opencv无法打开USB摄像头

[复制链接] · 发表于 2019-3-26 14:28:46

sudo dnf install gstreamer-rockchip
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后，无法打开UVC摄像头：camera.py:



import numpy as np

import cv2

import matplotlib.pyplot as plot

 cap = cv2.VideoCapture(0)

while(True):

 ret,frame = cap.read()

 cv2.imshow("capture",frame)

if cv2.waitKey(1) & 0xFF == ord('q'):

       break

cap.release()
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执行：python camera.py

OpenCV(3.4.1) Error: Unspecified error (GStreamer: unable to start pipeline

) in cvCaptureFromCAM_GStreamer, file /builddir/build/BUILD/opencv-3.4.1/modules/videoio/src/cap_gstreamer.cpp, line 890

VIDEOIO(cvCreateCapture_GStreamer(CV_CAP_GSTREAMER_V4L2, reinterpret_cast<char *>(index))): raised OpenCV exception:



OpenCV(3.4.1) /builddir/build/BUILD/opencv-3.4.1/modules/videoio/src/cap_gstreamer.cpp:890: error: (-2) GStreamer: unable to start pipeline

 in function cvCaptureFromCAM_GStreamer



OpenCV(3.4.1) Error: Unspecified error (unicap: failed to get info for device

) in CvCapture_Unicap::initDevice, file /builddir/build/BUILD/opencv-3.4.1/modules/videoio/src/cap_unicap.cpp, line 139

VIDEOIO(cvCreateCameraCapture_Unicap(index)): raised OpenCV exception:



OpenCV(3.4.1) /builddir/build/BUILD/opencv-3.4.1/modules/videoio/src/cap_unicap.cpp:139: error: (-2) unicap: failed to get info for device

 in function CvCapture_Unicap::initDevice



OpenCV(3.4.1) Error: Assertion failed (size.width>0 && size.height>0) in imshow, file /builddir/build/BUILD/opencv-3.4.1/modules/highgui/src/window.cpp, line 364

Traceback (most recent call last):

  File "camera.py", line 7, in <module>

    cv2.imshow("capture",frame)

cv2.error: OpenCV(3.4.1) /builddir/build/BUILD/opencv-3.4.1/modules/highgui/src/window.cpp:364: error: (-215) size.width>0 && size.height>0 in function imshow
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本地视频也无法打开！

只看该作者 · 发表于 2019-3-30 11:16:32

hisping 发表于 2019-3-27 20:51
试下

你好，这个已经安装了，现在可以打开本地视频，但是USB摄像头还是无法开启（USB摄像头是UVC免驱，且在UBUNTU上验证可用）

只看该作者 · 发表于 2019-3-30 12:01:54

hisping 发表于 2019-3-27 20:51
试下

本地视频可以打开，但是USB免驱摄像头还是无法打开

OpenCV(3.4.1) Error: Unspecified error (GStreamer: unable to start pipeline

) in cvCaptureFromCAM_GStreamer, file /builddir/build/BUILD/opencv-3.4.1/modules/videoio/src/cap_gstreamer.cpp, line 890

VIDEOIO(cvCreateCapture_GStreamer(CV_CAP_GSTREAMER_V4L2, reinterpret_cast<char *>(index))): raised OpenCV exception:



OpenCV(3.4.1) /builddir/build/BUILD/opencv-3.4.1/modules/videoio/src/cap_gstreamer.cpp:890: error: (-2) GStreamer: unable to start pipeline

 in function cvCaptureFromCAM_GStreamer



OpenCV(3.4.1) Error: Unspecified error (unicap: failed to get info for device

) in CvCapture_Unicap::initDevice, file /builddir/build/BUILD/opencv-3.4.1/modules/videoio/src/cap_unicap.cpp, line 139

VIDEOIO(cvCreateCameraCapture_Unicap(index)): raised OpenCV exception:



OpenCV(3.4.1) /builddir/build/BUILD/opencv-3.4.1/modules/videoio/src/cap_unicap.cpp:139: error: (-2) unicap: failed to get info for device

 in function CvCapture_Unicap::initDevice



OpenCV(3.4.1) Error: Assertion failed (size.width>0 && size.height>0) in imshow, file /builddir/build/BUILD/opencv-3.4.1/modules/highgui/src/window.cpp, line 364

Traceback (most recent call last):

  File "open_camera.py", line 13, in <module>

    video_demo()

  File "open_camera.py", line 7, in video_demo

    cv.imshow("UVC",frame)

cv2.error: OpenCV(3.4.1) /builddir/build/BUILD/opencv-3.4.1/modules/highgui/src/window.cpp:364: error: (-215) size.width>0 && size.height>0 in function imshow

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只看该作者 · 发表于 2019-4-2 10:12:09

之前遇到相似的问题, ls /dev/video*看看是不是有多个摄像头设备
如果有多个摄像头设备, USB不一定是video0, 插拔下看下是video#
然后改代码中打开摄像头部分
cap = cv2.VideoCapture(“/dev/video#”)

只看该作者 · 发表于 2020-8-27 10:10:52

4.此时应该可以正常显示图片及打开摄像头，但无法打开视频文件，需安装gstreamer

sudo dnf install https://download1.rpmfusion.org/ ... usion-free-release-$(rpm -E %fedora).noarch.rpm
sudo dnf install gstreamer1-libav