CODEWITHSUNDEEP
javascriptandroidweb-audio-api
bhINC
bhINC

Reputation: 9

How can i play raw samples PCM_16 audio data record from Android in Web (using Web-Audio or other)?

In my app on Android, i use AudioRecord and send continuouslly an bytes array PCM_16 to Node.js server. 

byte[] audioBuffer = new byte[mAudioBufferSampleSize];
    mAudioRecord.startRecording();
    int audioRecordingState = mAudioRecord.getRecordingState();
    if (audioRecordingState != AudioRecord.RECORDSTATE_RECORDING) {
        Log.e(TAG, "AudioRecord is not recording");
        return;
    } else {
        Log.v(TAG, "AudioRecord has started recording...");
    }

    while (inRecordMode) {
        int samplesRead = mAudioRecord.read(audioBuffer, 0,
                mAudioBufferSampleSize);
        Log.v(TAG, "Got samples: " + samplesRead);
        if (WebSocketManager.roomSocket.isConnected()) {            
            WebSocketManager.roomSocket.send(audioBuffer);

        }
    }

After that, i can stream it to the web browser in ArrayBuffer type and try to convert it to an Float32Array to be buffer for an instance of AudioContext. But i can't hear any thing or with loud noise.

    function onMessage(evt) {
    var context = new AudioContext();
    var source = context.createBufferSource();
    source.connect(context.destination);

    array = new Int8Array(evt.data);
    abs = new Float32Array(evt.data);
    arrays = new Float32Array(abs.length);

    ab = context.createBuffer(1, array.length, 44100);
    ab.getChannelData(0).set(arrays);
    source.buffer = ab;
    source.start(0);
        // then do it

    }

So anyone can give me an advance, please? P/s: use decodeAudioData just give an null error

Sorry for my poor English

Upvotes: 0

Views: 1385

Answers (1)

cwilso
cwilso

Reputation: 13928

The array you're getting is each sample 0-32k (range of a uint16). Each sample in an AudioBuffer's channel data is a float32 - nominal range of -1 to +1.

You need to convert the data in each sample, not just assign the value and rely on conversion.

Upvotes: 1

Related Questions