Add field name for subtitles

Co-authored by: pukkandan, tpikonen

Based on: yt-dlp#310, ytdl-org/youtube-dl#26112

yt_dlp/YoutubeDL.py

@@ -3005,10 +3005,17 @@ def list_subtitles(self, video_id, subtitles, name='subtitles'):
             return
         self.to_screen(
             'Available %s for %s:' % (name, video_id))
+
+        def _row(lang, formats):
+            exts, names = zip(*((f['ext'], f['name']) for f in reversed(formats)))
+            if len(set(names)) == 1:
+                names = names[:1]
+            return [lang, ', '.join(names), ', '.join(exts)]
+
         self.to_screen(render_table(
-            ['Language', 'formats'],
-            [[lang, ', '.join(f['ext'] for f in reversed(formats))]
-                for lang, formats in subtitles.items()]))
+            ['Language', 'Name', 'Formats'],
+            [_row(lang, formats) for lang, formats in subtitles.items()],
+            hideEmpty=True))
 
     def urlopen(self, req):
         """ Start an HTTP download """

yt_dlp/extractor/common.py

@@ -250,6 +250,8 @@ class InfoExtractor(object):
                     entry and one of:
                         * "data": The subtitles file contents
                         * "url": A URL pointing to the subtitles file
+                    It can optionally also have:
+                        * "name": Name or description of the subtitles
                     "ext" will be calculated from URL if missing
     automatic_captions: Like 'subtitles'; contains automatically generated
                     captions instead of normal subtitles

yt_dlp/postprocessor/ffmpeg.py

@@ -474,8 +474,7 @@ def run(self, information):
         filename = information['filepath']
 
         ext = information['ext']
-        sub_langs = []
-        sub_filenames = []
+        sub_langs, sub_names, sub_filenames = [], [], []
         webm_vtt_warn = False
         mp4_ass_warn = False
 
@@ -485,6 +484,7 @@ def run(self, information):
                 self.report_warning('JSON subtitles cannot be embedded')
             elif ext != 'webm' or ext == 'webm' and sub_ext == 'vtt':
                 sub_langs.append(lang)
+                sub_names.append(sub_info.get('name'))
                 sub_filenames.append(sub_info['filepath'])
             else:
                 if not webm_vtt_warn and ext == 'webm' and sub_ext != 'vtt':
@@ -510,10 +510,13 @@ def run(self, information):
         ]
         if information['ext'] == 'mp4':
             opts += ['-c:s', 'mov_text']
-        for (i, lang) in enumerate(sub_langs):
+        for i, (lang, name) in enumerate(zip(sub_langs, sub_names)):
             opts.extend(['-map', '%d:0' % (i + 1)])
             lang_code = ISO639Utils.short2long(lang) or lang
             opts.extend(['-metadata:s:s:%d' % i, 'language=%s' % lang_code])
+            if name:
+                opts.extend(['-metadata:s:s:%d' % i, 'handler_name=%s' % name,
+                             '-metadata:s:s:%d' % i, 'title=%s' % name])
 
         temp_filename = prepend_extension(filename, 'temp')
         self.to_screen('Embedding subtitles in "%s"' % filename)