FPS Optimization

import cv2, time

cap = cv2.VideoCapture(0)
t0, n = time.time(), 0
while True:
    ok, f = cap.read()
    if not ok: break
    n += 1
    if n % 30 == 0:
        fps = n / (time.time() - t0)
        print(f"FPS: {fps:.1f}")
    cv2.imshow("f", f)
    if cv2.waitKey(1) == 27: break

import cv2, threading, queue

class ThreadedCam:
    def __init__(self, src=0):
        self.cap = cv2.VideoCapture(src)
        self.cap.set(cv2.CAP_PROP_BUFFERSIZE, 1)
        self.q = queue.Queue(maxsize=1)
        self.stop = False
        threading.Thread(target=self._loop, daemon=True).start()

    def _loop(self):
        while not self.stop:
            ok, f = self.cap.read()
            if not ok: break
            if self.q.full():
                try: self.q.get_nowait()
                except queue.Empty: pass
            self.q.put(f)

    def read(self): return self.q.get()
    def close(self):
        self.stop = True; self.cap.release()

from concurrent.futures import ProcessPoolExecutor
pool = ProcessPoolExecutor(max_workers=2)
future = pool.submit(heavy_cv_func, frame)
# মূল thread অন্য কাজ চালিয়ে পরে result নেয়
result = future.result()

import time
def t(name):
    return (name, time.time())

start = time.time()
ts = []
ok, f = cap.read();           ts.append(t("read"))
f2 = cv2.resize(f,(640,360)); ts.append(t("resize"))
g  = cv2.cvtColor(f2,6);      ts.append(t("gray"))
e  = cv2.Canny(g,80,180);     ts.append(t("canny"))

prev = start
for name, now in ts:
    print(f"{name:8s} {(now-prev)*1000:6.2f} ms"); prev = now