MP3 Digital Audio Jukebox

Group ID dec011

Robert Fancsalszki, David Govek, James Leatherby, Tom Mitchell, Kenneth L. Reed Jr., John D. Woods

Faculty Advisor: Doug Jacobson

Client: David Govek

Submitted February 15, 2000

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TABLE OF CONTENTS

Table of Contents................................................................................................................. i List of Tables ...................................................................................................................... ii List of Figures .................................................................................................................... iii Abstract ............................................................................................................................... 1 Definition of Terms............................................................................................................. 2 Introduction......................................................................................................................... 3

Background ..................................................................................................................... 3 Technical Problem .......................................................................................................... 3 Operating Environment................................................................................................... 3 Intended Users and Uses................................................................................................. 4 Assumptions and Limitations ......................................................................................... 4

Design Requirements .......................................................................................................... 5 Design Objectives ........................................................................................................... 5 Functional Requirements ................................................................................................ 5 Design Constraints .......................................................................................................... 5 Measurable Milestones ................................................................................................... 6

End-Product Description..................................................................................................... 8 Approach and Design.......................................................................................................... 9

Technical Approaches..................................................................................................... 9 Technical Design ............................................................................................................ 9 Testing Description......................................................................................................... 9 Risks and Risk Management......................................................................................... 10

Budget and Timeline......................................................................................................... 11 Financial Budget ........................................................................................................... 11 Personnel Effort Budget................................................................................................ 11 Project Schedule............................................................................................................ 13

Project Team Information................................................................................................. 14 Summary........................................................................................................................... 14

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LIST OF TABLES

Table 1 Financial Budget (Estimate) Table 2 Personal effort budget (Estimate) Table 3 Contact Information

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LIST OF FIGURES

Figure 1 Project schedule (Gantt chart)

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ABSTRACT

Currently, there exists no easy to use, affordable music mass storage device available to the home audio enthusiast. Specifically speaking, there exists no method for storing large quantities of high quality on-demand digital audio. The MP3 Digital Audio Jukebox (MP3 Jukebox) addresses this demand by using a unique combination of existing magnetic media, digital signal processing, and a highly efficient audio compression algorithm. By combining these aspects with the ability to acquire audio from a variety of standard audio sources and a user-friendly interface, this device provides affordable music mass storage capabilities to the home user.

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DEFINITION OF TERMS

A/D Converter (Analog to Digital Converter or ADC) – converts analog input into digital output

ATAPI (AT Attachment Packet Interface) – an extension of IDE that allows connection to CD-ROMs

CODEC (enCOder and DECoder) – an algorithm that encodes and decodes data files

D/A Converter (Digital to Analog Converter or DAC) – converts digital input into analog output

DSP Chip (Digital Signal Processing Chip) – a semiconductor chip that processes streaming digital signals

IDE (Integrated Drive Electronics) – an interface for mass storage devices in which the controller is integrated into the storage device; e.g. hard disk

IEC (International Electrotechnical Commission) – organization in Geneva that sets international standards for the electrical and electronics fields IEC created the Joint Technical Committee for information technology with ISO

ISO (International Standards Organization) – organization founded in 1946, comprised of the national standards organizations of many countries, and responsible for creating international standards

MP3 (MPEG Layer 3) – a perceptual digital audio compression algorithm developed by Fraunhofer Institut

MPEG (Moving Picture Expert Group) – a working group of ISO/IEC in charge of the development of international standards for compression, decompression, processing, and coded representation of moving pictures, audio, and their combination

RAM (Random Access Memory) – temporary storage space that can be accessed very rapidly and in a non-sequential manner

ROM (Read Only Memory) – a permanent, non-sequential storage device from which one can read but not write

SPDIF (Sony Phillips Digital Interface Format) – a standard protocol and medium for digital data transfer developed by Sony and Phillips commonly used to transfer digital audio

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INTRODUCTION

BACKGROUND

The compact disc revolutionized the home audio environment by providing an easy to use medium for storing digital audio. Digital audio provided an unprecedented sound quality and dynamic range, and it does not suffer from degradation over time. Today, the Compact disc has become a staple of the home audio environment. Many people have collections of hundreds of CDs. Most CDs, however, contain music form only one artist. The desire to listen a variety of music led to the development of CD changers that can hold multiple CDs at the same time, allowing users to create play lists spanning multiple CDs. As people’s collections expand, however, it becomes increasingly difficult both to keep track of music and to create play lists of varieties of music.

The MPEG layer-3 digital audio CODEC compresses digital audio significantly enough to facilitate storing vast quantities of CD quality digital audio on existing storage devices. Such a device would allow users to condense entire CD libraries into a single compact unit.

TECHNICAL PROBLEM

There exists no current convenient and inexpensive technology for storing vast libraries of digital audio for use in a home stereo environment.

A viable solution must

• Record and locally store audio files into the MP3 digital audio format. • Play audio stored in the MP3 digital audio format. • Store a sufficient quantity of music. • Be able to seek through tracks during play. • Provide audio outputs in analog and digital formats compatible with existing home stereo

equipment. • Be controllable via standard infrared remote controls, serial PC control, and face-

mounted buttons. • Have a large face-mounted display showing the current song name, time, and other

standard display information. The display must facilitate browsing the stored music library and creating play lists.

• Not be damaged by unexpected loss of power. • Continue playing despite moderate physical shock.

OPERATING ENVIRONMENT

The MP3 Jukebox is intended for home or office use. It operates in an environment suitable for other stereo components. It will be subject to unexpected power loss and moderate shock, and must be able to withstand these with no dire effects. It is not designed to survive any extreme temperature conditions.

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INTENDED USERS AND USES

The MP3 Jukebox allows one to consolidate one’s personal music collection into a single central location. The MP3 Jukebox is intended for home audiophiles, people with large music collections, people who record radio shows for later listening, offices or restaurants seeking an easy method of providing background music, people who currently use their home computers to play MP3s, and anyone who desires easy access to a variety of music.

ASSUMPTIONS AND LIMITATIONS

Assumptions • The user has a stereo with which to integrate the device. • Motorola’s microcontroller and DSP evaluation modules can be used to prototype. • The DSP used will be powerful enough to encode incoming audio in real time. • The device will be used in a suitable environment.

Product Limitations • The device’s display will be in English. • The device’s software will not be user-upgradeable. • The device will have storage space initially limited to approximately 350 hours. • The user will select the audio quality from a range referenced by a list of commonly

known media types (e.g. the user can select “telephone,” “tape,” “CD,” and “DVD” quality).

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DESIGN REQUIREMENTS

DESIGN OBJECTIVES

The project goal provides an inexpensive technology that will: record and locally store audio files into MP3 format, play audio in MP3 format, and provide output in analog and digital audio formats. The device must have a user interface resembling those of other home stereo components. The device must have controls similar to those of compact disc players, including play, pause, stop, next, previous, rewind, fast-forward, shuffle, and program.

FUNCTIONAL REQUIREMENTS

The product will

• Record and locally store audio files into MP3 format – Audio will be acquired from a CD-ROM or an audio input line. MP3 data will be stored on a local hard drive.

• Play audio in MP3 format – Audio files that have been stored on the local hard drive will be decoded and output for listening.

• Provide audio output standard analog and digital formats – The output will be available in both the digital form as well as the converted analog form.

• Have controls similar to those of compact disc players – Play, stop and pause – as expected – Next track, previous track – stepping alphabetically or through the play list – Fast-forward, rewind (seek) – search through the currently playing track – Shuffle – at the conclusion of each track, the next track is randomly selected – Program – it is possible for the user to create “play lists”, or lists of songs in the desired play order

DESIGN CONSTRAINTS

Some of the design constraints that must be considered include:

• The device must have the ability to recover from a power failure. More specifically, when the device loses power unexpectedly, there must be no unrecoverable damage to the software or storage device.

• The product must have user-friendly control. A user who knows how to operate a CD player should be able to play existing tracks.

• The processors should be powerful enough to provide high quality output. • The ultimate product cost must be comparable to other home stereo components and

music archiving devices.

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MEASURABLE MILESTONES

Architecture Digital-to-analog section

• The DACs can be made to produce audio signals. • The ADCs can be read from when fed audio signals. • The analog input gain to the ADCs is properly balanced.

DSP-Microcontroller

• The M68331 can talk to the DSP56362. • The M68331 can control the DSP56362’s audio input source (digital or analog). • The M68331 can control the DSP56362. The M68331 can cause an asynchronous reset,

perform a software restart, cause a mode switch (decode to encode), and request information regarding input formats.

Power management

• The M68331 receives a hardware interrupt when the system power becomes unstable. IDE controller

• The IDE controller is implemented via programmable logic. • The M68331 can issue drive commands and read disk registers.

Display controller

• The display board is constructed and the display controller functional. • The M68331 can write to the display buffer.

Input and control system

• The input switches and buttons are wired. • The M68331 can poll the button registers. • The remote receiver can decode signals. • The M68331 can poll the remote buffer.

File System The file system is able

• To initialize a disk. • To read raw data to given sectors. • To write raw data to given sectors. • To manage address block entries. • To create, delete, and move files. • To return file-relevant information including size, name, free space, and an alphabetical

file list. • To seek through files during read operations. • To perform an emergency shutdown when signaled. • To start up and examine a device for physical configuration and existing format. • To examine a storage device to determine if the device’s data is safe and intact. • To recognize a CD-ROM drive. • To recognize an ISO-9660 CD-ROM. • To provide a file list from the root directory of a CD-ROM. • To copy a named file from the CD-ROM to the local disk. • To recognize an audio CD and report the number of tracks.

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• To read digital audio from an audio CD as though it were a linear-access file.

Other supporting software • The input control driver merges the remote control and the face controls. • The display driver allows simple control of menus, display, etc. • The IDE driver provides an interface between the file system and the physical disks.

System Software The system software is able

• To pass an MP3 stream from memory to a pseudo-decoder port. • To perform stop, play and pause actions. • To perform track skips through a fixed track array. • To load a track list from an external source. The software can track through this list.

Also, this is a good point to incorporate shuffle-play. • To begin to manage the display. • To read streams from the file system emulator. • To allocate disk space and write a file header to begin recording. • To pass an MP3 stream from a pseudo-encoder to the file system emulator. • To trap system events such as power loss and critical errors. This includes managing

system integrity. • To fully manage the display, including the ability to program play lists.

Integration • The system will turn on. • Software can be loaded to the controllers. • The display can be properly controlled. • Data can be passed to the physical disks. • The file system can be made to access the disk. • The file system can access the CD-ROM • The bootstrap is functional, and the system performs a power-on self-test. • The system software interfaces with the file system. • The system software interfaces with the encoder-decoder. • The system software properly controls the display. • The device recovers from power failures. • The device passes all performance and reliability testing.

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END-PRODUCT DESCRIPTION

The MP3 Jukebox is an MP3 recording and playback device capable of storing several thousand songs for the home or office user. The MP3 Jukebox will accept music from other stereo component devices and home PCs and encode them to MP3 format, storing these music files internally. Then, via remote control or through the front control panel, the MP3 Jukebox will play back the MP3’s through the provided outputs to a stereo amplifier. An easy to use screen will provide access to the thousands of songs stored inside the device, and will allow the user to delete or add more.

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APPROACH AND DESIGN

TECHNICAL APPROACHES

All approaches described will either use a LED matrix or LCD display. An IDE controller chip will provide control for the hard disk and CD-ROM. The device inputs will remain analog though primary use of RCA jacks, while the device will serve dual outputs: one analog (RCA) and the other digital (SPDIF). The user interface will remain simple and function mainly like today’s stereo CD players.

Approach 1: Create an integrated system based on the Motorola M68331 microcontroller and DSP56362 signal processor including complete system architecture, ROMs and memory integration.

Approach 2: Create an integrated system based in the evaluations boards available for the Motorola M68331 microcontroller and DSP56362 signal processor.

TECHNICAL DESIGN

The team decided to go with Approach 2 for the following reasons:

• Saving time on a very large project • Material and cost savings • Simplicity • Adequate knowledge of components

TESTING DESCRIPTION

There are two major developmental branches of this design, hardware and software. The testing will therefore be done in different manner and in different times.

Software Software will be written and debugged in two environments: an emulator on a Windows computer to test the data encoding and decoding, and a fully functional version of the MP3 Jukebox. Each portion of the code will be tested at least twice in each environment, in the design and one linking stages. Design refers to the compilation and running of the code before the completion of the encapsulated object. One linking refers to the attachment of two independent pieces of encapsulated code. As each piece links, the whole product subsequently becomes tested. Extensive piecewise testing is required due to the huge size of the total code and the many threading problems that may arise.

Hardware Hardware testing will remain separate for each piece of electronic hardware. Each piece of hardware will include a CAD design test as well as a physical test. After completion of the total design, both integrated CAD and physical tests will be preformed. Physical testing becomes extensive when applying node voltage checks, current checks, output voltage and load acceptance checks, etc.

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RISKS AND RISK MANAGEMENT

The DSP currently used in the design is unavailable. Resolution: Use a slower DSP chip that is capable of obtaining and writing software to translate the audio files into base data and storing it into RAM or on a separate section of the internal storage until the slower DSP can encode and save all the necessary information

Unable to complete Software requirements for encoding, decoding of MP3’s. Resolution 1: Request help from additional students from an “Ongo" coded project.

Resolution 2: Seek knowledgeable professionals for assistance. As there are a number of shareware MP3 encoders for Windows and Macintosh based systems, it seems likely that some of them have authors that might be convinced to assist in helping the project designers to understand the techniques of encoding/decoding.

Resolution 3: Seek assistance from real time software project graduate students on campus. Several other projects are doing real time thread management software that might be of assistance to the design group.

One or more students leave the project. Resolution: Downgrade the complexity of the project by removing one or more optional components of the system, including the remote control, the internal CD drive, the computer USB interface.

Designing individual circuit boards becomes too difficult/time consuming. Resolution: Utilize evaluation boards that have built in features that can be taken advantage of for the groups benefit.

Note: This risk has already been encountered and resolved.

Difficulties are encountered interfacing different microcontrollers. Resolution 1: Change device choices to those of same company.

Note: Implemented

Resolution 2: Obtain additional support from company that produces hardware.

Resolution 3: Obtain support from other school sources.

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BUDGET AND TIMELINE

FINANCIAL BUDGET

Estimated Budget (Table Form)

Table 1

ITEM ESTIMATED COST Project poster $150 Electronic components $150 DSP chip and board $200 Microcontroller and board $100 LED matrix display $25 Tools $50 Frame (unit’s box) $50 CD-ROM $50 Hard disk $250 Total estimated budget $1025

The financial budget allows us to prepare for the cost of the materials needed for the prototype.

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PERSONNEL EFFORT BUDGET

Estimated Budget (Table Form)

Table 2

PERSONNEL ORIGINAL ESTIMATED EFFORT

John D. Woods 640 hours

Kenneth L.Reed Jr. 450 hours

James C. Leatherby 300 hours

Robert Fancsalszki 400 hours

Dave Govek 320 hours

Tom Mitchell 425 hours

Total estimated effort 2535 hours

The personal effort budget allows us to roughly estimate the amount of time that we will spend on the project. This estimate may change after further understanding of the tasks.

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PROJECT SCHEDULE

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PROJECT TEAM INFORMATION

Table 3

NAME MAILING ADDRESS TELEPHONE E-MAIL ADDRESS EE OR CPRE

John D. Woods 4315 Marcopia Drive 515-296-0106 jdwoods@iastate.edu CPRE

Kenneth L. Reed Jr. Friley 3328 Kimball 515-572-5514 skipper1@iastate.edu EE

James C. Leatherby Box 71 515-232-6502 jleather@iastate.edu CPRE

Robert Fancsalszki 439 S Maple Street #4 515-232-4589 dethleaf@iastate.edu CPRE

David Govek Storms 9104 Griffith 515-572-1963 dgovek@iastate.edu CPRE

Tom Mitchell Storms 9156 Griffith 515-572-1998 tree250@iastate.edu CPRE

Project Team Advisor Dr. Doug Jacobson

Project Client David Govek

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SUMMARY

Currently, there exists no easy to use, affordable music mass storage device available to the home audio enthusiast. Specifically speaking, there exists no method for storing large quantities of high quality on-demand digital audio. The MP3 Jukebox addresses this demand by using a unique combination of existing magnetic media, digital signal processing, and a highly efficient audio compression algorithm. By combining these aspects with the ability to acquire audio from a variety of standard audio sources and a user-friendly interface, this device provides affordable music mass storage capabilities to the home user.

Using Motorola digital signal processors integrated with common and inexpensive mass storage solutions solves the problem of decoding, encoding and storing audio files. The MP3 Jukebox will combine the best features of home stereo systems with the power of personal computer systems.

The MP3 Jukebox will be both easy and convenient to use as well as easy to manufacture. The rigorous testing schedules and techniques utilized will reduce final costs in terms of labor. The possible risks have been analyzed. Problems already encountered have been smoothly solved. Given the combination of our approach, knowledge of the involved risks, proper time management, manageable budget, and rigorous testing schedule, the MP3 Jukebox can be realized.