Here is what I have at the moment. If interested, I can show a side by side video from the camera, and what is showing on MM.

Config:

{
  module: 'MMM-MPlayer',
  disabled: false,
  position: "top_center",
  header: "Driveway",
  config: {
    layout: '',
    streamInterval: 30000,
    monitorAspect: '0',
    noAspect: false,
    noBorder: true,
    rotate: -1,
    windowPosition: '',
    windowSize: '',
    windowWidth: '',
    windowWidthNoNewAspect: false,
    windowHeightNoNewAspect: false,
    rtspStreamOverTcp: true,
    rtspStreamOverHttp: true,
    preferIpv4: true,
    ipv4onlyProxy: false,
    videoOutputDriver: 'xv,gl,gl_nosw,vdpau,',
    noSound: true,
    mplayerOption: '',  
    windows: [
      {
        windowSize: { width: 990, height: 557 },
        windowPosition: { x: 471, y: 20 },
        streams: [
           'rtsp://admin:Camadmin@172.16.0.37:554/cam/realmonitor?channel=1&subtype=0'
          //'http://admin:Camadmin@172.16.0.37/cgi-bin/snapshot.cgi?1' 
                 ]
      }
    ]
  }
},

Data:

pi@raspberrypi:~ $ grep version ~/MagicMirror/package.json
        "version": "2.30.0",
pi@raspberrypi:~ $ cat /proc/device-tree/model; echo
Raspberry Pi 4 Model B Rev 1.5
pi@raspberrypi:~ $ lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 12 (bookworm)
Release:        12
Codename:       bookworm
pi@raspberrypi:~ $ uname -a
Linux raspberrypi 6.12.47+rpt-rpi-v8 #1 SMP PREEMPT Debian 1:6.12.47-1+rpt1~bookworm (2025-09-16) aarch64 GNU/Linux
pi@raspberrypi:~ $ free -h -t
               total        used        free      shared  buff/cache   available
Mem:           3.7Gi       931Mi       1.9Gi       122Mi       1.1Gi       2.8Gi
Swap:          199Mi          0B       199Mi
Total:         3.9Gi       931Mi       2.1Gi

pi@raspberrypi:~ $ ps -eaf | grep mplayer | grep -v grep
pi          5635    5458 27 19:37 ?        00:01:03 mplayer rtsp://admin:Camadmin@172.16.0.37:554/cam/realmonitor?channel=1&subtype=0 -vf rotate=-1 -monitoraspect 0 -noborder -geometry 471:20 -x 990 -y 557 -rtsp-stream-over-tcp -prefer-ipv4 -vo xv,gl,gl_nosw,vdpau, -nosound
pi@raspberrypi:~ $ pm2 flush
[PM2] Flushing /home/pi/.pm2/pm2.log
[PM2] Flushing:
[PM2] /home/pi/.pm2/logs/MagicMirror-out.log
[PM2] /home/pi/.pm2/logs/MagicMirror-error.log
[PM2] Logs flushed
pi@raspberrypi:~ $ pm2 restart MagicMirror
Use --update-env to update environment variables
[PM2] Applying action restartProcessId on app [MagicMirror](ids: [ 0 ])
[PM2] [MagicMirror](0) ✓
┌────┬────────────────┬─────────────┬─────────┬─────────┬──────────┬────────┬──────┬───────────┬──────────┬──────────┬──────────┬──────────┐
│ id │ name           │ namespace   │ version │ mode    │ pid      │ uptime │ ↺    │ status    │ cpu      │ mem      │ user     │ watching │
├────┼────────────────┼─────────────┼─────────┼─────────┼──────────┼────────┼──────┼───────────┼──────────┼──────────┼──────────┼──────────┤
│ 0  │ MagicMirror    │ default     │ 2.30.0  │ fork    │ 5704     │ 0s     │ 13   │ online    │ 0%       │ 2.9mb    │ pi       │ enabled  │
└────┴────────────────┴─────────────┴─────────┴─────────┴──────────┴────────┴──────┴───────────┴──────────┴──────────┴──────────┴──────────┘
pi@raspberrypi:~ $ sleep 20
pi@raspberrypi:~ $ grep 'MMM-MPlayer' ~/.pm2/logs/MagicMirror-*.log

/home/pi/.pm2/logs/MagicMirror-out.log:[2025-10-28 19:41:36.725] [LOG]   Module helper loaded: MMM-MPlayer
/home/pi/.pm2/logs/MagicMirror-out.log:[2025-10-28 19:41:37.509] [LOG]   Connecting socket for: MMM-MPlayer
/home/pi/.pm2/logs/MagicMirror-out.log:[2025-10-28 19:41:37.510] [LOG]   Starting MMM-MPlayer module ...
/home/pi/.pm2/logs/MagicMirror-out.log:[2025-10-28 19:41:40.746] [INFO]  [MMM-MPlayer] (launchMPlayer) - Launch mplayer process for window-0 ...
/home/pi/.pm2/logs/MagicMirror-out.log:[2025-10-28 19:41:40.762] [INFO]  [MMM-MPlayer] Launched mplayer process for window-0 with PID 5921
/home/pi/.pm2/logs/MagicMirror-out.log:[2025-10-28 19:41:40.762] [INFO]  [MMM-MPlayer] DISPLAY=:0 mplayer rtsp://admin:Camadmin@172.16.0.37:554/cam/realmonitor?channel=1&subtype=0 -vf rotate=-1 -monitoraspect 0 -noborder -geometry 471:20 -x 990 -y 557 -rtsp-stream-over-tcp -prefer-ipv4 -vo xv,gl,gl_nosw,vdpau, -nosound
/home/pi/.pm2/logs/MagicMirror-out.log:[2025-10-28 19:41:43.181] [INFO]  [MMM-MPlayer] [window-0] stdout: [lavf] stream 0: video (h264), -vid 0
pi@raspberrypi:~ $

Just changed from MMM-RTSPStream to MMM-Mplayer because of issues. That solved the issue with the processor being continuously maxed out. However, video from my ip cam is still delayed and stutters losing a lot of frames. I can play it outside of MagicMirror on another computer using the cameras web interface or with VLC using the same url as MM and both show in real time. Tried a bunch of settings, no luck.

Curious for those that have this working properly, real time, what kind of camera are you using. What is your connection type. . . rtsp, http, resolutions, etc …

A bit of history first. I had a Pi3B 32 bit that ran MM and MMM_RTSPStream using omxplayer that worked well. However, it was a bit outdated and upgraded to a Pi4 8Gb, and changed to 64bit. Found out omxplayer was supported under 64bit. Tried to get it to work but was very unstable with ffmpeg & vlc. Go I gave up. Now I have some time to get back to it again.
Installed latest ffmpeg, vlc, MM, & MMM-RTSPStream. Vlc multiple issues, ffmpeg I got to somewhat work, and seems reliable - not crashing or locking up. However the video is very choppy, and lags 12-15 seconds. So at this point, digging around a bit, I found some issues that may help point to where the problem is.
First item here is the string being passed to ffmpeg:

ffmpeg -rtsp_transport tcp -i rtsp://admin:Campassword@172.16.0.37:554/cam/realmonitor?channel=1&subtype=0&unicast=true -pix_fmt yuv420p -f mpegts -codec:v mpeg1video -codec:a mp2 -r 30 -rtsp_transport tcp -

I have not researched this yes, just looking for someone that may be able to say that looks good, or something is wrong.

The second item, which should probably be the first.
As soon as ffmpeg loads, all four cores on the processor sit in the +90% usage constantly. Now this is the same camera that ran on the old Pi without issue. I have changed resolution down to 648x480, bit rates to 512 variable and constant, frame intervals will only go down to 30, and still when started the processor maxes out.

So maybe I’m going down a rabbit hole looking at he issue being ffmpeg. If anyone has any thoughts, they are appreciated.

I had run my MM for a long time with no issues on a old Pi3b. Upgraded everything to a new Pi 4current, and have issues with showing video from the security camera outside. Found OMX player is no longer supported and switched to VLC. Video shows up, plays, all is good. However, it will only display on the top left side of the screen, and I want it back at top_center. No matter what I try to do, it always comes up top left. I can modify all the module and stream height/width settings but they have no effect. I’m guessing I am missing something here in the config, or there is an error that I just don’t see. Any thoughts/suggestions on what is wrong here:

{
module: “MMM-RTSPStream”,
disabled: false,
position: “top_center”,
config: {
debug: false,
autoStart: true,
rotateStreams: ‘false’,
rotateStreamTimeout: 10,
moduleWidth: 100,
moduleHeight: 100,
localPlayer: ‘vlc’,
remotePlayer: ‘none’,
showSnapWhenPaused: false,
remoteSnaps: false,
shutdownDelay: 1,
stream1: {
name: ‘Driveway’,
url: ‘rtsp://mmm:password@172.16.0.37:554/cam/realmonitor?channel=1&subtype=0’,
frameRate: ‘20’,
protocol: ‘tcp’,
width: 100,
height: 100,
ffmpegPort: 9999,
},
},
},

Will a touch screen work with MMM-CalendarExt2? For example have the current month displayed, and then be able to scroll to the next month, or months ahead like a phone calendar.