added isLiveDvrEnabled to YoutubeStreamExtractor

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/extractors/YoutubeStreamExtractor.java

@@ -1579,6 +1579,11 @@ public class YoutubeStreamExtractor extends StreamExtractor {
                 .getArray("contents"));
     }
 
+    @Override
+    public boolean isLiveDvrEnabled() throws ParsingException {
+        return playerResponse.getObject("videoDetails").getBoolean("isLiveDvrEnabled");
+    }
+
     /**
      * Enable or disable the fetch of the Android client for all stream types.
      *

extractor/src/main/java/org/schabi/newpipe/extractor/stream/StreamExtractor.java

@@ -581,6 +581,15 @@ public abstract class StreamExtractor extends Extractor {
         return false;
     }
 
+    /**
+     * Whether the stream is scrubbable backwards.
+     *
+     * @return whether the stream is scrubbable backwards
+     */
+    public boolean isLiveDvrEnabled() throws ParsingException {
+        return false;
+    }
+
     public enum Privacy {
         PUBLIC,
         UNLISTED,

extractor/src/main/java/org/schabi/newpipe/extractor/stream/StreamInfo.java

@@ -273,6 +273,11 @@ public class StreamInfo extends Info {
         } catch (final Exception e) {
             streamInfo.addError(e);
         }
+        try {
+            streamInfo.setLiveDvrEnabled(extractor.isLiveDvrEnabled());
+        } catch (final Exception e) {
+            streamInfo.addError(e);
+        }
 
         // Additional info
         try {
@@ -381,6 +386,7 @@ public class StreamInfo extends Info {
     private List<StreamSegment> streamSegments = List.of();
     private List<MetaInfo> metaInfo = List.of();
     private boolean shortFormContent = false;
+    private boolean isLiveDvrEnabled = false;
 
     /**
      * Preview frames, e.g. for the storyboard / seekbar thumbnail preview
@@ -727,4 +733,12 @@ public class StreamInfo extends Info {
     public void setShortFormContent(final boolean isShortFormContent) {
         this.shortFormContent = isShortFormContent;
     }
+
+    public boolean isLiveDvrEnabled() {
+        return isLiveDvrEnabled;
+    }
+
+    public void setLiveDvrEnabled(final boolean isLiveDvrEnabled) {
+        this.isLiveDvrEnabled = isLiveDvrEnabled;
+    }
 }