show cpu usage

app.py

@@ -4,12 +4,14 @@ from cv2.typing import MatLike
 import threading
 import time
 import os
+import psutil
 
 class Session:
-    def __init__(self, id: str, latest_frame: MatLike, measured_fps: float, show_fps: bool):
+    def __init__(self, id: str, latest_frame: MatLike, measured_fps: float, cpu_usage: float, show_fps: bool):
         self.id = id
         self.latest_frame: MatLike = latest_frame
         self.measured_fps = measured_fps
+        self.cpu_usage = cpu_usage
         self.show_fps = show_fps
 
 app = Flask(__name__)
@@ -38,29 +40,32 @@ def frame_processor(session_id: str):
         while True:
             ret, frame = cap.read()
 
+            # measure FPS
+            frame_count += 1
+            now = time.time()
+            if now - last_time >= rolling_duration:  
+                session.measured_fps = frame_count / (now - last_time)
+                session.cpu_usage = psutil.cpu_percent(interval=None)
+                frame_count = 0
+                last_time = now
+
             if not ret:
                 cap.set(cv2.CAP_PROP_POS_FRAMES, 0)
                 continue
             else:
                 if session.show_fps:
-                    text = f"{session_id}: {session.measured_fps:.0f}"
                     font = cv2.FONT_HERSHEY_SIMPLEX
                     font_scale = 1
                     thickness = 2
                     color = (0, 255, 0)
-                    (text_width, text_height), _ = cv2.getTextSize(text, font, font_scale, thickness)
-                    x = frame.shape[1] - text_width - 10
-                    y = 30
-                    cv2.putText(frame, text, (x, y), font, font_scale, color, thickness, cv2.LINE_AA)
-                session.latest_frame = frame
+                    text = f"ID: {session_id}\n FPS: {session.measured_fps:.0f}\n CPU: {session.cpu_usage:02.0f}%"
 
-            # measure FPS
-            frame_count += 1
-            now = time.time()
-            if now - last_time >= rolling_duration:
-                session.measured_fps = frame_count / (now - last_time)
-                frame_count = 0
-                last_time = now
+                    y0, dy = 30, 36
+                    for i, line in enumerate(text.split('\n')):
+                        (text_width, text_height), _ = cv2.getTextSize(line, font, font_scale, thickness)
+                        x = frame.shape[1] - text_width - 10
+                        y = y0 + i*dy
+                        cv2.putText(frame, line, (x, y), font, font_scale, color, thickness, cv2.LINE_AA)
 
             # control framerate
             next_frame_time += frame_duration
@@ -70,6 +75,8 @@ def frame_processor(session_id: str):
             else:
                 next_frame_time = time.time()
 
+            session.latest_frame = frame
+
 def stream_mjpeg(session_id: str):
     global sessions
 
@@ -93,7 +100,7 @@ def video_feed():
     session_id = request.args.get("id", "default")
 
     if session_id not in [s.id for s in sessions]:
-        session = Session(session_id, None, 0, True)
+        session = Session(session_id, None, 0, 0, True)
         sessions.add(session)
         threading.Thread(target=frame_processor, args=[session_id], daemon=True).start()