* requires:

 * sox for input preprocessing

 * convolve

 * hist
  * fftw-dev for libfftw, librfftw
  * glib-2.0
  * gtk+-2.0

 * the makefile currently uses pkg-config to determine the 
   library paths for the libraries.
   $ apt-get install pkg-path

* input and output

 * input must be 8bit signed single channel audio
 * for convolve the sampling rate does not matter
 * hist calculates absolute frequency with sampling rate fixed to 22050
   but doesnt care if its not the actual sampling rate
 * output is exaclty the same format


* usage of hist

 $ hist windowtitle
   windowtitle will be used as title for the histogram

   hist reads a block from stdin, performs a fft on it and displays the data
   in a logarithmic display (x,y is logarithmic)

* usage of convolve

 $ convolve kernelfile

   convolve first reads the kernel file. the kernel file must have a structure like (BNF):

 	file = { float }.
   
   the number of numbers in the file must match the current kernel size which is compiled
   into the convolve.

   example:

	0.0 -2.0 0.0 2.0 0.0

   which would be something like a highpass filter

   then the convolve application reads samples from the input and convolves it
   with the configured kernel. 

   the convolved data is written to stdout.


* synth

  simple synth creating tones on a mathematical model of ck's

* synth2
  
  simple synth reading ck's from a file

* vocoder 

  

  removes frequencies from input

* song


  ./song | ./play.sh

  plays the song in "song.txt" using something like in "synth"


* midi

  ./midi file.mid | ./play.sh

* typical usage:

sox mm.wav -1 -r 22050 -c 1 -t raw - | ./hist "orig" | ./convolve hp.kernel | ./hist "filt" | play -1 -r 22050 -c 1 -t raw -s  -

mpg123 test.mp3 --wav mm.wav
sox mm.wav -1 -r 22050 -c 1 -t raw mm.raw
cat mm.raw | ./hist "orig" > /dev/null
cat mm.raw | ./convolve hp.kernel  > hp.raw
cat hp.raw | ./hist "hp" | play -1 -r 22050 -c 1 -t raw -s -