E305 Digital Audio and Video (4 Modular Credits) This document addresses the content related abilities, with reference to the module. Abilities of thinking, learning, problem solving, team work, communication, debating and defending are addressed by the system wide curricular practices at the institute. Module Synopsis This course will cover topics in digital audio and video. We begin with a brief overview of current digital audio and video systems and standards. We then characterize the property of a typical digital audio signal in terms of the commonly used parameters. Next, through practical session using a popular chipset, we will learn how to generate digital audio signal, process, compress data and create audio effects employing various encoding schemes. The next part of the course is spent understanding how an analogue video signal is being converted to a digital signal. We will learn how different video format and various components of compression are performed before the signal is pre-processed for transmission to the air. We will also investigate how the effect of channel impairments on the quality of the transmitted digital video signal and how these impairments can be mitigated in a real condition. Module Learning Outcomes Throughout the course, students will learn: Digitization of Video Signal Rationale for digitizing video signal. Recognize the difference between an analogue and a digital video signal. Describe the various interfaces components of a digital video system. Understand the fundamental process in color subsampling. Model these color subsampling processes mathematically. Video Compression Explain reasons for using compression on video signal. Explain how spatial and temporal redundancy reduction is performed. Explain the methods to perform inter and intra frame compression/coding. Describe the various software algorithms used in video encoding and decoding of I,B,P frames. Describe the various Levels and Profiles in an ISO MPEG- system. Packetization of Digital Video Introduce various broadcast standards (i.e. DVB, ATSC, ISDB) Compare the MPEG- Program Stream and Transport Stream (TS). Learn how a video clip is packetized based on the MPEG- TS Derive the useful data rate of Digital Video system using different transmission parameters. Explain how TV services are mapped onto the MPEG- TS. Learn how the TV receiver obtain synchronization with the transmitter. Understand how MPEG- can carry SDTV and HDTV TV services.
Recognize the challenges needed for future transmission services such as 3DTV. Digital Video Transmission Chain Describe the system architecture of a digital video transmission chain. List the frequency spectrum allocation for a DVB system. Describe the various components in the end-to-end transmission. Transmit a real digital video signal, complying to the DVB standard. Learn how a Digital TV receiver process this transmitted signal Recognize the worldwide trends in digital switchover for TV signals and Digital Dividend. Channel impairments on a digital video signal List the different sources of channel impairments. Describe the effects on the video quality from each source of impairment. Use the various models to calculate for propagation loss Learn the measurement techniques to assess these impairment. Describe the techniques used to mitigate these impairment Learn to simulate such impairments using commercially available instruments. Audio Fundamentals Rationale for digitizing audio signal. Recognize the difference between an analogue and a digital audio signal. Describe the various components of a typical audio system. Describe how to characterize audio system performance Understand how to model audio parameters mathematically. Understand how to measure audio parameters using Audio Analyzer. Audio DSP Architecture overview & System development Understand some common features of Digital Signal Processors Understand DSP hardware architectures, data path and memory organization. Familiarized with the Code Composer Studio software environment and development flow. Create a test bench and performed basic program on DSP using Matlab Learn DSP hardware, interface skills and software programming. Analog-to-Digital Conversion Understand the digitization of audio signals and its related hardware Understand the sampling theorem and determine the sampling rate for various digital audio sources Understand the concept of aliasing and how to find and prevent aliased frequencies Understand the concept of quantization and quantization error Bit allocation algorithm and entropy coding Describe types of ADC and DAC and their specifications Audio Processing : Equalizers and Recursive Audio Filter Understand the concept of equalization, convolution and filtering
Understand the concept of truncation through windowing Know how to design FIR filter by windowing the IDTFT of an ideal filter Understand the concept of linear phase FIR filters and their applications Design a FIR filter on audio signals and implement on DSP to achieve certain SNR specifications. Digital Audio Compression Understand the need for compression and signal redundancy Understand and compare various recording media and audio compression formats ( CD, MP3, WAV, AAC ) Identify types of audio interfaces ( Optical, SPDIF, AES, MIDI) Understand basic audio coding principles, sub-band coding. MPEG compression and MP3 encoding Digital Audio Mixing / Sound Effects Understand principles of Surround Sound, echo, chord and reverberation creation. Understand different types of Dolby sounds, DTS, Dolby 5.1, Dolby Prologic standards. Understand how to create delayed audio effects using DSP Digital Audio Transmission Understand concepts of analog and digital audio transmission processes Introduced principles of Digital Audio Broadcasting ( DAB ) and transmission techniques Understand other types of audio transmissions ( Bluetooth, internet audio) and their characteristics. Module Syllabus This module aims to provide an understanding of the concepts behind the practical and theoretical applications of Digital Audio and Video. 1. Understand the basic principles behind the digitization of video signal as well as the various available format and interfaces.. Conduct simple practical session to build, transmit and receive a digital video signal 3. Able to understand and suggest schemes to mitigate effect of poor video quality due to the different types of channel impairment. 4. Understand the basic principles and processes of digital audio processing from sampling and quantization of analog audio, compression and storage, filtering, mixing of signals to wireless transmission. 5. Reinforce and apply DSP theories on audio DSP platform. 6. Conduct practical lab sessions to characterize audio signals performance, to capture and digitize analog audio, implement digital filter, create surround effects, and transmit audio signals wirelessly.
Module Coverage Allocated time per day Module Coverage (One day-one problem PBL pedagogy) Discussions in Study Cluster Resource gathering and team work Formal Lab Experiment (a) Format and Interfaces of Digital Video YcrCb Format Format and Interfaces (b) Video Compression Picture Frame Encoding (I,B,P), GOP. Motion Estimation/Compensation DCT, Quantization, VLC, Zigzag scanning, Huffman, Levels and Profiles, Comparison of H.64 and other emerging compression schemes. (c) Packetization of Digital Video (d) MPEG-, Program Stream, Transport Stream, Packet Structure PSI/Service Information, Introduction to provisioning of real TV services Digital Video Transmission Chain System architecture and components of a Digital Video Transmission Chain, Frequency spectrum for DTV Transmitting and Receiving a DV signal. Network Capacity.
(e) Channel Impairments on digital video Different sources and effects of Channel Impairments Simulating and Assessing Channel Impairments (f) Future Trends in Digital Video Worldwide DTV Standards Digital Switchover and Digital Dividend Whte space Devices (g) Audio Fundamentals Analog vs digital audio Audio system components Audio characteristics Audio Parameters and measurement Class D Amp (h) DSP Architecture / Development DSP Features DSP Architecture Code Composer Studio software environment Test bench setup and programming (i) Analog-to-Digital Conversion Sampling, Quantization Quantization error, aliasing Bit allocation, Entropy coding ADC, DAC, CODEC specifications (j) Audio Equalizers & Recursive Filter Equalization, convolution, filtering Windowing, I DTFT FIR, IIR filters DSP implementation (k) Audio Compression Signal redundancy
Lossless / lossy data compression Audio compression formats Digital audio interface Coding Principles, sub-band coding MPEG compression, MP3 encoding (l) Audio Mixing / Sound Effects Mixing Principle of operation Echo, chord, reverberation Surround, Dolby, DTS, Prologic DSP Implementation (m) Digital Audio Transmission Total Analog audio vs digital audio transmission DAB Principle Wireless audio transmission ( internet radio, Bluetooth, Wifi ) = 15 Problems = 90 hrs