README for ~4Dgifts/toolbox/src/demos/audio/amesh/ameshC:
For a demo of this program an a machine with audio hardware type:
make demo
ameshC is a program which makes audio visible by plotting a
real-time history of sequential power spectra computed from an
audio input stream.
Sample code included in {ameshC.c, power.c, fft.h} contains functionality for
* FFT - Fast Fourier Transforms
* Audio input
* Track Ball like viewing rotation
* Sample line drawing and tmesh GL code
Libraries used
* libgl_s shared GL library
* libm math library
* libaudio audio library (required to build ameshC)
ameshC requires an Indigo or a 4D/35 with audio option to run
Running ameshC:
0] Bring up the audio control panel "apanel." apanel can be
started from within the "Tools" section of the Toolchest
1a] attach an audio input to the audio line in jack
or
1b] Bring up apanel and select "Source: Mic"
2] Set the Input Rate to 8 Khz
3] Press the Meter button in Apanel
4] Adjust the Input level sliders on the Audio control Panel
so that the meters move at least half the way up the scale
5] Start ameshC
6] You can adjust the Input Rate on the Audio Control Panel
to vary the display.
ameshC Controls
* left button: hold down and move to zoom in and out
* middle button: hold down and move to rotate your viewing angle
* right button: brings up a pop-up menu with lots of display whizzies
Recommended reading for information on Fast Fourier Transforms and audio:
"C Algorithms for Digital Signal Processing"
by Paul M. Embree and Bruce Kimble
Prentice Hall 1991
ISBN 0-13-133406-9
"Elements of Computer Music"
by F. Richard Moore
Prentice Hall 1991
ISBN 0-13-252552-6
"The Measurement of Power Spectra"
by R.B. Blackman and J.W.Tukey
Dover Books 1958
ISBN 0-486-60507-8
I hope you enjoy this program.
Please let me know if you make any cool additions
David S. Maynard
Silicon Graphics Computer Systems
dsm@sgi.com
February 25, 1992
Source
Documentation
Reference
OR, ...