c/goertzel/README.md

   1 # Goertzel
   2 Scriptable tone detection and audio analysis
   3
   4 ## Contents
   5
   6 * **goertzel.c**
   7   * Does all the dirty work using Goertzel algorithm
   8   * http://en.wikipedia.org/wiki/Goertzel_algorithm
   9   * Detect specified tones and print their levels
  10   * Filter tones using tresholds
  11      * Eg.: Print levels only when treshold is crossed (=event detection)
  12   * TODO
  13      * treshold hysteresis
  14
  15 * Sample scripts using goertzel.c
  16   * **dtmf.sh**: decodes DTMF signals in audio
  17   * **histogram.pl**: shows goertzel output in ASCII graphs
  18   * **histogram.sh**: example using histogram.pl to draw realtime equalizer
  19   * **sleepmon.sh**: Generates frequency on soundcard output and detects it on input
  20      * Can be used to detect and log motion using soundcard and PIR sensor or NC switch
  21   * TODO
  22      * Guitar tuner
  23      * Send me more...