RxAndroidAudio

RxAndroidAudio (RxAA) is a android library for Rx-style sound input and output.

And yes, it's written in Kotlin.

Setup

To add RxAA to your project, include the following in your project level build.gradle file:

allprojects {
		repositories {
			...
			maven { url "https://jitpack.io" }
		}
	}

And on your application level build.gradle:

compile 'com.github.dsokolov:RxAndroidAudio:0.6'

Usage

First of all create an audio options. There are some predefined AudioOptions instances.

val playbackAudioOptions = AudioOptions.PCM_44100_MONO_PLAYBACK
val recordAudioOptions = AudioOptions.PCM_44100_MONO_RECORD

Then you can record raw audio to file:

val source = RecordObservable.create16bit(recordAudioOptions)
val destination = OutputStreamSubscriber.create16bit(FileOutputStream(fileName), recordAudioOptions)
val subs = Observable.
        create(source).
        onBackpressureDrop().
        subscribeOn(Schedulers.newThread()).
        subscribe(destination)

or play raw audio from file;

val source = InputStreamObservable.create16bit(FileInputStream("/mnt/sdcard/temp.pcm"), playbackAudioOptions)
val destination = PlaybackSubscriber.create16Bit(playbackAudioOptions)
val subs = Observable.
        create(source).
        onBackpressureDrop().
        subscribeOn(Schedulers.newThread()).
        subscribe(destination)

You can apply filters for you sound stream. For example, lowpass filter on 440Hz:

val lowpassFilter = LowpassFilter.crate16bit(440f, 1f, playbackAudioOptions)
val subs = Observable.
        create(source).
        onBackpressureDrop().
        map { data -> lowpassFilter.filter(data) }.
        subscribeOn(Schedulers.newThread()).
        subscribe(destination)

Please take a look at app module for more usage examples.

Contribution

Feel free create issues, pull requests and forks.

License

Copyright 2016 Dmitry I. Sokolov

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.