Add support for timedtext captions

src/invidious/routes/api/v1/videos.cr

@@ -90,6 +90,10 @@ module Invidious::Routes::API::V1::Videos
     # as well as some other markup that makes it cumbersome, so we try to fix that here
     if caption.name.includes? "auto-generated"
       caption_xml = YT_POOL.client &.get(url).body
+
+      if caption_xml.starts_with?("<?xml")
+      	webvtt =caption.timedtext_to_vtt(caption_xml,tlang)
+      else
 	      caption_xml = XML.parse(caption_xml)
 	
 	      webvtt = String.build do |str|
@@ -131,15 +135,21 @@ module Invidious::Routes::API::V1::Videos
 	          END_CUE
 	        end
 	      end
+	  end
     else
       # Some captions have "align:[start/end]" and "position:[num]%"
       # attributes. Those are causing issues with VideoJS, which is unable
       # to properly align the captions on the video, so we remove them.
       #
       # See: https://github.com/iv-org/invidious/issues/2391
+      webvtt = YT_POOL.client &.get("#{url}&format=vtt").body
+      if webvtt.starts_with?("<?xml")
+		webvtt = caption.timedtext_to_vtt(webvtt)
+      else
 	      webvtt = YT_POOL.client &.get("#{url}&format=vtt").body
 	        .gsub(/([0-9:.]{12} --> [0-9:.]{12}).+/, "\\1")
 	  end 
+    end
 
     if title = env.params.query["title"]?
       # https://blog.fastmail.com/2011/06/24/download-non-english-filenames/

src/invidious/videos/caption.cr

@@ -31,6 +31,59 @@ module Invidious::Videos
       return captions_list
     end
 	
+	def timedtext_to_vtt(timedtext : String, tlang = nil) : String
+		#In the future, we could just directly work with the url. This is more of a POC
+		cues = [] of XML::Node
+		tree = XML.parse(timedtext)
+		tree = tree.children.first()
+		
+		tree.children.each do |item|
+			if item.name == "body"
+				item.children.each do |cue|
+					if cue.name == "p"
+					cues << cue
+					end
+				end
+				break
+			end
+		end
+		result = String.build do |result|
+			result << <<-END_VTT
+			WEBVTT
+			Kind: captions
+			Language: #{tlang || @language_code}
+	
+	
+			END_VTT
+			cues.each_with_index do |node,i|
+				start_time = node["t"].to_f.milliseconds
+				
+				duration = node["d"]?.try &.to_f.milliseconds
+				
+				duration ||= start_time
+				
+				if cues.size > i + 1
+				  end_time = cues[i + 1]["t"].to_f.milliseconds
+				else
+				  end_time = start_time + duration
+				end
+				
+				start_time = "#{start_time.hours.to_s.rjust(2, '0')}:#{start_time.minutes.to_s.rjust(2, '0')}:#{start_time.seconds.to_s.rjust(2, '0')}.#{start_time.milliseconds.to_s.rjust(3, '0')}"
+				
+				end_time = "#{end_time.hours.to_s.rjust(2, '0')}:#{end_time.minutes.to_s.rjust(2, '0')}:#{end_time.seconds.to_s.rjust(2, '0')}.#{end_time.milliseconds.to_s.rjust(3, '0')}"
+				text = String.build do |text|
+					node.children.each do |s|
+						text << s.content
+					end
+				end
+				result << start_time + " --> " + end_time + "\n"
+				result << text + "\n"
+				result << "\n"
+			end
+		end
+		return result
+	end
+	
     # List of all caption languages available on Youtube.
     LANGUAGES = {
       "",
@@ -164,5 +217,6 @@ module Invidious::Videos
       "Yoruba",
       "Zulu",
     }
+    	
   end
 end