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• Use wmode:transparent

  7 juin 2010, par Scott Schiller

  m demo/animation-2a/index.html Use wmode:transparent

• Video from images in Python

  26 février 2018, par R. Patterson

  I can draw a series of images using plt.draw() and plt.pause() so it produces something similar to an animation in the python window. I have modified each of the images with various labels, drawings etc.

  import numpy as np
  
  from PIL import Image
  
  import matplotlib.pyplot as plt
  
  import math
  
  
  
  def display(Intensity):
  
      l = plt.Line2D(Intensity[0],Intensity[1],color='yellow') #draw ROI/IAL
  
      ax = plt.gca()
  
      ax.add_line(l)
  
      plt.axis('off')
  
      plt.pause(0.05)
  
      plt.draw()
  
      plt.clf()
  
  
  
  #rotate region of interest
  
  def rotate(origin,Intensity,increment):
  
      ox, oy = origin #coordinates of centre or rotation
  
      x_points=[]
  
      y_points=[]
  
      angle=math.radians(increment)#change in angle between each image
  
      for i in range(0,len(Intensity[0])):
  
          px, py = Intensity[0][i], Intensity[1][i]
  
          qx = ox+math.cos(angle)*(px-ox)-math.sin(angle)*(py-oy)
  
          x_points.append(qx)
  
          qy = oy+math.sin(angle)*(px-ox)+math.cos(angle)*(py-oy)
  
          y_points.append(qy)
  
      rotatecoordinates=[]
  
      rotatecoordinates.append(x_points)
  
      rotatecoordinates.append(y_points)
  
      return rotatecoordinates
  
  
  
  def animation(list, Intensity):
  
      inc=0
  
      for value in list:
  
          item = np.array(value)
  
          rotated=rotate([128,128],Intensity,inc)
  
          im=plt.imshow(item, interpolation='nearest')
  
          display(rotated)
  
          inc+=1
  
  
  
  Image_list=[]
  
  for i in range(0,50):
  
      array=np.linspace(0,1,256*256)
  
      mat=np.reshape(array,(256,256))
  
      img=Image.fromarray(np.uint8(mat*255),'L') #create images
  
      Image_list.append(img)
  
  
  
  myROI=([100,150,150,100,100],[100,100,150,150,100]) #region of interest on image
  
  animation(Image_list,myROI)

  I would like to produce a video file using the images produced. I can’t use the module imageio, imagemagick, opencv, cv2 etc. I think ffmpeg would work, I have the following code.

  def save():
  
      os.system("ffmpeg -r 1 -i img%01d.png -vcodec mpeg4 -y movie.mp4") 

  I don’t understand how to use it in relation to the code I already have. It doesn’t take any arguments, how would I relate it to the images I have ? I know how to use imagej/fiji to produce videos from images but I would like to do this in python and also it runs out of memory (I have a lot of images, over 2000). Any help would be appreciated, thank you.

• how to reencode with ffmpeg (with limited x264)

  26 mai 2012, par sarfraz

  Until now I used this script to reencode my rips for my box (tv decoder) :

  ^_^ ( ~ ) -> cat ~/++/src/convert.sh 
  
  #! /bin/bash
  
  
  
  name=$(path -r "$1") # it gives the file name without the extension
  
  
  
  [ "$1" = *.mp4 ] && ffmpeg -i "$name".mp4 -vcodec copy -acodec copy "$name".mkv
  
  x264 --preset veryfast --tune animation --crf 18 --vf resize:720,576,16:15 -o "$name".tmp.mkv "$name".mkv
  
  mkvmerge -o "$name [freeplayer sd]".mkv "$name".tmp.mkv --no-video "$1"
  
  rm -rf "$name".tmp.mkv
  
  [ "$1" = *.mp4 ] && rm -rf "$name".mkv
  
  exit 0
  
  
  
  #EOF

  It works on my ubuntu and archlinux laptops. But it doesn’t on my desktop witch runs fedora.
  Google says that the x264 package shiped by rpmfusion doesn,t support lavf and ffms2.
  And I cannot unistall it because smplayer (witch i like) needs it.

  Ok, so I have to compile it. Google then says "you have to build ffmpeg, ffms2 tnen x264 ensuring that the flags are correctly refered." Well, didn’t work (ffms2 cannot find LIBAV - even when I am telling where - and x264 does’t configure with lavf...)

  My question is : can I use ffmpeg alone to do what my script does.
  I have ffmpeg version 0.8.11, x264 0.116.2048 59cb2eb and gcc : 4.6.1 20110804 (Red Hat 4.6.1-7)

  Any hint wound be appreciated.

  EDIT : Ok, I found that : ffmpeg -i input file -acodec copy -vcodec libx264 -preset veryfast -tune animation [that part I don’t have] output

  PS : english is not my native, plz forgive any spelling fault.