Code changes to enable player thumbnail seekbar preview in NewPipe

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

@@ -1049,7 +1049,16 @@ public List<Frameset> getFrames() throws ExtractionException {
                 storyboardsRenderer = storyboards.getObject("playerStoryboardSpecRenderer");
             }
 
-            final String[] spec = storyboardsRenderer.getString("spec").split("\\|");
+            if (storyboardsRenderer == null) {
+                return Collections.emptyList();
+            }
+
+            final String storyboardsRendererSpec = storyboardsRenderer.getString("spec");
+            if (storyboardsRendererSpec == null) {
+                return Collections.emptyList();
+            }
+
+            final String[] spec = storyboardsRendererSpec.split("\\|");
             final String url = spec[0];
             final ArrayList<Frameset> result = new ArrayList<>(spec.length - 1);
 

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

@@ -1,18 +1,27 @@
 package org.schabi.newpipe.extractor.stream;
 
+import java.io.Serializable;
 import java.util.List;
 
-public final class Frameset {
-
-    private List<String> urls;
-    private int frameWidth;
-    private int frameHeight;
-    private int totalCount;
-    private int durationPerFrame;
-    private int framesPerPageX;
-    private int framesPerPageY;
-
-    public Frameset(List<String> urls, int frameWidth, int frameHeight, int totalCount, int durationPerFrame, int framesPerPageX, int framesPerPageY) {
+public final class Frameset implements Serializable {
+
+    private final List<String> urls;
+    private final int frameWidth;
+    private final int frameHeight;
+    private final int totalCount;
+    private final int durationPerFrame;
+    private final int framesPerPageX;
+    private final int framesPerPageY;
+
+    public Frameset(
+            final List<String> urls,
+            final int frameWidth,
+            final int frameHeight,
+            final int totalCount,
+            final int durationPerFrame,
+            final int framesPerPageX,
+            final int framesPerPageY) {
+
         this.urls = urls;
         this.totalCount = totalCount;
         this.durationPerFrame = durationPerFrame;
@@ -86,7 +95,7 @@ public int getDurationPerFrame() {
      *     <li><code>4</code>: Bottom bound</li>
      * </ul>
      */
-    public int[] getFrameBoundsAt(long position) {
+    public int[] getFrameBoundsAt(final long position) {
         if (position < 0 || position > ((totalCount + 1) * durationPerFrame)) {
             // Return the first frame as fallback
             return new int[] { 0, 0, 0, frameWidth, frameHeight };

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

@@ -335,6 +335,12 @@ private static StreamInfo extractOptionalData(StreamInfo streamInfo, StreamExtra
             streamInfo.addError(e);
         }
 
+        try {
+            streamInfo.setPreviewFrames(extractor.getFrames());
+        } catch (Exception e) {
+            streamInfo.addError(e);
+        }
+
         streamInfo.setRelatedItems(ExtractorHelper.getRelatedItemsOrLogError(streamInfo, extractor));
 
         return streamInfo;
@@ -386,6 +392,11 @@ private static StreamInfo extractOptionalData(StreamInfo streamInfo, StreamExtra
     private List<StreamSegment> streamSegments = new ArrayList<>();
     private List<MetaInfo> metaInfo = new ArrayList<>();
 
+    /**
+     * Preview frames, e.g. for the storyboard / seekbar thumbnail preview
+     */
+    private List<Frameset> previewFrames = Collections.emptyList();
+
     /**
      * Get the stream type
      *
@@ -711,6 +722,14 @@ public void setMetaInfo(final List<MetaInfo> metaInfo) {
         this.metaInfo = metaInfo;
     }
 
+    public List<Frameset> getPreviewFrames() {
+        return previewFrames;
+    }
+
+    public void setPreviewFrames(final List<Frameset> previewFrames) {
+        this.previewFrames = previewFrames;
+    }
+
     @Nonnull
     public List<MetaInfo> getMetaInfo() {
         return this.metaInfo;