Add support download subType xml.

fetchYoutubeSubtitle.py

@@ -30,7 +30,8 @@ def getUrlFromSubtitles(item, lang='en', subType="vtt"):
     for subtitle in item[l]:
         # print("getUrlFromSubtitles subtitle: %s" % subtitle)
         if l != "live_chat" and subType =="xml":
-            return subtitle.get("url").replace("fmt="+subtitle.get("ext"),"")
+            # print("subtitle source url: {}".format(subtitle.get("url")))
+            return subtitle.get("url").replace("&fmt="+subtitle.get("ext"),"")
         if subtitle.get("ext") == subType:
             return subtitle.get("url")
     return None
@@ -56,15 +57,18 @@ async def fetchSubtitlebyType(url: str, lang: Optional[str] = 'en', subType="vtt
             title = info_dict.get("title", "unknow")
             seconds = info_dict.get("duration")
             duration = str(seconds) if seconds else ""
+            isSrt = False
             if info_dict.get("extractor") == "youtube" and subType == "srt":
                 subType = "xml"
+                isSrt = True
 
             for subtitle_item in ["subtitles", "automatic_captions"]: # "requested_subtitles" item is dict
                 if info_dict.get(subtitle_item):
                     subtitle_url = getUrlFromSubtitles(info_dict.get(subtitle_item), lang, subType)
                     if subtitle_url:
+                        # print("subtitle_url: {}".format(subtitle_url))
                         with ydl.urlopen(subtitle_url) as response:
-                            subtitle = xml_caption_to_srt(response.read().decode()) if subType == "xml" else response.read().decode()
+                            subtitle = xml_caption_to_srt(response.read().decode()) if isSrt else response.read().decode()
                             print("url{}, title:{}, duration:{} len(subtitle): {}".format(url, title, duration, len(subtitle)))
                             return {"title": title, "duration": duration,"subtitle": subtitle}
     except Exception as e: