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VIDEO TECHNOLOGIES

VIDEO TECHNOLOGIES. Iwan Sonjaya,ST.MMT,MT Computer and Informatics Engineering Dept. State Polytechnic Of Jakarta. Video Technologies. ANALOG. DIGITAL. Analog Video Technology. Analog means ?. Analog Video Technology. Analog Formats Videotape VHS (remember BETA?) 8mm Laserdisc

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VIDEO TECHNOLOGIES

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  1. VIDEO TECHNOLOGIES Iwan Sonjaya,ST.MMT,MT Computer and Informatics Engineering Dept.State Polytechnic Of Jakarta

  2. Video Technologies ANALOG DIGITAL

  3. Analog Video Technology • Analog means ?

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

  5. Analog Video Technology • Videotape • Laserdisc

  6. Video (Analog Tape) Positives • Familiar, common hardware • VCRs, players, camcorders • Perceived image “quality” • Impact of screen size • Full color depth (~ 24-bit)

  7. Video (Analog Tape) Positives • RECORDABLE & erasable • Inexpensive hardware & tapes • Can be digitized 

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

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

  10. Analog Video Technologies • Videotape • Laserdisc (Laser videodisc)

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

  12. Laserdiscs +/- Advantages • Higher video quality • Multi-channel sound • Double-sided • Still frame & special effects • Potential for random access • Non-linear = hyper

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

  14. Video Technologies ANALOG DIGITAL

  15. Video • Video, like sound, is recorded and played an as analog signal • Analog video must be digitized in order for it to put into a multimedia file • Digital video has many advantages, but file size is important

  16. Video • Several elements determine file size: • Frame rate • Image size • Color depth • To determine file size use the following formula: • Frames per second X image size X color depth / 8 = file size

  17. Video Compression and Editing • There are two types of video compression • Lossless – preserves the exact image throughout the compression • Lossy – eliminates some of the data in the image (provides greater compression ratios than lossless) • Remember – there is always a trade off, file size versus image quality

  18. Video on the Internet • There are two types of video transfer over the Internet • HTTP (Hypertext Transfer Protocol) – downloads the entire video to the hard drive on the user’s computer • RTSP (Real-Time Streaming Protocol) – is a continuous-playing, streaming technology in which the user’s computer is in constant contact with the server playing the video

  19. Video Tips

  20. Video Tips

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

  22. Creating Digital Video Hardware • AnalogDigitizing 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”)

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

  24. 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

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

  26. 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?

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

  28. Digital Video Concepts DV 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

  29. 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

  30. 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

  31. Impact of File Size 1 min video can take minutes to download

  32. DV Formats • QuickTime (mov) • Background / compatibility • Video for Windows (avi) • WMV • MPEG (mpg, mp#) • Current standard ? • Video CD / DVD • Streaming competition (later) • Real vs MS vs QT

  33. ‘Exotic’ DV • VCD (Video CD) • Mpeg-1 • Common outside US • QTVR • Lighthouse (HS) • Orlando Art Museum

  34. Other Digital Video Topics • Creating digital video • Capturing • Editing • Producing • DVD • Streaming

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