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

2. Video Technologies ANALOG DIGITAL

3. Analog Video Technology Analog means ? Analog means ?

4. Analog Video Technology

5. Videotape Videotape Laserdisc Laserdisc

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

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

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

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

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

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

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

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

14. Video Technologies ANALOG DIGITAL

15. VideoVideo Video, like sound, is recorded and played an as analog signal 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 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 Digital video has many advantages, but file size is important

16. VideoVideo Several elements determine file size: Several elements determine file size:  Frame rate  Image size  Color depth To determine file size use the following formula: 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 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 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 Color depth Reducing the color depth to less than 256 colors gives a markedly poorer-quality image. Frame rate Reducing the frame rate to less than 15 frames per second causes a noticeable and distracting jerkiness that is usually unacceptable. File sizeA technique for reducing file size is to minimize the use of video in the image that appears on the screen – that is, to create video only for the parts of an object that are changing, such as a flickering candle. The video could be played over and over to create the motion of a flickering candle.

20. Video Tips Display sizeIn most multimedia titles, you do not need to show full-screen video. The video can be played in a window that can be as small as one-fourth or even one-sixteenth the size of the screen. Conclusion: Changing the image size and compressing the file become the primary ways of reducing file size. In most cases, a one-quarter screen image (320 X 240), an 8- bit (256 colors) color depth, and a 15 frames per second frame rate are acceptable in a multimedia title.

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

22. Creating Digital Video Hardware Analog Digitizing Gear Analog Digitizing Gear  $50 - $1000+  Internal, external, both Digital camcorder + IEEE 1394 Digital camcorder + IEEE 1394  “ Firewire ” or “ i Link ” Many digital ‘ still ’ cameras Many digital ‘ still ’ cameras  Highly variable results PC / web cameras ( “ golf balls ” ) PC / web cameras ( “ golf balls ” )

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

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

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

26. Digital Video Concepts Image Size ( ‘ window ’ on screen) Image Size ( ‘ window ’ on screen)  Pixel dimensions Common Sizes 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 Image pixel dimensions  Just like still images FPS FPS  Frames per second  Number required? Color depth (bits) Color depth (bits)  Increasingly, no option

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

29. Digital Video Benefits Inexpensive hardware to create Inexpensive hardware to create Edit electronically with software (non-linear editing) Edit electronically with software (non-linear editing) Just another (large) file = transmission potential Just another (large) file = transmission potential  FTP, email, or on web pages  Keep file size down!  Or stream it More flexible use 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 Broadway AVI & M-JPEG Codec compatibility / availability Codec compatibility / availability  Storage requirements / downloads

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

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

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

34. Other Digital Video Topics Creating digital video Creating digital videoCreating digital videoCreating digital video  Capturing Capturing  Editing Editing  Producing Producing DVD DVDDVD Streaming StreamingStreaming