Multimedia Technology Lecture 8 Aims of the Lecture
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Multimedia Technology Lecture 8 Aims of the Lecture






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  • Multimedia = large files and complex processes. Speed is of the essence + the ability to delegate some activities to individual hardware MMX Multimedia Extensions Intel CPU Technology that is specifically designed for Multi Media Applications Other processor manufacturers have similar enhancements (e.g. AMD 3DNow!)

Multimedia Technology Lecture 8 Aims of the Lecture Multimedia Technology Lecture 8 Aims of the Lecture Presentation Transcript

  • Multimedia Technology Lecture 8
  • Aims of the Lecture
    • To have an understanding of different standards for H/W and multimedia files
    • To appreciate the particular difficulties involved in using MM files and the way that we use technology to overcome them
  • Computer architecture
    • Basic PC architecture strongly affects ability to process large multimedia files
    • MMX
      • More Instructions
      • More on-chip memory
      • Faster execution of instructions
    • Bus – ISA, PCI, SCSI, USB
  • USB, PCI & ISA                                                        
  • One Cycle Number of cycles per second = frequency HZ Amplitude Sound Waves Digitised wave 111 110 101 100 011 010 001 000
  • Sound
    • Nature of sound:
      • High Quality
        • stereo, Dolby surround
      • Lower quality
        • Mono, speech quality
    • Digital sound - consider sampling rate, no. of bits per sample and no. of channels
    • Sound formats e.g.MP3, WAV, AIFF, MIDI
    • Sound cards e.g. Creative labs series
    • Recording using Microsoft sound recorder
    • Recording and editing using WaveStudio, WaveLab etc
    • Speech recognition and text-to-speech
    • Streaming Audio
      • Used e.g. for Radio via the internet
      • Environments include Windows Media Player and Real Audio
  • Audio CD
    • Laser disc technology
    • 60 - 74 minute time limit
    • Transfer about 150 kB/s
    • Error detection and correction
    • Audio playback using CD Player, Microsoft Windows Media Player or any proprietary audio CD player
    • Media Player will play back a variety of sound (and video) formats.
  • CD-ROM
    • CD-ROM: Basic (1x) 650 Mbytes
    • Transfer about 150 kbytes/s, 60 -74 min
    • Double (2x) and higher speeds (3x) , … (24x), etc
    • Interfacing
      • EDIE (ATAPI), SCSI
    • Many different formats
      • CD, CDR, CDRW
  • Digital Versatile Disc (DVD)
    • 5” optical disc
    • Resolution better than 500 lines
    • One side, single layer 4.7 GB - 133 min video
    • Two sides, two layers 17 GB
    • Transfer speed better than 8x CD ROM with average of 4.7 Mbps
    • image rate 30 images/s
    • New Developments
      • Blu-Ray
        • Single sided 13 hours of video
        • Double sided 50GB data
        • Speeds up to 36 Mbps
        • Will require new devices
  • Care of Compact Disks
    • The guaranteed life expectancy is 2 to 5 years
      • Potential life expectancy could be 100 years
    • Do not expose to excessive heat or sunlight
    • Do not eat, smoke or drink near a disk
    • Do not touch the underside of the disk
    • Do not stack disks
    • Store the disk in it’s box when not in use
    • Hold the disk by it’s edges
  • Graphics
    • Monitor - definitions of raster, resolution, refresh, interlaced etc
    • Graphics adapters - see standards
    • Colour models - RGB,etc, colour depth
    • Bit-mapped graphics versus structured graphics
    • Enhanced colour resolution
    • Colour mapped display
    • Image Formats
      • Aim is to strike a balance between compression and quality
        • JPEG
        • GIF
    • Other formats
        • BMP, PCX, TIFF
        • Have larger file sizes and are used much less frequently on the web
    • VRAM and Accelerated Graphics Port (AGP)
  • Use of graphics on the Web
    • A Marquee or “Ticker”
      • Text that scrolls across the screen
      • Often used for stock updates / sports results etc.Animated GIF
    • Need to focus on the time the page(s) will take to download
      • Choose Appropriate file formats
      • Use thumbnails
  • Acquiring & Viewing Digital images
    • Optical scanner
    • Pictures from camcorders - requires frame grabber
    • Digital camera MPEG
    • Real Video
    • Windows Media Player
    • From WWW (use Save As) or E-mail (using MIME)
    • Picture viewing and editing e.g. Adobe Photoshop, Paint, Microsoft Photo Editor, Photo Studio SE
    • For multimedia, convert picture to lowest acceptable size and resolution
    • Compression standards
      • E.g. MPEG, Quicktime, Real Video, Windows Media Player
  • Video
    • Definition of frame rate, key frames etc
    • Acquire video clips for WWW
    • Play back e.g. using Media Player (a Video for Windows Device)
    • DVD
    • Codec standards
    • hardware/capture and general purpose
    • motion compensation
    • Embed video clips in documents, web pages etc
  • Streaming & Video Conferencing
    • Streaming
      • Microsoft Active Movie Player
      • Stream Works
      • Quick Time (Apple)
      • RealPlayer (includes RealPix, RealText, RealAudio, RealVideo, RealFlash)
    • Web Casting – Broadcasting via the internet
    • Video Conferencing
      • VideoLogic’s Captivator PCI
      • Winnov’s Videum - colour camera, capture board and TV tuner
      • Composite video (NTSC, PAL)
      • S-video
      • RGB and YUV models
  • Software: Authoring
    • Combining multimedia clips into a sequence for delivery on Compact Disc or via the web
    • Allows you to modify a segment (clip) of a video or a sound
    • Examples of packages available
    • Video and Audio Editing
        • Adobe Premier
        • Ulead Systems MediaStudio Pro
      • Multimedia Authoring
        • PowerPoint
        • Macromedia Director
        • Macromedia Authorware
        • Macromedia Flash
  • Virtual Reality (VR)
    • Display of 3D images that you can explore and manipulate interactively
    • Has many applications since it allows the user to simulate a real environment
      • Flight Simulation
      • Model a Construction Project
      • Perform Surgery
    • Virtual Reality Modelling Language (VRML)
  • Further References
      • Look at the multimedia special feature
      • Try the interactive lab on understanding multimedia
      • Multimedia Authoring Software