https://github.com/jpmec/oscillixir

An Elixir audio synthesizer
https://github.com/jpmec/oscillixir

Last synced: about 1 month ago
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An Elixir audio synthesizer

• Host: GitHub
• URL: https://github.com/jpmec/oscillixir
• Owner: jpmec
• Created: 2016-01-18T04:45:18.000Z (almost 9 years ago)
• Default Branch: develop
• Last Pushed: 2016-02-04T14:49:21.000Z (almost 9 years ago)
• Last Synced: 2024-08-02T19:31:41.298Z (4 months ago)
• Language: Elixir
• Size: 57.6 KB
• Stars: 2
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

• awesome-open-synth - Oscillixir

README

        
# Oscillixir

An attempt at making an audio synthesizer in Elixir.

## Components

### Time Source

The Source.Timer module provides a time source for audio signal.

It periodically notifies the Sequence.Range which creates a series of time values.

By default:

    * The Source.Timer generates an event notification every 10 ms.

    * The Sequence.Range generates 441 time events with interval of 0.000022675736961451248.

The result is a sequence of time events representing 44100 Hz.

### Oscillators

An Oscillator is notified with a time, and creates a signal event.

The supported oscillators are:

    * Square

    * Saw

    * Triangle

    * Sine

## Background Research and Design Choices

For CD-quality audio:

* the sample rate is 44,100 samples per second.

* has a sample size of 16 bits

* has 2 channels

The common range of human hearing is 20 Hz to 20 kHz.  Humans can hear as low as 12 Hz.

1/44100 second/samples = 0.000022675736961451248 second/sample ~= 23 microsecond/sample

(0.001 second) / (0.000023 second/sample) = 43.47826086956522 samples ~= 43 samples

The Erlang timer is only accurate to 1 millisecond.

Erlang rem function only works on integers.

:math.sin/1 is the Erlang sine function

The base time unit will be 1 microsecond.

This allows many of the calculations to be performed as integers.

## Installation

If [available in Hex](https://hex.pm/docs/publish), the package can be installed as:

  1. Add oscillixir to your list of dependencies in `mix.exs`:

        def deps do

          [{:oscillixir, "~> 0.0.1"}]

        end

  2. Ensure oscillixir is started before your application:

        def application do

          [applications: [:oscillixir]]

        end