Audio to MIDI Converter Team Obama Advisor: Dr. William Hunt Adnan Burkic Sean Earley Jon Kump Brian Tyson Georgia Institute of Technology 3/16/2010

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 Interface o Industry standard for electronic music devices What is a VST Plug-in? o Virtual Studio Technology o 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 time o Can be measured using host program o Needs to be less than 20ms Pitch detection accuracy o Ensure detected pitch matches played pitch for all notes on guitar

Scheduled Milestones Completed o VST audio input & MIDI output interface o Peak detection o Audio level normalization April 2nd - Pitch detection Completion April 16th - MIDI event generation May 6th - Final Presentation and Demonstration

Cost Analysis Product DescriptionQuantityUnit Price Price SynthMaker Standard License 1 $255 Estimated Labor 650 hrs $30$19,500 Misc. Cables/Hardware for Test Purposes 1 $125 Product Cost Total $19,880

Future Developments Pitch Bend Bass Guitar Alternate Tunings

Questions? Challenges VST Pitch Detetion MIDI Output