Homebridge Camera FFmpeg mjpeg error
**Describe The Problem:**
I installed [Pavel Khlebovich's IP webcam app](https://play.google.com/store/apps/details?id=com.pas.webcam&hl=de&gl=US) on my old HTC One M8. I made the configuration according to the following [example](https://sunoo.github.io/homebridge-camera-ffmpeg/configs/IP-Webcam-App.html). The screenshot which is updated every 10s in the [Home App](https://apps.apple.com/de/app/home/id1110145103) works and it is a good quality. But when I start the video stream, the picture is very blurry and the FPS are very low. I already set forceMax to true, set a lower bitrate and set maxFPS to 0. But that doesn't help either. When I look at the live stream via the ip address in the browser, the picture and the fps are good.

**To Reproduce:**
1. View the camera stream
2. See error

**Logs:**

```
[3/28/2021, 17:58:33] [Camera FFmpeg] [Kamera] Starting video stream: 1280 x 720, 30 fps, 299 kbps (AAC-eld)
[3/28/2021, 17:58:34] [Camera FFmpeg] [Kamera] [mjpeg @ 0x36e2f70] [error] overread 7
[3/28/2021, 17:58:37] [Camera FFmpeg] [Kamera] [mjpeg @ 0x36e2f70] [error] overread 8
[3/28/2021, 17:58:37] [Camera FFmpeg] [Kamera] [mjpeg @ 0x36e2f70] [error] overread 8
[3/28/2021, 17:58:38] [Camera FFmpeg] [Kamera] [mjpeg @ 0x36e2f70] [error] overread 4
[3/28/2021, 17:58:39] [Camera FFmpeg] [Kamera] [mjpeg @ 0x36e2f70] [error] overread 8
[3/28/2021, 17:58:40] [Camera FFmpeg] [Kamera] [mjpeg @ 0x36e2f70] [error] overread 8
[3/28/2021, 17:58:40] [Camera FFmpeg] [Kamera] [mjpeg @ 0x36e2f70] [error] overread 8
[3/28/2021, 17:58:41] [Camera FFmpeg] [Kamera] [mjpeg @ 0x36e2f70] [error] overread 8
[3/28/2021, 17:58:42] [Camera FFmpeg] [Kamera] [mjpeg @ 0x36e2f70] [error] overread 8
[3/28/2021, 17:58:42] [Camera FFmpeg] [Kamera] Stopped video stream.
```

**Homebridge Config:**
```
{
            "name": "Camera FFmpeg",
            "cameras": [
                {
                    "name": "Kamera",
                    "unbridge": false,
                    "videoConfig": {
                        "source": "-re -i http://192.168.2.167:8080/video -i http://192.168.2.167:8080/audio.opus",
                        "maxStreams": 2,
                        "maxWidth": 1920,
                        "maxHeight": 1080,
                        "maxFPS": 30,
                        "mapvideo": "0",
                        "mapaudio": "1",
                        "audio": true
                    }
                }
            ],
            "platform": "Camera-ffmpeg"
         }
```


**Environment:**

* **Node.js Version**: 12.19.0
* **NPM Version**: 6.14.8
* **Homebridge Version**: 1.3.4
* **Homebridge Camera FFmpeg Version**: 3.1.2
* **Homebridge Config UI X Plugin Version**: 4.41.0
* **Operating System**: Raspbian 

