Audio
SW
/ VisualPAM
Description
VisualPAM is a real-time
sound visualization program using the
OpenGL 3D graphics API. Originally, a basic structure of this program was developed as a homework1
for the
course Music256a
at
Stanford. It
is impemented for the purpose of developing
a
psycho-acoustic model for audio coding, which is an ongoing project. I
hope this program to help my own psycho-acoustic model to be enhanced.
It displays real-time 3D animated audio
spectrum, time-domain waveform and its psycho-acoustics information
using mic-input. Psycho-acoustics information2 includes:
- Masking Threshold: the audibility threshold for signals in the presence of the masking signal
- Perceptual Entropy: the average minimum number of bits per freq. sample needed to code a signal without any perceptual difference
- Block Switching Info: the
window length which is changed during the coding of a signal to adjust
the frequency selectivity of the filter bank (0 = long window, 1=short
window)
How to use
- switch between psycho-acoustics information and time waveform by 'p' key
- use Hanning/Hamming/Blackman/Rectangular windows by 'n/m/k/c' keys
- boost or cut spectrum gain by '1'(boost) / '2'(cut) keys
- quit this program by 'q' key
- change display modes
- reset view point to the intial state
- freeze display frame
- toggle spectrum display (waterfall display on/off) by 'w' key
- toggle log-axis by 'l' key
- increase and decrease spectrum bandwidth by ']'(increase) / '['(derease) keys
- increase and decrease display frame per sec. by '+'(increase) / '-'(decrease) keys
- move around to the left/right by left/right arrow keys
- move up/down by up/down arrow keys
- going closer/away by page up/down keys
Download
Please email me for
any questions and suggestions on this program. =)
- Mac OS X:
- Win32 / Linux: coming soon!!
[NOTE]
This program uses GLUT (OpenGL Utility Toolkit) and RtAudio.
Posted on
Mar. 15, 2010