4 multimedia basics

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4 multimedia basics

  1. 1. 1 About Multimedia Introduction to Multimedia What does multimedia mean to you? Multimedia is any presentation that combines several media such as text, animation, graphics, sound, video and streaming content. Multimedia is the convergence of digital media. This means media producers must learn how to use multimedia to create content for TV, radio, video, and the Web.
  2. 2. 2 Types of Multimedia Introduction to Multimedia Still Media Any media or image that can be viewed within one single frame or a single image that does not change. Examples: Photos or graphic images, logos, etc.
  3. 3. 3 Types of Multimedia Introduction to Multimedia Dynamic Media Examples: Animation, video, audio, etc.
  4. 4. 4 Types of Multimedia Introduction to Multimedia Interactive Media Examples: Animation, Web sites, CD/DVD authoring, software programming, etc.
  5. 5. 5 Types of Multimedia Introduction to Multimedia Animation
  6. 6. 6 Types of Multimedia Introduction to Multimedia Digital Video
  7. 7. 7 Types of Multimedia Introduction to Multimedia Digital Audio
  8. 8. 8 Types of Multimedia Introduction to Multimedia Streaming Media So what is streaming anyway? Streaming software like RealServer or QuickTime takes your video/audio file, segments it, and sends the pieces to a buffer on your hard drive. Then, the buffer renders the packets together to play like a continuous file, resulting in a smooth, high-quality track with a painless download time.
  9. 9. 9 Types of Software Introduction to Multimedia Software Text and Graphics: MS Word, Macromedia Freehand, Adobe Illustrator, Adobe Photoshop (bitmap), Macromedia Flash (vector-based) Animation: Macromedia Flash and Director Digital Video: iMovie2, Adobe Premiere, Final Cut Pro
  10. 10. 10 Types of Software Introduction to Multimedia Software Digital Audio: Pro Tools, Sound Forge, iTunes Streaming: QuickTime, RealServer Third-Party and Others: Adobe AfterEffects (add filters & effects to video), Cleaner 5 (encoding/compressing video, audio, etc.), Real Media, Sorenson Pro
  11. 11. 11 QuickTime Introduction to Multimedia What is QuickTime? It’s a file that tells the computer what kind of media to present and when to present it. The software is a gateway for distributing media including images, music, MP3 and more. QuickTime lets you experience more than 200 kinds of digital media with a Mac or PC.
  12. 12. 12 Hardware and Equipment Introduction to Multimedia Hardware and Equipment • Windows PC/Mac G4 • 300-512 Mb RAM • 30-40 GB Hard Drive • CD ROM, DVD RAM (CD-R, DVD-R) • Two 17” Monitors • FireWire or ATA Drives (30+ GB) • Removable Media
  13. 13. 13 Hardware and Equipment Introduction to Multimedia Hardware and Equipment • 3CCD Digital Video Camcorder (Sony, Canon) • Digital Still Camera - 3-5 mega pixels* (Nikon, Sony) • Converter or Deck (from DV to SVHS) • Scanner (Hewlett Packard, Epson) • Printer (optional) * high-end
  14. 14. 14 End of Presentation Introduction to Multimedia More Information • For software, visit www.macromedia.com (free 30- day trials of Flash, Dreamweaver and more!) Other Links: • www.cnet.com (latest prices, tutorials, and more) • www.techsoup.org (CompuMentor’s site) • Presentation by: Nettrice R. Gaskins, current Director of the BNN Multimedia Center & President of DigitalArt Communities, Inc. Email: nettrice@onebox.com
  15. 15. 15 Multimedia in the past… For VIDEO: VCRs, Laserdiscs, videodiscs For SOUND: cassette player or stereo system For GRAPHICS: Film Slides or OHPs For TEXT: as OHPs (overhead projectors)
  16. 16. 16 Definition of Multimedia Interactive multimedia means that all of these elements are put together is such a way that the user can control all or some aspects of your software. Multimedia is a collection of various elements called media that when combined form a single unit. These media elements include video, sound, graphics, animation, and text. The multimedia designer’s job is to put together a product that is both easy to use and interesting.
  17. 17. 17 Convergence of industries & technologies  Multimedia is the convergence of different technologies. Technologies of sound, video, graphic design, publishing and animation combine in an interactive way in:  Web applications (publishing, streaming audio, hypertext, graphic design)  Movies (digital video, animation)  CD ROM development (audio, PC, DVD)
  18. 18. 18 Applications of Multimedia  Games Industry - PC, Video console, etc.  Entertainment – Television, movies  Education – Educational software, interactive programs  Training and Development
  19. 19. 19 Multimedia PC Specification  750-MHz processor  64 MB RAM  DVD drive recommended for Consumer & Office systems; required for Entertainment PCs.  CD ROM Rewritable (for creation of multimedia)  56-Kbps V.90 modem (Consumer and Entertainment)  17” monitor, 3D graphics accelerator card  Speakers with sound card  LOTS of hard drive space
  20. 20. 20 Creating Multimedia - Hardware In order to create a multimedia application, you will access to:  Microphone and speakers  Scanner (capture images)  video capture card (capture video)  VCR (play video to be captured)  Digital camera / still camera (capture images)  Connection to the internet (capture images/text, research)
  21. 21. 21 Creating Multimedia - Software In order to create multimedia application, you will need:  Macromedia Director  Image editing software – Fireworks, Photoshop, Paint Shop Pro, etc.  Sound editing software – Cooledit, etc.  Video editing software – Adobe Premier, Videowave, etc. Try www.download.com for trialware or shareware of sound, image or video editing software.
  22. 22. 22 Creating Multimedia - Skills In order to create multimedia application, be: Organised. Creating a multimedia project is time-consuming. You must be organised and set time-goals for yourself. Creative. Spend time analysing other software and websites. Search for graphic design techniques, etc.
  23. 23. 23 Standards There are no standard multimedia platforms, however there are multimedia standards on individual platforms. Examples include QuickTime (originally Apple), AVI, MP3, MPEG, JPG, GIF, PAL, NTSC, etc.
  24. 24. 25 What is multimedia?  A computer-based interactive communications process that incorporates: – text, – graphics, – sound, – animation, and – video.
  25. 25. 26 Why Multimedia?  User control  Individualization  Interactivity
  26. 26. 27 Interactivity: the Key Component  Learner Control: The user determines what content is delivered, when it is delivered, & how it is delivered.  Nonlinear:  Linear:
  27. 27. 28 Categories of Multimedia Titles  Entertainment  Education: A.D.A.M.  Corporate Communications – Marketing & training – Presentations & training  Reference
  28. 28. 29 Categories of Multimedia Titles (Continue)  Edutainment  Training  Recreation
  29. 29. 30 Delivering Multimedia  Compact Disc (CD)  Digital Video (Versatile) Disc (DVD)  Kiosk  Online (Internet & Intranet)
  30. 30. 31 Multimedia Personal Computer  MPC: Level 1 (1990)  MPC2: Level 2 (1991)  MPC3: Level 3 (1993) – 8MB – Pentium 75 MHz – 540 MB Hard Drive – 4X Speed CD-ROM – 640x480 Pixels Video Display (65,536 colors)
  31. 31. 32 Playback System  Processor  Memory  Monitor & Video Card  Audio Card  CD-ROM Drive & DVD-ROM Drive
  32. 32. 33 Development System  Processor  Memory  Video capture card  Monitor
  33. 33. 34 Development System (Continue)  Peripherals – Scanner – External storage  Zip drive (100 MB)  Jazz drive (1 GB) – CD, DVD recorder – Digital camera, Digital Video Camera – Microphone – other
  34. 34. 35 What is Multimedia? • Human behavior – sensory, memory, reactionary • Five senses – sound, touch, sight, taste, smell • A combination of these provides a rich learning environment • Only sound and sight can be captured in computer systems (why?)
  35. 35. 36 What is Multimedia? • Sight and sound are captured in a computer system as video, audio, and data • A medium refers to any one of data such as text, digitized voice, digitized video, still digitized images, and graphics.
  36. 36. 37 What is Multimedia? Multimedia - is the combination of two or more media.
  37. 37. 38 User perspective • The user gets input in the form of data, voice, video, image, graphics, or a combination of these • The user generates information in one or more of these media
  38. 38. 39 User perspective U S E R Data Voice Video Image Graphics Data Voice Video Image Graphics
  39. 39. 40 What is a Multimedia System? • A multimedia system is characterized by the creation, processing, storage, manipulation, rendition and distribution of multimedia information • Temporal relationship (time) between media makes multimedia different from normal data – synchronization
  40. 40. 41 Multimedia System Requirements • Very high processing power - processing and movement of large amounts of data in real-time • File system capable of handling multimedia information • File formats that exploit the inherent properties of the multimedia information
  41. 41. 42 Multimedia System Requirements • Efficient and high I/O rate • Multimedia operating system • Storage and memory • Network support • Software tools and applications
  42. 42. 43 Analog vs Digital Signals • Voice, music – analog signal – continuous • They must be digitized for computer manipulation • Conversion is carried out by signal encoder • Signal decoder
  43. 43. 44 Sampling • E.g. voice can be sampled at 11 KHz, 22KHz, 44KHz • Music has a higher range. • Human hearing 20-20,000 Hz • CD quality sound is 44KHz
  44. 44. 45 Quantization • 1bit = 1 Binary Digit • 8 bits = 8b = 1 byte = 1B • 1000B = 1KiloBytes = 1KB • 1000KB = 1 MegaByte = 1MB • 1000MB = 1GigaByte = 1GB • 1000GB = 1 TeraByte = 1TB • …
  45. 45. 46 Binary Code Decimal Binary 1 0001 2 0010 3 0011 4 0100 5 0101 6 0110 7 0111 8 1000 9 1001
  46. 46. 47 Quantization • The value of each sample is also represented digitally • In the discrete domain not all the values of the continuous domain can be found • How many bits are sufficient? • Music – 16 bits • Pictures – 24 bits
  47. 47. 48 Types of Media • Discrete – Text – data – image – graphics • Continuous – Audio – Video
  48. 48. 49 Text and Data • Numbers can be converted from decimal to binary • Characters can be converted using a look up chart called ASCII • Each character is assigned a decimal number e.g. A = 65 • Data files are usually small
  49. 49. 50 Graphics • Graphics are constructed by the composition of primitive objects such as lines, circles, polygons, curves, and splines • Each object is stored as an equation • Each object has a number of attributes – shape – size – color (border) – color (fill) – shadow etc
  50. 50. 51 Graphics • Takes less space than bitmaps for uncomplicated pictures • Not suitable for photographs with a lot of shades etc.
  51. 51. 52 Images • Continuous-tone pictures are digitized • Images are bitmaps • Divide the picture into pixels – picture cells • E.g. 100 x 100 • Each pixel has a n bit quantization • N = 1, 2, 4, 8, 16, 24
  52. 52. 53 Images Bits Number of colors 1 2 2 4 4 16 8 256 16 65536 24 16777216
  53. 53. 54 Color • Three primary colors - RGB • Additive color mixing leads to a color gamut • eg. Black = 0R + 0G + 0B • Java applet to mix colors http://www.phy.ntnu.edu.tw/java/image/rgb Color.html • Java applet to display color gamut http://www.cs.rit.edu/~ncs/color/a_chroma. html
  54. 54. 55 Aspect Ratio • Screen width / screen height 4 3 4/3 = 1.33
  55. 55. 56 Audio • Sampling rate and quantization • Mono, stereo or surround (number of channels) • CD specification • DVD specification
  56. 56. 57 CD-DA • CD - Digital Audio • Stereo, 44KHz Sampling, 16 bit quantization • 73 minutes of music on CD
  57. 57. 58 Surround Sound• Mono - one channel • Stereo - Two channels • Five channel - Left , center, right, left surround, right surround
  58. 58. 59 Video • Most colors of the visible spectrum can be constructed from three primary colors • Red, Green, Blue RGB • Each uses an 8 bit representation • 256 levels of each color • Total 24 bit = 16 million colors
  59. 59. 60 Video • Frame rate – 12, 15, 25, 30 frames/sec • NTSC video uses 30 frames / sec • NTSC has 4:3 aspect ratio – Length/height = AR – 1, 1.33, 1.66, 1.85, 2, 2.5 etc.
  60. 60. 61 Aspect Ratios
  61. 61. 62 Aspect Ratios
  62. 62. 63 Aspect Ratio
  63. 63. 64 Letterbox • When showing a widescreen movie on a 1.33 screen, letterboxing is used to display the entire frame
  64. 64. 65 Pan and Scan • Broadcast television uses pan and scan to utilize the entire height of the screen thus losing information on the sides
  65. 65. Definition of Multimedia Multi (Latin multus - numerous) Media, medium (Latin medius, medium: middle, center, intermediary; Latin mediat: intermediary, means) Multiple types of information captured, stored, manipulated, transmitted, and presented. Specifically: Images, Video, Audio (+Speech) and Text Related terms: hypermedia, hypertext Problem: “hypertext”, “hypermedia”, “multimedia” so overused/generalized they now convey little meaning
  66. 66. Top Ten Misconceptions about Multimedia Computing Ramesh Jain, founding chairman of Virage and CTO of Praja, www.praja.com, presented the following “top ten” MISCONCEPTIONS list as part of his keynote speech at the ACM Multimedia Conference, Ottawa, Canada, October 2, 2001: 10. Video = Multimedia. 9. Multimedia = multi X separate medium. 8. All information is ONLY in the images or video. 7. Editing of media is almost always off-line. 6. Query by example is best access method.
  67. 67. Top Ten Misconceptions about Multimedia Computing, Continued 5. All users have PhDs in multimedia computing. 4. Users have no memory or context. 3. Computers are for computing. 2. Medium is the message. 1. We work for computers. Ramesh Jain concluded his keynote talk with the observation: Information Builds Experience, Experience is Life.
  68. 68. Audio Images Information Retrieval Storage Systems Networking Psychology HCI Data Compression Natural Language Processing Multimedia CPU Power Video
  69. 69. Multimedia Physics • Sound is a waveform • Imagery is a waveform • light is electromagnetic radiation with different intensity in spatial coordinates • color corresponds to wavelength (red is the longest wavelength visible by people) • Introductory treatment of “light behaves as both particle and wave” at http://www.howstuffworks.com/light1.htm • “Distributed Multimedia” by Palmer Agnew and Anne Kellerman, published by Atomic Dog Publishing, http://www.atomicdogpublishing.com
  70. 70. A Quick Introduction to Light Waves • Derived from: http://www.pbs.org/deepspace/classroom/activity2.html • Waves characterized by wavelength and frequency • Light is a type of electromagnetic radiation in a range for which our eyes are sensitive • Sound is not electromagnetic radiation, but sound is a wave as well. Higher pitches are caused by higher frequencies of vibrating molecules that reach your eardrum. Lower pitches are likewise caused by lower frequencies. wavelength
  71. 71. Wavelength/ Frequency Spectrum Long radio waves Microwaves X-rays Gamma rays TV, FM Infrared Ultraviolet 700 nm 600 nm 500 nm 400 nm 4.5x1014 Hz 5x1014 Hz 6x1014 Hz 7x1014 Hz
  72. 72. Migration from Analog to Digital Representation • Analog signals to sensors • E.g. vinyl records • Fidelity is faithfulness to the original • Digital representation (1960s) • Sampling • Quantizing • Coding • Limiting factors in move to digital: • Storage limits • CPU speeds • I/O speeds • Network bandwidth
  73. 73. Why Digital? • Universal storage, transmission format • CD, Internet • Precision (range of values, number of bits, floating point) • Lossless transmission/storage BUT: • Sampling rate distorts information • Size requirements may be huge compared to analog, e.g., 4.2 million pixels for single 35 mm photograph!  results in lots of work on perception-based lossy digital compression strategies
  74. 74. Why Perception Matters http://www.libertarian.on.ca/images/Florida%20Recount.jpg
  75. 75. Audio • Sounds • Hear 15 Hz to 20 kHz • Speech is 50 Hz to 10 kHz • Speech Recognition • It is hard to wreck a nice beach / It is hard to recognize speech • Ice cream / I scream • Synthesis • Speech • Music • MIDI for 127 instruments, 47 percussion sounds • Notes, timing
  76. 76. Speech Recognition Issues • Continuous vs. discrete • Vocabulary size • Channel (microphone) • Environment (location of microphone and speaker) • Speaker dependent/speaker independent • Context (language model) • Interactivity (dialog model)
  77. 77. Acoustic Modeling Describes the sounds that make up speech Lexicon Describes which sequences of speech sounds make up valid words Language Model Describes the likelihood of various sequences of words being spoken Speech Recognition Speech Recognition Knowledge Sources
  78. 78. Speech Variations Style Variations careful, clear, articulated, formal, casual spontaneous, normal, read, dictated, intimateVoice Quality breathy, creaky, whispery, tense, lax, modal Context sport, professional, interview, free conversation, man-machine dialogue Speaking Rate normal, slow, fast, very fast Stress in noise, with increased vocal effort (Lombard reflex), emotional factors (e.g. angry), under cognitive load
  79. 79. Video • Video is made up of frames • Frame rate = delay between successive frames • Minimal change between frames • Sequencing creates the illusion of movement • 16 frames per second (fps) is “smooth” • Standards: NTSC 29.97 fps, PAL fps, HDTV 60 fps • Interlacing • Display scan rate is different • Monitor refresh rate, e.g., 60-70 Hz = ~1/second
  80. 80. Captured vs. Synthetic • Animation vs. Video • Vector Graphics vs. Bitmap/Raster Pictures • Synthesizer vs. Recording • Storage? Manipulation? Processor Requirements? • Fidelity to real world • Hybrids are possible
  81. 81. Why is Multimedia Important? • Our society - • captures its experience, • records its accomplishments, • portrays its past • informs its masses ……in pictures, audio and video • For many, CNN has become the “publication of record” • Multimedia learning leverages “multiple intelligences” • Multimedia Digital Libraries are an essential component of • formal, informal, and professional learning • distance education, telemedicine
  82. 82. Technology Push vs. Market Pull • Home Entertainment • Catalog Ordering • Multimedia Training, Education • Videoconferencing • Professional Video Services • Videomail • Speech Recognition
  83. 83. Hype vs. Reality What is feasible, under what circumstances? What is possible? What is impossible? What is unlikely?

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