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Autres articles (78)

  • Use, discuss, criticize

    13 avril 2011, par

    Talk to people directly involved in MediaSPIP’s development, or to people around you who could use MediaSPIP to share, enhance or develop their creative projects.
    The bigger the community, the more MediaSPIP’s potential will be explored and the faster the software will evolve.
    A discussion list is available for all exchanges between users.

  • Le profil des utilisateurs

    12 avril 2011, par

    Chaque utilisateur dispose d’une page de profil lui permettant de modifier ses informations personnelle. Dans le menu de haut de page par défaut, un élément de menu est automatiquement créé à l’initialisation de MediaSPIP, visible uniquement si le visiteur est identifié sur le site.
    L’utilisateur a accès à la modification de profil depuis sa page auteur, un lien dans la navigation "Modifier votre profil" est (...)

  • Configurer la prise en compte des langues

    15 novembre 2010, par

    Accéder à la configuration et ajouter des langues prises en compte
    Afin de configurer la prise en compte de nouvelles langues, il est nécessaire de se rendre dans la partie "Administrer" du site.
    De là, dans le menu de navigation, vous pouvez accéder à une partie "Gestion des langues" permettant d’activer la prise en compte de nouvelles langues.
    Chaque nouvelle langue ajoutée reste désactivable tant qu’aucun objet n’est créé dans cette langue. Dans ce cas, elle devient grisée dans la configuration et (...)

Sur d’autres sites (13104)

  • even though my code is running without an error, it does not generate plot or video. I have xming runing

    23 octobre 2017, par Amin Abbasi

    This is my first code and I am really new to coding. I am trying to create a video or just plot my code.Eeven though my code is running without an error, I can’t get the video or the plot to generate. I have xming running and I have plotted a sample to make sure it not a computer Issue. I have also tried the following on GitHub but no success :
    https://jakevdp.github.io/blog/2013/05/19/a-javascript-viewer-for-matplotlib-animations/

    # -*- coding: utf-8 -*-
    import numpy as np
    def solver(I, V, f, c, L, dt, cc, T, user_action=None):
       """Solve u_tt=c^2*u_xx + f on (0,L)x(0,T]."""
       Nt = int(round(T/dt))
       t = np.linspace(0, Nt*dt, Nt+1) # Mesh points in time
       dx = dt*c/float(cc)
       Nx = int(round(L/dx))
       x = np.linspace(0, L, Nx+1) # Mesh points in space
       C2 = cc**2 # Help variable in the scheme
       # Make sure dx and dt are compatible with x and t
       dx = x[1] - x[0]
       dt = t[1] - t[0]
       if f is None or f == 0 :
           f = lambda x, t: 0
       if V is None or V == 0:
           V = lambda x: 0
       u       = np.zeros(Nx+1) # Solution array at new time level
       u_n     = np.zeros(Nx+1) # Solution at 1 time level back
       u_nm1   = np.zeros(Nx+1) # Solution at 2 time levels back
       import time; t0 = time.clock() # Measure CPU time
       # Load initial condition into u_n
       for i in range(0,Nx+1):
           u_n[i] = I(x[i])
       if user_action is not None:
           user_action(u_n, x, t, 0)
       # Special formula for first time step
       n = 0
       for i in range(1, Nx):
           u[i] = u_n[i] + dt*V(x[i]) + \
               0.5*C2*(u_n[i-1] - 2*u_n[i] + u_n[i+1]) + \
               0.5*dt**2*f(x[i], t[n])
       u[0] = 0; u[Nx] = 0
       if user_action is not None:
           user_action(u, x, t, 1)
       # Switch variables before next step
       u_nm1[:] = u_n; u_n[:] = u
       for n in range(1, Nt):
           # Update all inner points at time t[n+1]
           for i in range(1, Nx):
               u[i] = - u_nm1[i] + 2*u_n[i] + \
                       C2*(u_n[i-1] - 2*u_n[i] + u_n[i+1]) + \
                       dt**2*f(x[i], t[n])
           # Insert boundary conditions
           u[0] = 0; u[Nx] = 0
           if user_action is not None:
               if user_action(u, x, t, n+1):
                   break
           # Switch variables before next step
           u_nm1[:] = u_n; u_n[:] = u
       cpu_time = time.clock() - t0
       return u, x, t,
    def test_quadratic():
       """Check that u(x,t)=x(L-x)(1+t/2) is exactly reproduced."""
       def u_exact(x, t):
           return x*(L-x)*(1 + 0.5*t)
       def I(x):
           return u_exact(x, 0)
       def V(x):
           return 0.5*u_exact(x, 0)
       def f(x, t):
           return 2*(1 + 0.5*t)*c**2
       L = 2.5
       c = 1.5
       cc = 0.75
       Nx = 6 # Very coarse mesh for this exact test
       dt = cc*(L/Nx)/c
       T = 18
       def assert_no_error(u, x, t, n):
           u_e = u_exact(x, t[n])
           diff = np.abs(u - u_e).max()
           tol = 1E-13
           assert diff < tol
       solver(I, V, f, c, L, dt, cc, T,
               user_action=assert_no_error)
    def viz(
       I, V, f, c, L, dt, C, T,umin, umax, animate=True, tool='matplotlib'):
       """Run solver and visualize u at each time level."""
       def plot_u_st(u, x, t, n):
           """user_action function for solver."""
           plt.plot(x, u, 'r-')
    #                 xlabel='x', ylabel='u',
    #                 axis=[0, L, umin, umax],
    #                 title='t=%f' % t[n], show=True)
           # Let the initial condition stay on the screen for 2
           # seconds, else insert a pause of 0.2 s between each plot
           time.sleep(2) if t[n] == 0 else time.sleep(0.2)
           plt.savefig('frame_%04d.png' % n) # for movie making
       class PlotMatplotlib:
           def __call__(self, u, x, t, n):
               """user_action function for solver."""
               if n == 0:
                   plt.ion()
                   self.lines = plt.plot(x, u, 'r-')
                   plt.xlabel('x'); plt.ylabel('u')
                   plt.axis([0, L, umin, umax])
                   plt.legend(['t=%f' % t[n]], loc='lower left')
               else:
                   self.lines[0].set_ydata(u)
                   plt.legend(['t=%f' % t[n]], loc='lower left')
                   plt.draw()
               time.sleep(2) if t[n] == 0 else time.sleep(0.2)
               plt.savefig('tmp_%04d.png' % n) # for movie making
       if tool == 'matplotlib':
           import matplotlib.pyplot as plt
           plot_u = PlotMatplotlib()
       elif tool == 'scitools':
           import scitools.std as plt # scitools.easyviz interface
           plot_u = plot_u_st
       import time, glob, os
       # Clean up old movie frames
       for filename in glob.glob('tmp_*.png'):
           os.remove(filename)
       # Call solver and do the simulaton
       user_action = plot_u if animate else None
       u, x, t, cpu = solver_function(
           I, V, f, c, L, dt, C, T, user_action)
       # Make video files
       fps = 4 # frames per second
       codec2ext = dict(flv='flv', libx264='mp4', libvpx='webm',
                        libtheora='ogg') # video formats
       filespec = 'tmp_%04d.png'
       movie_program = 'ffmpeg' # or 'avconv'
       for codec in codec2ext:
           ext = codec2ext[codec]
           cmd = '%(movie_program)s -r %(fps)d -i %(filespec)s '\
                 '-vcodec %(codec)s movie.%(ext)s' % vars()
           os.system(cmd)
       if tool == 'scitools':
           # Make an HTML play for showing the animation in a browser
           plt.movie('tmp_*.png', encoder='html', fps=fps,
                     output_file='movie.html')
       return cpu
  • Php - Get video duration from a file hosted on amazon S3 server

    8 mai 2017, par Michael Lee

    I am developing back-end API with php to get the duration from a video file hosted on amazon S3. The API server is hosted on amazon EC2 and the video file is uploaded on amazon S3. The problem is when I request to API server, it has to response the information of the video file hosted on amazon S3 such as duration, file size, resolution etc. At least, it must response the video. I’ve followed codes by using ffmpeg such as below, but it’s not working.

    <?php
    $file = 'https://videoapptest-bucket.s3.amazonaws.com/video/10/44__55_f03876434e48d5fed7d6982b0cf578de_u_00000.ts';
    $result = shell_exec('ffmpeg -i ' . escapeshellcmd($file) . ' 2>&1');
    preg_match('/(?<=Duration: )(\d{2}:\d{2}:\d{2})\.\d{2}/', $result, $match);
    print_r($match);
    ?>

    How can I get the video duration from a file hosted on amazon s3 with ffmpeg or another tool ?

  • Revision 67023 : manquait la requete pour creer un user sous mysql

    23 octobre 2012, par l.oiseau2nuit@… — Log

    manquait la requete pour creer un user sous mysql