OBS Replay Buffer for IT Support

IT support tool that runs OBS Studio's replay buffer silently on VDI sessions, giving users a system tray button to save the last N minutes of screen activity when an issue occurs. Clips are saved to a central UNC share organized by username.

How It Works

1. DEM runs Start-OBSReplayBuffer.ps1 as a logon task
2. The script validates all required project files are accessible — each path is polled for up to 2 minutes before failing, to handle slow network share availability at logon
3. OBS config files are deployed to %APPDATA%\obs-studio\ automatically
4. OBS launches hidden; the script waits for the process to appear, locates the new OBS log file, then confirms the replay buffer has actually started before proceeding
5. A WPF notification window informs the user that screen recording is active, shows the shield tray icon so they know what to look for, and auto-dismisses after 30 seconds
6. A system tray icon remains in the taskbar — right-click → Save Replay
7. On save, the script sends the request via WebSocket, then verifies a new .mkv file appears on disk before confirming success
8. A WPF confirmation window shows the saved filename and file size, and auto-dismisses after 30 seconds

Architecture

Component	Role
DEM Logon Task	Runs Start-OBSReplayBuffer.ps1 at logon — only DEM task required
config.psd1	Central config — UNC path, buffer duration, OBS executable path, IT contact number
Start-OBSReplayBuffer.ps1	Validates project files (with retry), deploys OBS config, creates user capture folder, writes OBS profile, launches OBS, confirms replay buffer started via log, launches startup notification, launches tray icon
Show-ReplayTray.ps1	WinForms system tray icon — right-click menu with Save Replay / Exit
Invoke-ReplaySave.ps1	Sends SaveReplayBuffer to OBS via WebSocket v5, verifies the file was written to disk, launches save confirmation notification
Show-Notification.ps1	WPF popup launched as a separate interactive process — handles both BufferStarted and ReplaySaved notification types via -Type parameter
obs-config/	OBS config files — deployed to %APPDATA%\obs-studio\ at logon by the script

Repository Structure

obs-replay-buffer/
├── config.psd1
├── scripts/
│   ├── Start-OBSReplayBuffer.ps1
│   ├── Show-ReplayTray.ps1
│   ├── Invoke-ReplaySave.ps1
│   └── Show-Notification.ps1
└── obs-config/
    ├── global.ini
    └── scenes/
        └── ITMonitor.json

Prerequisites

• OBS Studio 28+ — delivered via App Volumes AppStack or installed directly on the machine (WebSocket v5 is built in — no plugin needed)
• VMware DEM to run the logon task
• A UNC share writable by VDI users for clip storage
• A network share to host this repo's files, accessible from all VDI machines

App Volumes is optional. If OBS Studio is installed directly on the machine (e.g. via SCCM, Intune, or manual install), App Volumes is not required. Set OBSExecutable in config.psd1 to the correct path and the script will work as-is.

Configuration

Edit config.psd1 before deploying:

Key	Description	Default
UNCPath	Base UNC path for clip storage — username subfolder created automatically	\\server\ITCaptures
LogPath	Directory path for script logs — supports %USERNAME% and other environment variables; each script writes its own log file	\\server\ITLogs\%USERNAME%
BufferSeconds	Replay buffer duration in seconds	120
WebSocketPort	OBS WebSocket port — must match [OBSWebSocket] in obs-config/global.ini	4455
OBSExecutable	Full path to obs64.exe on the target machine	C:\Program Files\obs-studio\bin\64bit\obs64.exe
ProfileName	OBS profile name — must match the folder under obs-config/profiles/	ITMonitor
SceneCollection	OBS scene collection name — must match the filename under obs-config/scenes/	ITMonitor
ITContactNumber	IT help desk phone number shown in startup and save confirmation popups	555-555-5555

Deployment

Step 1 — Host the repo on a network share

Place this repo (or a copy of it) on a share accessible from all target machines, e.g.:

\\stcu-fs01\IT-Tools\OBS-Record\

Step 2 — DEM: Logon task

Create one logon task in DEM (scoped to the target user group). Set it to not wait for completion.

powershell.exe -ExecutionPolicy Bypass -NonInteractive -WindowStyle Hidden -File "\\stcu-fs01\IT-Tools\OBS-Record\scripts\Start-OBSReplayBuffer.ps1"

This is the only DEM task needed. The script handles all config file deployment, folder creation, and launching both OBS and the tray icon. It will exit cleanly (code 1) if any required project file is inaccessible after the 2-minute retry window, or exit 0 if OBS is already running.

No DEM file transfer tasks are needed. The script deploys global.ini and the scene collection from the repo to %APPDATA%\obs-studio\ at each logon. basic.ini is written dynamically so the correct UNC path, primary monitor resolution, and monitor device ID are baked in per session.

Step 3 — OBS Studio (App Volumes or native install)

Option A — App Volumes: Assign the OBS AppStack to the same user group.

Option B — Native install: Ensure OBS Studio 28+ is installed at the path set in OBSExecutable in config.psd1. No other configuration is needed.

User Experience

• At logon, a WPF popup notifies the user that screen recording is active, explains the replay buffer, shows the shield tray icon so they know what to look for, and includes the IT contact number — auto-dismisses after 30 seconds or on OK
• A shield icon remains in the system tray — right-click → Save Replay to save the last BufferSeconds of screen activity
• After a save, a WPF confirmation popup shows the saved filename and file size — auto-dismisses after 30 seconds or on OK
• Clips appear at \\server\ITCaptures\<username>\ named by timestamp
• Logs are written to \\server\ITLogs\<username>\ — three files, one per script, overwritten on each run:
  • OBSReplayBuffer.log — startup, path validation, OBS launch verification, and config deployment
  • OBSReplayBuffer-Tray.log — tray lifetime and save attempts
  • OBSReplayBuffer-Save.log — WebSocket steps and file verification for each save attempt

Changing the Buffer Duration

Update BufferSeconds in config.psd1. The value is written into the OBS profile at each logon, so no repackaging or redeployment is needed.

Notes

Startup Verification

Start-OBSReplayBuffer.ps1 performs three checks after launching OBS before showing the user notification:

1. Process check — polls for the obs64 process for up to 30 seconds
2. Log file check — waits up to 30 seconds for OBS to create a new session log file
3. Replay buffer check — polls the log file for a replay buffer started message for up to 2 minutes

If any check times out, the script exits with code 1 and logs the failure. The tray icon is not launched.

Save Verification

After OBS acknowledges the SaveReplayBuffer request, Invoke-ReplaySave.ps1 polls the user's capture folder for up to 30 seconds for a new .mkv file. If no file appears, the save is treated as failed. This catches cases where OBS accepts the request but fails to write the file.

VDI Compatibility

This tool is designed for VDI environments running without a physical GPU (e.g. Microsoft Basic Render Driver):

• Video encoder: x264 (software) is used explicitly — hardware encoders (NVENC, QSV, AMF) are not available on most VDI machines
• Display capture: compatibility mode (BitBlt) is used instead of DXGI or WGC, which do not work reliably on virtual displays
• Monitor ID: the startup script uses EnumDisplayDevices with EDD_GET_DEVICE_INTERFACE_NAME to detect the active session's display device path at logon — this handles RDP/VDI sessions where the display UID varies per user or session

WebSocket Settings

OBS 29+ stores WebSocket server settings in global.ini under [OBSWebSocket], not in a separate plugin_config JSON file. The global.ini in this repo includes the WebSocket configuration directly:

[OBSWebSocket]
FirstLoad=false
ServerEnabled=true
ServerPort=4455
AlertsEnabled=false
AuthRequired=false

OBS Tray Icon vs. IT Tray Icon

OBS places its own tray icon when minimized. Users will see two icons — the OBS icon and the IT Screen Recorder shield icon. The OBS icon can be right-clicked to quit OBS, which would break the replay buffer. If this is a concern, a future enhancement could suppress the OBS tray icon via an OBS config setting.