Poor bitrate and video quality with latest beta and CPU pegging
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**Describe The Bug:**
<!-- A clear and concise description of what the bug is. -->
The bitrate has dropped dramatically with the latest beta release.  I also see cpu pegging on raspi.

Earlier this morning:
homebridge.log:[7/17/2020, 7:27:35 AM] [Camera-ffmpeg] RIGHT Front Cam: [info] frame=21304 fps= 33 q=-0.0 size=  111902kB time=00:17:45.05 bitrate= 860.7kbits/s dup=2130 drop=0 speed=1.67x    
homebridge.log:[7/17/2020, 7:27:36 AM] [Camera-ffmpeg] RIGHT Front Cam: [info] frame=21323 fps= 33 q=-0.0 size=  112016kB time=00:17:46.00 bitrate= 860.8kbits/s dup=2132 drop=0 speed=1.67x    
homebridge.log:[7/17/2020, 7:27:36 AM] [Camera-ffmpeg] RIGHT Front Cam: [info] frame=21340 fps= 33 q=-0.0 size=  112230kB time=00:17:46.85 bitrate= 861.8kbits/s dup=2134 drop=0 speed=1.67x

Now:
[7/17/2020, 9:39:34 AM] [Camera-ffmpeg] RIGHT Front Cam: [info] frame= 4979 fps= 33 q=-0.0 size=    4078kB time=00:04:08.80 bitrate= 134.3kbits/s dup=498 drop=0 speed=1.67x    
[7/17/2020, 9:39:34 AM] [Camera-ffmpeg] RIGHT Front Cam: frame= 4997 fps= 33 q=-0.0 size=    4096kB time=00:04:09.70 bitrate= 134.4kbits/s dup=500 drop=0 speed=1.67x    
[7/17/2020, 9:39:35 AM] [Camera-ffmpeg] RIGHT Front Cam: frame= 5014 fps= 33 q=-0.0 size=    4108kB time=00:04:10.55 bitrate= 134.3kbits/s dup=501 drop=0 speed=1.67x    
[7/17/2020, 9:39:35 AM] [Camera-ffmpeg] RIGHT Front Cam: [info] frame= 5032 fps= 33 q=-0.0 size=    4124kB time=00:04:11.45 bitrate= 134.4kbits/s dup=503 drop=0 speed=1.67x    
[7/17/2020, 9:39:36 AM] [Camera-ffmpeg] RIGHT Front Cam: [info] frame= 5050 fps= 33 q=-0.0 size=    4135kB time=00:04:12.35 bitrate= 134.2kbits/s dup=505 drop=0 speed=1.67x 

**To Reproduce:**
<!-- Steps to reproduce the behavior. -->
Run the latest release.
Tail the log, view the bitrate.
**Expected behavior:**
<!-- A clear and concise description of what you expected to happen. -->
I should be seeing bitrates in the mid-800's.
**Logs:**
<!-- Bug reports that do not contain logs may be closed without warning. -->

```
[7/17/2020, 9:36:55 AM] [Camera-ffmpeg] Snapshot from FRONT DOOR (Axis) at 480:270
[7/17/2020, 9:36:56 AM] [Camera-ffmpeg] Snapshot from LEFT Side Cam at 480:270
[7/17/2020, 9:37:03 AM] [Camera-ffmpeg] Starting RIGHT Front Cam video stream (640x360, 20 fps, 132 kbps, 1316 mtu)... debug enabled
[7/17/2020, 9:37:03 AM] [Camera-ffmpeg] RIGHT Front Cam command: ffmpeg -rtsp_transport tcp -r 18 -i rtsp://root:XXXXXXXXXX@192.168.1.233/axis-media/media.amp?streamprofile=Media?tcp&resolution=1280x720 -map 0:0 -vcodec h264_omx -pix_fmt yuv420p -r 20 -f rawvideo -preset ultrafast -tune zerolatency -vf scale=640:360 -b:v 132k -bufsize 264k -maxrate 132k -payload_type 99 -ssrc 11128696 -f rtp -srtp_out_suite AES_CM_128_HMAC_SHA1_80 -srtp_out_params gSDjJemjJP+W6PSw8VDIJ24CKdP7Hzkaf8+9bAS/ srtp://192.168.1.43:55541?rtcpport=55541&localrtcpport=55541&pkt_size=1316 -loglevel level+verbose
[7/17/2020, 9:37:03 AM] [Camera-ffmpeg] RIGHT Front Cam: [info] 
[7/17/2020, 9:37:03 AM] [Camera-ffmpeg] RIGHT Front Cam: ffmpeg version 4.2.2-d1e8be3 Copyright (c) 2000-2019 the FFmpeg developers
[info]   built with gcc 6.3.0 (Raspbian 6.3.0-18+rpi1+deb9u1) 20170516
[info]   configuration: --pkgconfigdir=/build/workspace/lib/pkgconfig --prefix=/build/workspace --pkg-config-flags=--static --extra-cflags=-I/build/workspace/include --extra-ldflags=-L/build/workspace/lib --extra-libs='-lpthread -lm' --enable-static --disable-debug --disable-shared --disable-ffplay --disable-doc --enable-openssl --enable-gpl --enable-version3 --enable-nonfree --enable-pthreads --enable-libvpx --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libx264 --enable-runtime-cpudetect --enable-libfdk-aac --enable-avfilter --enable-libopencore_amrwb --enable-libopencore_amrnb --enable-filters --enable-decoder=h264 --enable-network --enable-protocol=tcp --enable-libspeex --enable-demuxer=rtsp --enable-omx-rpi --enable-mmal --enable-indev=alsa --enable-outdev=alsa
[info]   libavutil      56. 31.100 / 56. 31.100
[info]   libavcodec     58. 54.100 / 58. 54.100
[info]   libavformat    58. 29.100 / 58. 29.100
[info]   libavdevice    58.  8.100 / 58.  8.100
[info]   libavfilter     7. 57.100 /  7. 57.100
[info]   libswscale      5.  5.100 /  5.  5.100
[info]   libswresample   3.  5.100 /  3.  5.100
[info]   libpostproc    55.  5.100 / 55.  5.100[7/17/2020, 9:37:03 AM] [Camera-ffmpeg] RIGHT Front Cam: [tcp @ 0x267f030] [verbose] Starting connection attempt to 192.168.1.233 port 554[7/17/2020, 9:37:03 AM] [Camera-ffmpeg] RIGHT Front Cam: [tcp @ 0x267f030] [verbose] Successfully connected to 192.168.1.233 port 554[7/17/2020, 9:37:04 AM] [Camera-ffmpeg] RIGHT Front Cam: [rtsp @ 0x267cf80] [verbose] SDP:
v=0
o=- 815368507048721138 1 IN IP4 192.168.1.233
s=Session streamed with GStreamer
i=rtsp-server
t=0 0
a=tool:GStreamer
a=type:broadcast
a=range:npt=now-
a=control:rtsp://192.168.1.233:554/axis-media/media.amp?streamprofile=Media?tcp&resolution=1280x720
m=video 0 RTP/AVP 96
c=IN IP4 0.0.0.0
b=AS:50000
a=rtpmap:96 H264/90000
a=fmtp:96 packetization-mode=1;profile-level-id=4d0029;sprop-parameter-sets=Z00AKeKQCgC3YC3AQEBpB4kRUA==,aO48gA==
a=ts-refclk:local
a=mediaclk:sender
a=control:rtsp://192.168.1.233:554/axis-media/media.amp/stream=0?streamprofile=Media?tcp&resolution=1280x720
a=framerate:30.000000
a=transform:1.000000,0.000000,0.000000;0.000000,1.000000,0.000000;0.000000,0.000000,1.000000
[7/17/2020, 9:37:04 AM] [Camera-ffmpeg] RIGHT Front Cam: [rtsp @ 0x267cf80] [verbose] setting jitter buffer size to 0[7/17/2020, 9:37:04 AM] [Camera-ffmpeg] RIGHT Front Cam: [h264 @ 0x2680520] [verbose] Reinit context to 1280x720, pix_fmt: yuvj420p[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: [info] Input #0, rtsp, from 'rtsp://root:XXXXXXXXXX@192.168.1.233/axis-media/media.amp?streamprofile=Media?tcp&resolution=1280x720':
[info]   Metadata:
[info]     title           : Session streamed with GStreamer
[info]     comment         : rtsp-server
[info]   Duration: 
[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: N/A, start: 0.033344, bitrate: N/A
[info]     Stream #0:0: Video: h264 (Main), 1 reference frame, yuvj420p(pc, bt709, progressive, center), 1280x720 [SAR 1:1 DAR 16:9], 30 fps, 30 tbr, 90k tbn, 180k tbc[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: [warning] Codec AVOption preset (Set the encoding preset (cf. x264 --fullhelp)) specified for output file #0 (srtp://192.168.1.43:55541?rtcpport=55541&localrtcpport=55541&pkt_size=1316) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some encoder which was not actually used for any stream.[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: [warning] Codec AVOption tune (Tune the encoding to a specific scenario) specified for output file #0 (srtp://192.168.1.43:55541?rtcpport=55541&localrtcpport=55541&pkt_size=1316) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some encoder which was not actually used for any stream.[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: [info] Stream mapping:
[info]   Stream #0:0 -> #0:0 (h264 (native) -> h264 (h264_omx))
[info] Press [q] to stop, [?] for help[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: [h264 @ 0x269be70] 
[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: [verbose] 
[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: Reinit context to 1280x720, pix_fmt: yuvj420p
[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: [Parsed_scale_0 @ 0x267cb50] [verbose] w:640 h:360 flags:'bicubic' interl:0[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: [graph 0 input from stream 0:0 @ 0x29ffab0] [verbose] w:1280 h:720 pixfmt:yuvj420p tb:1/18 fr:18/1 sar:1/1 sws_param:flags=2[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: [swscaler @ 0x2a00880] [warning] deprecated pixel format used, make sure you did set range correctly[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: [Parsed_scale_0 @ 0x267cb50] [verbose] w:1280 h:720 fmt:yuvj420p sar:1/1 -> w:640 h:360 fmt:yuv420p sar:1/1 flags:0x4[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: [h264_omx @ 0x26996f0] [info] Using OMX.broadcom.video_encode[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: [h264_omx @ 0x26996f0] [verbose] OMX state changed to 2
[h264_omx @ 0x26996f0] [verbose] OMX state changed to 3
[h264_omx @ 0x26996f0] [verbose] OMX port 201 settings changed
[info] Output #0, rtp, to 'srtp://192.168.1.43:55541?rtcpport=55541&localrtcpport=55541&pkt_size=1316':
[info]   Metadata:
[info]     title           : Session streamed with GStreamer
[info]     comment         : rtsp-server
[info]     encoder         : Lavf58.29.100
[info]     Stream #0:0: Video: h264 (h264_omx), 1 reference frame, yuv420p(center), 640x360 [SAR 1:1 DAR 16:9], q=2-31, 132 kb/s, 20 fps, 90k tbn, 20 tbc
[info]     Metadata:
[info]       encoder         : Lavc58.54.100 h264_omx[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: [verbose] *** 1 dup![7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: [verbose] 
[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: *** 1 dup![7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: [info] frame=   20 fps=0.0 q=-0.0 size=      16kB time=00:00:00.90 bitrate= 144.5kbits/s dup=2 drop=0 speed=1.77x    
[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: [verbose] 
[7/17/2020, 9:37:05 AM] [Camera-ffmpeg] RIGHT Front Cam: *** 1 dup![7/17/2020, 9:37:06 AM] [Camera-ffmpeg] RIGHT Front Cam: [verbose] *** 1 dup![7/17/2020, 9:37:06 AM] [Camera-ffmpeg] RIGHT Front Cam: [info] frame=   45 fps= 44 q=-0.0 size=      37kB time=00:00:02.10 bitrate= 143.7kbits/s dup=4 drop=0 speed=2.06x    
[7/17/2020, 9:37:06 AM] [Camera-ffmpeg] RIGHT Front Cam: [verbose] *** 1 dup![7/17/2020, 9:37:06 AM] [Camera-ffmpeg] RIGHT Front Cam: [verbose] 
[7/17/2020, 9:37:06 AM] [Camera-ffmpeg] RIGHT Front Cam: *** 1 dup!
```

**Homebridge Config:**

```json
                    "name": "RIGHT Front Cam",
                    "manufacturer": "Axis",
                    "videoConfig": {
                        "source": "-rtsp_transport tcp -r 18 -i rtsp://root:XXXXXXX@192.168.1.233/axis-media/media.amp?streamprofile=Media?tcp&resolution=1280x720",
                        "stillImageSource": "-i http://root:XXXXXXX@192.168.1.233/axis-cgi/jpg/image.cgi",
                        "maxStreams": 3,
                        "maxFPS": 20,
                        "vcodec": "h264_omx",
                        "debug": true
                    }
                },
```

**Screenshots:**
<!-- If applicable, add screenshots to help explain your problem. -->

**Environment:**

* **Node.js Version**: <!-- node -v -->
* **NPM Version**: <!-- npm -v -->
homebridge-camera-ffmpeg@2.3.1 
* **Homebridge Version**: <!-- homebridge -V -->
homebridge@1.2.0-beta.30 
* **Homebridge Camera FFmpeg Version**:
* **Homebridge Config UI X Plugin Version**:
* **Operating System**: <!-- Raspbian / Ubuntu / Debian / Windows / macOS / Docker -->
Raspbian Buster
 4.19.118-v7l+
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