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• Compress Videos using FFMPEG and JNI

  1er octobre 2014, par Mr.G

  I want to create an android application which can locate a video file (which is more than 300 mb) and compress it to lower size mp4 file.

  i already tried to do it with this

  This tutorial is a very effective since you ’re compressing a small size video (below than 100 mb)

  So i tried to implement it using JNI .

  i managed to build ffmpeg using this

  But currently what I want to do is to compress videos . I don’t have very good knowledge on JNI. But i tried to understand it using following link

  If some one can guide me the steps to compress video after open file it using JNI that whould really great , thanks

• FFMPEG file writer in python 2.7

  6 avril 2017, par byBanachTarskiIamcorrect

  Trying to animate a string in python, i think my code is fine but just having difficulties with the file writer. My code is (based off https://jakevdp.github.io/blog/2012/08/18/matplotlib-animation-tutorial/) :

  import numpy as np
  
  import scipy as sci
  
  import matplotlib.pyplot as plt
  
  import matplotlib.animation as animation
  
  plt.rcParams['animation.ffmpeg_path'] = 'C:\FFMPEG\bin\ffmpeg'
  
  
  
  
  
  s1=10.15
  
  gamma=(np.pi*np.sqrt(2))/2
  
  gamma=sci.special.jn_zeros(0,10)
  
  gamma1=gamma[9]
  
  gamma2=gamma[8]
  
  print gamma1,gamma2
  
  
  
  sigma=np.linspace(0,2*s1,10000)
  
  
  
  def xprime(sigma,t):
  
      alpha = gamma1*(np.cos(np.pi*t/s1)*np.cos((np.pi*sigma)/s1))
  
      beta = gamma1*(np.sin(np.pi*t/s1)*np.sin((np.pi*sigma)/s1))
  
      xprime=np.cos(alpha)*np.cos(beta)
  
      return xprime
  
  
  
  def yprime(sigma,t):
  
      alpha = gamma2*(np.cos(np.pi*t/s1)*np.cos((np.pi*sigma)/s1))
  
      beta = gamma2*(np.sin(np.pi*t/s1)*np.sin((np.pi*sigma)/s1))
  
      yprime=np.cos(alpha)*np.sin(beta)
  
      return yprime
  
  
  
  fig = plt.figure()
  
  ax = plt.axes(xlim=(-0.4, 0.4), ylim=(-3, 3))
  
  line, = ax.plot([], [], lw=2)
  
  
  
  def init():
  
      line.set_data([], [])
  
      return line,
  
  
  
  def animate(i):
  
      sigma=np.linspace(0,2*s1,10000)
  
      t = (i*2*s1)/200
  
      yint=sci.integrate.cumtrapz(yprime(sigma,t),sigma)
  
      xint=sci.integrate.cumtrapz(xprime(sigma,t),sigma)
  
      line.set_data(xint, yint)
  
      return line,
  
  
  
  
  
  anim = animation.FuncAnimation(fig, animate, init_func=init,
  
                             frames=200, interval=20, blit=True)
  
  
  
  FFwriter=animation.FFMpegWriter()
  
  anim.save('basic_animation.mp4', writer=FFwriter, fps=30, extra_args=['-vcodec', 'libx264'])
  
  
  
  plt.show()

  Currently getting the error message

  RuntimeError: Passing in values for arguments for arguments fps, codec, bitrate, extra_args, or metadata is not supported when writer is an existing MovieWriter instance. These should instead be passed as arguments when creating the MovieWriter instance.'

  I think my error is in the calling or placement of the FFMpeg file but i’m unsure what i’m doing wrong. Probably very obvious but can’t see it at the moment / unsure what the error message actually means.

• moving text in video with ffmpeg every 3 minute and 5 minute

  21 novembre 2018, par Amy Bomer

  I have a problem. I have found a tutorial on how to add text in videos using ffmpeg. but I want every 3 minute. I get the script only 10 second 1 time. I want 3 minute 1 time.

  my script :

  ffmpeg -i input.mp4 -filter:v drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSans.ttf:text='Hello World':fontcolor=white@1.0:fontsize=16:y=h-line_h-100:x=w/10*mod(t\,10):enable=gt(mod(t\,20)\,10)" -codec:v libx264 -codec:a copy -y output.mp4

  source of : here

  help me setting always 3 minute and speed text 10 second

  please ask for an explanation from each script above and please help so that every 3 minute the text appears

  thank you