Mark subtitleslangs (requested_subtitles) for try speed up.

fetchYoutubeSubtitle.py

@@ -40,15 +40,16 @@ def getUrlFromSubtitleItem(item, lang="en", subType="vtt"):
 
 def getRequestedSubtitlesUrl(info_dict, lang, subType):
     item = info_dict.get("requested_subtitles")
-    langs = item.keys()
-    for l in langs:
-        if l.startswith(lang):
-            item = {l: [item[l]]} if type(item[l]) == dict else item
-            url = getUrlFromSubtitleItem(item, l, subType)
-            if url:
-                if debug:
-                    print("getRequestedSubtitlesUrl lang:{} url:{}".format(l, url))
-                return url
+    if item:
+        langs = item.keys()
+        for l in langs:
+            if l.startswith(lang):
+                item = {l: [item[l]]} if type(item[l]) == dict else item
+                url = getUrlFromSubtitleItem(item, l, subType)
+                if url:
+                    if debug:
+                        print("getRequestedSubtitlesUrl lang:{} url:{}".format(l, url))
+                    return url
     return None
 
 
@@ -128,7 +129,7 @@ async def fetchSubtitlebyType(
         "writeautomaticsub": True,
         # "listsubtitles": True,
         # "subtitlesformat": subType, # mark due to default youtube no srt and xml format
-        "subtitleslangs": [reqLang],
+        # "subtitleslangs": [reqLang],
         "skip_download": True,
         "socket_timeout": 10,
         "extractor_retries": 0,