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• FFMPEG saving frame from video works in localhost but not working in live server

  5 janvier 2018, par Mukesh

  I’m using FFMPEG to take a frame from a video. My code is working all fine in localhost but, fails to execute in server.

  Code I’m executing :

  $ffmpeg = \FFMpeg\FFMpeg::create();
  
  
  
  $video = $ffmpeg->open($File_temp_name);
  
  
  
  $video
  
       ->frame(\FFMpeg\Coordinate\TimeCode::fromSeconds(1))
  
       ->save($saveLocation);

  This code is executing fine in localhost but, when I execute the same in server it is showing an error

  Exception 'FFMpeg\Exception\RuntimeException' with message 'Unable to save framesexception 'Alchemy\BinaryDriver\Exception\ExecutionFailureException' with message 'ffmpeg failed to execute command'

  Command Getting executed is :

  '/usr/bin/ffmpeg' '-y' '-ss' '00:00:01.00' '-i' '/tmp/php02MmoD' '-vframes' '1' '-f' 'image2' '/home/project/public_html/dev/frontend/web/uploads/temp-video-frames/1499319488-act-thumbnail.jpg'

  I’ve tried to execute the command in terminal and found it executing without any error and save frame in desired location. But, when I run it through my code it is throwing above error

• Making animations by matplotlib and saving the video files

  20 janvier 2016, par Richard.L

  I have been studying the 1D wave equations and making the animation of the equation. But there are some problems when using the anim.save of animation to save the video file. I have already installed ffmpeg on my computer (a Windows machine) and set the environment variables. But it keeps telling me this :

  UserWarning: MovieWriter ffmpeg unavailable
  
  ...
  
  RuntimeError: Error creating movie, return code: 4 Try running with --verbose-debug

  

  Here is my code :

  from numpy import zeros,linspace,sin,pi
  
  import matplotlib.pyplot as mpl
  
  from matplotlib import animation
  
  mpl.rcParams['animation.ffmpeg_path'] = 'C:\\ffmpeg\\bin\\ffmpeg.exe'
  
  
  
  def I(x):
  
      return sin(2*x*pi/L)
  
  
  
  def f(x,t):
  
      return sin(0.5*x*t)
  
  
  
  def solver0(I,f,c,L,n,dt,t):
  
      # f is a function of x and t, I is a function of x
  
      x = linspace(0,L,n+1)
  
      dx = L/float(n)
  
      if dt <= 0:
  
          dt = dx/float(c)
  
      C2 = (c*dt/dx)**2
  
      dt2 = dt*dt
  
      up = zeros(n+1)
  
      u = up.copy()
  
      um = up.copy()
  
      for i in range(0,n):
  
          u[i] = I(x[i])
  
      for i in range(1,n-1):
  
          um[i] = u[i]+0.5*C2*(u[i-1] - 2*u[i] + u[i+1]) + dt2*f(x[i],t)
  
      um[0] = 0
  
      um[n] = 0    
  
      while t <= tstop:
  
          t_old = t
  
          t += dt
  
          #update all inner points:
  
          for i in range(1,n-1):
  
              up[i] = -um[i] + 2*u[i] + C2*(u[i-1] - 2*u[i] + u[i+1]) + dt2*f(x[i],t_old)    
  
          #insert boundary conditions:
  
          up[0] = 0
  
          up[n] = 0
  
          #update data structures for next step
  
          um = u.copy()
  
          u = up.copy()   
  
      return u
  
  
  
  c = 1.0 
  
  L = 10
  
  n = 100
  
  dt = 0
  
  tstop = 40
  
  
  
  fig = mpl.figure()
  
  ax = mpl.axes(xlim=(0,10),ylim=(-1.0,1.0))
  
  line, = ax.plot([],[],lw=2)
  
  
  
  def init():
  
      line.set_data([],[])
  
      return line,
  
  
  
  def animate(t):
  
      x = linspace(0,L,n+1)
  
      y = solver0(I, f, c, L, n, dt, t)
  
      line.set_data(x,y)
  
      return line,
  
  
  
  anim = animation.FuncAnimation(fig, animate, init_func=init,
  
                                 frames=200, interval=20, blit=True)
  
  
  
  anim.save('seawave_1d_ani.mp4',writer='ffmpeg',fps=30)
  
  mpl.show()

  I believe the problem is in the part of the animation instead of the three functions above. Please help me find what mistake I have made.

• Saving frames for mov file with multiple streams using python-ffmpeg

  3 novembre 2024, par Dolev Shapira

  I have a mov file with multiple video streams, and I'm trying to use ffmpeg python bindings to read each stream and save all of its frames.

  


  To do so, I've made a code similar to this one :

  


  import numpy as np
from PIL import Image
import ffmpeg

# Explore streams using probe
probe = ffmpeg.probe(file)
video_streams = [stream for stream in probe['streams'] if stream['codec_type'] == 'video']

for stream in video_streams:
    out, _ = (
        ffmpeg
        .input(file,stream_index=int(stream["index"]))
        .output('pipe:', format='rawvideo', pix_fmt='rgb24')
        .run(capture_stdout=True)
    )
    video = (
        np
        .frombuffer(out, np.uint8)
        .reshape([-1, height, width, 3])
    )
    stream_dir = video_streams_dir / int(stream["index"])
    stream_dir.mkdir(exist_ok=True)
    for i in range(video.shape[0]):
        Image.fromarray(video[i,...]).save(stream_dir / f"{video_name}__{i:04d}.jpeg")


  


  However stream_index=int(stream["index"]) appears to be an invalid parameter, so my question is, how do I specify the input stream for the input node ?

  


  Note : It works without that parameter with the first (I believe) video stream.

  


  Update : Found this thread and it appears that ffmpeg does allow it, still haven't tried implementing my own solution based on it.