Question

在OpenCV中打开视频文件

然而，在运行代码块时没有任何反应。我的代码如下：

import numpy as np
import cv2

cap = cv2.VideoCapture('768x576.avi')   

while(cap.isOpened()):
    ret, frame = cap.read()

    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

    cv2.imshow('frame',gray)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

cap.release()
cv2.destroyAllWindows()

我在我的系统上安装了ffmpeg＆amp;在我的系统路径中。另外我也在我的机器上安装了gstreamer。此文件可以在Windows媒体播放器中打开，在ffmpeg＆amp;也在VLC开幕。

我在这里不知所措，因为这应该是一个直接的教程。

编辑1：我安装了许多不同的编解码器，包括K-Lite Codec Pack和XVid。如果我用ffmpeg -i打开文件，这就是我得到的

C:\sandbox>ffmpeg -i 768x576.avi
ffmpeg version N-64539-gc8b2cf4 Copyright (c) 2000-2014 the FFmpeg developers
  built on Jul  8 2014 22:10:23 with gcc 4.8.3 (GCC)
  configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-av
isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enab
le-iconv --enable-libass --enable-libbluray --enable-libcaca --enable-libfreetyp
e --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-
libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libope
njpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsox
r --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab -
-enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx
--enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-
libxavs --enable-libxvid --enable-decklink --enable-zlib
  libavutil      52. 91.100 / 52. 91.100
  libavcodec     55. 68.102 / 55. 68.102
  libavformat    55. 45.100 / 55. 45.100
  libavdevice    55. 13.102 / 55. 13.102
  libavfilter     4. 10.100 /  4. 10.100
  libswscale      2.  6.100 /  2.  6.100
  libswresample   0. 19.100 /  0. 19.100
  libpostproc    52.  3.100 / 52.  3.100
Input #0, avi, from '768x576.avi':
  Metadata:
    encoder         : MEncoder 2:1.0~rc2-0ubuntu19
  Duration: 00:01:19.50, start: 0.000000, bitrate: 818 kb/s
    Stream #0:0: Video: msmpeg4v3 (div3 / 0x33766964), yuv420p, 768x576, 816 kb/
s, 10 fps, 10 tbr, 10 tbn, 10 tbc
At least one output file must be specified

编辑2：当我尝试逐行执行此操作时，会发生以下情况

C:\sandbox>python
Python 2.7.7 |Anaconda 2.0.1 (64-bit)| (default, Jun 11 2014, 10:40:02) [MSC v.1
500 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
Anaconda is brought to you by Continuum Analytics.
Please check out: http://continuum.io/thanks and https://binstar.org
>>>
>>> import numpy as np
>>> import cv2
>>> print cv2.__version__
2.4.9
>>>
>>> cap = cv2.VideoCapture('768x576.avi')
>>> print cap
<VideoCapture 0000000002DC3810>
>>> print cap.get(5)
0.0
>>>

编辑3：答案不是100％的回答，但那个兔子洞的评论引导我进入OpenCV VideoCapture cannot read video in Python but able in VS11这就是我如何找出问题

Answer 1

如果在Windows上，并且您确定已成功打开文件most probably you need a codec pack。

用openCV打开视频

1 个答案: