Unable to pull certain rstp stream reliably
I use a program called "happytime-rtsp-server" which turns my system into an rtsp server. I'm able to pull my webcam with `rtsp://IP:554/videodevice` flawlessly, however trying to pull the screen capture stream `rtsp://IP:554/screenlive` fails to get any thumbnails or stream video in the home app.

To repro, download happytime-rtsp-server, then pull your screen into the camera-ffmpeg plugin using rtsp://yourip:554/screenlive

The trouble-camera name in the config is "homebridge status"

Note I can pull the stream fine in vlc or my own cctv software. I've got quite a few cameras added through this camera-ffmpeg plugin and all the other ones stream on or off wifi really well! 

Homebridge Config:

```json
{
    "bridge": {
        "name": "Homebridge xx",
        "username": "xx",
        "port": xx, 
        "pin": "xx"
    },
    "accessories": [],
    "platforms": [
        {
            "name": "Config",
            "port": 8581,
            "auth": "form",
            "theme": "dark-mode",
            "tempUnits": "c",
            "lang": "auto",
            "platform": "config"
        },
        {
            "name": "Camera FFmpeg",
            "cameras": [
                {
                    "name": "Front Door",
                    "manufacturer": "Hikvision",
                    "model": "DS-2CD6332FWD-I",
                    "serialNumber": "x",
                    "firmwareRevision": "V5.4.5 build 170323",
                    "videoConfig": {
                        "source": "-fflags nobuffer -rtsp_transport tcp -i rtsp://admin:password@192.168.1.64:554/Streaming/Channels/101/",
                        "maxWidth": 0,
                        "maxHeight": 0,
                        "maxFPS": 0,
                        "maxBitrate": 0,
                        "forceMax": true,
                        "vcodec": "copy",
                        "encoderOptions": "-preset ultrafast",
                        "audio": true,
                        "debug": false
                    }
                },
                {
                    "name": "Front PTZ",
                    "manufacturer": "Canon",
                    "model": "VB-S31D",
                    "serialNumber": "731263300071",
                    "firmwareRevision": "Ver. 1.1.1",
                    "videoConfig": {
                        "source": "-fflags nobuffer -rtsp_transport tcp -i rtsp://system:password@127.0.0.1:8554/live?&serverip=192.168.1.240&serverport=6001&channelnumber=1&ssl=true",
                        "maxWidth": 0,
                        "maxHeight": 0,
                        "maxFPS": 0,
                        "maxBitrate": 0,
                        "forceMax": true,
                        "vcodec": "copy",
                        "encoderOptions": "-preset ultrafast"
                    }
                },
                {
                    "name": "Back Yard",
                    "manufacturer": "Axis",
                    "model": "P3225-LV MkII",
                    "serialNumber": "xx",
                    "firmwareRevision": "9.30.1",
                    "videoConfig": {
                        "source": "-fflags nobuffer -rtsp_transport tcp -i rtsp://system:password@127.0.0.1:8554/live?&serverip=192.168.1.240&serverport=6001&channelnumber=3&ssl=true",
                        "maxWidth": 0,
                        "maxHeight": 0,
                        "maxFPS": 0,
                        "maxBitrate": 0,
                        "forceMax": true,
                        "vcodec": "libx264",
                        "videoFilter": "none",
                        "encoderOptions": "-preset ultrafast",
                        "debug": false
                    }
                },
                {
                    "name": "Living Room",
                    "manufacturer": "Dell",
                    "model": "Inspiron 3220 WebCam",
                    "serialNumber": "NA",
                    "firmwareRevision": "Ubuntu",
                    "videoConfig": {
                        "source": "-fflags nobuffer -rtsp_transport tcp -i rtsp://192.168.1.247:554/videodevice",
                        "maxWidth": 0,
                        "maxHeight": 0,
                        "maxFPS": 0,
                        "maxBitrate": 0,
                        "forceMax": true,
                        "vcodec": "copy",
                        "encoderOptions": "-preset ultrafast",
                        "debug": false
                    }
                },
                {
                    "name": "Server Room",
                    "manufacturer": "Dynacolor",
                    "model": "NV223",
                    "serialNumber": "xx",
                    "firmwareRevision": "z120120420NSA",
                    "videoConfig": {
                        "source": "-fflags nobuffer -rtsp_transport tcp -i rtsp://192.168.1.250/h264",
                        "maxWidth": 0,
                        "maxHeight": 0,
                        "maxFPS": 0,
                        "maxBitrate": 0,
                        "forceMax": true,
                        "vcodec": "copy",
                        "encoderOptions": "-preset ultrafast"
                    }
                },
                {
                    "name": "Homebridge Status",
                    "videoConfig": {
                        "source": "-fflags nobuffer -rtsp_transport tcp -i rtsp://192.168.1.247:554/screenlive",
                        "maxWidth": 0,
                        "maxHeight": 0,
                        "maxFPS": 0,
                        "maxBitrate": 0,
                        "forceMax": true,
                        "vcodec": "copy",
                        "encoderOptions": "-preset ultrafast",
                        "debug": true
                    }
                }
            ],
            "platform": "Camera-ffmpeg"
        },
        {
            "name": "Sun Lamp",
            "addCustomCharacteristics": true,
            "switchModels": [
                "HS100"
            ],
            "deviceTypes": [
                "plug",
                "bulb"
            ],
            "platform": "TplinkSmarthome"
        },
        {
            "platform": "cmdSwitch2",
            "name": "CMD Switch",
            "switches": [
                {
                    "name": "LRRTSP",
                    "on_cmd": "net start \"RTSP Restart\" && net stop \"RTSP Restart\"",
                    "off_cmd": "net start \"RTSP Restart\" && net stop \"RTSP Restart\"",
                    "state_cmd": "ping 192.168.1.247 | findstr Reply"
                }
            ]
        },
        {
            "platform": "cmdAccessory",
            "name": "CMD Accessory",
            "switches": [
                {
                    "name": "RTSP Server",
                    "on_cmd": "",
                    "off_cmd": "net start \"RTSP Restart\" && net stop \"RTSP Restart\"",
                    "state_cmd": "ping 192.168.1.247 | findstr Reply",
                    "polling": true,
                    "interval": 30,
                    "manufacturer": "Apple",
                    "type": "Switch"
                }
            ]
        }
    ],
    "disabledPlugins": [
        "homebridge-tplink-hs100-lightbulbs",
        "homebridge-cmd4",
        "homebridge-cmdswitch2"
    ]
}
```


Homebridge Console:

```
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] Video stream requested: 1280 x 720, 30 fps, 299 kbps
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] Starting video stream: native x native, native fps, ??? kbps
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] Stream command: C:\Users\UnbendableStraw\AppData\Roaming\npm\node_modules\homebridge-camera-ffmpeg\node_modules\ffmpeg-for-homebridge\ffmpeg.exe -fflags nobuffer -rtsp_transport tcp -i rtsp://192.168.1.247:554/screenlive -an -sn -dn -codec:v copy -pix_fmt yuv420p -color_range mpeg -f rawvideo -preset ultrafast -payload_type 99 -ssrc 15077496 -f rtp -srtp_out_suite AES_CM_128_HMAC_SHA1_80 -srtp_out_params k9n/xIsLzYAJJPu/DgQiE8W36cTX4POGEMkdpuYK srtp://192.168.1.130:54121?rtcpport=54121&pkt_size=1316 -loglevel level+verbose
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [info] ffmpeg version N-96777-gebee808595-ffmpeg-windows-build-helpers Copyright (c) 2000-2020 the FFmpeg developers
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [info]   built with gcc 8.3.0 (GCC)
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [info]   configuration: --pkg-config=pkg-config --pkg-config-flags=--static --extra-version=ffmpeg-windows-build-helpers --enable-version3 --disable-debug --disable-w32threads --arch=x86_64 --target-os=mingw32 --cross-prefix=/ffmpeg-windows-build-helpers/sandbox/cross_compilers/mingw-w64-x86_64/bin/x86_64-w64-mingw32- --enable-libcaca --enable-gray --enable-libtesseract --enable-fontconfig --enable-gmp --enable-gnutls --enable-libass --enable-libbluray --enable-libbs2b --enable-libflite --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopus --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvo-amrwbenc --enable-libvorbis --enable-libwebp --enable-libzimg --enable-libzvbi --enable-libmysofa --enable-libopenjpeg --enable-libopenh264 --enable-liblensfun --enable-libvmaf --enable-libsrt --enable-demuxer=dash --enable-libxml2 --enable-opengl --enable-libdav1d --enable-libsvthevc --enable-libaom --enable-libvpx --enable-nvenc --enable-nvdec --extra-libs=-lharfbuzz --extra-libs=-lm --extra-libs=-lpthread --extra-cflags=-DLIBTWOLAME_STATIC --extra-cflags=-DMODPLUG_STATIC --extra-cflags=-DCACA_STATIC --enable-amf --enable-libmfx --enable-gpl --enable-avisynth --enable-frei0r --enable-filter=frei0r --enable-librubberband --enable-libvidstab --enable-libx264 --enable-libx265 --enable-libxvid --enable-libxavs --enable-avresample --extra-cflags='-mtune=generic' --extra-cflags=-O3 --enable-static --disable-shared --prefix=/ffmpeg-windows-build-helpers/sandbox/cross_compilers/mingw-w64-x86_64/x86_64-w64-mingw32 --enable-nonfree --enable-decklink --enable-libfdk-aac
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] 
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [info]   libavutil      56. 41.100 / 56. 41.100
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [info]   libavcodec     58. 70.100 / 58. 70.100
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [info]   libavformat    58. 38.101 / 58. 38.101
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [info]   libavdevice    58.  9.103 / 58.  9.103
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [info]   libavfilter     7. 76.100 /  7. 76.100
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [info]   libavresample   4.  0.  0 /  4.  0.  0
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [info]   libswscale      5.  6.100 /  5.  6.100
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [info]   libswresample   3.  6.100 /  3.  6.100
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [info]   libpostproc    55.  6.100 / 55.  6.100
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] 
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [tcp @ 0000024e6c396200] [verbose] Starting connection attempt to 192.168.1.247 port 554
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] 
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [tcp @ 0000024e6c396200] 
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [verbose] Successfully connected to 192.168.1.247 port 554
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] 
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [rtsp @ 0000024e6c393280] [verbose] SDP:
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] v=0
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] o=- 0 0 IN IP4 192.168.1.247
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] s=session
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] c=IN IP4 192.168.1.247
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] t=0 0
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] a=control:*
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] a=range:npt=0-
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] m=video 0 RTP/AVP 96
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] a=rtpmap:96 H264/90000
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] a=fmtp:96 packetization-mode=1;profile-level-id=000028;sprop-parameter-sets=Z01AKNoB4AiflhAAAAMAEAAAAwHo8YMq,aO88gA==
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] a=control:realvideo
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] m=application 0 RTP/AVP 98
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] a=rtpmap:98 vnd.onvif.metadata/90000
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] a=control:metadata
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] 
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] 
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [rtsp @ 0000024e6c393280] [verbose] setting jitter buffer size to 0
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] 
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] [rtsp @ 0000024e6c393280] [verbose] setting jitter buffer size to 0
[2/25/2021, 4:35:52 PM] [Camera FFmpeg] [Homebridge Status] 
[2/25/2021, 4:35:53 PM] [Camera FFmpeg] [Homebridge Status] [h264 @ 0000024e6c397880] [verbose] Reinit context to 1920x1088, pix_fmt: yuv420p
[2/25/2021, 4:35:53 PM] [Camera FFmpeg] [Homebridge Status] 
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] [info] Input #0, rtsp, from 'rtsp://192.168.1.247:554/screenlive':
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] [info]   Metadata:
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] [info]     title           : session
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] [info]   Duration: N/A, start: 0.000000
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] , bitrate: N/A
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] [info]     Stream #0:0: Video: h264 (Main), 1 reference frame, yuv420p(progressive, left), 1920x1080 (1920x1088), 15 fps, 15 tbr, 90k tbn, 30 tbc
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] [info]     Stream #0:1: Data: none
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] 
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] [info] Output #0, rtp, to 'srtp://192.168.1.130:54121?rtcpport=54121&pkt_size=1316':
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] [info]   Metadata:
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] [info]     title           : 
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] session
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] [info]     encoder         : Lavf58.38.101
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] [info]     Stream #0:0: Video: h264 (Main), 1 reference frame, yuv420p(tv, progressive, left), 1920x1080 (0x0), q=2-31, 15 fps, 15 tbr, 90k tbn, 15 tbc
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] [info] Stream mapping:
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] [info]   Stream #0:0 -> #0:0 (copy)
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] [info] Press [q] to stop, [?] for help
[2/25/2021, 4:35:54 PM] [Camera FFmpeg] [Homebridge Status] 
[2/25/2021, 4:35:55 PM] [Camera FFmpeg] [Homebridge Status] [info] frame=    6 fps=0.0 q=-1.0 size=     435kB time=00:00:02.35 bitrate=1514.2kbits/s speed=4.57x    
[2/25/2021, 4:35:55 PM] [Camera FFmpeg] [Homebridge Status] [info] frame=   14 fps= 13 q=-1.0 size=     544kB time=00:00:02.88 bitrate=1543.2kbits/s speed=2.72x    
[2/25/2021, 4:35:56 PM] [Camera FFmpeg] [Homebridge Status] [info] frame=   22 fps= 14 q=-1.0 size=     960kB time=00:00:03.41 bitrate=2300.0kbits/s speed=2.15x    
[2/25/2021, 4:35:56 PM] [Camera FFmpeg] [Homebridge Status] [info] frame=   30 fps= 14 q=-1.0 size=    1042kB time=00:00:03.95 bitrate=2158.7kbits/s speed=1.86x    
[2/25/2021, 4:35:57 PM] [Camera FFmpeg] [Homebridge Status] [verbose] No more output streams to write to, finishing.
[2/25/2021, 4:35:57 PM] [Camera FFmpeg] [Homebridge Status] [info] frame=   31 fps= 13 q=-1.0 Lsize=    1181kB time=00:00:04.04 bitrate=2389.4kbits/s speed=1.74x    
[2/25/2021, 4:35:57 PM] [Camera FFmpeg] [Homebridge Status] [info] video:1168kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.094794%
[2/25/2021, 4:35:57 PM] [Camera FFmpeg] [Homebridge Status] 
[2/25/2021, 4:35:57 PM] [Camera FFmpeg] [Homebridge Status] [verbose] Input file #0 (rtsp://192.168.1.247:554/screenlive):
[2/25/2021, 4:35:57 PM] [Camera FFmpeg] [Homebridge Status] [verbose]   Input stream #0:0 (video): 33 packets read (1197804 bytes); 
[2/25/2021, 4:35:57 PM] [Camera FFmpeg] [Homebridge Status] [verbose]   Input stream #0:1 (data): 53 packets read (23055 bytes); 
[2/25/2021, 4:35:57 PM] [Camera FFmpeg] [Homebridge Status] [verbose]   Total: 86 packets (1220859 bytes) demuxed
[2/25/2021, 4:35:57 PM] [Camera FFmpeg] [Homebridge Status] [verbose] Output file #0 (srtp://192.168.1.130:54121?rtcpport=54121&pkt_size=1316):
[2/25/2021, 4:35:57 PM] [Camera FFmpeg] [Homebridge Status] [verbose]   Output stream #0:0 (video): 31 packets muxed (1195841 bytes); 
[2/25/2021, 4:35:57 PM] [Camera FFmpeg] [Homebridge Status] [verbose]   Total: 31 packets (1195841 bytes) muxed
[2/25/2021, 4:35:57 PM] [Camera FFmpeg] [Homebridge Status] [AVIOContext @ 0000024e6d180bc0] [verbose] Statistics: 0 seeks, 947 writeouts
[2/25/2021, 4:35:57 PM] [Camera FFmpeg] [Homebridge Status] 
[2/25/2021, 4:35:57 PM] [Camera FFmpeg] [Homebridge Status] FFmpeg exited with code: 0 and signal: null (Error)
[2/25/2021, 4:35:57 PM] [Camera FFmpeg] [Homebridge Status] Stopped video stream.
```
