Question

我在开车后,在我重新开车后,突然使用我的cam。

[ WARN:0] global /io/opencv/modules/videoio/src/cap_v4l.cpp (802) open VIDEOIO ERROR: V4L: can t open camera by index 0
Traceback (most recent call last):
  File "test.py", line 20, in <module>
    retval, buffer_img = cv2.imencode( .jpg , frame)
cv2.error: OpenCV(4.1.2) /io/opencv/modules/imgcodecs/src/loadsave.cpp:877: error: (-215:Assertion failed) !image.empty() in function  imencode

cap = cv2.VideoCapture(0)  # here it throws an error


import json
while(True):
    # Capture frame-by-frame
    ret, frame = cap.read()

    retval, buffer_img = cv2.imencode( .jpg , frame)

    resdata = base64.b64encode(buffer_img)

    resdata = "data:image/png;base64,"+ str(resdata.decode("utf-8"))
    PARAMS = { image : resdata}

    # Our operations on the frame come here
    #gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

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

# When everything done, release the capture
cap.release()
cv2.destroyAllWindows()

我也尝试了cap = cv2.VideoCapture(1),但显示可以发现照相机。

我如何解决这一问题?

Answer 1

我有同样的错误。图1

cap = cv2.VideoCapture(-1)

这个问题已经解决。

Answer 2

当我创立了2.VideoCapture(0)不止一个例子时,我就谈同样的问题。因此,如果贵国的法典含有多处初始化或多处称呼V2.VideoCapture(0)的章节,就会检查。我面临这一问题,同时以减速方式操作激光器服务器,因为它称电压器是2倍。

import cv2
cap = cv2.VideoCapture(0)
cap2 = cv2.VideoCapture(0)
while True:

    ret, frame = cap.read()
    cv2.imshow( frame ,frame)
    if cv2.waitKey(1) & 0xFF == ord( q ):
        break

cap.release()
cv2.destroyAllWindows()

Error:

python3 debugCamera.py 
[ WARN:0] global /io/opencv/modules/videoio/src/cap_v4l.cpp (887) open VIDEOIO(V4L2:/dev/video0): can t open camera by index

Answer 3

Most likely a permission issue on /dev/video0.

Check if you are part of "video" group.
id -a

if you don t see video in your group list add sudo usermod -a -G video

for Ubuntu users:(20.04)
sudo usermod -a -G video $LOGNAME

记录和记录。

Answer 4

I had the same problem, Just change 0 to 1,then to -1 and back again to 0. Don t know why this worked for me.

Answer 5

我也遇到了同样的问题,并尝试了几种方法,例如:cv2.VideoCapture(-1)或cv2.VideoCapture(1),但没有取得多大成功。

我在读了后继承了该条和。

Answer 6

在https://github.com/opencv/ opencv/issues/19527“rel=”https://github.com/ opencv/issues/19527上,我找到了解决办法。录像带在功能中而不是外面。这为我工作(乌图)

def frame_generation():

camera = cv2.VideoCapture(0) #resolved, correct position

while(True):

Answer 7

我将不谈这一部分。你试图做些什么,这里只是一部能够打开你每次照相机的法典,

python: 3.7.3

OpenCV: 4.1.0

import cv2
cap = cv2.VideoCapture(0)
while True:

    ret, frame = cap.read()
    cv2.imshow( frame ,frame)
    if cv2.waitKey(1) & 0xFF == ord( q ):
        break

cap.release()
cv2.destroyAllWindows()

Answer 8

我也存在同样的问题。只是将其改为1,而且它正在完全运作。我猜测它与你使用的照相器数量有关。

例如,我猜测我有Iruin外部摄像机,这是我第一次选择,我当时没有把这个选择连接起来。

这里是错误和改正的代码。

global /tmp/pip-req-build-f51eratu/opencv/modules/videoio/src/cap_v4l.cpp (890) open VIDEOIO(V4L2:/dev/video0): can t open camera by index

Code to change:

vid = cv2.VideoCapture(1)

Answer 9

看来,《任择议定书》正在使用一种Raspberry PI。 Raspberry正在转向新的系统,以管理照相机,因此,当用户通过<条码>向OS升级时,照相系统会得到新的图书馆,而遗留的照相系统是残疾的。为了让遗留的照相系统再次发挥作用,尝试

sudo raspi-config

然后选择

3 Interface Options    Configure connections to peripherals

然后选择

I1 Legacy Camera Enable/disable legacy camera support

并遵循各项指示,以便能够并继而更换。

当然,由于遗产制度被扭曲,这一摊位只能长时间工作。

Answer 10

就我而言,我只是把游乐重新连接到我们的港口,然后解决! 我认为,造成这一错误的原因是以错误的方式关闭窗口。请检查在关闭窗户后是否对终点站权有任何例外。

Answer 11

我在乌班图也存在这个问题。

我通过这些 com子解决这一问题。

sudo adduser username video sudo usermod -a -G video username

用户名称——是贵装置的名称

页: 1

a)

(a) 从(b)到(b)到(b)项的复制指数

页: 1

只字不提:

摄像机 = cv2.VideoCapture(1000)

Answer 12

每一只 an子,但只改变照相机,从-1升至1,然后回到零。

Answer 13

video = cv2.VideoCapture(0,cv2.CAP_DSHOW)

这为我工作。

Answer 14

就六氯环己烷而言,确保利用V4L(为lin子提供录像)建造开放式六氯环己烷。

Answer 15

我每次在重新启用或更换摄像机和插头之后都这样做。

chmod 777 /dev/video0

Answer 16

Don t know if this is still an issue. In my case, I was getting the same error until I unplugged and plugged the usb camera. Even if I reboot, the error happened.

It s similar to someone said: my camera was already been captured. The problem is that it was not used by my script, so it was hard to identify.

A few days before the issue, I installed the motion library, but just to test something and I didn t use it anymore. The motion starts at boot, so the camera was being captured by the service. That s why only the unplug-plug worked.

我对图书馆无动于衷,错误已经发生。

Answer 17

正如其他捐助者指出的,对我来说,解决办法只是把照相机从USB港口拆开,然后把照照相机推回,而Raspberry PI 乌本巴的OS正在运行。

Answer 18

这个问题是由于中断。例如,用关键的q来结束处决,不会突然关闭窗户。

我再次打开终点站,再次执行同样的文字,从而解决了同一问题。

友情链接