Automatic White Balance or adjust white balance
I'm using a Pi Zero with NoIR module and homebridge-camera-ffmpeg in a bird box. The low light conditions give a very pink colour. Is there a way to adjust the white balance or switch automatic white balance on or off? Or to set it to grayscale?

**Homebridge Config:**

```json
            "platform": "Camera-ffmpeg",
            "cameras": [
                {
                    "name": "Birdhouse Camera",
                    "manufacturer": "Raspberry Pi",
                    "model": "Raspberry Pi NoIR Camera V2.1",
                    "serialNumber": "0000000007a4193e",
                    "videoConfig": {
                        "source": "-f v4l2 -r 30 -s 1280x720 -i /dev/video0",
                        "stillImageSource": "-re -f video4linux2 -ss 0.9 -i /dev/video0 -vframes 1",
                        "maxBitrate": 1024,
                        "maxStreams": 2,
                        "maxWidth": 1280,
                        "maxHeight": 720,
                        "maxFPS": 30,
                        "vcodec": "h264_omx"
                    }
                }
            ]
```

**Screenshots:**
![video feed in Home app](https://i.imgur.com/B9OQHEr.jpg)

**Environment:**

* **Node.js Version**: v12.16.1
* **NPM Version**: v6.14.5
* **Homebridge Version**: 1.1.0
* **Homebridge Camera FFmpeg Version**: v1.2.2
* **Homebridge Config UI X Plugin Version**: v4.22.0
* **Operating System**: Raspbian GNU/Linux Buster (10)

