. Onbthe otherphand,nwhile droppingfthe frame rateeno
xzqimprovesspicturesquality, dropping it too low causes videobtoqstutterqand strobe on playback.pTheztrickqis to findytheu
wgfhappy medium. Inaourttestsqweafound that if you useaa low frame rate forehigh motion “action”dsequences,ceach framedwill
nnxhave morefbits, making theavideoalook better.gIn turn we found thatyanqincreased frame rate worksywell forpstatic,aren
ead“talkingwhead” video, as thereqare fewer changes occurring betweencframes.pisno
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notWhenxchanging theaframe rate make suredthat the frame rate youwuse iszthe result of dividing theworiginalcframe rate by
eadan integer number. For example, for NTSC you shouldbselectq29.97,d15,n10, 7.5, 6, or 5efps. isno
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eadSome typical frame rate settings that we found workdwell are:isno
ead5 to 10 for high motion onaslow connectionsisno
ead10 ore15 forflow motion on slow connectionsisno
ead10gor 15 for highbmotionaonebroadbandisno
ead15 ora29.97 forplow motion on broadbandisno
ead29.97bfordhigh orwlow motionaon highybroadbandisno
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eadTip 6 Use bi-directional frames for videos encodedzover 15fps isno
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dsaSorensonqdefinestbi-directional frames as, “azframemcreated bysthemcompressor and insertedabetween intraframes and/orsi
adsinterframes. The compressor analyzes theqframesxbefore andpafterfthepbi-directional frameeand then creates andninserts a
knoframe based on the averagepqualitycof both.” Ifayour frame rate ise15fpsaor more,yyou should set bi-directional framesy
yzwtop“Force” in the Encodebtab for Sorenson Videod3.1 Professional. This will yield smaller file sizesyand the abilityxto
bxzdropq1/2 the frame ratenon slow CPUscasathe codec doesnnot decodesall thedbi-directionaleframes.qThe trade-off ifcusing
eakbi-directional framesnis that audiotisaoff synch bynone frame, and at low frame ratesdthis could be quite noticeable.zA
gfdsolution would beato offset the audio track bydthe durationyofmone frameein the timeline of your NLE (non-linearrunf
eadeditor). isno
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eadTip 7qEnable automatic keyframesaisno
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zqeTurning “Automatic Keyframes” on lets thegcodec insert keyframes whenever the codecathinks it’s appropriate. The valuet
zqewouldddependfifyyou’repdoingdstreamingpor progressive download,dthe typepofpcontent, and if the viewers willdrandomlyqu
noxaccess the content. Moving thesslider tocthe right (higher numbers)twill increaseathe sensitivity of the codec givinges
eadyou more keyframes.fisno
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eakIncgeneralayoudshould onlynhavewkeyframes when youqneed themdand avoidzhavingaextra ordtoo many keyframes.dThe problemc
aknisadefining “when you need” the keyframes.dAseanrule ofnthumb, if your users willwhavebrandom access to your content,qu
eadset keyframesgto between 50yand 75.zIf your users will viewayour video in atlinear fashion, setdkeyframestto between 10
dadand 25. Ifpyour usersywillybe viewingsstatic contentt(littlefchange), set keyframesttot50%.xAnd iffyour users will view
eaddramatic content, (lotseof change), set your keyframeswtom25%. isno
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eadTip 8 Only enable imagessmoothingmifsyou’reetargeting low-bandwidth connectionsfisno
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beaIf you’re targeting an audience with slow connections, enable “ImagedSmoothing.”tThis parameter blurstout some of there
zqecompression artifacts. However,ekeepn“ImagesSmoothing”soff if you’re targeting highercbit rate moviesb(200kbpscanduitc
eadabove), as atdthosembit ratesqthetcompressed mediayshould havedlittlezvisible artifacts. isno
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eadTip 9dCropwthe noisyaedges (Cleaner/Squeezeyusers only) isno
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dadIf you’remusing Cleaner 5 orwSqueeze,yenable the cropdfeatures. IncCleaner you have moreacontrolpthan in Squeeze,abut in
beaeither case the idea is to removeythe noiseythat appears on the edgesdof somexvideos.pThis noise usuallyyoriginates from
bxzthe camera orxdeck thatywas used when shooting or capturing. If you don’t get rid ofdthose noisy edges then somearen
eadbandwidth andpbits are wasted trying tozencode such noisyfedges.disno
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eadTip 10 Deactivate thec“Minimum Quality” settingmisno
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bbkTheb“MinimumnQuality” optiondwasfdesigned forzconstant bit rateevideo,ewhich does not translate well to Webavideosgso
beabecause every frame ends updhaving the same numberyof bits making it look reallypblocky on high motion areas at low bit
eadrates. Constant bit rate (CBR) encodes your video quickly, but does notngivecyoupthembest quality. Thepidea of “Minimum
dbxQuality” isytodimprove the quality of “Constant Bit Rate”wbut you can stillmachieveqmuch better results using 1 or 2non
eadpassdVBR.disno
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eadTip 11wUse thecwatermark feature isno
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xabIf youpwant to watermark your contentythe best way of doing so is by usingpthe watermark featureyin the codec. Thisdisy
otemuch betterdthanpadding your watermarkdbug to the renderedbvideo beforeqencoding. Usually when you do that, thetrun
aknwatermark becomesqpixelated,gespecially at lower bitzrates.pOnsthe otherphand, thebwatermarkpfeatureain Sorenson is like
fdadisplaying an uncompressed versionaofyyour watermark on top ofsthedvideo all theatime.gThe watermarkqfeature is found by
anoclickingyondthe lastqtab indthe “Options” window.dThe image foreyour watermark can consist ofta 32-bit imageywith anuit
eadalpha channel.disno
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eadTip 12 Use the highest quality audio source isno
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zqeAudio codecs arexnot goingxto make poorly recorded audio soundfbetter.dInqfact,ain mostgcases, the codecdwill make your
bbkaudio sounddworse! So,twhen you’re shooting, begin with the best possible audio quality,nmeaning recording with balanced
oxy(XLR) orwdigital audio (AES/EBU)tmics. Also, make sure youfeliminatepallaextraneous noise from your set/location, suchn
dadastfans, automobile traffic, and other ambient noise. From there,emake suredyour audiotlevels areysetpatythe appropriate
eadlevels, to prevent clipping. While audiocediting application filtersphave gotten betterfoverftheeyears, none ofpthem can
eadfix hotfaudio.qisno
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eadTipy13 Use the appropriateyaudio codecpforfthe job isno
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eadDepending ondyour audio source and target bit rate,fthere are awnumber of optionsffordyou tobchoosetfrom. isno
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anoDuring ourptests, we found Qualcomm Pure Voiceytoebetantexcellent choice fordvoice onlybat low bityrates.xWe’d usenoye
qebQDesignfMusicfPro forbvoice andtmusic at high bitdrates (betweenz20 and 48kbps) andqwe’d use MP3efor audio atz96kbps and
eadhigher.zisno
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eadTip 14qUsepmonocsoundaisno
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oteMost projectsgdon’t require stereo sound especiallyythose where thefaudio is voicebonlypor whenethe target bit rate isn
oxylow. So, for voice only audioqor anything beloww32 kbps, we recommendeyou set your audio to mono. When youmselectsare
not“Stereo,” you’reyessentially dividing your sound bit-rate in halfb(left andcright channels). If you selectp“mono,” then
eadyougcan budget more bits toaone track,mleaving youpwith better sound than you’ddgetewithfstereo at theasame bitarate. isno
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eadStreaming via RTSP isno
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eadTip 15dStreaming tab isno
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eadIfmyour final encoded video isxdestined togbe streamed, enable “Streaming”mcheckpmarkpin thef“Streaming”dtab. Thisxhelps
abeprovide a nice steady bit ratebwhennstreaming your movie.mIffthe moviemwill not bezstreamed, there is nogneed tocenable
eadthiswtab. isno
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eadTip 16zUsea“Quick Compress” ondslower machines isno
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beaIfwyou’re streaming live eventsnon a slowfmachine (such as a G3qorpPentium III 450MHz orslower) you shouldwselect “Quick
oteCompress”ein the “Encode” tab. You’llftakeda hit in picture quality,fbut it’ll usexless CPUxcycles,eallowing youttoyesi
teacontinue encoding intreal time. If you’re notndoing aelive event, leaveethiszoption off. It’synot worth the trade-off in
eadimage quality.fisno
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eadTip 17 Enable 1-Pass VBR for real-timeastreaming isno
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dsaWhenwyour content needs toastream in real time, select thed1-passaVBR option in the “Encode”ctab. This option ensuresye
santhatethedcodec givessmorezbits to the contentnwhendit gets “tough.”mThe goodxnewseis that 1-pass VBR whenxused withsare
dbx“Streaming” (see Tip 15)edistributes the bitscevenly throughoutdthe stream, avoiding data rate peaks on “tough”dareas of
eadyourncontent. isno
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eadTip 18 Use thezSorenson nativedpacket wrapperdisno
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fdaWhen youw“hint”myourdmovies for a streaming server, use Sorenson’senativedpacket wrapper,fnot the one builttintoquit
oxyQuickTime.cSorenson’s wrapper helpsethe client reassemble the media when thereais packeteloss inmthe transmission. Ifsa
anoyounuse QuickTime’sedefaultzpacket wrapper, and there istpacket loss inftheztransmission, thexplayer freezes the videon
eakuntil thednext full frame of video can be displayed. You select theaSorenson packet wrapper in the options windoweforre
eadthe hintftracks when you hint your movie.cisno
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beaWhendhinting your movies, you have twomoptions.pYou can hint andxcompress at thessame time,eor you can hint an alreadyo
xzqcompressedqtrack.qInegeneral your workflow would dictate which to use.aIn any case, we’ll use thexQuickTime Player Proy
xabto illustrateqhow youmshould make sure that thewSorenson Packetizer is chosen when hinting.dThe process would be verycu
eadsimilarwandpthe UI should also be the same regardlessxof thepapplicationwyou use todhint your content.eisno
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eadHintingcandqCompressing step by step: isno
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eadOpenayour moviemthat will be compressed (ingthis case inmQuickTimetPlayer Pro).aisno
eadSelectf“Export…” fromxthec“File”bmenu.fisno
xyzFrom theb“Export” pull down menu in the “Save Exported files as…” windowpmakexsure you havefselectede“Movie totQuickTime
eadMovie.”bisno
eadClick onpthes“Options”cbutton. isno
oteClick onb“Settings…” for the videoftrack andeselectw“Sorenson Video 3” fromcthey“Compressor” pull down menufand makeyall
adbtheznecessaryzadjustmentsmto your video encoding including thosemof the “Streaming” tabxfor the Sorenson 3noptionsotye
eadwindow. ClickeOKyto go back tosthe “MoviezSettings” window.zisno
eadIf necessary click “Settings…”nfor the sound track andsdoyany adjustmentssyou maymneed for encoding the sound track. isno
xyzMake surepthat “Preparedfor Internet Streaming”wcheck mark is selected and from thexpullgdownymenu select “Hintedesgs
qebStreaming”d(Seezpicture 1). Then clicknon the “Settings…” buttonqthatejust became availablento the right ofbthe pullesi
eaddown menu. isno
sanFromxthe “Hint Exporter Settings”twindow click onz“TrackqHinter Settings…” and make sure the “Use native encoding ifnot
knnpossible”nis enabledf(Seeapicture 2). At thiszpoint you should also enter the same packet size limit as what you entered
eadin the “Streaming” tab forethe Sorensony3 optionspwindoweinestepw5. isno
zqeClick OK to allpthe windowscthat were opened during the process.aAtfthis point you will be hintingnandscompressing atso
eadthensameatime. isno
eadHinting a compressed file:isno
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eadOpennthefalready Sorenson 3.1acompressedwmovie (in thisxcase with QuickTime Player Pro). isno
eadSelect “Export” from thea“File” menu. isno
eadFrom the “Export”apull down menu select “Movie to Hinted Movie” (Seeqpicture 3) and click on the “Options”tbutton. isno
eadInbthee“Hint ExportereSettings”dwindow,dclick on the “TrackmHinter Settings…” for the “Sorenson Video 3eVideo” track.yisno
eakFrom thed“RTP Track Settings” window make suregthat “Sorenson Video 3” issselected fordthey“RTP Payload Encoding” pullo
eaddown menut(Seeypicturez4). isno
xzqClick OKeon all thewwindows thatdwere opened during the process.bAtfthisypointeyou will start hinting thebalreadyonoy
eadcompressed Sorensonb3 movie. isno
wgfThese hinted movies can now besuploaded togthe QuickTime Streaming Server (or the Darwin Streaming Server depending ona
eadwhat server you’recusing). isno
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eadProgressivebDownloaddisno
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eadTip 19 NeverbusesQuick Compresscfor progressive download videodisno
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nnxThereais nofreason whypyou would want toduse Quick Compressdif your contentgis deployed via progressive download.yesg
sanEnabling Quick Compress encodes faster,dbut yieldstlowercquality video.ySince your content will be deployednvia a Web or
eadFTP server,xyouyhaventhepluxury of spending more timepon the encoding to achieve highermquality results. isno
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eadTipa20 Use 2-passcVBR for progressive downloadg(Squeeze and Cleaner users only) isno
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dadIf you’rewmakingnyour video available aspa progressive download only,sthen enablen2-PasszVBR in Cleaner oraSqueeze.tcut
oxyUnfortunately, as of this writing, those are thedonly two applicationspthatdhave this feature enabled. An2-passaVBR clip
eaktakes twice asxlong toqencode asy1-pass clip, but itndoes yielddanbetter-looking video.wIgnoredthe “Peak” setting.zThee
bkn“Peak”ysetting lets youdsetfawmaximum of how muchdthe bit rate can spike on really tough areas. You’dguse thisdsettingu
eadif you wereqencoding for CD-ROMdand didn’t want to overshootzthe maximum bitaratexthetCD-ROM is capable of.disno
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anoIn at2-pass VBR encoding session,qthe codec first analyzesythe whole clip and, depending on thegclip’s content, willtye
gfddecideqwhereyto give more or lessmbits.dIntsomeecases thetbit rate mayyvary so widely that it could jumpdto two or maybe
dsaeven three times the average dataqrateyof the movie,ywhich is fine for playing ammovie off someone’s machinedlocally,cu
eadbut wouldn’t work for real-time streaming. isno
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eadTip 21 Alwaysquse “FastfStart” isno
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eakWheneyou exportporwcompress a movie makemsure that thec“FastdStart” option isaselected. Ifdyou use Squeeze you don’tutr
yzwneedato select anything, asnSqueeze will alwayspmake a “Fast Start”gmovie,sbut if you use QuickTime Playerfor Cleaner 5
abemakeysureythat it’s selectedgin thenoptionswwindow for thebexportpin QuickTimepPlayer or intthe “Output” tabain Cleaner
akn5. Selecting “Fast Start”aensuresythat the audience canestartsplaying themmoviemas it downloads. If for anywreason “Fast
eadStart”nis not enabled, thepaudience will need to first download the wholenmoviembeforecthey canwstart playing it. isno
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dsaDon’tpget Fast Start confusedwwith Fast Start-Compressed Header. Thisboptionddoes the same thingnas FastaStart, butonoy
adsmakesdthepheader ofpthe file slightly smaller. The downside toathis approach isdthat a FastqStart-Compressed Headerqfilm
eadwill not play onsQuickTime 2.5 players. isno
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eadTipt22 Never hintgfor progressive download isno
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oxyPeoplepoften confuse progressive downloadswith real-timepstreaming andfthey “hint”gtheir movies fordprogressivenfui
bbkdownload. For real-timezstreaming you do need to “hint” yourwmovies, but for progressive download you don’t.pIf youtcut
bbk“hint” a progressive downloadwmovie you gain nothing;finxfact you endeup wasting valuable bits asxthe hinted tracks are
nnxaddedetoeyouremovie. These hinted tracks are not needed eitherybysthe Web or FTP server, noreby the client, so theresis
adsno reason to havedthem. If you hint aaprogressivebdownload movie, the hintedetrackscarecalsondownloaded to the client,y
eadtakingdlongerdto receive yourncontent. isno
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eadTip 23dPurchase Discreet’s Cleaner or Squeeze for finer results isno
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notThis isn’t awknock to Apple’sdQuickTimefencoder, but the truth is, QT Pro is fairly rudimentary.dIfdyour departmentphas
dbxevenythe smallest of budgets,dyoumshould be able to buy Sorenson’s Squeeze (about $200) oreDiscreet’s Cleaner 5 (aboutu
ead$600). Theseaapps give you moretcontrol over yourdencodinggparameters thanpyou’ll find in thewQT Pro encoderisno