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I know similar threads exist, no trick worked for me though, so I am asking here again. I am using two Logitech C922 webcams. Theoretically, they can records with 60fps on 720p. However, using OpenCV (version 4.1.0) and this code

import numpy as np
import cv2

width = 160
height = 120
fps = 30

fourcc = cv2.VideoWriter_fourcc('M','J', 'P', 'G')
out1 = cv2.VideoWriter('cam1.avi',fourcc, fps, (width,height))
out2 = cv2.VideoWriter('cam2.avi',fourcc, fps, (width,height))

cap1 = cv2.VideoCapture(0)
cap1.set(cv2.CAP_PROP_FOURCC,  1196444237)
cap1.set(3,width)
cap1.set(4,height)
cap1.set(cv2.CAP_PROP_FPS, fps)
cap2 = cv2.VideoCapture(2)
cap2.set(cv2.CAP_PROP_FOURCC,  1196444237)
cap2.set(3,width)
cap2.set(4,height)
cap2.set(cv2.CAP_PROP_FPS, fps)



while(True):
    # Capture frame-by-frame
    ret1, frame1 = cap1.read()
    ret2, frame2 = cap2.read()

    out1.write(frame1)
    out2.write(frame2)

    # Display the resulting frame
    #cv2.imshow('cam1',frame1)
    #cv2.imshow('cam2', frame2)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

cap1.release()
cap2.release()
out1.release()
out2.release()
cv2.destroyAllWindows()

I only get about 10fps. Is there any fix by now? (I am on Ubuntu 18.04 if that matters)

EDIT: Output from v4l2-ctl --list-formats-ext is

ioctl: VIDIOC_ENUM_FMT
    Index       : 0
    Type        : Video Capture
    Pixel Format: 'YUYV'
    Name        : YUYV 4:2:2
        Size: Discrete 640x480
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 160x90
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 160x120
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 176x144
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 320x180
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 320x240
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 352x288
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 432x240
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 640x360
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 800x448
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 800x600
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 864x480
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 960x720
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 1024x576
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 1280x720
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 1600x896
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 1920x1080
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 2304x1296
            Interval: Discrete 0.500s (2.000 fps)
        Size: Discrete 2304x1536
            Interval: Discrete 0.500s (2.000 fps)

    Index       : 1
    Type        : Video Capture
    Pixel Format: 'MJPG' (compressed)
    Name        : Motion-JPEG
        Size: Discrete 640x480
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 160x90
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 160x120
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 176x144
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 320x180
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 320x240
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 352x288
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 432x240
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 640x360
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 800x448
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 800x600
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 864x480
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 960x720
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 1024x576
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 1280x720
            Interval: Discrete 0.017s (60.000 fps)
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 1600x896
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
        Size: Discrete 1920x1080
            Interval: Discrete 0.033s (30.000 fps)
            Interval: Discrete 0.042s (24.000 fps)
            Interval: Discrete 0.050s (20.000 fps)
            Interval: Discrete 0.067s (15.000 fps)
            Interval: Discrete 0.100s (10.000 fps)
            Interval: Discrete 0.133s (7.500 fps)
            Interval: Discrete 0.200s (5.000 fps)
Luca Thiede
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  • For tests try if You can get for one camera 60 fps. Use for it cv2.CAP_DSHOW in VideoCapture: 'cap1 = cv2.VideoCapture(0 + cv2.CAP_DSHOW)' – Piotr Kurowski May 23 '19 at 07:38
  • Or You can try with multithreading – Piotr Kurowski May 23 '19 at 07:38
  • 2
    What do you get from running `v4l2-ctl --list-formats-ext` in terminal ? – Christoffer May 23 '19 at 08:13
  • @PiotrKurowski if I run it with cv2.CAP_DSHOW I get None for frame1. If I am just setting cv2.VideoCapture(0) I am actually able to record on 30 fps as long as I have only one cv2.VideoCapture. As soon as I am adding the second one, the frame rate gets cut in half. If I am using the propertarian software, I am able to record on 30fps with both cameras though, so in principle it should be possible. – Luca Thiede May 24 '19 at 05:44
  • @Christoffer I added the output in the question. – Luca Thiede May 24 '19 at 05:47
  • I also noticed, that when I am timing the cap1.read() and cap2.read() lines, it takes 0.006s for the first cap1.read() and 0.05s for the second cap2.read(). Even though 0.006 should be fast enough for 30fps, it is still not working. (The write operation is also not the bottleneck when I am timing it) – Luca Thiede May 24 '19 at 06:12
  • Another things I noticed, when I am using one camera, I first get 30fps, when I am then using the second camera as well both fall to 10-15fps, and if I then switch back to just one camera, I also get only 10-15fps on that one camera. Also sometimes the fps are changing while I am recording. – Luca Thiede May 24 '19 at 07:09
  • It could be that you are limited on USB bandwidth but since you are running in such a low resolution I really don't think that's the issue. As @PiotrKurowski mentioned you could try multithreading like so: https://stackoverflow.com/a/46865932/9758354 – Christoffer May 24 '19 at 07:22
  • Yeah, plus it works with Logitechs software with two cameras even on higher resolutions. I will try the multi threading. Otherwise I will have to bu a new camera. Do you know by any chance cameras that are guaranteed/tested to work with opencv? – Luca Thiede May 24 '19 at 07:31

0 Answers0