Opencv: Melepaskan VideoCapture / Webcam tidak berfungsi

Ditransfer dari http://code.opencv.org/issues/3672

|| Martijn van der Veen on 2014-05-02 21:02
|| Priority: Normal
|| Affected: branch 'master' (3.0-dev)
|| Category: python bindings
|| Tracker: Bug
|| Difficulty: Medium
|| PR: 
|| Platform: x64 / Linux

Melepaskan VideoCapture / Webcam tidak berfungsi

Using python (3.4) bindings on Ubuntu 14.04 with build-in webcam using v4l4, master branch:

In [2]: cap = cv2.VideoCapture(0)
HIGHGUI ERROR: V4L/V4L2: VIDIOC_S_CROP

In [3]: a,b = cap.read() # although error, reading frame works (a=True, b=np.array)

In [4]: cap.release()

In [5]: cap.isOpened()
Out[5]: False

In [6]: cap = cv2.VideoCapture(0)
HIGHGUI ERROR: V4L2: Pixel format of incoming image is unsupported by OpenCV

In [7]: a,b = cap.read()
VIDIOC_STREAMON: Bad file descriptor


After calling .release(), webcam light stays on and webcam stays unreachable for other programs (e.g., Cheese).

Sejarah

Martijn van der Veen pada 02-05-2014 21:24

(Btw, the webcam _is_ released when python exits, but in some cases that's not enough - e.g., for running programs that need to release the webcam now and then.)

Alexander Smorkalov pada 04-05-2014 15:58

-   Category set to python bindings

Andrew Senin pada 06-05-2014 14:21

Hello Martijn, 

Since our resources are limited please consider investigating this issue and creating a fixing pull request (http://code.opencv.org/projects/opencv/wiki/How_to_contribute). All help to the project is highly appreciated!
-   Difficulty set to Medium
-   Assignee set to Martijn van der Veen
-   Status changed from New to Open

Maksim Shabunin pada 27-04-2015 09:12

-   Target version changed from 3.0-beta to 3.0

Maksim Shabunin pada 28-04-2015 13:42

Can not reproduce with the 3.0-rc1 release. Webcam is successfully released and reopened.

Can you, please, try to reproduce it with the latest version? Probably it has been fixed already.
-   Assignee changed from Martijn van der Veen to Maksim Shabunin

Maksim Shabunin pada 28-04-2015 13:42

-   Status changed from Open to Incomplete