Dev2.7 heuristic thumbnails

record-and-playback/core/lib/recordandplayback/generators/presentation.rb

@@ -23,6 +23,16 @@
 require 'rubygems'
 require 'nokogiri'
 
+class Range
+  def intersection(other)
+    raise ArgumentError, 'value must be a Range' unless other.kind_of?(Range)
+    new_min = self.cover?(other.min) ? other.min : other.cover?(min) ? min : nil
+    new_max = self.cover?(other.max) ? other.max : other.cover?(max) ? max : nil
+    new_min && new_max ? new_min..new_max : nil
+  end
+  alias_method :&, :intersection
+end
+
 module BigBlueButton
   class Presentation
     # Get the presentations.
@@ -110,35 +120,81 @@ def self.get_text_from_slide(textfiles_dir, slide_num)
     end
 
     # Get from events the presentation that will be used for preview.
-    def self.get_presentation_for_preview(process_dir)
+    def self.get_presentation_for_preview(process_dir, heuristic_thumbnails, number_thumbnails)
       events_xml = "#{process_dir}/events.xml"
       BigBlueButton.logger.info("Task: Getting from events the presentation to be used for preview")
-      presentation = {}
+      presentation = []
       doc = Nokogiri::XML(File.open(events_xml))
       presentation_filenames = {}
       doc.xpath("//event[@eventname='ConversionCompletedEvent']").each do |conversion_event|
         presentation_filenames[conversion_event.xpath("presentationName").text] = conversion_event.xpath("originalFilename").text
       end
-      doc.xpath("//event[@eventname='SharePresentationEvent']").each do |presentation_event|
-        # Extract presentation data from events
-        presentation_id = presentation_event.xpath("presentationName").text
-        presentation_filename = presentation_filenames[presentation_id]
-        # Set textfile directory
-        textfiles_dir = "#{process_dir}/presentation/#{presentation_id}/textfiles"
-        # Set presentation hashmap to be returned
-        unless presentation_filename == "default.pdf"
-          presentation[:id] = presentation_id
-          presentation[:filename] = presentation_filename
-          presentation[:slides] = {}
-          for i in 1..3
-            if File.file?("#{textfiles_dir}/slide-#{i}.txt")
-              text_from_slide = self.get_text_from_slide(textfiles_dir, i)
-              presentation[:slides][i] = { :alt => text_from_slide == nil ? '' : text_from_slide }
+      sesseion_end = doc.xpath('//event[last()]')[0].attributes['timestamp'].value.to_i
+      slide_events = doc.xpath("//event[@eventname='GotoSlideEvent']")
+      slide_time = {}
+      current_slide = nil
+      current_ts = nil
+      slide_events.each_with_index do |e, i|
+        if i > 0
+          time_shown = current_ts..e.attributes["timestamp"].value.to_i
+          if slide_time[current_slide]
+            slide_time[current_slide].push(time_shown)
+          else
+            slide_time[current_slide] = [time_shown]
+          end
+        end
+        current_slide = e.at('id').text
+        current_ts = e.attributes["timestamp"].value.to_i
+      end
+      if current_ts
+        time_shown = current_ts..sesseion_end
+        if slide_time[current_slide]
+          slide_time[current_slide].push(time_shown)
+        else
+          slide_time[current_slide] = [time_shown]
+        end
+      end
+      #BigBlueButton.logger.info("slide_time: #{slide_time}")
+
+      record_time = []
+      record_events = doc.xpath("//event[@eventname='RecordStatusEvent']")
+      record_events.each_with_index do |e, i|
+        if i.odd?
+          record_time.push(record_events[i-1].attributes["timestamp"].value.to_i..e.attributes["timestamp"].value.to_i)
+        end
+      end
+      if record_events.size.odd?
+        record_time.push(record_events[-1].attributes["timestamp"].value.to_i..sesseion_end)
+      end
+      #BigBlueButton.logger.info("record_time: #{record_time}")
+
+      # Intersect with the recorded periods
+      slide_time_recorded = {}
+      slide_time.each do |id, periods|
+        periods.each do |period|
+          record_time.each do |record|
+            intersected_period = period.intersection(record)
+            if slide_time_recorded[id]
+              slide_time_recorded[id].push(intersected_period)
+            else
+              slide_time_recorded[id] = [intersected_period]
             end
           end
-          # Break because something else than default.pdf was found
-          break
         end
+        slide_time_recorded[id].compact! if slide_time_recorded[id]
+      end
+      #BigBlueButton.logger.info("slide_time_recorded: #{slide_time_recorded}")
+
+      slide_time_sort = slide_time_recorded.map{|k, v| [k, v.inject(0){|s, n| s += n.size}] }.sort_by{|_, v| -v} if heuristic_thumbnails
+      BigBlueButton.logger.info("Thumbnail candidates: #{slide_time_sort}")
+      slide_time_sort.each do |st|
+        break if presentation.size >= number_thumbnails
+        p, s = st[0].split('/')
+        presentation_filename = presentation_filenames[p]
+        next if presentation_filename == "default.pdf"
+        textfiles_dir = "#{process_dir}/presentation/#{p}/textfiles"
+        text_from_slide = self.get_text_from_slide(textfiles_dir, s) if File.file?("#{textfiles_dir}/slide-#{s}.txt")
+        presentation.push({ :id => p, :filename => presentation_filename, :i => s, :alt => text_from_slide == nil ? '' : text_from_slide, :duration => st[1] })
       end
       presentation
     end

record-and-playback/presentation/scripts/presentation.yml

@@ -11,6 +11,10 @@ deskshare_output_framerate: 5
 audio_offset: 0
 include_deskshare: true
 
+# Generate thumbnails from most viewed slides
+heuristic_thumbnails: false
+number_thumbnails: 3
+
 # For PRODUCTION
 publish_dir: /var/bigbluebutton/published/presentation
 video_formats:

record-and-playback/presentation/scripts/publish/presentation.rb

@@ -1388,7 +1388,7 @@ def copy_media_files_helper(media, media_files, package_dir)
         ## Remove empty playback
         metadata.search('recording/playback').each(&:remove)
         ## Add the actual playback
-        presentation = BigBlueButton::Presentation.get_presentation_for_preview(@process_dir.to_s)
+        presentation = BigBlueButton::Presentation.get_presentation_for_preview(@process_dir.to_s, @presentation_props['heuristic_thumbnails'], @presentation_props['number_thumbnails'])
         Nokogiri::XML::Builder.with(metadata.at('recording')) do |xml|
           xml.playback do
             xml.format('presentation')
@@ -1399,10 +1399,10 @@ def copy_media_files_helper(media, media_files, package_dir)
               xml.extensions do
                 xml.preview do
                   xml.images do
-                    presentation[:slides].each do |key, val|
-                      attributes = { width: '176', height: '136', alt: val[:alt]&.to_s || '' }
+                    presentation.each do |p|
+                      attributes = { width: '176', height: '136', alt: p[:alt]&.to_s || '', duration: p[:duration]/1000 }
                       xml.image(attributes) do
-                        xml.text("#{playback_protocol}://#{playback_host}/presentation/#{@meeting_id}/presentation/#{presentation[:id]}/thumbnails/thumb-#{key}.png")
+                        xml.text("#{playback_protocol}://#{playback_host}/presentation/#{@meeting_id}/presentation/#{p[:id]}/thumbnails/thumb-#{p[:i]}.png")
                       end
                     end
                   end