Audio to MIDI ConverterTeam Obama

Advisor: Dr. William HuntAdnan BurkicSean EarleyJon Kump

Brian Tyson 

Georgia Institute of Technology4/27/2010

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

  

Design Overview

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 capability

• Intuitive, easy to use interface

VST Compatibility

• Compatible with most digital audio workstations (DAWs), but not all

• DAW needs to support receiving MIDI events from VST plugin

• If DAW is not supported, program can be run as stand-alone executable

Latency

• Difference in time DAW receives guitar note to time synthesizer plays sound

• Optimally less than 20ms

• Measured difference using host program

Latency Measurement

• Top waveform is guitar audio

• Bottom waveform is synthesizer audio

• Each square of bottom grid represents 20ms

• By using a pixel ruler, average latency was found to be 23.8ms

Pitch Detection

• Each note played on guitar needs to generate correct MIDI note

• Easy to verify by simply playing each note on guitar and verify correct MIDI note is output

• Pitch detection was found to be accurate for every possible note on a standard tuned guitar

Pitch Bend

• Feature was successfully implemented

• Performance varies depending on note played and degree of bend

• Can be enabled or disabled as needed

Graphical User Interface

Demonstration Illustration

Marketable Changes

• Improved latency

• Optimized pitch bend

• Expand to more third-party software

• Support for non standard tunings

• Support for other instruments

Questions?