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• H.264 is patented. What happens when developing a commercial app in Android using H264 codec in ffmpeg ? [closed]

  26 mai 2013, par user1914692

  H.264 is patented.

  In countries where patents on software algorithms are upheld, vendors
  and commercial users of products that use H.264/AVC are expected to
  pay patent licensing royalties for the patented technology[14] that
  their products use.

  What happens when developing a commercial app in Android using H264 codec in ffmpeg ?

  Here there are two situations :
  (1) decode online video stream, and display it.

  (2) encode contents to a video file using H.264.

  [Update :]
  From what I googled, here are some simple pieces of information :
  (1) decode : free
  (2) encode : H.264 encoded internet video that is free to end users will never be charged royalties.
  On August 26, 2010 MPEG LA announced that H.264 encoded internet video that is free to end users will never be charged royalties. See Wiki H.264
  (3) encode : for other situations except the one in (2), I guess it might be for commercial use.

  For more, see Ref : "Know your rights : H.264, patent licensing, and you" 2010/05/04

• ffplay - how to have video and audio waveform [duplicate]

  19 février 2018, par francis

  This question already has an answer here :

  • ffplay / ffmpeg setup table with audio and video filters
    
    1 answer
    

  I’ve been trying out various commands trying to figure out how to have a stack of video and audio waveform according to : https://trac.ffmpeg.org/wiki/FancyFilteringExamples#waveform

  Video only :

  ffplay -i abc.mp4 -vf "split[a][b];[a]waveform=e=1,split=1[c];[c]crop=in_w:16:0:0,lutyuv=y=val:v=180[high]; [b][high]vstack=2"

  Audio only :

  ffplay -f lavfi 'amovie=april.flac,asplit=2[out1][a]; [a]showwaves=s=640x240[waves]; [waves] vstack[out0]'

  But there isn’t any that combines and shows the top half as video and bottom half as the audio waveform. Is it possible ?

• Screen recorder in Ubuntu using python

  3 août 2013, par mridul

  I am a hobby programmer and trying to make screen-recorder in Ubuntu using python.
  Using this code able to take screenshot.

  import wx
  
  app = wx.App(False)
  
  s = wx.ScreenDC()
  
  w, h = s.Size.Get()
  
  b = wx.EmptyBitmap(w, h)
  
  m = wx.MemoryDCFromDC(s)
  
  m.SelectObject(b)
  
  m.Blit(0, 0, w, h, s, 0, 0)
  
  m.SelectObject(wx.NullBitmap)
  
  b.SaveFile("screenshot.png", wx.BITMAP_TYPE_PNG)

  And using loop I take more pictures and create video using these screen shots.My code is given bellow,

  import wx,os
  
  app=wx.App(False)
  
  s = wx.ScreenDC()
  
  w, h = s.Size.Get()
  
  b = wx.EmptyBitmap(w, h)
  
  m = wx.MemoryDCFromDC(s)
  
  i=0
  
  while i<50:
  
     m.SelectObject(b)
  
     m.Blit(0, 0, w, h, s, 0, 0)
  
     m.SelectObject(wx.NullBitmap)
  
     b.SaveFile('{0:05d}.png'.format(i), wx.BITMAP_TYPE_PNG)
  
     i+=1
  
  os.system('ffmpeg -f image2 -r 8 -i %05d.png -vcodec mpeg4 -y movie1.mp4')
  
  i=0  
  
  while i<50:
  
     os.remove('{0:05d}.png'.format(i))
  
     i += 1   `

  In above code I take 50 pictures and store as 00000.png to 00049.png and make video using ffmpeg.
  After creating video I delete all pictures.

  Current Problems :

  • Very small delay between screen shoots. If try to record videos using this code out put is not perfect.
  • For recording long time it is not efficient. It take lot of hard drive memory to store screen shoots. And use more CPU .

  What I do for get code more efficient ? Using pure python how to create video from pictures ? Is there any alternative methods to record screen ?
  I like to improve my code.