wav-gen

A utility program to generate wave forms as either a wav file or a rust array initialisation.

The later can be used for embedded projects where a waveform needs to be generated.

Example Usage

Sine wave

To generate a sine wave with:

• a frequency of 643 hertz
• a duration of 3 seconds
• an output wav file sine.wav

 wav-gen wav sine --frequency 643 --duration 3 sine.wav

Note: it is assumed throughout that a wav-gen alias has been crated for the executable wav-gen.exe

Sweeping Sine Wave

To generate a sine wave that:

• sweeps between the frequencies of 300 hertz and 1000 hertz
• has a duration of 5 seconds
• is in the wav file sweep.wav

wav-gen wav sweep --start 300  --finish 1000 --duration 5 sweep.wav

Harmonics

To generate a wave that has a set of harmonics first define the harmonics using a csv file (for example harmonics.csv):

frequency,amplitude
500.0 , 0.3
700.0 , 0.2
750.0 , 0.1

This specifies a wave with harmonics at 500Hz, 700Hz and 750Hz with respective amplitudes 0.3, 0.2 and 0.1. The amplitudes will be normalised.

Then use:

wav-gen wav harmonics --infile harmonics.csv output_wave_file.wav

Rust Data Arrays

To generate a sine waveform of 500Hz as a rust data array of 44140 words use the following

wav-gen rust sine --frequency 500 --length 44100  ./wave.rs

The generated rust source code file looks like:

pub static DATA: [i16; 1024] = [
   // i16 values
];

The i16 values alternate between the left channel first and then the right channel. For stereo, each channel has the same value.

If the structure has been, for instance, generated in the file wave.rs then it can be imported with:

use wave;

Alternatively monophonic data arrays can be generated:

wav-gen rust sine --frequency 500 --length 1024 --mono ./wave_mono-rs

This works the same for the other wave types such as sweep and harmonics.

A different name for the rust data structure can be specified:

wav-gen rust sweep --start 500 --finish 1500 --name SWEEP_DATA ./sweep.rs

The generated rust source code looks like:

pub static SWEEP_DATA: [i16; 1024] = [
         0,     0,    71,    71,   143,   143,   214,   214,   285,   285,
       355,   355,   423,   423,   490,   490,   554,   554,   616,   616,
       // ... more i16 values ...
       947,   947,   777,   777,
];

For sine waves and harmonics, instead of generating a rust source code file with a large number of samples, only one cycle can be generated by using the --cycle flag, e.g.:

wav-gen rust sine --frequency 2000 --cycle  ./src/SINE_DATA.rs

More options

For more options use:

wav-gen help