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• How can I save an animation from matplotlib as a mp4 video file ? [duplicate]

  19 décembre 2018, par Manza

  This question already has an answer here :

  • How can I overcome this key word error ?
    
    4 answers
    

  I’m trying to render a animation.ArtistAnimation object into a 24 fps video file in format mp4.

  I have search about and I reached this. However, even after compiling ffmpeg I get this error message :

  C:\Users\trite\OneDrive\Documentos\MusiTex\Python\venv\Scripts\python.exe 
  
  "C:/Users/trite/OneDrive/Documentos/MusiTex/Python/venv/Saving Animation.py"
  
  Traceback (most recent call last):
  
    File "C:\Users\trite\OneDrive\Documentos\MusiTex\Python\venv\lib\site- 
  
  packages\matplotlib\animation.py", line 161, in __getitem__
  
      return self.avail[name]
  
  KeyError: 'ffmpeg'
  
  
  
  During handling of the above exception, another exception occurred:
  
  
  
  Traceback (most recent call last):
  
    File "C:/Users/trite/OneDrive/Documentos/MusiTex/Python/venv/Saving 
  
  Animation.py", line 20, in <module>
  
      FFMpegWriter = manimation.writers['ffmpeg']
  
    File "C:\Users\trite\OneDrive\Documentos\MusiTex\Python\venv\lib\site- 
  
  packages\matplotlib\animation.py", line 164, in __getitem__
  
      'Requested MovieWriter ({}) not available'.format(name))
  
  RuntimeError: Requested MovieWriter (ffmpeg) not available
  
  
  
  Process finished with exit code 1
  
  </module>

  What is the problem with ?

  I would really appreciate if you can help me. Actually, if there is other ways to saving/render this kind of object into a video file (preferably mp4) I will be delighted to hear them.

  Thank you very much

• Efficient way to create variant playlists from mp4 for HLS

  3 mars 2021, par nnaj20

  I am totally new to video encoding and options, and just learned about Apple's HLS requirements.

  


  So far, I've been able to get something working for my iOS app. However, I find the entire process to be very slow and manual. Now, having to repeat this for several more locales (video translations), I can't imagine there isn't a better way.

  


  Controlling bitrate

  


  To have control over the bitrate, I use HandBrake to create a new .mp4 file with the appropriate video encoder setting, for each bitrate I want (192k, 400k, 1m, etc.). THEN, I move onto creating the playlists. This alone takes several minutes—is there a better way ? tsrecompressor seemed close, but it just streams to a local port and doesn't save any playlists.

  


  Creating playlists from MP4

  


  Then I use Apple's suite of command-line tools (mediafilesegmenter, variantplaylistcreator, mediastreamvalidator, hlsreport) to generate the playlists, combine into a master playlist, validate, etc. I suppose this part could be somewhat automated with a script. I've seen others use FFMPEG, but I think the latter 3 Apple tools would still need to be sequentially applied.

  


  Do you see anything that can be obviously optimized ?

  


• Convert AVFrame to CVPixelBufferRef to use in function CVOpenGLESTextureCacheCreateTextureFromImage

  7 juin 2013, par hard gamer

  I've a custom video player on iOS platform, I read many threads for performance tuning about using CVOpenGLESTextureCacheCreateTextureFromImage API. But, this API is always used with Apple decoders, so as Apple decoders provide CVPixelBufferRef, I can not find any way to convert ffmpeg's AVFrame to CVPixelBufferRef...

  Can anyone guide me for this topic ?

  Is it possible to use CVOpenGLESTextureCacheCreateTextureFromImage API for AVFrames of ffmpeg ? If yes, how ?