在Python中使用OpenCV从文件中打开视频

I am trying to use OpenCV2 with my Conda environment for Python 2.7.

我正在尝试将OpenCV2与我的Conda环境一起用于Python 2.7。

My installation was basically the same as what was described in this question.

我的装置基本上和问题中描述的一样。

I retrieved OpenCV like so:

我找到了OpenCV:

conda install --channel https://conda.anaconda.org/menpo opencv3

I can import the library cv2 and print the version, which is 3.1.0. So far so good. I can even load an image and display it:

我可以导入库cv2并打印版本，即3.1.0。目前为止一切都很顺利。我甚至可以加载一个图像并显示它:

import cv2

img = cv2.imread('desertfloor.jpg')
cv2.imshow('foo',img)
cv2.waitKey(0)
cv2.destroyAllWindows()

This works just fine. But when I go to load a video in the same directory:

这样做挺好。但当我在同一个目录下加载视频时:

vid = cv2.VideoCapture('bbb.avi') # Big Buck Bunny
returnval,frame = vid.read()
print returnval

The returned value is False, which tells me that the frame wasn't returned correctly. When I check vid.isOpened(), it is False as well. Since it doesn't return an error, it's really hard to tell what's going on. I've heard that ffmpeg can cause some issues if it's not installed properly (whatever that means), but I can't tell if that's what's going on here.

返回的值为False，这告诉我没有正确返回框架。当我检查vi .is open()时，它也是假的。因为它不会返回错误，所以很难判断发生了什么。我听说如果没有正确安装ffmpeg可能会导致一些问题(不管这意味着什么)，但我无法判断这里是否发生了这种情况。

Can anyone tell me why the video isn't opening properly?

谁能告诉我为什么视频不能正常打开?

1 个解决方案

#1

The error is most probably due to the reason of missing codecs. The VideoCapture simply displays False, in case of missing codecs rather than displaying actual error.

这个错误很可能是由于缺少编解码器的原因造成的。VideoCapture仅仅显示为False，以防缺少codecs而不显示实际的错误。

If using pre-built binaries, for Python in Windows. The third-party ffmpeg are not available as it should be built from source. For the same reason, I have provided the link of pre-built binaries, built and wrapped with OpenCV-compatible API.

如果使用预构建的二进制文件，则在Windows中使用Python。第三方ffmpeg是不可用的，因为它应该从源代码构建。出于同样的原因，我提供了预构建的二进制文件的链接，这些二进制文件是用兼容opencv的API构建和封装的。

https://drive.google.com/open?id=0Bzxd9GL63enNMEpPV0lWRng1VW8

The binaries are built for opencv-3.0.0, rename it with respect to OpenCV version.

这些二进制文件是为OpenCV -3.0.0构建的，针对OpenCV版本重命名它。

For 32-bit architecture, OpenCV version X.Y.Z -> opencv_ffmpegXYZ.dll
For 64-bit architecture, OpenCV version X.Y.Z -> opencv_ffmpegXYZ_64.dll

copy this renamed file, in c:\Python27\, or wherever python is installed (different in case, if using any open source distribution of the Python, like Anaconda). After this VideoCapture should work fine.

复制这个重命名的文件，在c:\Python27\，或任何python安装的地方(如果使用任何python的开放源码发行版，如Anaconda)。拍完这个视频后应该没问题。

Hope this helps !!

希望这有助于! !

#1