D435 FPS doesn't Exceed 40

[bhomaidan1990]

Required Info
Camera Model	D435
Firmware Version	05.15.00.02
Operating System & Version	Ubuntu 20.04
Kernel Version (Linux Only)	5.15.0-76-generic
Platform	PC
SDK Version	2.50.0
Language	Python
Segment	Robot

Issue Description

I can't reach 60 fps as described in the datasheet, I'm connected using the original Cable to USB 3.1 port, using realsense-viewer it says ~ 58 - 59 FPS, but I can't reach the same FPS using python.

#!/usr/bin/env python3

import time
import numpy as np
import pyrealsense2.pyrealsense2 as rs

class RS_FPS:
    def __init__(self):
        # Start reading frames
        self.pipeline = rs.pipeline()
        config = rs.config()
        # RGB Stream USB 3.1 / FPI 60 doesn't work with USB 2.0
        config.enable_stream(rs.stream.color, 640, 480, rs.format.bgr8, 60) # bgr8/rgb8
        config.enable_stream(rs.stream.depth, 640, 480, rs.format.z16,  60)

        # Start streaming
        self.pipeline.start(config)

        sensor = self.pipeline.get_active_profile().get_device().query_sensors()[1]
        sensor.set_option(rs.option.enable_auto_exposure, True)
        sensor.set_option(rs.option.auto_exposure_priority, False)

        align_to = rs.stream.color
        self.align = rs.align(align_to)

    def run(self):
        nb_frames = 0
        self.tic = time.time()
        while True:
            # Get frameset of color and depth
            frames = self.pipeline.wait_for_frames()

            # Align the depth frame to color frame
            aligned_frames = self.align.process(frames)

            # Get aligned frames
            # aligned_depth_frame is a 640x480 depth image
            aligned_depth_frame = aligned_frames.get_depth_frame() 
            color_frame = aligned_frames.get_color_frame()

            # Validate that both frames are valid
            if not aligned_depth_frame or not color_frame:
                continue
            
            depth_image = np.asanyarray(aligned_depth_frame.get_data())
            color_image = np.asanyarray(color_frame.get_data())

            self.toc = time.time()
            nb_frames += 1
            delta_time = self.toc - self.tic
            cur_fps = np.around(nb_frames / delta_time, 1)

            print("FPS: {}".format(cur_fps))

if __name__=="__main__":
    RS_FPS_ = RS_FPS()
    RS_FPS_.run()

[MartyG-RealSense]

Hi @bhomaidan1990 Comparing frames to time to calculate an FPS value may not be accurate. At #7488 (comment) a RealSense team member provides technical information about how FPS is calculated in the RealSense SDK.

You could instead retrieve the camera metadata parameter ACTUAL_FPS

https://github.com/IntelRealSense/librealsense/blob/master/doc/frame_metadata.md#employing-metadata-attributes-in-demos

[bhomaidan1990]

@MartyG-RealSense Thanks