Recherche avancée

Sur d’autres sites (6996)

• matplotlib ArtistAnimation returns a blank video

  28 mars 2017, par Mpaull

  I’m trying to produce an animation of a networkx graph changing over time. I’m using the networkx_draw utilities to create matplotlib figures of the graph, and matplotlib’s ArtistAnimation module to create an animation from the artists networkx produces. I’ve made a minimum reproduction of what I’m doing here :

  import numpy as np
  
  import networkx as nx
  
  import matplotlib.animation as animation
  
  import matplotlib.pyplot as plt
  
  
  
  # Instantiate the graph model
  
  G = nx.Graph()
  
  G.add_edge(1, 2)
  
  
  
  # Keep track of highest node ID
  
  G.maxNode = 2
  
  
  
  fig = plt.figure()
  
  nx.draw(G)
  
  ims = []
  
  
  
  for timeStep in xrange(10):
  
  
  
      G.add_edge(G.maxNode,G.maxNode+1)
  
      G.maxNode += 1
  
  
  
      pos = nx.drawing.spring_layout(G)
  
      nodes = nx.drawing.draw_networkx_nodes(G, pos)
  
      lines = nx.drawing.draw_networkx_edges(G, pos)
  
  
  
      ims.append((nodes,lines,))
  
      plt.pause(.2)
  
      plt.cla()
  
  
  
  im_ani = animation.ArtistAnimation(fig, ims, interval=200,            repeat_delay=3000,blit=True)
  
  im_ani.save('im.mp4', metadata={'artist':'Guido'})

  The process works fine while displaying the figures live, it produces exactly the animation I want. And it even produces a looping animation in a figure at the end of the script, again what I want, which would suggest that the animation process worked. However when I open the "im.mp4" file saved to disk, it is a blank white image which runs for the expected period of time, never showing any of the graph images which were showed live.

  I’m using networkx version 1.11, and matplotlib version 2.0. I’m using ffmpeg for the animation, and am running on a Mac, OSX 10.12.3.

  What am I doing incorrectly ?

• Validation failed : Video Paperclip::Errors::NotIdentifiedByImageMagickError

  28 mars 2017, par ACIDSTEALTH

  I have a model with an attached video. I want to create a scaled version of the video along with a series of thumbnails. I have the following setup :

  has_attached_file :video,
  
      styles: {
  
          original: { format: 'mp4', processors: [:transcoder] },
  
          large: { geometry: "720x720", format: 'jpg', processors: [:thumbnail] },
  
          medium: { geometry: "540x540", format: 'jpg', processors: [:thumbnail] },
  
          thumb: { geometry: "180x180", format: 'jpg', processors: [:thumbnail] }
  
      },
  
      default_url: ""

  When I test this in my development environment it works perfectly. The video and all images are correctly sized. When I deploy to Heroku however, I get the following error :

  Validation failed: Video Paperclip::Errors::NotIdentifiedByImageMagickError
  
  /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.2/lib/active_record/validations.rb:78:in `raise_validation_error'
  
  /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.2/lib/active_record/validations.rb:50:in `save!'
  
  /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.2/lib/active_record/attribute_methods/dirty.rb:30:in `save!'
  
  /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.2/lib/active_record/transactions.rb:324:in `block in save!'
  
  /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.2/lib/active_record/transactions.rb:395:in `block in with_transaction_returning_status'
  
  /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.2/lib/active_record/connection_adapters/abstract/database_statements.rb:232:in `block in transaction'
  
  /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.2/lib/active_record/connection_adapters/abstract/transaction.rb:189:in `within_new_transaction'
  
  /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.2/lib/active_record/connection_adapters/abstract/database_statements.rb:232:in `transaction'
  
  /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.2/lib/active_record/transactions.rb:211:in `transaction'
  
  /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.2/lib/active_record/transactions.rb:392:in `with_transaction_returning_status'
  
  /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.2/lib/active_record/transactions.rb:324:in `save!'
  
  /app/vendor/bundle/ruby/2.3.0/gems/activerecord-5.0.2/lib/active_record/suppressor.rb:45:in `save!'
  
  /app/app/models/concerns/snapshot_methods.rb:37:in `copy_from_ziggeo!'
  
  /app/app/workers/snapshot_transcoder.rb:16:in `perform'
  
  /app/vendor/bundle/ruby/2.3.0/gems/resque-status-0.5.0/lib/resque/plugins/status.rb:161:in `safe_perform!'
  
  /app/vendor/bundle/ruby/2.3.0/gems/resque-status-0.5.0/lib/resque/plugins/status.rb:137:in `perform'

  What am I missing here ? I’ve searched for NotIdentifiedByImageMagickError and scanned numerous other questions on this issue, but have not had any success fixing my problem.

  Most of the solutions I’ve seen involve setting Paperclip.options[:command_path] = "/usr/bin/identify" in development. Since my problem is only on production, I tried applying this to production, subbing in the correct path for my production environment, like so :

  Paperclip.options[:command_path] = "/app/vender/imagemagick/bin/identify"

  This had no effect. Neither did /app/vender/imagemagick/bin.

• Paperclip geometry ignored

  27 mars 2017, par ACIDSTEALTH

  I have a model called Snapshot, which represents a user-recorded video. I want to take the input video file and scale it to fit within a 720x720 box (ImageMagick documentation). I then want to capture some screenshots of the video to represent it in my app. These sizes are specified accordingly in my model.

  I expect the output of this to be an original video with a maximum width of 720px (assuming it was recorded in landscape mode), a large JPG image with a maximum width of 540px, etc.

  When I attach the video file and save the model, the images and video file are processed but the result is not what I expected. The video file has a resolution of 960x720 and the images are all square (540x540, 360x360, etc).

  I’m not sure if I’m doing something wrong or if this is just a bug with Paperclip. Here is my code :

  class Snapshot < ApplicationRecord
  
      has_attached_file :video,
  
          styles: {
  
              original: { geometry: "720x720", format: 'mp4' },
  
              large: { geometry: "540x540", format: 'jpg' },
  
              medium: { geometry: "360x360", format: 'jpg' },
  
              thumb: { geometry: "180x180", format: 'jpg' }
  
          },
  
          default_url: "", processors: [:transcoder]
  
      validates_attachment_content_type :video, content_type: /\Avideo\/.*\Z/
  
      validates_attachment_size :video, less_than: 100.megabytes
  
  end

  I have also tried adjusting the geometry to 720x720>, 540x540>, etc. When I did this, the attachments’ resolution was unchanged, which seems to go completely against my understanding of how ImageMagick geometry works. I have numerous other models with image-only attachments that do not suffer from this issue.

  Here is a snippet from my Gemfile.lock so you can see which versions I am running :

  delayed_paperclip (3.0.1)
  
    activejob (>= 4.2)
  
    paperclip (>= 3.3)
  
  paperclip (5.1.0)
  
    activemodel (>= 4.2.0)
  
    activesupport (>= 4.2.0)
  
    cocaine (~> 0.5.5)
  
    mime-types
  
    mimemagic (~> 0.3.0)
  
  paperclip-av-transcoder (0.6.4)
  
    av (~> 0.9.0)
  
    paperclip (>= 2.5.2)
  
  paperclip-optimizer (2.0.0)
  
    image_optim (~> 0.19)
  
    paperclip (>= 3.4)

  Update
  I retried this with a video recorded in portrait mode (iPhone 6 front-facing webcam) and the video file’s output size was 720x720. The images were still square as before.