From 8773af1b0b4db70426c8ca647dee60f67e28fdb0 Mon Sep 17 00:00:00 2001
From: Koushik Dutta <koushd@gmail.com>
Date: Sat, 14 Jan 2023 18:14:48 -0800
Subject: [PATCH] videoanalysis: fix detection expiration.

---
 plugins/objectdetector/src/denoise.ts | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/plugins/objectdetector/src/denoise.ts b/plugins/objectdetector/src/denoise.ts
index 0e7be4c24..d0d910683 100644
--- a/plugins/objectdetector/src/denoise.ts
+++ b/plugins/objectdetector/src/denoise.ts
@@ -96,6 +96,8 @@ export function denoiseDetections<T>(state: DenoisedDetectionState<T>,
         state.previousDetections = [];
 
     const now = options.now || Date.now();
+    const lastDetection = state.lastDetection || now;
+    const sinceLastDetection = now - lastDetection;
 
     const externallyTracked = currentDetections.filter(d => d.id);
     if (externallyTracked.length) {
@@ -122,9 +124,12 @@ export function denoiseDetections<T>(state: DenoisedDetectionState<T>,
             }
         }
 
-        for (const tracked of state.externallyTracked.values()) {
-            if (now - tracked.lastSeen > options.timeout) {
-                options?.expiring(tracked);
+        for (const previous of state.externallyTracked.values()) {
+            if (now - previous.lastSeen) {
+                previous.durationGone += sinceLastDetection;
+                if (previous.durationGone >= options.timeout) {
+                    options?.expiring(previous);
+                }
             }
         }
     }
@@ -151,8 +156,6 @@ export function denoiseDetections<T>(state: DenoisedDetectionState<T>,
     // }
 
 
-    const lastDetection = state.lastDetection || now;
-    const sinceLastDetection = now - lastDetection;
     const previousCopy = previousDetections.slice();
     previousDetections.splice(0, previousDetections.length);
     const map = new Map<string, DenoisedDetectionEntry<T>>();