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Essentials of AV Technology

Introduction to AV Systems

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Part OneIntroduction to AV Systems

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AV Systems EssentialsYou will learn about:

What defines a system

Why systems are important

The purpose of a system

Active and passive systems

Where AV systems can be found

Types of AV systems

How an AV system is created

Ergonomics

Subsystems

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AV System Applications

Defining an AV system

AV systems Usage

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AV Systems Goals

Communicate and share

Meet an objective

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Overview of AV System Creation

Wants and Needs

Design

Install

Support

Allied trades

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Active and Passive Systems

Active Systems

- Lighting, audio, projection

Passive systems

-Wall coverings, furniture, screens

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AV SubsystemsAn AV system can include several subsystems

Stand Alone

Support of objective

Multiple subsystems that supports larger system 

Subsystems are only a small part of a larger complete system.

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AV Systems SummaryYou have now learned about systems in general. The topics you have covered in this section are:

What defines a system

Examples of where AV systems can be found

Types of AV systems

Why AV systems are important

The purpose of an AV system

The overview for creating an AV system

AV allied trades

Active and passive systems

The definition of a subsystem

Indicators of subsystems

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Part TwoAnalog and Digital Signals

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Analog and Digital Signals Introduction

This section will cover:

• Analog and Digital Signals

• Waveforms

• Digital Signal Processing and Sampling

• Bit Depth of a Digital Signal

• Bit Rate

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Analog and Digital Signals

Analog: continuous waveform

always varying states

Digital: "On (1)" and "Off (0)" positions only

2 states

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Waveforms

Analog Waveform Digital Waveform

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Digital Signal Processing and Sampling

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Bit Depth of a Digital Signal

Bit Depth: The number of states in which to describe the sampled voltage level.

4-bit grayscale: a 4-bit pixel has 16 potential shades

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Bit RateBit Rate: Quantity of information over time in a digital

signal stream

Format Bit Rate

Mp3 128-160 Kbit/s

AudioCD 1411.2 Kbit/s

VideoCD 1 Mbit/s

DVD 5 Mbit/s

HDTV 20Mbit/s

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Signal Compression

Reduces file size

Codecs

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Digital FormatsContainers:

File structure

Defines how data is arranged

MOV, AVI, WMV, MPEG-2

Codecs:

Compression algorithms

Compression/DECompression

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Lossless and Lossy Compression

Lossless: Same as original

Lossy: Approximation of original data

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Noise and Signal Transmission

Analog signal-to-noise ratio affected

Digital signals more resistant

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Amplifiers and Signal Transmission

Analog - signal to noise ratio affected

Digital - signals more resistant to noise

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Analog and Digital Signal Considerations

Analog Recordings

Duplicating of continuous signals

Short lifetime

Short lifetime

Digital Recordings

Duplicating list of numbers

Long lifetime

Copies are equal quality

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Analog and Digital Signals Summary

Representation of digital data

Sampling rate vs. digital signal accuracy

Bit depth determines precision

Digital video file formats

Lossless and lossy compression

Analog recordings and the duplication process

Digital recording advantages