FR: ability to select which audio output to use (internal speakers, HDMI, headphones, etc.) (Was: Only playing through MacBook internal sound card)

[ivancevich]

All works fine when playing music through the MacBook speakers (on-board audio interface). But, when I switch to an external card (Native Instruments Audio 4 DJ, in my case) no sound is emitted. If I switch back to the internal card it sounds again.

[rhclayto]

Obviously a very old issue (but still open). I managed to allow configurable output device selection with the ALSA backend (only tested & probably only working with ALSA).

Changes to index.js:

_open () {
  // ...
  if (this.device == null) {
    debug('setting default %o: %o', 'device', 'default');
    this.device = 'default';
  }
  // ...
}
// ...
_format (opts) {
  // ...
  if (opts.device != null) {
      debug('setting %o: %o', 'device', opts.device)
      this.device = opts.device
  }
  // ...
  const r = binding.open(this.audio_handle, this.channels, this.sampleRate, format, this.device)
  // ...
}

Changes to binding.cc:

NAN_METHOD(Open) {
  // ...
  String::Utf8Value str(info[4]->ToString());
  ao->device = (char*)*str;
  // ...
}

Run node-gyp rebuild in the module directory to rebuild the bindings/C code.

Instantiate a speaker instance with the 'device' option:

// Create the Speaker instance
const Player = new Speaker({
  channels: 1,
  bitDepth: 16,
  sampleRate: 16000,
  // This is the bluez-alsa pseudo-device, & will make the audio stream go to the Bluetooth headset.
  device: 'bluealsa:HCI=hci0,DEV=00:6A:8E:16:C5:F2,PROFILE=sco'
});

My fork at https://github.com/rhclayto/node-speaker does this. Hope that helps somebody.

[eropple]

@rhclayto Maybe you should file a pull request? This looks like exactly like what I was going to spend my Sunday doing.

[rhclayto]

Okie dokie, I created a pull request: https://github.com/TooTallNate/node-speaker/pull/104

[LinusU]

This was fixed with #105 released as 0.4.1