Tempo and Loudness
Tracking via Frequency and Time Domain Analysis for Polyphonic Music
ISE-575/b final
project: Spring 2006
By
Erdem Unal
ENERGY ANALYSIS
The Objective: To locate the note onsets
in each channel
The Algorithm: Short-term Energy Method is used to estimate the
energy of the signal. STE calculations require the signal divided into windows
of a fixed time period. Here we used windows of 10ms length and extracted the
energy for each window for the corresponding samples with the following
formula.
Each window indexed with k is overlapped to the next window by 50% for smoother energy
calculations.
Calculated Energy Graphs for Each Band:
A Threshold energy value is defined from held-out
data, and note onsets are detected accordingly. All the defined note onsets are
then added up into a vector called trigger.
