What is this?

This repo contains a small C program that outputs a sine wave of a determined frequency in binary form. That means that when you say something like

./wave 100.0

You will only see gibberish. However, it is useful because you can pipe the output to aplay or sox and be able to play music.

Installing

  git clone https://github.com/efferifick/wave
  cd wave
  make install

One can further specify install path by

make prefix=/path/to install

Usage

  usage:
	wave [options] [FREQ1 FREQ2 FREQ3 ..]
  options:

  -h                    Prints out this message.
  --help

  -v                    Prints out program version.
  --version

  -a DOUBLE             Sets amplitude value.
  --amplitude DOUBLE    Default: 1.0

  -r INT                Sets sampling rate.
  --rate INT            Default: 48000 (Hz).

  -s INT                Sets number of samples to be taken.
  --samples INT         Defaults: 48000. (Equivalent to 1 second on default
                          rate)

  -f PATH               Sets input file.
  --file PATH

  NOTES:
    For best results amplitude should be in the range of [0, 1].

    If no arguments are given, input is expected from stdin. This is useful
    for piping. Input is expected as though reading from a file. Ex.

      
        echo 48000 1.0 440 | ./wave | sox -t raw -r 48000 -e \
        floating-point -c 1 -b 32 - -tcoreaudio

    If reading from a file or stdin, the program expects this input format.

        <SAMPLES> <AMPLITUDE> <FREQ1> <FREQ2> <...>
        <SAMPLES> <AMPLITUDE> <FREQ1> <FREQ2> <...>
        <SAMPLES> <AMPLITUDE> <FREQ1> <FREQ2> <...>

    Each line will output after the one before has run out of samples.

    Get the source or file an issue at:
        https://github.com/efferifick/wave

The output is given by a float. This is done so that we can play its output with the standard audio format PCM 32 bytes.

Example to produce music

on linux:

cd examples
m4 -R music.m4f -Q chopsticks.txt | awk '{$1 = $1*48000; print $0}' | wave | aplay -f FLOAT_LE -r 48000 -c 1 -q

on mac:

cd examples
m4 -R music.m4f -Q chopsticks.txt | awk '{$1 = $1*48000; print $0}' | wave | sox -t raw -r 48000 -e floating-point -c 1 -b 32 - -tcoreaudio

Uninstalling

make uninstall