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Class: ActiveStorage::Previewer::VideoPreviewer

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
self, ::ActiveStorage::Previewer
Instance Chain:
self, ::ActiveStorage::Previewer
Inherits: ActiveStorage::Previewer
Defined in: activestorage/lib/active_storage/previewer/video_previewer.rb

Class Attribute Summary

Class Method Summary

::ActiveStorage::Previewer - Inherited

.accept?

Implement this method in a concrete subclass.
.new

Instance Attribute Summary

::ActiveStorage::Previewer - Inherited

#blob

Instance Method Summary

::ActiveStorage::Previewer - Inherited

#preview

Override this method in a concrete subclass.
#capture,
#download_blob_to_tempfile

Downloads the blob to a tempfile on disk.
#draw

Executes a system command, capturing its binary output in a tempfile.
#instrument, #logger, #open_tempfile, #service_name, #tmpdir

Constructor Details

This class inherits a constructor from ActiveStorage::Previewer

Class Attribute Details

.ffmpeg_exists? ⇒ Boolean (readonly)

[ GitHub ] 

  


# File 'activestorage/lib/active_storage/previewer/video_previewer.rb', line 12



def ffmpeg_exists?
  return @ffmpeg_exists unless @ffmpeg_exists.nil?

  @ffmpeg_exists = system(ffmpeg_path, "-version", out: File::NULL, err: File::NULL)
end


  







Class Method Details



  

    .accept?(blob)  ⇒ Boolean 
  



  

    
  





  


  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/previewer/video_previewer.rb', line 8



def accept?(blob)
  blob.video? && ffmpeg_exists?
end


  








  

    .ffmpeg_path  
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/previewer/video_previewer.rb', line 18



def ffmpeg_path
  ActiveStorage.paths[:ffmpeg] || "ffmpeg"
end


  







Instance Method Details



  

    #draw_relevant_frame_from(file, &block)   (private)
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/previewer/video_previewer.rb', line 32



def draw_relevant_frame_from(file, &block)
  draw self.class.ffmpeg_path, "-i", file.path, *Shellwords.split(ActiveStorage.video_preview_arguments), "-", &block
end


  








  

    #preview(**options)  
  

  [ GitHub ]


  

  


# File 'activestorage/lib/active_storage/previewer/video_previewer.rb', line 23



def preview(**options)
  download_blob_to_tempfile do |input|
    draw_relevant_frame_from input do |output|
      yield io: output, filename: "#{blob.filename.base}.jpg", content_type: "image/jpeg", **options
    end
  end
end