Multimedia Concepts:Multimedia Concepts:Video TechnologiesVideo Technologies
ANALOG
DIGITAL
Analog Video Analog Video TechnologyTechnology
Analog means ? Analog means ?
Analog Video TechnologyAnalog Video TechnologyAnalog FormatsAnalog Formats VideotapeVideotape
VHS (remember BETA?)VHS (remember BETA?) 8mm8mm
LaserdiscLaserdisc Familiar? Obsolete?Familiar? Obsolete? Why discuss?Why discuss?
Analog Video TechnologyAnalog Video Technology
VideotapeVideotape LaserdiscLaserdisc
Video (Analog Tape)Video (Analog Tape)PositivesPositives
Familiar, common hardwareFamiliar, common hardware VCRs, players, camcordersVCRs, players, camcorders
PerceivedPerceived image “quality” image “quality”Impact of screen sizeImpact of screen size
Full color depth (~ 24-bit)Full color depth (~ 24-bit)
Video (Analog Tape)Video (Analog Tape)PositivesPositives
RECORDABLERECORDABLE & erasable & erasable Inexpensive hardware & tapesInexpensive hardware & tapes Can be digitized Can be digitized
Video (Analog Tape)Video (Analog Tape)NegativesNegatives
Quality of NTSC Quality of NTSC (standard N. Am. television) (standard N. Am. television)
TV vs. MonitorTV vs. Monitor Fundamentally linearFundamentally linear
Hard to use segmentsHard to use segments ExampleExample(s)(s) Computer control ??Computer control ??
Video (Analog Tape)Video (Analog Tape)NegativesNegatives
Limited manipulationLimited manipulation Costly hardware to editCostly hardware to edit Quality loss by generationQuality loss by generation
Distance distribution Distance distribution Limited rapid sharingLimited rapid sharing cf. video conferencingcf. video conferencing
Analog Video Analog Video TechnologiesTechnologies VideotapeVideotape LaserdiscLaserdisc
(Laser videodisc) (Laser videodisc)
Laserdisc (Analog) Laserdisc (Analog) OverviewOverview
Precursor to DVD Precursor to DVD Advantages & DisadvantagesAdvantages & Disadvantages Laserdisc technologyLaserdisc technology Advanced systemsAdvanced systems
LaserdiscsLaserdiscs +/- AdvantagesAdvantages Higher video qualityHigher video quality Multi-channel soundMulti-channel sound Double-sidedDouble-sided Still frame & special effectsStill frame & special effects Potential for random accessPotential for random access
Non-linear = hyperNon-linear = hyper
Laserdiscs Laserdiscs +/- DisadvantagesDisadvantages ‘ ‘Special’ hardwareSpecial’ hardware
Unfamiliar at homeUnfamiliar at home BulkyBulky Cost of hardware Cost of hardware
vs VCR (or DVD)vs VCR (or DVD) No local recordingNo local recording
Multimedia Concepts:Multimedia Concepts:Video TechnologiesVideo Technologies
ANALOG
DIGITAL
Digital VideoDigital VideoWhat is it?What is it? Most commonly:Most commonly:
Analog video – Analog video – digitizeddigitized Computer filesComputer files
Newer technology:Newer technology: Original digital video (DV)Original digital video (DV) Bits on a Bits on a digital tapedigital tape
Creating Digital VideoCreating Digital VideoHardwareHardware AnalogAnalog Digitizing GearDigitizing Gear
$50 - $1000+$50 - $1000+ Internal, external, bothInternal, external, both
Digital camcorder + IEEE 1394 Digital camcorder + IEEE 1394 “ “Firewire” or “i Link”Firewire” or “i Link”
Many digital ‘still’ camerasMany digital ‘still’ cameras Highly variable resultsHighly variable results
PC / web cameras (“golf balls”)PC / web cameras (“golf balls”)
Creating Digital VideoCreating Digital VideoSoftwareSoftware Comes with hardwareComes with hardware Capture, then editCapture, then edit
Not necessarily same softwareNot necessarily same software Varied features, e.g. formats Varied features, e.g. formats Varied learning curveVaried learning curve
Match to need & skillMatch to need & skill iMovie / Movie Maker to PremieriMovie / Movie Maker to Premier
Other Digital Video SourcesOther Digital Video Sources Clip video (CD / Web)Clip video (CD / Web) Download from web sitesDownload from web sites
Varies by video formatVaries by video format “ “Screen capture” softwareScreen capture” software
CamtasiaCamtasia, , CamStudioCamStudio, etc., etc. Morphing softwareMorphing software Animation software Animation software
FlashFlash, et al – beyond our scope, et al – beyond our scope Class web page has linksClass web page has links
Digital Video ConceptsDigital Video Concepts
Video = “frames”Video = “frames” How many / sec?How many / sec?
Apply still image fileApply still image file size concept size concept
Video = ++MBVideo = ++MB Forget KB Forget KB
Digital Video ConceptsDigital Video Concepts Image Size (‘window’ on screen)Image Size (‘window’ on screen)
Pixel dimensionsPixel dimensions Common SizesCommon Sizes
160 x 120 (‘1/16’)160 x 120 (‘1/16’) 320 x 240 (‘1/4’)320 x 240 (‘1/4’) 640 x 480 (‘full’ screen)640 x 480 (‘full’ screen) 720 x 480 (DVD, ‘wider’ screen)720 x 480 (DVD, ‘wider’ screen) What does a viewer really see?What does a viewer really see?
Digital Video ConceptsDigital Video ConceptsDV File Size FactorsDV File Size Factors Image pixel dimensionsImage pixel dimensions
Just like still imagesJust like still images FPSFPS
Frames per secondFrames per second Number required?Number required?
Color depth (bits)Color depth (bits) Increasingly, no optionIncreasingly, no option
Digital Video ConceptsDigital Video ConceptsDV File Size FactorsDV File Size Factors Video (file) format (more later)Video (file) format (more later)
QuickTime / AVI / WMVQuickTime / AVI / WMV MPEG (mpg)MPEG (mpg) StreamingStreaming
CODECCODEC Compression / decomp algorithmCompression / decomp algorithm Sometime selectable (cf. audio)Sometime selectable (cf. audio)
Audio qualityAudio quality Limited impactLimited impact
Digital Video Digital Video BenefitsBenefits Inexpensive hardware to createInexpensive hardware to create Edit electronically withEdit electronically with
software (non-linear editing) software (non-linear editing) Just another (large) file = Just another (large) file =
transmission potential transmission potential FTP, email, or on web pagesFTP, email, or on web pages Keep file size down!Keep file size down! Or Or streamstream it it
More flexible useMore flexible use
Digital Video Digital Video IssuesIssues Image quality (e.g. jaggies)Image quality (e.g. jaggies) Limited resizing (pixels, jerky)Limited resizing (pixels, jerky) Differing formats / architecturesDiffering formats / architectures Non-standard compression schemesNon-standard compression schemes
Broadway AVI & M-JPEGBroadway AVI & M-JPEG Codec compatibility / availabilityCodec compatibility / availability
Storage requirements / downloadsStorage requirements / downloads
Impact of File SizeImpact of File Size K/sec 100K 1MB
28.8K 3.0 33 sec 6 min
56K 6.0 17 sec 3 min
T1 Cable / DSL
150 variable
0.7 sec 7 sec
1 min video can take minutes to download
DV FormatsDV Formats QuickTime (mov)QuickTime (mov)
Background / compatibilityBackground / compatibility Video for Windows (avi)Video for Windows (avi) WMVWMV MPEG (mpg, mp#)MPEG (mpg, mp#)
Current standard ?Current standard ? Video CD / DVDVideo CD / DVD
Streaming competition (later)Streaming competition (later) Real vs MS vs QTReal vs MS vs QT
‘‘Exotic’ DVExotic’ DV VCD (Video CD)VCD (Video CD)
Mpeg-1 Mpeg-1 Common outside USCommon outside US
QTVRQTVR Lighthouse (HS)Lighthouse (HS) Orlando Art MuseumOrlando Art Museum
Other DigitalOther Digital Video Topics Video Topics Creating digital videoCreating digital video DVDDVD StreamingStreaming
