Spectrogram Drawer

Spectrogram drawer for heart, lung and bowel sounds

$3

``sh
npm i @stethio/spectrogram-drawer --save
`

$3

#### 1. Import AudioEngine

`ts
import AudioEngine from '@stethio/spectrogram-drawer';
`

#### 2. Add Canvas to View:

`html

`
#### 3. Initialize:

`ts
this.audioEngine = await new AudioEngine().initAudioEngine('canvasID', 'YOUR_SDK_KEY');
let constraints = { audio: true }
navigator.mediaDevices.getUserMedia(constraints)
.then(async (stream) => {
this.audioContext = new AudioContext();
await this.audioEngine.startIt(false);
this.audioEngine.loadOpusDecoder();
})
`
Config:
- mode: 'HEART' | 'LUNG'
- gain for HEART: minimum 1 to maximum 3
- gain for LUNG: minimum 1 to maximum 20

#### 4. Send Audio input

##### Load Audio files

`ts
const audioContext = new AudioContext();
fetch('audio.wav')
.then(response => response.arrayBuffer())
.then(arrayBuffer => audioContext.decodeAudioData(arrayBuffer))
.then(audioBuffer => {
this.audioEngine.testAudioInput(audioBuffer.getChannelData(0));
});
`

##### Live input stream with getUserMedia.

`ts
navigator.mediaDevices.getUserMedia({audio: true})
.then((stream) => {
const context = new AudioContext({sampleRate: 16000});
const source = context.createMediaStreamSource(stream);
const processor = context.createScriptProcessor(1024, 1, 1);

source.connect(processor);
processor.connect(context.destination);

processor.onaudioprocess = (e) => {
this.audioEngine.testAudioInput(e.inputBuffer.getChannelData(0));
};
});
`

$3

##### 1. Pause
`ts
this.audioEngine.pause();
`
##### 2. Stop
`ts
this.audioEngine.stop();
`
##### 3. Resume
`ts
this.audioEngine.resume();
`
##### 4. Change Playback Speed
`ts
this.audioEngine.playbackSpeedChange(speed); // speed [0.25, 0.5, 0.75, 1, 1.25, 1.50, 1.75, 2]
`
##### 5. Disable Auto Gain and Noise Filters
`ts
this.audioEngine.setAutoGainFlag(false); // By default, the gain is enabled
this.audioEngine.setFilterFlag(false); // By default, the filter is enabled
`


##### NOTE`: We are supporting 5 canvases to be displayed at the same time in a screen