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• Matplotlib animation won't save

  17 décembre 2014, par abe678

  I am trying to learn how to create matplotlib animations by using Jake Vanderplas’s basic example, but I’m having trouble getting the figure to save. I installed ffmpeg on my Mac via homebrew.

  The only changes that I have made are to add :

  import matplotlib
  
  matplotlib.use('TKAgg')

  When I run this script I receive the following error :

  anim.save('basic_animation.mp4', fps=30, extra_args=['-vcodec', 'libx264'])
  
  TypeError: save() got an unexpected keyword argument 'extra_args'

  Based on the many other similar questions, I’ve tried setting the ffmpeg path with

  plt.rcParams['animation.ffmpeg_path']

  but that also gives me an error :

  File "/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/matplotlib/__init__.py", line 660, in __setitem__
  
    See rcParams.keys() for a list of valid parameters.' % (key,))
  
  KeyError: 'animation.ffmpeg_path is not a valid rc parameter.See rcParams.keys() for a list of valid parameters.'

  After removing the rcParams setting, I also tried adjusting the save command to avoid the aforementioned TypeError :

  try:
  
      anim.save('basic_animation.mp4', fps=30, extra_args=['-vcodec', 'libx264'])
  
  except TypeError:
  
      anim.save('basic_animation.mp4', fps=30)

  This runs with no error, but the mp4 file is not created. I have read over every thread and tried every solution I can find, but nothing changes. The plt.show() call works just fine. Can anyone please point me in the right direction ? Thanks !

  Update : I’m using matplotlib version 1.1.1

• Installed ffmpeg, added to path, still can't save animation from Jupyter Notebook

  29 avril 2017, par dredre_420

  I’m trying to simulate a two-body orbit system working on Jupyter Notebook (python). Since the animation can’t display in-line I tried installing ffmpeg and adding it to the system path using steps outlined here : http://adaptivesamples.com/how-to-install-ffmpeg-on-windows/.

  However, when I try to save my animation using anim.save('orbit.mp4', fps=15, extra_args=['-vcodec', 'libx264']), I still get the error message : ValueError: Cannot save animation: no writers are available. Please install mencoder or ffmpeg to save animations.

  Not sure what else to try at this point, very inexperienced programmer here.

• Record audio data to an existing media file using FFMPEG API

  3 février 2021, par bbdd

  My task is to record the received audio data in a media file. I have no problem with this, everything works fine. But, when closing the audio file, I will no longer be able to re-open it and write the audio data to the end of the audio file. How do I solve this problem ? And in general, is it possible to write new data to the end of an existing media file ?

  


  This is a piece of code where I record the trailer and close the media file :

  


  // Writing the stream trailer to an output
// media file and free the file private data.
av_write_trailer(p_oFrmCtx);
avformat_close_input(&p_oFrmCtx);