RxJava2 Reactive Audio Recorder

A reactive (RxJava 2) implementation of the AudioRecord API for recording raw (pcm) audio-data

Usage

Create an instance of RecorderOnSubscribe giving it the path to the file

Java

ObservableAudioRecorder recorder = new ObservableAudioRecorder.Builder(MediaRecorder.AudioSource.CAMCORDER)
                                          .sampleRate(22050)
                                          .stereo()
                                          .file(Environment.getExternalStorageDirectory() + "/sample.wav")
                                          .build();

Kotlin

ObservableAudioRecorder recorder = ObservableAudioRecorder.Builder(MediaRecorder.AudioSource.CAMCORDER)
                                      .sampleRate(22050)
                                      .stereo()
                                      .file(Environment.getExternalStorageDirectory().absolutePath + "/sample.wav")
                                      .build()

Use the recorder OnSubscribe to create an observable

Java

Observable.create(recorder)
          .subscribe(shorts -> {
              ...
              recorder.writeDataToFile(shorts);
          }, throwable -> errorhandling(throwable));

Kotlin

Observable.create(observableAudioRecorder)
        .subscribe({ shorts ->
            ...
            observableAudioRecorder!!.writeDataToFile(shorts)
        }) { throwable -> errorhandling(throwable) }

After setting up the Observer, manipulate the recording-process by using these methods

Name	Description
start()	Starts the recorder and moves it to Recording state
stop()	Stops the recorder and moves it to Stopped state
pause()	Pauses the recorder and moves it to Paused state
resume()	Resumes the recorder if it's in Paused state
isRecording()	Returns true if the recorder is in Recording state
isRecordingStopped()	Checks whether the recorder is in Stopped state or not

Helper methods for wave file write operations

Name	Description
writeDataToFile(shorts)	Writes the short buffers to wave file
completeRecording()	Writes the Wave header info to the file (Call it after stop() method)

Download

Repository available on https://jitpack.io/#hannesa2/RxAudioRecorder

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

dependencies {
    implementation 'com.github.hannesa2:RxAudioRecorder:2.0'
}

License

Copyright 2018 Hannes Achleitner

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.