无法使用 Python/opencv 关闭/打开 CameraCapture：设备或资源繁忙

Question

当我尝试使用 Python 重新打开 opencv 的 CameraCapture 时，我得到：

libv4l2: error setting pixformat: Device or resource busy
HIGHGUI ERROR: libv4l unable to ioctl S_FMT

libv4l2: error setting pixformat: Device or resource busy
libv4l1: error setting pixformat: Device or resource busy
HIGHGUI ERROR: libv4l unable to ioctl VIDIOCSPICT

虽然我的应用程序使用 PyQt 和其他各种模块在更大的上下文中运行，但我能够隔离问题。因此，当我点击“r”（重新加载）时，捕获对象被删除，但我无法重新打开与相机的连接，因为它仍然处于活动状态：

#!/usr/bin/env python

from opencv.cv import *  
from opencv.highgui import *  

import sys
import time
import gc

cvNamedWindow("w1", CV_WINDOW_AUTOSIZE)
camera_index = 1
capture = cvCreateCameraCapture(camera_index)

def repeat():
    global capture #declare as globals since we are assigning to them now
    global camera_index
    frame = cvQueryFrame(capture)
    cvShowImage("w1", frame)
    c = cvWaitKey(10)

    if c == "q":
        sys.exit(0)

    if c == "r":

        print 'reload'

        #del frame
        del capture

        # pretty useless sleeping, garbage collecting, etc.
        #gc.collect()
        #import pdb; pdb.set_trace()
        #print gc.get_objects()
        #print gc.DEBUG_UNCOLLECTABLE
        #time.sleep(2)

        capture = cvCreateCameraCapture(camera_index)

if __name__ == "__main__":
    while True:
        repeat()

类似问题的提示对我不起作用： cant find ReleaseCapture in opencv while using python? 和/或 OpenCV / Array should be CvMat or IplImage / Releasing a capture object

Answer 1

问题是您没有使用 OpenCV API 发布捕获组件。

你不应该这样做del capture。正确的做法是通过：

cvReleaseCapture(capture)