Method startOnCOMThread

driver_wasapi_windows.go:195–315

()

}

func (c *wasapiContext) startOnCOMThread() (ferr error) {
	if c.enumerator == nil {
		e, err := _CoCreateInstance(&uuidMMDeviceEnumerator, nil, uint32(_CLSCTX_ALL), &uuidIMMDeviceEnumerator)
		if err != nil {
			return err
		}
		c.enumerator = (*_IMMDeviceEnumerator)(e)
		defer func() {
			if ferr != nil {
				c.enumerator.Release()
				c.enumerator = nil
			}
		}()
	}

	device, err := c.enumerator.GetDefaultAudioEndPoint(eRender, eConsole)
	if err != nil {
		if errors.Is(err, _E_NOTFOUND) {
			return errDeviceNotFound
		}
		return err
	}
	defer device.Release()

	id, err := device.GetId()
	if err != nil {
		return err
	}
	c.currentDeviceID = id

	if c.client != nil {
		c.client.Release()
		c.client = nil
	}

	client, err := device.Activate(&uuidIAudioClient2, uint32(_CLSCTX_ALL), nil)
	if err != nil {
		return err
	}
	c.client = (*_IAudioClient2)(client)

	if err := c.client.SetClientProperties(&_AudioClientProperties{
		cbSize:     uint32(unsafe.Sizeof(_AudioClientProperties{})),
		bIsOffload: 0,                    // false
		eCategory:  _AudioCategory_Other, // In the example, AudioCategory_ForegroundOnlyMedia was used, but this value is deprecated.
	}); err != nil {
		return err
	}

	// Check the format is supported by WASAPI.
	// Stereo with 48000 [Hz] is likely supported, but mono and/or other sample rates are unlikely supported.
	// Fallback to WinMM in this case anyway.
	const bitsPerSample = 32
	nBlockAlign := c.channelCount * bitsPerSample / 8
	var channelMask uint32
	switch c.channelCount {
	case 1:
		channelMask = _SPEAKER_FRONT_CENTER