雖然 ROCK64 只有 USB Camera 可用︰
既已經安裝了 OpenCV ，當然得試試看也︰
rock64@rock64:~$ python3 Python 3.5.3 (default, Sep 27 2018, 17:25:39) [GCC 6.3.0 20170516] on linux Type "help", "copyright", "credits" or "license" for more information. >>> import cv2 >>> cv2.__version__ '4.0.1-dev' >>> camera = cv2.VideoCapture(0) (python3:9042): GStreamer-CRITICAL **: gst_element_get_state: assertion 'GST_IS_ELEMENT (element)' failed >>>
結果嚇一跳呦★
當真
塞翁得馬，焉知非禍耶？！
夫禍福之轉而相生，其變難見也。 近塞上之人有善術者，馬無故亡而入胡，人皆弔之。其父曰：「此何遽不為福乎！」居數月，其馬將胡駿馬而歸，人皆賀之。其父曰：「此何遽不能為禍乎！」家富良馬，其子好騎，墮而折其髀，人皆弔之。其父曰：「此何遽不為福乎！」居一年，胡人大入塞，丁壯者引弦而戰，近塞之人，死者十九，此獨以跛之故，父子相保。故福之為禍，禍之為福，化不可極，深不可測也。
不過無獨有偶乎！？
/opencv
Videocapture error while reading from camera using backend (i.e. Ffmpeg, Gstreamer, Direct Show) #11806
又得練功夫啦☆
System information (version)
Detailed description
compile with GDB.
(process:24917): GStreamer-CRITICAL **: gst_element_get_state: assertion ‘GST_IS_ELEMENT (element)’ failed
ERROR! Unable to open camera
[Thread 0x7fffc5ec2700 (LWP 24921) exited]
[Inferior 1 (process 24917) exited with code 0377]
compile the videocapture_basic.cpp file using the following command.
OPENCV_LOG_LEVEL=DEBUG OPENCV_VIDEOIO_DEBUG=1 ./output[ INFO:0] VIDEOIO: Enabled backends(7, sorted by priority): FFMPEG(1000); GSTREAMER(990); V4L2(980); CV_IMAGES(970); CV_MJPEG(960); FIREWIRE(950); GPHOTO2(940)
[ WARN:0] VIDEOIO(createGStreamerCapture(filename)): trying …
(video_stream:17022): GStreamer-CRITICAL **: gst_element_get_state: assertion ‘GST_IS_ELEMENT (element)’ failed
[ WARN:0] VIDEOIO(createGStreamerCapture(filename)): result=(nil) isOpened=-1 …
terminate called after throwing an instance of ‘char const*’
Aborted (core dumped)
Steps to reproduce
After compiling the sample code in file opencv/samples/cpp/videocapture_basic.cpp changing line 28 and executing the output file getting the error
int apiID = cv::CAP_GSTREAMER