audio to midi converter team obama

Audio to MIDI ConverterTeam Obama

Advisor: Dr. William HuntAdnan BurkicSean EarleyJon Kump

Brian Tyson 

Georgia Institute of Technology3/16/2010

Project Overview• Audio to MIDI converter plug-in designed for guitar

• Guitar can control any MIDI device in real-time• Software will be targeted toward guitarists and record

producers• Software solution requiring no hardware• Software will be approximately $50, cheaper than

competing hardware products  

Important acronyms

• What is MIDI?o Musical Instrument Digital Interfaceo  Industry standard for electronic music devices

  •  What is a VST Plug-in?

o Virtual Studio Technologyo Requires host application o Industry standard for music related plug-ins

Design Goals

• VST plug-in compatible with any third-party software•  Low latency to allow real time performance•  Fast and accurate pitch detection(monophonic)•  Pitch Bend

Design Illustration

• Interface mockup

Graphical User Interface

Design Challenges

• How to code a VST?• How to detect pitch?• How to output MIDI?

SynthMaker

AMDF Pitch Detection

• Average Magnitude Difference Function• Time-Domain• Fast and simple• Not capable of accurate polyphonic pitch detection 

AMDF Theory

A4 (2/440)

G4 (2/392)

E4(2/330)

(Delay in Seconds)

Input, Delayed Input              Input+Delayed Input

MIDI Output

• MIDIEvent block• Currently researching the

structure of the MIDI protocol

• Final step of the project

Acceptance Testing

• Latency needs to be perceived as real timeoCan be measured using host programoNeeds to be less than 20ms

• Pitch detection accuracyoEnsure detected pitch matches played

pitch for all notes on guitar

Scheduled Milestones

• Completed o VST audio input & MIDI output interfaceo Peak detectiono Audio level normalization

• April 2nd - Pitch detection Completion • April 16th - MIDI event generation • May 6th - Final Presentation and Demonstration

Cost Analysis

Product Description Quantity Unit Price

Price

SynthMaker Standard License 1 $255 $255

Estimated Labor 650 hrs $30 $19,500

Misc. Cables/Hardware for Test Purposes 1 $125 $125

Product Cost Total $19,880

Future Developments

• Pitch Bend

• Bass Guitar• Alternate Tunings

Questions?

Challenges •  VST

 • Pitch Detetion

  • MIDI Output