Support multiple subs per lang, differentiate by name

Add a new column 'name' to --list-subs output.

Output all the subtitles for a given lang with a different 'name' with
--write-sub --sub-lang foo.

The name will be a component in the output subtitle file names, before
the language code, if it is not empty.

Also adapt ffmpeg postprocessing funcs accoordingly.

youtube_dl/YoutubeDL.py

@@ -1673,26 +1673,30 @@ class YoutubeDL(object):
 
         formats_query = self.params.get('subtitlesformat', 'best')
         formats_preference = formats_query.split('/') if formats_query else []
-        subs = {}
+        subs = collections.defaultdict(list)
         for lang in requested_langs:
             formats = available_subs.get(lang)
             if formats is None:
                 self.report_warning('%s subtitles not available for %s' % (lang, video_id))
                 continue
+            named = collections.defaultdict(list)
+            for f in formats:
+                named[f.get('name', '')].append(f)
+            for name, fmts in named.items():
                 for ext in formats_preference:
                     if ext == 'best':
-                    f = formats[-1]
+                        f = fmts[-1]
                         break
-                matches = list(filter(lambda f: f['ext'] == ext, formats))
+                    matches = [f for f in fmts if f['ext'] == ext]
                     if matches:
                         f = matches[-1]
                         break
                     else:
-                f = formats[-1]
+                        f = fmts[-1]
                         self.report_warning(
                             'No subtitle format found matching "%s" for language %s, '
                             'using %s' % (formats_query, lang, f['ext']))
-            subs[lang] = f
+                subs[lang].append(f)
         return subs
 
     def __forced_printings(self, info_dict, filename, incomplete):
@@ -1813,11 +1817,13 @@ class YoutubeDL(object):
             # that way it will silently go on when used with unsupporting IE
             subtitles = info_dict['requested_subtitles']
             ie = self.get_info_extractor(info_dict['extractor_key'])
-            for sub_lang, sub_info in subtitles.items():
+            for sub_lang, sub_info_list in subtitles.items():
+                for sub_info in sub_info_list:
                     sub_format = sub_info['ext']
-                sub_filename = subtitles_filename(filename, sub_lang, sub_format, info_dict.get('ext'))
+                    sub_name = sub_info.get('name', '')
+                    sub_filename = subtitles_filename(filename, sub_lang, sub_name, sub_format, info_dict.get('ext'))
                     if self.params.get('nooverwrites', False) and os.path.exists(encodeFilename(sub_filename)):
-                    self.to_screen('[info] Video subtitle %s.%s is already present' % (sub_lang, sub_format))
+                        self.to_screen('[info] Video subtitle %s is already present' % (sub_filename))
                     else:
                         self.to_screen('[info] Writing video subtitles to: ' + sub_filename)
                         if sub_info.get('data') is not None:
@@ -2226,10 +2232,15 @@ class YoutubeDL(object):
             return
         self.to_screen(
             'Available %s for %s:' % (name, video_id))
+        table = []
+        for lang, formats in subtitles.items():
+            named = collections.defaultdict(list)
+            for f in formats:
+                named[f.get('name', '')].append(f['ext'])
+            for name in named.keys():
+                table.append([lang, name, ', '.join(e for e in reversed(named[name]))])
         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'], table))
 
     def urlopen(self, req):
         """ Start an HTTP download """

youtube_dl/postprocessor/ffmpeg.py

@@ -385,15 +385,17 @@ class FFmpegEmbedSubtitlePP(FFmpegPostProcessor):
         filename = information['filepath']
 
         ext = information['ext']
-        sub_langs = []
+        sub_langs = set()
         sub_filenames = []
         webm_vtt_warn = False
 
-        for lang, sub_info in subtitles.items():
+        for lang, sub_info_list in subtitles.items():
+            for sub_info in sub_info_list:
                 sub_ext = sub_info['ext']
                 if ext != 'webm' or ext == 'webm' and sub_ext == 'vtt':
-                sub_langs.append(lang)
-                sub_filenames.append(subtitles_filename(filename, lang, sub_ext, ext))
+                    sub_langs.add(lang)
+                    sub_name = sub_info.get('name', '')
+                    sub_filenames.append(subtitles_filename(filename, lang, sub_name, sub_ext, ext))
                 else:
                     if not webm_vtt_warn and ext == 'webm' and sub_ext != 'vtt':
                         webm_vtt_warn = True
@@ -611,15 +613,17 @@ class FFmpegSubtitlesConvertorPP(FFmpegPostProcessor):
             return [], info
         self._downloader.to_screen('[ffmpeg] Converting subtitles')
         sub_filenames = []
-        for lang, sub in subs.items():
+        for lang, sublist in subs.items():
+            for sub in sublist:
                 ext = sub['ext']
                 if ext == new_ext:
                     self._downloader.to_screen(
                         '[ffmpeg] Subtitle file for %s is already in the requested format' % new_ext)
                     continue
-            old_file = subtitles_filename(filename, lang, ext, info.get('ext'))
+                name = sub.get('name', '')
+                old_file = subtitles_filename(filename, lang, name, ext, info.get('ext'))
                 sub_filenames.append(old_file)
-            new_file = subtitles_filename(filename, lang, new_ext, info.get('ext'))
+                new_file = subtitles_filename(filename, lang, name, new_ext, info.get('ext'))
 
                 if ext in ('dfxp', 'ttml', 'tt'):
                     self._downloader.report_warning(
@@ -636,10 +640,13 @@ class FFmpegSubtitlesConvertorPP(FFmpegPostProcessor):
                         f.write(srt_data)
                     old_file = srt_file
 
-                subs[lang] = {
+                    slist_new = [s for s in subs[lang] if s.get('name', '') != name]
+                    slist_new.append({
+                        'name': name,
                         'ext': 'srt',
                         'data': srt_data
-                }
+                    })
+                    subs[lang] = slist_new
 
                     if new_ext == 'srt':
                         continue
@@ -649,9 +656,12 @@ class FFmpegSubtitlesConvertorPP(FFmpegPostProcessor):
                 self.run_ffmpeg(old_file, new_file, ['-f', new_format])
 
                 with io.open(new_file, 'rt', encoding='utf-8') as f:
-                subs[lang] = {
+                    slist_new = [s for s in subs[lang] if s.get('name', '') != name]
+                    slist_new.append({
+                        'name': name,
                         'ext': new_ext,
                         'data': f.read(),
-                }
+                    })
+                    subs[lang] = slist_new
 
         return sub_filenames, info

youtube_dl/utils.py

@@ -3002,8 +3002,8 @@ def determine_ext(url, default_ext='unknown_video'):
         return default_ext
 
 
-def subtitles_filename(filename, sub_lang, sub_format, expected_real_ext=None):
-    return replace_extension(filename, sub_lang + '.' + sub_format, expected_real_ext)
+def subtitles_filename(filename, sub_lang, sub_name, sub_format, expected_real_ext=None):
+    return replace_extension(filename, (sub_name + '.' if sub_name else '') + sub_lang + '.' + sub_format, expected_real_ext)
 
 
 def date_from_str(date_str):