Barcode Reader¶

Decode QR codes and 1D/2D barcodes from live camera streams. Each detection creates a searchable Milestone bookmark and fires analytics events that the Rules engine can act on. Includes a QR Code library where you can generate, preview and export codes whose payload acts as a rule trigger.

Quick Start¶

Open the Management Client
Navigate to MIP Plug-ins > Barcode Reader > Barcode Channels
Right-click Barcode Channels → Create New
Pick a camera, leave defaults, click Save
Hold a barcode in front of the camera; detections appear in the Live Status log and on the camera timeline as bookmarks

Barcode Channels¶

Each Barcode Channel configures one running decoder, bound to one camera. A helper process runs inside the Event Server per enabled channel, pulling JPEG frames and running them through ZXing.

Channel fields¶

Setting	Purpose
Camera	Which camera to decode from
Enabled	Launch / stop the helper process for this channel
Camera Preview	Live MJPEG preview of the selected camera - the decoder sees the same frames
Barcode formats	Restrict to expected code types (fewer = faster). QR Code, Data Matrix, Aztec, PDF417, Code 128/39/93, EAN-13/8, UPC-A/E, ITF, Codabar
Try Harder	Spend more CPU per frame to catch low-contrast, partially blocked, or rotated codes
Auto Rotate	Retry each frame rotated 90/180/270 degrees. Useful for sideways-mounted cameras
Try Inverted	Retry with inverted colours for white-on-black codes
Create bookmarks for detections	One bookmark per detection (2 s pre-roll / 2 s post-roll on the camera timeline)
Target frame rate	Hard cap on decode attempts per second (real rate also capped by camera live FPS and decode time)
Downscale to width	Resize each frame before decoding. Big speed-up for 4K/8K cameras
Duplicate debounce	Suppress repeat detections of the same text within this window (ms)

Live Status panel¶

While a channel is selected the bottom of the detail pane shows:

Cam FPS - frames delivered by the camera per second
Decode FPS - frames actually run through the decoder per second
Inference avg / p95 - time spent in ZXing per frame
Max FPS - theoretical ceiling derived from inference time
Hint line - green when Target FPS has headroom, amber at the limit
Helper log - last 40 stderr lines incl. DETECT entries (newest first)

Camera offline / reconnect¶

If no frames arrive for ~8 seconds while the channel is live, the helper tears down and re-opens the subscription in place. Status transitions (Running → Error:NoFrames → Running) show up in the Live Status header. If the helper process itself dies, the Event Server background plugin restarts it within 10 seconds.

QR Codes¶

The QR Codes node stores a library of known codes. Each item pairs a friendly name with an exact Payload string; when a scanner decodes matching text, a dedicated QR Code Matched event fires with that QR Code item as the source - letting you attach a rule to a specific code.

Generating codes¶

The detail pane regenerates a QR preview live as you type the payload:

Copy PNG - 256 px PNG to the clipboard
Save PNG… - 512 px PNG to disk (suggested filename from the item name)

Error correction¶

Higher levels recover from more dirt/damage but produce denser codes.

Level	Recoverable damage
L	~7%
M	~15% (default)
Q	~25%
H	~30%

Payload uniqueness¶

Each QR Code must have a unique payload. The admin client refuses to save a second item with the same payload text and shows Payload is already used by '<name>'. This keeps rule targeting unambiguous.

Events¶

Register these on the Rules engine under event group Barcode Reader:

Event	Source kind	Fires when
Barcode Detected	Barcode Channel	any post-debounce decode on that channel
QR Code Matched	QR Code	decoded text equals the QR Code item's Payload (exact, case-sensitive)

The decoded text is attached to the event via CustomTag (bare text). Use these events to trigger emails, alarms, PTZ presets, HTTP callbacks - anything Rules supports.

Example rule - "Open barrier on token"¶

Create a QR Code item named "Gate Token" with Payload = GATE-TOKEN-42
Print the generated PNG, stick it on a delivery vehicle
In the Management Client go to Rules → Add Rule → Perform an action on <event>
Pick QR Code Matched under Barcode Reader, source = Gate Token
Pick an action (output trigger, preset, generic event, etc.)

Persistence & search¶

Bookmarks - each detection becomes a Milestone bookmark on the camera timeline. Header = decoded text (truncated to ~60 chars). Description = Format: {FORMAT} / Channel: {channel name}. Searchable in Smart Client's Search workspace via the Bookmarks filter.
Event Server log - per-channel DETECT / STATS / STATUS lines in C:\ProgramData\Milestone\XProtect Event Server\Logs\
Helper log - per-channel stderr trail mirrored to C:\ProgramData\Milestone\BarcodeReader\helper-{channelId}.log (5 MB rotating). Survives helper crashes and contains assembly-resolve hits/misses, unhandled exceptions, and process info (PID, arch, CLR, OS). Attach this file when reporting issues.
Milestone System Log - one entry per channel start / error / stop / helper crash

Troubleshooting¶

Problem	Fix
No detections	Narrow the format list; enable Try Harder; raise Target FPS
High CPU	Lower Target FPS; turn off Try Harder / Auto Rotate; enable Downscale
Status stuck on `Error:Connect`	Camera or Recording Server unreachable. Helper auto-retries
Status stuck on `Error:NoFrames`	Stall watchdog tripped. Check camera health; reconnect is automatic
`Helper exe not found`	Ensure `BarcodeReaderHelper.exe` lives next to `BarcodeReader.dll` in `MIPPlugins\BarcodeReader`
`Helper died (exit=255 NativeCrash)` in the Event Server log	Native dependency missing (typically a Media SDK / VC++ runtime DLL). Check the per-channel helper log under `C:\ProgramData\Milestone\BarcodeReader\` for the last stderr lines, then run Process Monitor on `BarcodeReaderHelper.exe` filtering `Result = NAME NOT FOUND` to find the missing DLL. Common cause: Recording Server not co-located with Event Server
`Helper died (exit=6 NativeDepsMissing)` or helper log says `Event Server Dir not found`	The helper could not locate the Milestone Event Server install dir on this host. Happens on OEM rebrands or non-default install paths where neither the registry probe (`HKLM\SOFTWARE\VideoOS\Server\InstallationPath`) nor the standard `C:\Program Files\Milestone\XProtect Event Server` path resolves. Fix: add the Event Server install dir to the Machine `PATH` environment variable, then restart `MilestoneEventServerService`. See OEM / non-default installs below
`Helper died (exit=4 ManagedException)`	A managed exception escaped the helper. Full stack trace is in the per-channel helper log
Bookmarks not appearing	Verify Create bookmarks for detections is checked; check the Event Server log for `BookmarkCreate failed`
QR Code Matched not firing	Remember match is exact + case-sensitive. Compare the `DETECT` log line payload against the stored QR Code item

OEM / non-default installs¶

The helper process delay-loads native Milestone DLLs (CoreToolkits.dll, IMV1.dll, FFmpeg avcodec-*.dll etc.) from the Event Server install directory. The helper auto-discovers that directory via, in order:

The path passed in by the plugin host (milestoneDir)
Walking up from the helper exe location (...\MIPPlugins\BarcodeReader\ → parent service install dir)
Registry: HKLM\SOFTWARE\VideoOS\Server\InstallationPath, HKLM\SOFTWARE\VideoOS\Recorder\InstallationPath, HKLM\SOFTWARE\VideoOS\Platform\InstallationPath
Hardcoded defaults: C:\Program Files\Milestone\XProtect Event Server and siblings

OEM rebrands ship under their own vendor folder and may omit the HKLM\SOFTWARE\VideoOS keys entirely. If steps 1-4 all fail, the helper fails fast with exit code 6 NativeDepsMissing and writes Event Server Dir not found to its log.

Fix on OEM hosts: add the Event Server install dir to the Machine PATH environment variable, then restart MilestoneEventServerService. The Windows native loader picks up PATH after its default search list, so the delay-load resolves once the directory is reachable that way. (https://www.architectryan.com/2018/03/17/add-to-the-path-on-windows-10/)