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• libx264 : Allow full-range yuv422 and yuv444 pixel formats

  17 mars 2015, par Carl Eugen Hoyos

  libx264 : Allow full-range yuv422 and yuv444 pixel formats
  Signed-off-by : Vittorio Giovara <vittorio.giovara@gmail.com>
  

  • [DBH] libavcodec/libx264.c

• How can I get matplotlib to show full subplots in an animation ?

  12 mars 2015, par Matt Stone

  I’m trying to write a simple immune system simulator. I’m modeling infected tissue as a simple grid of cells and various intracellular signals, and I’d like to animate movement of cells in one plot and the intensity of viral presence in another as the infection progresses. I’m doing so with the matshow function provided by matplotlib. However, when I plot the two next to each other, the full grid gets clipped unless I stretch out the window myself. I can’t address the problem at all when saving to an mp4.

  Here’s the default view, which is identical to what I observe when saving to mp4 :
  

  And here’s what it looks like after stretching out the viewer window
  

  I’m running Python 2.7.9 with matplotlib 1.4.2 on OS X 10.10.2, using ffmpeg 2.5.2 (installed via Homebrew). Below is the code I’m using to generate the animation. I tried using plt.tight_layout() but it didn’t affect the problem. If anyone has any advice as to how to solve this, I’d really appreciate it ! I’d especially like to be able to save it without viewing with plt.show(). Thanks !

  def animate(self, fname=None, frames=100):
  
      fig, (agent_ax, signal_ax) = plt.subplots(1, 2, sharey=True)
  
  
  
      agent_ax.set_ylim(0, self.grid.shape[0])
  
      agent_ax.set_xlim(0, self.grid.shape[1])
  
      signal_ax.set_ylim(0, self.grid.shape[0])
  
      signal_ax.set_xlim(0, self.grid.shape[1])
  
  
  
      agent_mat = agent_ax.matshow(self.display_grid(),
  
                                   vmin=0, vmax=10)
  
      signal_mat = signal_ax.matshow(self.signal_display(virus),
  
                                     vmin=0, vmax=20)
  
      fig.colorbar(signal_mat)
  
  
  
      def anim_update(tick):
  
          self.update()
  
          self.diffuse()
  
          agent_mat.set_data(self.display_grid())
  
          signal_mat.set_data(self.signal_display(virus))
  
          return agent_mat, signal_mat
  
  
  
      anim = animation.FuncAnimation(fig, anim_update, frames=frames,
  
                                     interval=3000, blit=False)
  
  
  
      if fname:
  
          anim.save(fname, fps=5, extra_args=['-vcodec', 'libx264'])
  
      else:
  
          plt.show()

• How to overlay only part of a video using ffmpeg or a similar tool (not the full frame) [closed]

  26 octobre 2024, par velw

  I have two videos (let's say 1.mp4 and 2.mp4). I would like to overlay only the top-right quarter of 2.mp4 onto 1.mp4.

  


  The output would be a single video with the content from 1.mp4 in the top left, bottom left and bottom right, and the content from 2.mp4 in the top right.

  


  (To be clear, I don't mean shrinking anything. The output would show only three quarters of the frame from 1.mp4 and only one quarter of the frame from 2.mp4)

  


  Is it possible to do this with ffmpeg or something similar ?