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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

• FFmpeg How to use alimiter Filter ?

  21 décembre 2016, par Matt McManis

  I cannot find enough documentation on the alimiter filter.

  https://ffmpeg.org/ffmpeg-filters.html#alimiter

  I used -filter_complex alimiter=limit=0.5 and it applied to the file but it boosted the volume.

  I thought it was supposed to hardlimit the volume down ?

  FFmpeg says through cmd limit range [0.0625 - 1]

  ffmpeg -i audio.wav -y -acodec libmp3lame -b:a 320k -ar 44100 -ac 2 -joint_stereo 1 -filter_complex alimiter=limit=0.5 audio.mp3

  Here’s a look at the two files through Adobe Audition

  Original

  

  FFmpeg alimiter 0.5

  

• FFMPEG on Heroku exceeds memory quota in testing

  5 juillet 2022, par Patrick Vellia

  After following this tutorial, and getting it to work locally on my own development environment, before really getting my hands dirty and working deeper on my own project implementation, I decided to push it up to Heroku to test in a staging environment.

  


  I had to have Heroku add the FFMPEG build-pack and turn on the Redis Server for ActionCable to work.

  


  I didn't link the staging to a cloud storage bucket on Google or Amazon yet, just allowed it to upload directly to the dymo disk for testing. So it would go into the storage directory as it would in development for now.

  


  the test MOV file is 186 MB in size.

  


  The system uploaded the file fine.

  


  According to the logs, it then copied the file from storage to tmp as the tutorial has us do.

  


  Then it called streamio-ffmpeg's transcode method.

  


  At this point, Heroku forcibly kills the dymo because it far exceeds the memory quota.

  


  As this is a test environment, it's only on the free tier of Heroku.

  


  I'm thinking I won't be able to directly process video projects on Heroku itself, unless I'm wrong ? Would it be better to call an API like Cloud Functions or Amazon Lambda, or spin up a Compute Engine long enough to process the FFMPEG command ?