
Recherche avancée
Autres articles (62)
-
Les vidéos
21 avril 2011, parComme les documents de type "audio", Mediaspip affiche dans la mesure du possible les vidéos grâce à la balise html5 .
Un des inconvénients de cette balise est qu’elle n’est pas reconnue correctement par certains navigateurs (Internet Explorer pour ne pas le nommer) et que chaque navigateur ne gère en natif que certains formats de vidéos.
Son avantage principal quant à lui est de bénéficier de la prise en charge native de vidéos dans les navigateur et donc de se passer de l’utilisation de Flash et (...) -
(Dés)Activation de fonctionnalités (plugins)
18 février 2011, parPour gérer l’ajout et la suppression de fonctionnalités supplémentaires (ou plugins), MediaSPIP utilise à partir de la version 0.2 SVP.
SVP permet l’activation facile de plugins depuis l’espace de configuration de MediaSPIP.
Pour y accéder, il suffit de se rendre dans l’espace de configuration puis de se rendre sur la page "Gestion des plugins".
MediaSPIP est fourni par défaut avec l’ensemble des plugins dits "compatibles", ils ont été testés et intégrés afin de fonctionner parfaitement avec chaque (...) -
Activation de l’inscription des visiteurs
12 avril 2011, parIl est également possible d’activer l’inscription des visiteurs ce qui permettra à tout un chacun d’ouvrir soit même un compte sur le canal en question dans le cadre de projets ouverts par exemple.
Pour ce faire, il suffit d’aller dans l’espace de configuration du site en choisissant le sous menus "Gestion des utilisateurs". Le premier formulaire visible correspond à cette fonctionnalité.
Par défaut, MediaSPIP a créé lors de son initialisation un élément de menu dans le menu du haut de la page menant (...)
Sur d’autres sites (10137)
-
can you help me customize the ffmpeg code ? [closed]
24 octobre 2023, par Fargo GofarI want to modify this code to change the name (a random set of characters including letters and numbers 10-20 characters long) of all videos of all extensions in the current folder :


FOR /F "tokens=*" %%G IN ('dir /b *.mp4') DO ffmpeg -i "%%G" ( YOUR COMMAND) "%%~nG_1.mp4"



-
A Comprehensive Guide to Robust Digital Marketing Analytics
30 octobre 2023, par Erin -
Python : ani.save very slow. Any alternatives to create videos ?
14 novembre 2023, par CzesklebaIm doing some simple diffusion calculations. I save 2 matrices to 2 datasets every so many steps (every 2s or so) to a single .h5 file. After that I then load the file in another script, create some figures (2 subplots etc., see/run code - i know could be prettier). Then I use matplotlib.animation to make the animation. In the code below, in the very last lines, I then run the ani.save command from matplotlib.


And that's where the problem is. The animation is created within 2 seconds, even for my longer animations (14.755 frames, done in under 2s at 8284 it/s) but after that, ani.save in line 144 takes forever (it didn't finish over night). It reserves/uses about 10gb of my RAM constantly but seemingly takes forever. If you run the code below be sure to set the frames_to_do (line 20) to something like 30 or 60 to see that it does in fact save an mp4 for shorter videos. You can set it higher to see how fast the time to save stuff increases to something unreasonable.


I've been fiddling this for 2 days now and I cant figure it out. I guess my question is : Is there any way to create the video in a reasonable time like this ? Or do I need something other than animation ?


You should be able to just run the code. Ill provide a diffusion_array.h5 with 140 frames so you dont have to create a dummy file, if I can figure out how to upload something like this safely. (The results are with dummy numbers for now, diffusion coefficients etc. are not right yet.)
I used dropbox. Not sure if thats allowed, if not I'll delete the link and uhh PM me or something ?




Here is the code :


import h5py
import matplotlib.pyplot as plt
import matplotlib.colors as mcolors
from matplotlib.animation import FuncAnimation
from tqdm import tqdm
import numpy as np


# saving the .mp4 after tho takes forever

# Create an empty figure and axis
fig, (ax1, ax2) = plt.subplots(1, 2, figsize=(16, 9), dpi=96)

# Load all saved arrays into a list
file_name = 'diffusion_array.h5'
loaded_u_arrays = []
loaded_h_arrays = []
frames_to_do = 14755 # for now like this, use # version once the slow mp4 convert is cleared up

# with h5py.File(file_name, 'r') as hf:
# for key in hf.keys():
# if key.startswith('u_snapshot_'):
# loaded_u_arrays.append(hf[key][:])
# elif key.startswith('h_snapshot_'):
# loaded_h_arrays.append(hf[key][:])

with h5py.File(file_name, 'r') as hf:
 for i in range(frames_to_do):
 target_key1 = f'u_snapshot_{i:05d}'
 target_key2 = f'h_snapshot_{i:05d}'
 if target_key1 in hf:
 loaded_u_arrays.append(hf[target_key1][:])
 else:
 print(f'Dataset u for time step {i} not found in the file.')
 if target_key2 in hf:
 loaded_h_arrays.append(hf[target_key2][:])
 else:
 print(f'Dataset h for time step {i} not found in the file.')

# Create "empty" imshow objects
# First one
norm1 = mcolors.Normalize(vmin=140, vmax=400)
cmap1 = plt.get_cmap('hot')
cmap1.set_under('0.85')
im1 = ax1.imshow(loaded_u_arrays[0], cmap=cmap1, norm=norm1)
ax1.set_title('Diffusion Heatmap')
ax1.set_xlabel('X')
ax1.set_ylabel('Y')
cbar_ax = fig.add_axes([0.05, 0.15, 0.03, 0.7])
cbar_ax.set_xlabel('$T$ / K', labelpad=20)
fig.colorbar(im1, cax=cbar_ax)


# Second one
ax2 = plt.subplot(1, 2, 2)
norm2 = mcolors.Normalize(vmin=-0.1, vmax=5)
cmap2 = plt.get_cmap('viridis')
cmap2.set_under('0.85')
im2 = ax2.imshow(loaded_h_arrays[0], cmap=cmap2, norm=norm2)
ax2.set_title('Diffusion Hydrogen')
ax2.set_xlabel('X')
ax2.set_ylabel('Y')
cbar_ax = fig.add_axes([0.9, 0.15, 0.03, 0.7])
cbar_ax.set_xlabel('HD in ml/100g', labelpad=20)
fig.colorbar(im2, cax=cbar_ax)

# General
fig.subplots_adjust(right=0.85)
time_text = ax2.text(-15, 0.80, f'Time: {0} s', transform=plt.gca().transAxes, color='black', fontsize=20)

# Annotations
# Heat 1
marker_style = dict(marker='o', markersize=6, markerfacecolor='black', markeredgecolor='black')
ax1.scatter(*[10, 40], s=marker_style['markersize'], c=marker_style['markerfacecolor'],
 edgecolors=marker_style['markeredgecolor'])
ann_heat1 = ax1.annotate(f'Temp: {loaded_u_arrays[0][40, 10]:.0f}', xy=[10, 40], xycoords='data',
 xytext=([10, 40][0], [10, 40][1] + 48), textcoords='data',
 arrowprops=dict(arrowstyle="->", connectionstyle="arc3,rad=0.3"), fontsize=12, color='black')
# Heat 2
ax1.scatter(*[140, 85], s=marker_style['markersize'], c=marker_style['markerfacecolor'],
 edgecolors=marker_style['markeredgecolor'])
ann_heat2 = ax1.annotate(f'Temp: {loaded_u_arrays[0][85, 140]:.0f}', xy=[140, 85], xycoords='data',
 xytext=([140, 85][0] + 55, [140, 85][1] + 3), textcoords='data',
 arrowprops=dict(arrowstyle="->", connectionstyle="arc3,rad=0.3"), fontsize=12, color='black')

# Diffusion 1
marker_style = dict(marker='o', markersize=6, markerfacecolor='black', markeredgecolor='black')
ax2.scatter(*[10, 40], s=marker_style['markersize'], c=marker_style['markerfacecolor'],
 edgecolors=marker_style['markeredgecolor'])
ann_diff1 = ax2.annotate(f'HD: {loaded_h_arrays[0][40, 10]:.0f}', xy=[10, 40], xycoords='data',
 xytext=([10, 40][0], [10, 40][1] + 48), textcoords='data',
 arrowprops=dict(arrowstyle="->", connectionstyle="arc3,rad=0.3"), fontsize=12, color='black')
# Diffusion 2
ax2.scatter(*[140, 85], s=marker_style['markersize'], c=marker_style['markerfacecolor'],
 edgecolors=marker_style['markeredgecolor'])
ann_diff2 = ax2.annotate(f'HD: {loaded_h_arrays[0][85, 140]:.0f}', xy=[140, 85], xycoords='data',
 xytext=([140, 85][0] + 55, [140, 85][1] + 3), textcoords='data',
 arrowprops=dict(arrowstyle="->", connectionstyle="arc3,rad=0.3"), fontsize=12, color='black')


# Function to update the animation
def update(frame, *args):
 loaded_u_array, loaded_h_array = args

 s_per_frame = 2 # during weld/cooling you save a state every 2s
 frames_to_room_temp = 7803 # that means this many frames need to be animated
 dt_big = 87 # during "just diffusion" you save every 10 frame but 87s pass in those

 # Update the time step shown
 if frame <= frames_to_room_temp:
 im1.set_data(loaded_u_array[frame])
 im2.set_data(loaded_h_array[frame])
 time_text.set_text(f'Time: {frame * s_per_frame} s')

 else:
 im1.set_data(loaded_u_array[frame])
 im2.set_data(loaded_h_array[frame])
 calc_time = int(((2 * frames_to_room_temp) + (frame - frames_to_room_temp) * 87) / 3600)
 time_text.set_text(f'Time: {calc_time} s')

 # Annotate some points
 ann_heat1.set_text(f'Temp: {loaded_u_arrays[frame][40, 10]:.0f}')
 ann_heat2.set_text(f'Temp: {loaded_u_arrays[frame][85, 140]:.0f}')
 ann_diff1.set_text(f'HD: {loaded_h_arrays[frame][40, 10]:.0f}')
 ann_diff2.set_text(f'HD: {loaded_h_arrays[frame][85, 140]:.0f}')

 return im1, im2 # Return the updated artists


# Create the animation without displaying it
ani = FuncAnimation(fig, update, frames=frames_to_do, repeat=False, blit=True, interval=1,
 fargs=(loaded_u_arrays, loaded_h_arrays)) # frames=len(loaded_u_arrays)

# Create the progress bar with tqdm
with tqdm(total=frames_to_do, desc='Creating Animation') as pbar: # total=len(loaded_u_arrays)
 for i in range(frames_to_do): # for i in range(len(loaded_u_arrays)):
 update(i, loaded_u_arrays, loaded_h_arrays) # Manually update the frame with both datasets
 pbar.update(1) # Update the progress bar

# Save the animation as a video file (e.g., MP4)
print("Converting to .mp4 now. This may take some time. This is normal, wait for Python to finish this process.")
ani.save('diffusion_animation.mp4', writer='ffmpeg', dpi=96, fps=60)

# Close the figure to prevent it from being displayed
plt.close(fig)