Top Banner

Click here to load reader

Multimedia Concepts: Video Technologies

Feb 24, 2016

ReportDownload

Documents

raleigh

Multimedia Concepts: Video Technologies. ANALOG. DIGITAL. Analog Video Technology. Analog means ? . Analog Video Technology. Analog Formats Videotape VHS (remember BETA?) 8mm Laserdisc Familiar? Obsolete? Why discuss?. Analog Video Technology. Videotape Laserdisc. - PowerPoint PPT Presentation

  • Multimedia Concepts:Video TechnologiesANALOGDIGITAL

  • Analog Video Technology Analog means ?

  • Analog Video TechnologyAnalog Formats Videotape VHS (remember BETA?) 8mm Laserdisc Familiar? Obsolete? Why discuss?

  • Analog Video Technology Videotape Laserdisc

  • Video (Analog Tape)Positives Familiar, common hardware VCRs, players, camcorders Perceived image qualityImpact of screen size Full color depth (~ 24-bit)

  • Video (Analog Tape)Positives RECORDABLE & erasableInexpensive hardware & tapesCan be digitized

  • Video (Analog Tape)Negatives Quality of NTSC (standard N. Am. television) TV vs. Monitor Fundamentally linear Hard to use segments Example(s) Computer control ??

  • Video (Analog Tape)Negatives Limited manipulation Costly hardware to edit Quality loss by generation Distance distribution Limited rapid sharing cf. video conferencing

  • Analog Video Technologies Videotape Laserdisc (Laser videodisc)

  • Laserdisc (Analog) Overview Precursor to DVD Advantages & Disadvantages Laserdisc technology Advanced systems

  • Laserdiscs +/- AdvantagesHigher video qualityMulti-channel soundDouble-sidedStill frame & special effectsPotential for random access Non-linear = hyper

  • Laserdiscs +/- Disadvantages Special hardware Unfamiliar at home Bulky Cost of hardware vs VCR (or DVD) No local recording

  • Multimedia Concepts:Video TechnologiesANALOGDIGITAL

  • Digital VideoWhat is it?Most commonly: Analog video digitized Computer files Newer technology: Original digital video (DV) Bits on a digital tape

  • Creating Digital VideoHardware Analog Digitizing Gear $50 - $1000+ Internal, external, both Digital camcorder + IEEE 1394 Firewire or i Link Many digital still cameras Highly variable results PC / web cameras (golf balls)

  • Creating Digital VideoSoftware Comes with hardware Capture, then edit Not necessarily same softwareVaried features, e.g. formats Varied learning curve Match to need & skill iMovie / Movie Maker to Premier

  • Other Digital Video Sources Clip video (CD / Web) Download from web sites Varies by video format Screen capture software Camtasia, CamStudio, etc. Morphing software Animation software Flash, et al beyond our scope Class web page has links

  • Digital Video Concepts Video = frames How many / sec? Apply still image file size concept Video = ++MB Forget KB

  • Digital Video Concepts Image Size (window on screen) Pixel dimensions Common Sizes 160 x 120 (1/16) 320 x 240 (1/4) 640 x 480 (full screen) 720 x 480 (DVD, wider screen) What does a viewer really see?

  • Digital Video ConceptsDV File Size Factors Image pixel dimensions Just like still images FPS Frames per second Number required? Color depth (bits) Increasingly, no option

  • Digital Video ConceptsDV File Size Factors Video (file) format (more later) QuickTime / AVI / WMV MPEG (mpg) Streaming CODEC Compression / decomp algorithm Sometime selectable (cf. audio) Audio quality Limited impact

  • Digital Video Benefits Inexpensive hardware to create Edit electronically with software (non-linear editing) Just another (large) file = transmission potential FTP, email, or on web pages Keep file size down! Or stream it More flexible use

  • Digital Video Issues Image quality (e.g. jaggies) Limited resizing (pixels, jerky) Differing formats / architectures Non-standard compression schemes Broadway AVI & M-JPEG Codec compatibility / availability Storage requirements / downloads

  • Impact of File Size1 min video can take minutes to download

    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

  • DV FormatsQuickTime (mov) Background / compatibilityVideo for Windows (avi)WMVMPEG (mpg, mp#) Current standard ? Video CD / DVDStreaming competition (later) Real vs MS vs QT

  • Exotic DVVCD (Video CD)Mpeg-1 Common outside US QTVRLighthouse (HS)Orlando Art Museum

  • Other Digital Video Topics Creating digital video DVD Streaming