如何正确为matplotlib.animation启用ffmpeg？ [英] How do I properly enable ffmpeg for matplotlib.animation?

问题描述

到目前为止，我已经尝试过使用ffmpeg进行堆栈操作，因此我可以制作一个缩时视频。

I have covered a lot of ground on stack so far trying to get ffmpeg going so I can make a timelapse video.

我在CentOS 7机器上，正在运行 python3.7.0a0 。

I am on a CentOS 7 machine, running python3.7.0a0.

python3
>>> import numpy as np
>>> np.__version__
'1.12.0'
>>> import matplotlib as mpl
>>> mpl.__version__
'2.0.0'
>>> import mpl_toolkits.basemap as base
>>> base.__version__
'1.0.7'

我发现此github要点关于安装ffmpeg的信息。我使用了铬源，并且安装时没有前缀选项（使用默认选项）。

I found this github gist on installing ffmpeg. I used the chromium source, and installed without a prefix option (using the default).

我已经确认ffmpeg已安装，尽管我对测试它是否有效一无所知。

I have confirmed that ffmpeg is installed, although I don't know anything about testing whether it works.

which ffmpeg
/usr/local/bin/ffmpeg

ffmpeg -version
ffmpeg version N-83533-gada281d Copyright (c) 2000-2017 the FFmpeg dev elopers
built with gcc 4.8.5 (GCC) 20150623 (Red Hat 4.8.5-11
configuration:
libavutil      55. 47.100 / 55. 47.100
libavcodec     57. 80.100 / 57. 80.100
libavformat    57. 66.102 / 57. 66.102
libavdevice    57.  2.100 / 57.  2.100
libavfilter     6. 73.100 /  6. 73.100
libswscale      4.  3.101 /  4.  3.101
libswresample   2.  4.100 /  2.  4.100

我尝试运行一些在网上找到的示例示例：

I tried to run a few sample examples I found online:

[1] http：// m atplotlib.org/examples/animation/basic_example_writer.html

[2] https://stackoverflow.com/a/23098090/3454650

在我尝试保存动画文件之前，一切正常。

Everything works fine up until I try to save the animation file.

[1]

 anim.save('basic_animation.mp4', writer = FFwriter, fps=30, extra_args=['-vcodec', 'libx264'])

[2]

im_ani.save('im.mp4', writer=writer)

我发现此处 ffmpeg的路径可能是必需的，因此我将其添加到了测试脚本的顶部：

I found here that explictly setting the path to ffmpeg might be necessary so I added this to the top of the test scripts:

plt.rcParams['animation.ffmpeg_path'] = '/usr/local/bin/ffmpeg'

我尝试了一些其他调整代码，但总是得到相同的响应，而我不知道如何开始解密：

I tried a few more tweaks in the code but always get the same response, which I do not know how to begin deciphering:

Traceback (most recent call last):
  File "testanim.py", line 27, in <module>
    writer.grab_frame()
  File "/usr/local/lib/python3.7/contextlib.py", line 100, in __exit__
    self.gen.throw(type, value, traceback)
  File "/usr/local/lib/python3.7/site-packages/matplotlib/animation.py", line 256, in saving
    self.finish()
  File "/usr/local/lib/python3.7/site-packages/matplotlib/animation.py", line 276, in finish
    self.cleanup()
  File "/usr/local/lib/python3.7/site-packages/matplotlib/animation.py", line 311, in cleanup
    out, err = self._proc.communicate()
  File "/usr/local/lib/python3.7/subprocess.py", line 836, in communicate
    stdout, stderr = self._communicate(input, endtime, timeout)
  File "/usr/local/lib/python3.7/subprocess.py", line 1474, in _communicate
    selector.register(self.stdout, selectors.EVENT_READ)
  File "/usr/local/lib/python3.7/selectors.py", line 351, in register
    key = super().register(fileobj, events, data)
  File "/usr/local/lib/python3.7/selectors.py", line 237, in register
    key = SelectorKey(fileobj, self._fileobj_lookup(fileobj), events, data)
  File "/usr/local/lib/python3.7/selectors.py", line 224, in _fileobj_lookup
    return _fileobj_to_fd(fileobj)
  File "/usr/local/lib/python3.7/selectors.py", line 39, in _fileobj_to_fd
    "{!r}".format(fileobj)) from None
ValueError: Invalid file object: <_io.BufferedReader name=6>

我的配置中是否存在格式错误的内容？我搜索了一段时间的这个错误的谷歌，但没有找到任何有关动画/ ffmpeg的。任何帮助将不胜感激。

Is there something with my configuration that is malformed? I searched google for this error for some time but never found anything relevant to animations / ffmpeg. Any help would be greatly appreciated.

更新：

@LordNeckBeard在这里指向我： https://trac.ffmpeg.org/wiki/CompilationGuide/Centos

@LordNeckBeard pointed me here: https://trac.ffmpeg.org/wiki/CompilationGuide/Centos

我在安装x264编码依赖项时遇到了问题。 libavcodec / *。c中的某些文件（在 make 输出中）报告了对多个函数的未定义引用。在追赶大雁之后，发现了这个： https：//mailman.videolan .org / pipermail / x264-devel / 2015-February / 010971.html

I ran into problems with installing the x264 encoding dependency. Some files in libavcodec/*.c (in the make output) were reporting undefined references to several functions. After a wild goose chase found this: https://mailman.videolan.org/pipermail/x264-devel/2015-February/010971.html

要修复x264安装，我只是添加了一些 configure 标志：

To fix the x264 installation, I simply added some configure flags:

./configure --enable-static --enable-shared --extra-ldflags="-lswresample -llzma"

---

更新：

---

UPDATE:

因此，解决了libx264问题后，所有安装均正常。我继续将ffmpeg二进制文件从 ffmpeg_build 文件夹复制到 / usr / local / bin / ffmpeg 中。

So everything installed fine after fixing the libx264 problems. I went ahead and copied the ffmpeg binary from the ffmpeg_build folder into /usr/local/bin/ffmpeg.

运行脚本后，我遇到了ffmpeg找不到libx264共享库的问题。我想我将不得不使用不同的前缀重新编译所有内容。我的直觉告诉我，在弄乱了所有内容之后，使用了一些已损坏的配置，周围有旧文件。

After running the script I was getting problems where ffmpeg could not find the libx264 shared object. I think I will have to recompile everything using different prefixes. My intuition tells me there are old files laying around after I have messed with everything, using some configuration that is broken.

所以我决定也许我应该尝试使用NUX ： http://linoxide.com/linux-how-to/install -ffmpeg-centos-7 /
我使用新的rpm安装了ffmpeg，但无济于事。由于缺少共享对象，我仍然无法运行ffmpeg。

So I decided maybe I should just try to use NUX: http://linoxide.com/linux-how-to/install-ffmpeg-centos-7/ I installed ffmpeg using the new rpm, but to no avail. I still was not able to run ffmpeg because of a missing shared object.

最后，而不是将usiong文件复制到我的 / usr / local /中bin 文件夹，我直接从build bin目录运行ffmpeg。事实证明，这确实可以正常工作！

Finally, instead of usiong files copied into my /usr/local/bin folder, I ran ffmpeg directly from the build bin directory. Turns out that this does work properly!

因此，从本质上讲，如果我想在全系统范围内安装ffmpeg，则需要再次使用非本地前缀从源代码进行手动编译。

So in essence, if I want to install ffmpeg system wide, I need to manually compile from sources again but using a nonlocal prefix.

推荐答案

我在您提供的输出中看不到 ffmpeg 特定信息；但是，您尝试使用libx264，但是您的ffmpeg配置丢失了-enable-gpl --enable-libx264 ，而使用该编码器进行编码是必需的。您可以下载用于Linux的 ffmpeg 二进制文件， macOS或不支持libx264的Windows，然后将您的脚本指向它。

I see no ffmpeg specific info in the output you provided; however you are attempting to use libx264, but your ffmpeg configure is missing --enable-gpl --enable-libx264 which are required to enable encoding with this encoder. You can download a ffmpeg binary for Linux, macOS, or Windows that does support libx264 then point your script to it.

或者，使用上述配置选项编译 ffmpeg 。

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