Class: Abrizer::Canvas

Inherits:
Object
  • Object
show all
Includes:
FilepathHelpers
Defined in:
lib/abrizer/canvas.rb

Overview

Creates a IIIF Canvas JSON-LD document.

Instance Method Summary collapse

Methods included from FilepathHelpers

#audio_filepath, #audio_filepath_fragmented, #basename, #canvas_filepath, #canvas_partial_filepath, #filename_directory, #first_image_filepath, #hlsts_aac_filepath, #hlsts_aac_partial_filepath, #hlsts_filepath, #hlsts_partial_filepath, #mp4_filepath, #mp4_partial_filepath, #mpd_filepath, #mpd_partial_filepath, #output_directory, #output_directory_basename, #poster_image_filepath, #poster_partial_filepath, #sprites_filepath, #sprites_partial_filepath, #vp9_filepath, #vp9_partial_filepath, #webvtt_input_filepath

Constructor Details

#initialize(filepath, output_directory, base_url) ⇒ Canvas

TODO: allow control of items/versions listed on canvas



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# File 'lib/abrizer/canvas.rb', line 8

def initialize(filepath, output_directory, base_url)
  @filename = filepath
  @output_directory = output_directory
  @base_url = base_url
  finder = AdaptationFinder.new(@filename)
  @adaptations = finder.adaptations
end

Instance Method Details

#aac_item(json) ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 134

def aac_item(json)
  if File.exist? hlsts_aac_filepath
    json.child! do
      json.id hlsts_aac_id
      json.type "Audio"
      json.format 'audio/aac'
    end
  end
end

#canvas_id ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 185

def canvas_id
  File.join media_base_url, canvas_partial_filepath
end

#captions_item(json) ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 144

def captions_item(json)
  # TODO: update captions for multiple captions
  captions_file = File.join output_directory, 'vtt/captions.vtt'
  if File.exist? captions_file
    json.child! do
      json.id vtt_id
      json.type 'Text'
      json.format 'text/vtt'
      json.kind 'captions'
      json.label 'English captions'
      json.language 'en'
      json._comments "How make explicit how whether to use these as captions or subtitles, descriptions, or chapters?"
    end
  end
end

#create ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 16

def create
  File.open(canvas_filepath, 'w') do |fh|
    fh.puts create_json
  end
end

#create_json ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 22

def create_json
  Jbuilder.encode do |json|
    json.set! '@context', 'http://iiif.io/api/presentation/3/context.json'
    json.id canvas_id
    json.type "Canvas"
    json.width max_width
    json.height max_height
    json.duration duration
    thumbnail_json(json)
    media_json(json)
  end
end

#duration ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 221

def duration
  informer = Abrizer::FfprobeInformer.new(mp4_filename)
  informer.duration.to_f
end

#hlsts_aac_id ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 201

def hlsts_aac_id
  File.join media_base_url, hlsts_aac_partial_filepath
end

#hlsts_id ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 197

def hlsts_id
  File.join media_base_url, hlsts_partial_filepath
end

#hlsts_item(json) ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 95

def hlsts_item(json)
  if File.exist? hlsts_filepath
    json.child! do
      json.id hlsts_id
      json.type "Video"
      # TODO: or "vnd.apple.mpegURL"
      json.format "application/x-mpegURL"
      json.width max_width
      json.height max_height
    end
  end
end

#max_height ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 234

def max_height
  @adaptations.last.height
end

#max_width ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 226

def max_width
  @adaptations.last.width
end

#media_base_url ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 181

def media_base_url
  File.join @base_url, output_directory_basename
end

#media_json(json) ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 45

def media_json(json)
  json.content do
    json.child! do
      json.type "AnnotationPage"

      json.items do
        json.child! do
          json.type 'Annotation'
          json.motivation 'painting'
          json.target canvas_id
          json.body do
            json.child! do
              json.type "Choice"
              json.choiceHint 'client'
              json.items do
                mpd_item(json)
                hlsts_item(json)
                vp9_item(json)
                mp4_item(json)
                aac_item(json)
              end
            end
            json.child! do
              json.type 'Choice'
              json.choiceHint 'client'
              json.items do
                captions_item(json)
              end
            end
          end
        end
        sprites_item(json)
      end

    end
  end
end

#min_height ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 238

def min_height
  @adaptations.first.height
end

#min_width ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 230

def min_width
  @adaptations.first.width
end

#mp4_filename ⇒ Object

TODO: DRY up with progressive_mp4.rb



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# File 'lib/abrizer/canvas.rb', line 251

def mp4_filename
  File.join output_directory, "progressive.mp4"
end

#mp4_height ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 246

def mp4_height
  @adaptations[-2].height
end

#mp4_id ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 205

def mp4_id
  File.join media_base_url, mp4_partial_filepath
end

#mp4_item(json) ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 121

def mp4_item(json)
  if File.exist? mp4_filepath
    json.child! do
      json.id mp4_id
      json.type "Video"
      #TODO: add mp4 codecs
      json.format "video/mp4"
      json.width mp4_width
      json.height mp4_height
    end
  end
end

#mp4_width ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 242

def mp4_width
  @adaptations[-2].width
end

#mpd_id ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 193

def mpd_id
  File.join media_base_url, mpd_partial_filepath
end

#mpd_item(json) ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 83

def mpd_item(json)
  if File.exist? mpd_filepath
    json.child! do
      json.id mpd_id
      json.type "Video"
      json.format "application/dash+xml"
      json.width max_width
      json.height max_height
    end
  end
end

#poster_id ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 189

def poster_id
  File.join media_base_url, poster_partial_filepath
end

#sprites_id ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 217

def sprites_id
  File.join media_base_url, sprites_partial_filepath
end

#sprites_item(json) ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 160

def sprites_item(json)
  if File.exist? sprites_filepath
    json.child! do
      json.type 'Annotation'
      json.motivation 'video-thumbnails'
      json.target canvas_id
      json.body do
        json.child! do
          json.id sprites_id
          json.type 'Text'
          json.format 'text/vtt'
          json.kind 'metadata'
          json.label 'image sprite metadata'
          json._comments "How to include resources like video image sprites like those created by https://github.com/jronallo/video_sprites and used by various players?"
        end
      end

    end
  end
end

#thumbnail_json(json) ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 35

def thumbnail_json(json)
  if File.exist? poster_image_filepath
    json.thumbnail do
      json.id poster_id
      json.type 'Image'
      json.format 'image/jpeg'
    end
  end
end

#vp9_id ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 209

def vp9_id
  File.join media_base_url, vp9_partial_filepath
end

#vp9_item(json) ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 108

def vp9_item(json)
  if File.exist? vp9_filepath
    json.child! do
      json.id vp9_id
      json.type "Video"
      #TODO: add webm codecs
      json.format "video/webm"
      json.width max_width
      json.height max_height
    end
  end
end

#vtt_id ⇒ Object 



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# File 'lib/abrizer/canvas.rb', line 213

def vtt_id
  File.join media_base_url, 'vtt/captions.vtt'
end