Use max so cameras without motion don't invlidate good data:

frigate/api/review.py

@@ -5,12 +5,7 @@ from datetime import datetime, timedelta
 from functools import reduce
 
 import pandas as pd
-from flask import (
+from flask import Blueprint, jsonify, make_response, request
-    Blueprint,
-    jsonify,
-    make_response,
-    request,
-)
 from peewee import Case, DoesNotExist, fn, operator
 
 from frigate.models import Recordings, ReviewSegment
@@ -391,7 +386,11 @@ def motion_activity():
     df.set_index(["start_time"], inplace=True)
 
     # normalize data
-    df = df.resample(f"{scale}S").mean().fillna(0.0)
+    df = (
+        df.resample(f"{scale}S")
+        .apply(lambda x: max(x, key=abs, default=0.0))
+        .fillna(0.0)
+    )
 
     # change types for output
     df.index = df.index.astype(int) // (10**9)

frigate/record/maintainer.py

@@ -75,7 +75,7 @@ class RecordingMaintainer(threading.Thread):
 
         for camera in self.config.cameras.values():
             self.camera_frame_area[camera.name] = (
-                camera.detect.width * camera.detect.height
+                camera.detect.width * camera.detect.height * 0.1
             )
 
     async def move_files(self) -> None:
@@ -319,12 +319,15 @@ class RecordingMaintainer(threading.Thread):
             total_motion_area += sum([area(box) for box in frame[2]])
 
         if video_frame_count > 0:
-            normalized_motion_area = int(
+            normalized_motion_area = min(
+                int(
                     (
                         total_motion_area
                         / (self.camera_frame_area[camera] * video_frame_count)
                     )
                     * 100
+                ),
+                100,
             )
         else:
             normalized_motion_area = 0