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• Importing PIL images into FFMPY/FFMPEG to save as GIF/video

  24 mai 2023, par Tricky Devil

  I would like to know how I can transfer PIL images to FFMPY to save it as video, or gif, since the PIL library's quantization method has strong quality losses in certain cases. I first do some modifications with PIL, and then want to export and save the result.

  


  I did not find any information on the topic online, beside one post with PIL to FFMPEG :
Pipe PIL images to ffmpeg stdin - Python
How could I implement something similar in FFMPY ?

  


  If I have for example this setup to begin with :

  


  import ffmpy
import PIL
from PIL import Image as Img

images = [Img.open('frame 1.png'),Img.open('frame 2.png')]#How do I convert them to FFMPEG?

#Here I modify the images using PIL

#Save with FFMPEG:
ff = ffmpy.FFmpeg(
    inputs={images ?: None},#How do I insert PIL images here?
    outputs={'output.gif': None},
    executable='ffmpeg\\bin\\ffmpeg.exe')
ff.run()


  


  How would I proceed to convert and save the images as a video using FFMPY ?
Is it possible by adding some steps inbetween ? I wouldn't want to have to save all PIL images first as images, and then import them and save them with FFMPY a second time, since that would be very time consuming with larger files.

  


• Loading and unloading C jni library based on when it's needed

  30 septembre 2014, par Alin

  I finally managed to compile ffmpeg for android and I’ve been able to use it in my app.

  Here is the scenario of my app :

  • I show the user a gridview with thumbnails of images and videos
  • the user can click on a cell and it is taken to image/video details where he can see the full image or play the video
  • the user can apply an image over an video and this is when ffmpeg is used

  So basically, the user might never actually use the watermarking option or he can do it very rare because the amount of available videos is way smaller than images.

  I am loading the ffmpeg library, first time it is needed by running :

  static {
  
       System.loadLibrary("ffmpeglib");
  
  }

  Now here are my questions :

  1. loading the library like this, uses app’s memory and resources ?
  2. can I unload the library, or better said, is it needed to unload it ? I have not found any java code like System.unloadLibrary to take care of unloading
  3. Since the library might be used rarely, wouldn’t a load => do encoding => unload be a better approach ? Or maybe having it loaded would allow easy reuse since no loading is necessary.
  4. If I use an IntentService to load the library and make the encoding, when the service completes the job, does the library gets unloaded ?

• ffmpeg - extract exact number of frames from video

  29 mars 2017, par Michael B

  I want to create a maximum of 30 images from a video (and tile them for a sprite sheet).

  I’ve tried using the ’select’ with ’mod’ but if the total number of frames does not fit neatly into the desired number of images (30) then I sometimes end up with more images, sometimes less.

  For example if my video is 72 frames long, my ’mod’ would be 72 / 30, which is 2.4.

  I’m running this from a python script so i’m doing something like the following for the filter :

  select='not(mod(n\," + str(mod) + "))'

  I think the mod has to be an integer (?) so I could either round down and use 2 which gives me 36 images or round up which gives me 24 images

  Whats the best way to get exactly 30 ? - obviously the interval wouldn’t be identical but thats fine.

  Maybe I could use a for loop to generate a list of the frames closest to the desired interval and then pass that in as the select filter ?

  e.g. to get the frames I would do something like this :

  nframes = 72 # number of frames in video
  
  outImages = 30 # number of images I want
  
  mod = float(nframes) / outImages # 2.4
  
  
  
  frames = []
  
  
  
  idx = 1
  
  
  
  while i < nframes:
  
      print str(idx) + ": " + str(math.floor(i+0.5)) 
  
      frames.append(int(math.floor(i+0.5)))
  
      idx += 1
  
      i += mod

  Then am I able to pass that (the frames list) into the ffmpeg command ? Or can I tell ffmpeg to do something similar ?