[SponsorBlock] Support `chapter` category (#5260)

Authored by: ajayyy, pukkandan

2 files changed, 15 insertions, 11 deletions

diff --git a/yt_dlp/postprocessor/modify_chapters.py b/yt_dlp/postprocessor/modify_chapters.py
index 6959222c8..b2b1acca4 100644
--- a/yt_dlp/postprocessor/modify_chapters.py
+++ b/yt_dlp/postprocessor/modify_chapters.py
@@ -16,7 +16,7 @@ class ModifyChaptersPP(FFmpegPostProcessor):
                  *, sponsorblock_chapter_title=DEFAULT_SPONSORBLOCK_CHAPTER_TITLE, force_keyframes=False):
         FFmpegPostProcessor.__init__(self, downloader)
         self._remove_chapters_patterns = set(remove_chapters_patterns or [])
-        self._remove_sponsor_segments = set(remove_sponsor_segments or []) - set(SponsorBlockPP.POI_CATEGORIES.keys())
+        self._remove_sponsor_segments = set(remove_sponsor_segments or []) - set(SponsorBlockPP.NON_SKIPPABLE_CATEGORIES.keys())
         self._ranges_to_remove = set(remove_ranges or [])
         self._sponsorblock_chapter_title = sponsorblock_chapter_title
         self._force_keyframes = force_keyframes
@@ -99,7 +99,7 @@ class ModifyChaptersPP(FFmpegPostProcessor):
             'start_time': start,
             'end_time': end,
             'category': 'manually_removed',
-            '_categories': [('manually_removed', start, end)],
+            '_categories': [('manually_removed', start, end, 'Manually removed')],
             'remove': True,
         } for start, end in self._ranges_to_remove)
 
@@ -290,13 +290,12 @@ class ModifyChaptersPP(FFmpegPostProcessor):
             c.pop('_was_cut', None)
             cats = c.pop('_categories', None)
             if cats:
-                category = min(cats, key=lambda c: c[2] - c[1])[0]
-                cats = orderedSet(x[0] for x in cats)
+                category, _, _, category_name = min(cats, key=lambda c: c[2] - c[1])
                 c.update({
                     'category': category,
-                    'categories': cats,
-                    'name': SponsorBlockPP.CATEGORIES[category],
-                    'category_names': [SponsorBlockPP.CATEGORIES[c] for c in cats]
+                    'categories': orderedSet(x[0] for x in cats),
+                    'name': category_name,
+                    'category_names': orderedSet(x[3] for x in cats),
                 })
                 c['title'] = self._downloader.evaluate_outtmpl(self._sponsorblock_chapter_title, c.copy())
                 # Merge identically named sponsors.
diff --git a/yt_dlp/postprocessor/sponsorblock.py b/yt_dlp/postprocessor/sponsorblock.py
index d79ed7ae7..befff0e1f 100644
--- a/yt_dlp/postprocessor/sponsorblock.py
+++ b/yt_dlp/postprocessor/sponsorblock.py
@@ -14,6 +14,10 @@ class SponsorBlockPP(FFmpegPostProcessor):
     POI_CATEGORIES = {
         'poi_highlight': 'Highlight',
     }
+    NON_SKIPPABLE_CATEGORIES = {
+        **POI_CATEGORIES,
+        'chapter': 'Chapter',
+    }
     CATEGORIES = {
         'sponsor': 'Sponsor',
         'intro': 'Intermission/Intro Animation',
@@ -23,7 +27,7 @@ class SponsorBlockPP(FFmpegPostProcessor):
         'filler': 'Filler Tangent',
         'interaction': 'Interaction Reminder',
         'music_offtopic': 'Non-Music Section',
-        **POI_CATEGORIES,
+        **NON_SKIPPABLE_CATEGORIES
     }
 
     def __init__(self, downloader, categories=None, api='https://sponsor.ajay.app'):
@@ -68,12 +72,13 @@ class SponsorBlockPP(FFmpegPostProcessor):
 
         def to_chapter(s):
             (start, end), cat = s['segment'], s['category']
+            title = s['description'] if cat == 'chapter' else self.CATEGORIES[cat]
             return {
                 'start_time': start,
                 'end_time': end,
                 'category': cat,
-                'title': self.CATEGORIES[cat],
-                '_categories': [(cat, start, end)]
+                'title': title,
+                '_categories': [(cat, start, end, title)],
             }
 
         sponsor_chapters = [to_chapter(s) for s in duration_match]
@@ -89,7 +94,7 @@ class SponsorBlockPP(FFmpegPostProcessor):
         url = f'{self._API_URL}/api/skipSegments/{hash[:4]}?' + urllib.parse.urlencode({
             'service': service,
             'categories': json.dumps(self._categories),
-            'actionTypes': json.dumps(['skip', 'poi'])
+            'actionTypes': json.dumps(['skip', 'poi', 'chapter'])
         })
         for d in self._download_json(url) or []:
             if d['videoID'] == video_id: