使用 cv2 VideoWriter 写入 numpy 数组

发布于 2025-01-05 17:24:50 字数 712 浏览 0 评论 0原文

我在使用 opencv2.3.1 VideoWriter 编写玩具示例视频时遇到问题，以下是我的做法：

writer = cv2.VideoWriter('test1.avi',cv.CV_FOURCC('P','I','M','1'),25,(640,480))
for i in range(1000):
    x = np.random.randint(10,size=(480,640)).astype('uint8')
    writer.write(x)
#del writer (with or without tested)

如果扩展名是 mpg，我尝试了所有可能的组合，结果是 0 字节文件，如果扩展名是 avi，则结果是 5.5kb。我应该说，有人指出我应该从源代码构建 ffmpeg 库，而不是 apt-get 它。好吧，我在这个网站的帮助下在一台新机器上做到了这一点 http://vinayhacks.blogspot.com/2011/11/installing-opencv-231-with-ffmpeg-on-64.html。编译 opencv 时也出现错误（该错误与 ffmpeg 有关）。现在我真的没有主意了，如何使用 OPENCV 生成视频？

提前致谢

原文

I have a problem with writing a toy example video using opencv2.3.1 VideoWriter, here is how I do it:

writer = cv2.VideoWriter('test1.avi',cv.CV_FOURCC('P','I','M','1'),25,(640,480))
for i in range(1000):
    x = np.random.randint(10,size=(480,640)).astype('uint8')
    writer.write(x)
#del writer (with or without tested)

I tried every possible combination resulting with a 0 bytes file if the extension was mpg, and 5.5kb if it was avi. I should say that some pointed out that I should build the ffmpeg library from source and not apt-get it. Well I did that on a fresh machine based on the help of this site http://vinayhacks.blogspot.com/2011/11/installing-opencv-231-with-ffmpeg-on-64.html. which also presented an error while compiling opencv(the error was related to ffmpeg). Now I am really out of ideas, How to generate a video using OPENCV?

Thanks in advance

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櫻之舞 2025-01-12 17:24:50

VideoWriter 的最后一个参数 isColor 具有默认值 True。
因此，如果将其更改为 False，则可以编写二维数组。

import cv2
import numpy as np

writer = cv2.VideoWriter('test1.avi', cv2.VideoWriter_fourcc(*'PIM1'), 25, (640, 480), False)
for i in range(100):
    x = np.random.randint(255, size=(480, 640)).astype('uint8')
    writer.write(x)

VideoWriter has last argument isColor with default value True.
So if you change it to False then you can write your 2D arrays.

import cv2
import numpy as np

writer = cv2.VideoWriter('test1.avi', cv2.VideoWriter_fourcc(*'PIM1'), 25, (640, 480), False)
for i in range(100):
    x = np.random.randint(255, size=(480, 640)).astype('uint8')
    writer.write(x)

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老子叫无熙 2025-01-12 17:24:50

你好，我是 opencv 的新手，我也遇到了同样的问题。看来 writer.write(x) 需要 x 是一个包含 RGB 值的数组，而不是标量。我通过这样做解决了这个问题：

import cv2
import cv2.cv as cv
import numpy as np

writer = cv2.VideoWriter('test1.avi',cv.CV_FOURCC('P','I','M','1'),25,(640,480))
for i in range(1000):
    x = np.random.randint(255,size=(480,640)).astype('uint8')
    x = np.repeat(x,3,axis=1)
    x = x.reshape(480, 640, 3)
    writer.write(x)

我认为有更干净的方法可以做到这一点，但我还没有找到。

Hello I am new to opencv and I had this same problem. It appears that the writer.write(x) Needs x to be an array whit RGB values and not scalars. I solved the issue by doing this:

import cv2
import cv2.cv as cv
import numpy as np

writer = cv2.VideoWriter('test1.avi',cv.CV_FOURCC('P','I','M','1'),25,(640,480))
for i in range(1000):
    x = np.random.randint(255,size=(480,640)).astype('uint8')
    x = np.repeat(x,3,axis=1)
    x = x.reshape(480, 640, 3)
    writer.write(x)

I assume there are cleaner ways to do it but I haven't found any.

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