fps - how to divide count by time function to determine fps

问题

I have a counter working that counts every frame. what I want to do is divide this by time to determine the FPS of my program. But I'm not sure how to perform operations on timing functions within python.

I've tried initializing time as

fps_time = time.time 
fps_time = float(time.time)
fps_time = np.float(time.time)
fps_time = time()

Then for calculating the fps,

FPS = (counter / fps_time)
FPS = float(counter / fps_time)
FPS = float(counter (fps_time))

But errors I'm getting are object is not callable or unsupported operand for /: 'int' and 'buildin functions'

thanks in advance for the help!

回答1:

Here is a very simple way to print your program's frame rate at each frame (no counter needed) :

import time

while True:
    start_time = time.time() # start time of the loop

    ########################
    # your fancy code here #
    ########################

    print("FPS: ", 1.0 / (time.time() - start_time)) # FPS = 1 / time to process loop

If you want the average frame rate over x seconds, you can do like so (counter needed) :

import time

start_time = time.time()
x = 1 # displays the frame rate every 1 second
counter = 0
while True:

    ########################
    # your fancy code here #
    ########################

    counter+=1
    if (time.time() - start_time) > x :
        print("FPS: ", counter / (time.time() - start_time))
        counter = 0
        start_time = time.time()

Hope it helps!

回答2:

Works like a charm

import time
import collections

class FPS:
    def __init__(self,avarageof=50):
        self.frametimestamps = collections.deque(maxlen=avarageof)
    def __call__(self):
        self.frametimestamps.append(time.time())
        if(len(self.frametimestamps) > 1):
            return len(self.frametimestamps)/(self.frametimestamps[-1]-self.frametimestamps[0])
        else:
            return 0.0
fps = FPS()
for i in range(100):
    time.sleep(0.1)
    print(fps())

Make sure fps is called once per frame

回答3:

You might want to do something in this taste:

def program():
  start_time = time.time() #record start time of program
  frame_counter = 0

  # random logic 
  for i in range(0, 100):
    for j in range(0, 100):
      # do stuff that renders a new frame
      frame_counter += 1 # count frame

  end_time = time.time() #record end time of program
  fps = frame_counter / float(end_time - start_time)

Of course you don't have to wait the end of the program to compute end_time and fps, you can do it every now and then to report the FPS as the program runs. Re-initing start_time after reporting the current FPS estimation could also help with reporting a more precise FPS estimation.

来源：https://stackoverflow.com/questions/43761004/fps-how-to-divide-count-by-time-function-to-determine-fps

标签

python

OpenCV

time

frame-rate

operations