CarnegieMellon

CarnegieMellon

Multimedia

Michael ChristelAlex Hauptmann

Rong Jin (TA)

http://www.cs.cmu.edu/~alex/mmCourse

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How to get in touch with us• Mike Christel

• christel@cs.cmu.edu

• http://www.cs.cmu.edu/~christel

• (412)268-7799 or x8-7799

• WeH5212

• Alex Hauptmann

• alex@cs.cmu.edu

• http://www.cs.cmu.edu/~alex

• (412)268-1448 or x8-1448

• WeH5124

– Office Hours by Appointment

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Teaching Assistant

• Rong Jin

• jin+@andrew.cmu.edu

• Office WeH5316

• Office hours by appointment

• (412)268-4050 or x8-4050

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Course Outline, Part 1 of 3

More details at www.cs.cmu.edu/~alex/mmCourse

October 22 Intro to Multimedia October 25 Multimedia Enabling Technologies, Macromedia

Flash Intro and DemoOctober 29 Sound Processing, Speech RecognitionNovember 1 Digital Video Creation and Transmission

November 5 Speech Synthesis

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Course Outline, Part 2 of 3

More details at www.cs.cmu.edu/~alex/mmCourse

November 8 Image Processing

November 12 Digital Music and Music Processing

November 15 Multimedia Internet Protocols, SMIL

November 19 Synthetic Interviews: A Multimedia Company (Experiences from the Field)

November 22 Programming for Interactive Multimedia (CGI Scripts/ASP)

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Course Outline, Part 3 of 3

More details at www.cs.cmu.edu/~alex/mmCourse

November 29 Content Analysis and Coding of Digital Audio and Video, Multimedia Storage and Retrieval Management.

December 3 Video Retrieval Evaluation and TestingMultimedia Interface Design, Digital Libraries

December 6 Visual Design, Multimedia Interface Design Guidelines, Multimedia use in the future (Experience on Demand)

December 10 Multimedia as Entertainment Technology, Virtual Reality

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Homeworks

• See http://www.cs.cmu.edu/~alex/mmCourse

• 9 Homeworks planned, 10 points each

• One hard homework will be worth 20 points

• No final, no midterm

• Publish homeworks on your web page - email us URL

• Space?

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Today: Intro to Multimedia

Apple Knowledge Navigator Vision 1988

AudioAudio

ImagesImages

InformationInformationRetrievalRetrieval

StorageStorageSystemsSystems

NetworkingNetworking PsychologyPsychology

HCIHCI

DataDataCompressionCompression

NaturalNaturalLanguageLanguageProcessingProcessing

MultimedMultimediaia

CPU PowerCPU Power

VideoVideo

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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

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Definition of Multimodal• Multi (latin multus - numerous)

• Modal (latin modus: manner)

• Traditionally refers to input/output formats:

• Input:

• sounds, speech (mike)

• gestures (camera, tablet)

• eye-gaze (camera),

• mouse,

• keyboard

• Output:

• sounds, speech

• video

• Pictures

• Animations

• Text

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Perceived Information

• Physical Variables

• Sound is a waveform

• An image is a waveform

• light is electromagnetic radiation with different intensity in spatial coordinates

• color corresponds to wavelength

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History of Multimedia I

• Analog signals to sensors

• E.g. vinyl records

• Fidelity is faithfulness to the original

• Digital representation (‘60s)

• Sampling

• Quantizing

• Coding

• codec, modem, (A/D and D/A)

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Hardware Advances• CPU• Bus • Network I/O• Keyboard, Mouse• Disk• Mike + A/D Board• Camera + A/D Board• Speakers (+ D/A Board)• Display

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History of Multimedia II

• Analog controls only

• Special hardware (Displays, Scanners, FFTs)

• Integrated hardware components

• Further Integration

• Other devices

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History of Multimedia III

Limiting Factors:

• Storage Limits

• CPU Speeds

• I/O Speeds

• Network Bandwidth

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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 ‘large’ compared to analog

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Digitization Process

• Sampling from an analog signal• Sampling Errors relate to signal frequencies

• Quantization Errors

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Text

• ASCII, Unicode• Formatted Text, Rich Text• Document Formats:

– Structured: Tex, HTML– Page Descriptions: Postscript, PDF

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Graphics

• Objects– circles, splines, rectangles, lines

• Editable– resize, reshape, move, colorize

• Synthetic

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Images (Pictures)

• Fixed digitized representation– bitmap, colors per pixel

• Editable in limited ways– retouch, cut and paste, remap colors, filter

[Photoshop tools]– no ‘model’ of the thing

• Captured– not just from real life, clip art, screen dump

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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– Ice cream I scream

• Synthesis– Speech– Music

MIDI for 127 instruments, 47 percussion soundsNotes, timing

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Speech Recognition Issues

• Continuous vs Discrete• Vocabulary Size• Channel (Microphone)• Environment (Location of mike and Speaker)• Speaker Dependent/Speaker Independent• Context (Language Model)• Interactivity (Dialog Model)

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Acoustic ModelingDescribes the sounds that

make up speech

LexiconDescribes which

sequences of speechsounds make up

valid words

Language ModelDescribes the likelihoodof various sequences of

words being spoken

Speech Recognition

Speech Recognition Knowledge Sources

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Speech Variations

Style Variationscareful, clear, articulated, formal, casual

spontaneous, normal, read,dictated, intimateVoice Quality

breathy, creaky,whispery, tense,

lax, modal

Contextsport, professional,

interview, free conversation,

man-machine dialogue

Speaking Ratenormal, slow, fast,

very fast

Stress in noise, with increased vocal

effort (Lombard reflex),emotional factors (e.g. angry),

under cognitive load

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Video

• Frames comprise the video– Frame rate = delay between successive frames– minimal change between frames

• Sequencing creates the illusion of movement> 16 fps is “smooth” Standards: 29.97 is NTSC, 25 is PAL, 60 is HDTVInterlacing

• Display scan rate is different – monitor refresh rate– 60 - 70 Hz (= 1/s)

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Captured vs. Synthetic

• Animation vs Video

• Graphics vs Pictures

• Synthesizer vs Recording

• Storage? Manipulation? Processor Requirements?

• Fidelity to real world

• Hybrids are possible

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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” Gardner, 1993

• Multimedia Digital libraries are an essential component of– formal, informal, and professional learning– distance education, telemedicine

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Technology Push vs Market Pull

– Home Entertainment– Catalog Ordering– Multimedia Training, Education– Videoconferencing– Professional Video Services– Videomail– Speech Recognition

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Hype vs. Reality

• What is feasible, under what circumstances?

• What is possible?

• What is impossible?

• What is unlikely?

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Multimedia Visions

• DARPA: Dominate the Battle Space• HP “1995”• LSI “Flash Point”• HP “Synergies”

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Intro to Multimedia

That’s all for today

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