在Raspberry Pi上由OpenCV 2.3.1使用Python创建的无视频文件 [英] No video file created by OpenCV 2.3.1 with Python on Raspberry Pi

问题描述

我正在尝试从网络摄像头(Logitech c210)捕获视频并从中创建视频文件.

I'm trying to capture video from a webcam(Logitech c210) and create a video file from it.

这是在2013年5月25日的Raspbian Wheezy上.

This is on Raspbian Wheezy 2013-05-25.

相机上的灯点亮约30秒钟，但未创建文件. 我的摄像头显示在OpenCV窗口中.

The light on the camera comes on for about 30 seconds but no file is created. I've had the webcam displaying in an OpenCV window.

我想知道这是否是编解码器问题，因为脚本可以在带有-1参数的Windows上运行?

I'm wondering if this is a codec problem as the script works on windows with the -1 parameter?

如果是的话，是否有推荐的Raspberry Pi编解码器?

If so are there any recommended codecs for Raspberry Pi?

如果我购买了mpeg2编解码器，那行得通吗?

If I buy the mpeg2 codec would that work?

我已经列出了我尝试过的编解码器，但是没有用.

I've listed the codecs that I've tried though none work.

脚本如下:

import cv2
import time

def InitialiseCamera():
    camera = cv2.VideoCapture(0)
    if camera is None:
        print('Warning: unable to access camera')
    else:
        print('initialized camera')
    return camera

def InitialiseWriter():
    fps = 5
    size = (640, 480)
    destinationFile = 'video.avi'

    # These are the codecs I've tried so far
    codec = cv2.cv.CV_FOURCC('I','4','2','0')
    #codec = cv2.cv.CV_FOURCC('A','V','C','1')
    #codec = cv2.cv.CV_FOURCC('Y','U','V','1')
    #codec = cv2.cv.CV_FOURCC('P','I','M','1')
    #codec = cv2.cv.CV_FOURCC('M','J','P','G')
    #codec = cv2.cv.CV_FOURCC('M','P','4','2')
    #codec = cv2.cv.CV_FOURCC('D','I','V','3')
    #codec = cv2.cv.CV_FOURCC('D','I','V','X')
    #codec = cv2.cv.CV_FOURCC('U','2','6','3')
    #codec = cv2.cv.CV_FOURCC('I','2','6','3')
    #codec = cv2.cv.CV_FOURCC('F','L','V','1')
    #codec = cv2.cv.CV_FOURCC('H','2','6','4')
    #codec = cv2.cv.CV_FOURCC('A','Y','U','V')
    #codec = cv2.cv.CV_FOURCC('I','U','Y','V')
    #codec = -1

    video  = cv2.VideoWriter(destinationFile, codec, fps, size, True);
    if video is None:
        print('Warning: unable to create video writer')
    else:
    print('initialized writer')
    return video

def CaptureVideo(c,w):
i = 0
    while i<150:
        i+=1
        f,img = c.read()
        try:
            w.write(img)
        except:
            print "Unexpected error: ", sys.exec_info()[0]
    print('complete')
    c.release()

if __name__ == '__main__':    
    cam = InitialiseCamera()
    writer = InitialiseWriter()
    CaptureVideo(cam,writer)

推荐答案

最终，我尝试了所有的fourcc编解码器，但都没有成功.

I eventually went through and tried all of the fourcc codecs and none worked.

与mpeg2编解码器相同.

Same with the mpeg2 codec.

我最终使用avconv创建并捕获了此行的视频:

I ended up using avconv to create and capture the video with this line:

import os
os.system("avconv -f video4linux2 -input_format mjpeg -i /dev/video0 output.avi")

os.system()用于运行终端命令.

os.system() is used to run a terminal command.

以后仍可以使用OpenCV处理视频文件.

OpenCV can still be used to process the video files at a later time.

希望这对某人有帮助.

这篇关于在Raspberry Pi上由OpenCV 2.3.1使用Python创建的无视频文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！