ffmpeg killed with signal ILL
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**Describe The Bug:**
<!-- A clear and concise description of what the bug is. -->
Cannot start stream on home app, snapshot are available, ffmpeg output to .mp4 in raspberry works but when streaming got error in ffmpeg.

**To Reproduce:**
<!-- Steps to reproduce the behavior. -->
- Open Home APP
- Open Camera Tile
- Keeps on loading, and in home bridge logs, shows SIGILL

**Expected behavior:**
<!-- A clear and concise description of what you expected to happen. -->
Supposed to stream to ios device

**Logs:**
<!-- Bug reports that do not contain logs may be closed without warning. -->

```
[7/22/2020, 12:28:10 AM] [Camera-ffmpeg] Starting Front Porch video stream (1280x720, 10 fps, 299 kbps, 1316 mtu)... debug enabled
[7/22/2020, 12:28:10 AM] [Camera-ffmpeg] Front Porch command: ffmpeg -rtsp_transport udp -v verbose -i rtsp://user:pass@192.168.1.x:554/onvif2 -map 0:0 -vcodec h264 -pix_fmt yuv420p -r 10 -f rawvideo -preset ultrafast -tune zerolatency -vf scale=1280:720 -b:v 299k -bufsize 598k -maxrate 299k -payload_type 99 -ssrc 15290808 -f rtp -srtp_out_suite AES_CM_128_HMAC_SHA1_80 -srtp_out_params uuid srtp://192.168.1.x:60881?rtcpport=60881&localrtcpport=60881&pkt_size=1316 -map 0:0 -acodec libfdk_aac -profile:a aac_eld -flags +global_header -f null -ar 16k -b:a 24k -bufsize 24k -ac 1 -payload_type 110 -ssrc 5874408 -f rtp -srtp_out_suite AES_CM_128_HMAC_SHA1_80 -srtp_out_params uuid srtp://192.168.1.x:58366?rtcpport=58366&localrtcpport=58366&pkt_size=188 -loglevel level+verbose
[7/22/2020, 12:28:10 AM] [Camera-ffmpeg] Front Porch: [info] 
[7/22/2020, 12:28:10 AM] [Camera-ffmpeg] Front Porch: 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

[7/22/2020, 12:28:10 AM] [Camera-ffmpeg] Front Porch: [tcp @ 0x2bf1310] 
[7/22/2020, 12:28:10 AM] [Camera-ffmpeg] Front Porch: [verbose] Starting connection attempt to 192.168.1.201 port 554

[7/22/2020, 12:28:11 AM] [Camera-ffmpeg] Front Porch: [tcp @ 0x2bf1310] [verbose] Successfully connected to 192.168.1.201 port 554

[7/22/2020, 12:28:13 AM] [Camera-ffmpeg] Front Porch: [rtsp @ 0x2bef2f0] 
[7/22/2020, 12:28:13 AM] [Camera-ffmpeg] Front Porch: [verbose] SDP:
v=0
o=- 1421069297525233 1 IN IP4 192.168.1.201
s=H.264 Video, RtspServer_0.0.0.2
t=0 0
a=tool:RtspServer_0.0.0.2
a=type:broadcast
a=control:*
a=range:npt=0-
m=video 0 RTP/AVP 96
c=IN IP4 0.0.0.0
b=AS:500
a=rtpmap:96 H264/90000
a=fmtp:96 packetization-mode=1;profile-level-id=42001F;sprop-parameter-sets=Z0IAH5WoFAFuQA==,aM48gA==
a=control:track1


[7/22/2020, 12:28:13 AM] [Camera-ffmpeg] Front Porch: [rtsp @ 0x2bef2f0] 
[7/22/2020, 12:28:13 AM] [Camera-ffmpeg] Front Porch: [verbose] setting jitter buffer size to 500

[7/22/2020, 12:28:15 AM] [Camera-ffmpeg] Front Porch: [h264 @ 0x2bf26e0] 
[7/22/2020, 12:28:15 AM] [Camera-ffmpeg] Front Porch: [verbose] Reinit context to 320x192, pix_fmt: yuv420p

[7/22/2020, 12:28:17 AM] [Camera-ffmpeg] Front Porch: [info] 
[7/22/2020, 12:28:17 AM] [Camera-ffmpeg] Front Porch: Input #0, rtsp, from 'rtsp://admin:Joseph0510@192.168.1.201:554/onvif2':
[info]   Metadata:
[info]     title           : H.264 Video, RtspServer_0.0.0.2
[info]   Duration: N/A, start: 0.067000, bitrate: N/A
[info]     Stream #0:0: Video: h264 (Baseline), 1 reference frame, yuv420p(progressive, left), 320x192, 15 tbr, 90k tbn, 180k tbc
[verbose] 
[7/22/2020, 12:28:17 AM] [Camera-ffmpeg] Front Porch: Matched encoder 'libx264' for codec 'h264'.

[7/22/2020, 12:28:17 AM] [Camera-ffmpeg] Front Porch: [warning] 
[7/22/2020, 12:28:17 AM] [Camera-ffmpeg] Front Porch: Codec AVOption b (set bitrate (in bits/s)) specified for output file #1 (srtp://192.168.1.106:58366?rtcpport=58366&localrtcpport=58366&pkt_size=188) 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.

[7/22/2020, 12:28:17 AM] [Camera-ffmpeg] Front Porch: [warning] 
[7/22/2020, 12:28:17 AM] [Camera-ffmpeg] Front Porch: Codec AVOption profile () specified for output file #1 (srtp://192.168.1.106:58366?rtcpport=58366&localrtcpport=58366&pkt_size=188) 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.

[7/22/2020, 12:28:17 AM] [Camera-ffmpeg] Front Porch: [info] Stream mapping:
[info]   Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
[info]   Stream #0:0 -> #1:0 (h264 (native) -> mpeg4 (native))
[info] Press [q] to stop, [?] for help

[7/22/2020, 12:28:17 AM] [Camera-ffmpeg] Front Porch: [h264 @ 0x2cc9320] [verbose] Reinit context to 320x192, pix_fmt: yuv420p

[7/22/2020, 12:28:17 AM] [Camera-ffmpeg] Front Porch: [Parsed_scale_0 @ 0x2c298a0] 
[7/22/2020, 12:28:17 AM] [Camera-ffmpeg] Front Porch: [verbose] 
[7/22/2020, 12:28:17 AM] [Camera-ffmpeg] Front Porch: w:1280 h:720 flags:'bicubic' interl:0
[graph 0 input from stream 0:0 @ 0x2c9be50] [verbose] w:320 h:192 pixfmt:yuv420p tb:1/90000 fr:15/1 sar:0/1 sws_param:flags=2

[7/22/2020, 12:28:17 AM] [Camera-ffmpeg] Front Porch: [Parsed_scale_0 @ 0x2c298a0] 
[7/22/2020, 12:28:17 AM] [Camera-ffmpeg] Front Porch: [verbose] w:320 h:192 fmt:yuv420p sar:0/1 -> w:1280 h:720 fmt:yuv420p sar:0/1 flags:0x4

[7/22/2020, 12:28:17 AM] [Camera-ffmpeg] [Front Porch] ffmpeg exited with code: null and signal: SIGILL (Unexpected)
```

**Homebridge Config:**

```json
"cameras": [
                {
                    "name": "Front Porch",
                    "videoConfig": {
                        "source": "-re -rtsp_transport udp -v verbose -i rtsp://user:pass@192.168.1.x:554/onvif2",
                        "maxStreams": 2,
                        "maxWidth": 1280,
                        "maxHeight": 720,
                        "maxFPS": 10,
                        "maxBitrate": 300,
                        "vcodec": "h264",
                        "mapaudio": "0:0",
                        "audio": true,
                        "debug": true
                    }
                }
            ],
            "platform": "Camera-ffmpeg"
```

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

**Environment:**

* **Node.js Version**: 11.15.0 <!-- node -v -->
* **NPM Version**: 6.14.6<!-- npm -v -->
* **Homebridge Version**: homebridge <!-- homebridge -V -->
* **Homebridge Camera FFmpeg Version**: 2.3.2
* **Homebridge Config UI X Plugin Version**: 4.23.2 
* **Operating System**: Raspbian<!-- Raspbian / Ubuntu / Debian / Windows / macOS / Docker -->


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