1. Video

2. Learning Outcomes Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
Menunjukkan Penggunaan Video pada Aplikasi Multimedia

3. Outline Materi Different Kind of Movies Analogue Video Digital Video
Compression Technique
Broadcast Video Standards
Digital Video Format
Using Digital Video

4. Different Kind of Movies
Movies from Film
Analog Video
Digital Video

5. Movie From Film
Sequential image frames are recorded on film using a light sensitive technology similar to still photography.
Film must be chemically developed
Editing requires physically cutting and splicing the film

6. Analogue video
Video information that is stored using television video signals, film, videotape or other non-computer media
Each frame is represented by a fluctuating voltage signal known as an analogue wave form or composite video.
Composite analogue video has all the video components: brightness, colour and synchronization
Then, combined into one signal for delivery
Usage : television
Problems: colour blending, low clarity, high generation lost, difficult to edit

7. Digital Video
Digital video is the digitisation of analogue video signals into numerical format
It creates the illusion of full motion by displaying a rapid sequence of changing images on a display device.
Conversion from analogue to digital format requires the use on an ADC (Analogue to Digital Converter)
A Digital to Analogue Converter (DAC) can be used to output digital video on analogue equipment

8. File Size Considerations
Several elements determine the file size, in additional to the length of the video. These including:
Frame rate
Number of images displayed within a specified amount of time to convey a sense of motion
Usually measured in frames per second
Standard video movie  30 fps, movie film  24 fps
Video digital  at least 15 fps
Frame or Image size
The width and height of each individual frame or image
Determines the quality of the image displayed and the processing involved to display that image
Standard full screen resolution is 640x480 pixels
Video screen display is one fourth the size of the full window screen (320x240)
Color depth/Resolution
Number of colors displayed on the screen at one time
Ranging from 1 bit to 8 bit, 16 or 24 bit per pixel

9. File Size Considerations
Quality directly related to frame size, image size and color depth.
Quality also depends on content. Motion picture needs higher frame rate
File size = Frame Size x Frame Rate x Color Depth x Time
Where:
Frame size = image size ( width x height in pixels)
Frame rate = frames per second
Color depth = measured in bytes
Time = time in seconds
This does not include any sound data !

10. Compression techniques
Since the size of raw digital video is so prohibitively large we need some means to compress the information
Video compression and decompression program, known as Codecs
Lossy compression techniques cause some information to be lost from the original image
Redundant information
Example: Image and video
JPEG and MPEG
Intraframe and Interframe
Lossless compression techniques do not lose information throughout the compression and decompression process
Example use in text images
Exactly same before and after compression
Technique is identify repeating words and assign them a code.
Decompression, the code would be changed back to the actual word.

11. Digital video editing Analogue tape editing is a linear process
To find the section you want, you may have to forward or rewind the video tape
To move a section to another place in the sequence you have to either re-record the section onto another tape or physically cut and splice the video tape
Digital video editing can be non-linear process
You can move sections around inside the computer and play those sections back in any order

12. Broadcast Video Standards
NTSC
North America, South America, Japan
525 interlaced resolution lines
30 frames per second (fps)
PAL (Phase Alternate Line)
Australia, South Africa, Europe
625 interlaced resolution lines
25 frames per second (fps)
SECAM
France, Russia
625 interlaced resolution lines
25 frames per second (fps)
HDTV
Six different formats
Aspect ratio is 16:9

13. Overscan

14. Digital Video File Formats
.MOV signifies Quicktime, an Apple standard. It is playable on Macintosh and Windows machines.
.AVI is a Microsoft standard that is playable on Windows and Macintosh machines.
.MPEG (.MPG) is playable on Unix and Windows machines. Macintoshes can play MPEG, but may have trouble with the audio track.
.RM files are used by RealNetworks streaming. They are playable on Windows, MacOS, and Unix computers.
.ASF files are a Microsoft streaming format, and play on Windows, MacOS, and Solaris.
.WMV files are a Microsoft format used in Microsoft MovieMaker

15. MPEG video
Named after the Moving Picture Experts Group who devised the compression and file formats
There are a number of MPEG formats:
MPEG-2 is used for digital TV broadcasts and DVDs
MPEG-1 is a format used for low quality video (generally displayed on computers)
MPEG-1 Layer 3 is the popular encoding mechanism for MP3 audio files (more on this later in this course)
MPEG-4 is a new format for multimedia presentations
Can require separate hardware to decode higher quality MPEG video data

16. MPEG compression example
A simple scene showing a car moving across a desert landscape
Only the difference between the current and next frame needs to be stored
This is called intraframe coding

17. QuickTime Developed by Apple, Inc.
Primarily for playback without any hardware assistance
Can achieve compression ratios of 25 to 200:1
The QuickTime format can also store audio, graphics, 3D and text making it more much versatile for multimedia applications

18. Microsoft AVI Audio Video Interleave format
Interleaving is a technique used to embed two or more things into the same stream of information
In every chunk of information you will find some video data and some audio data
...
8, 16 or 24 bits
Video
information
Audio
information

19. Consumer desktop video
Typified by the Apple iMac DV computer
IEEE 1394 or FireWire interface
Digital camcorders

20. How Video can be used effectively
Showing physical procedures. Some uses are:
Installing a board in a PC
Adjusting engine timing
Attracting and holding attention. Some uses are:
Advertising products and services
Teaching new skills to busy employees
Presenting scenarios. Some uses are:
Training technicians to respond to equipment malfunctions
Demonstrating possible uses for a product
Analyzing motion . Some uses are:
Body motion to improve athletic performance
Traffic patterns for transportation planning

21. Advantages and Disadvantages of using video
Carefully planned, well-executed video clips can make a dramatic difference in a multimedia project
Use video only when all other methods (text, still images) are not enough; don’t use it just because it’s possible
Video adds visual impact to multimedia applications:
Advantages
Captures interest
Increase retention
Clarifies complex physical actions and relationships
Can incorporate other media
Disadvantages
Is expensive to produce
Requires extensive memory and storage
Requires special equipment
Does not effectively illustrate abstract concepts and static situations