Add get subtitle with type support.

fetchYoutubeSubtitle.py

@@ -1,16 +1,51 @@
 import json
+import math
+import time
 from typing import Optional
+import xml.etree.ElementTree as ElementTree
+from html import unescape
 import yt_dlp
 
-def getVttUrlFromSubtitles(item, lang='en', vttType="vtt"):
+# yt-dlp subtitle types: json3,srv1,srv2,srv3,ttml,vtt, xml(youtube url with out extargs)
+
+# "subtitles": {
+#     "live_chat": [
+#       {
+#         "url": "https://www.youtube.com/watch?v=ANtM2bHRz04&bpctr=9999999999&has_verified=1",
+#         "ext": "json",
+#         "video_id": "ANtM2bHRz04",
+#         "protocol": "youtube_live_chat_replay"
+#       }
+#     ]
+#   }
+def getUrlFromSubtitles(item, lang='en', subType="vtt"):
     langs = item.keys()
-    key = lang if lang in langs else ('en' if 'en' in langs else list(langs)[0] )
-    for subtitle in item[key]:
-        if(subtitle.get("ext") == vttType):
+    if len(langs) == 0:
+        return None
+
+    l = lang if lang in langs else ('en' if 'en' in langs else list(langs)[0] )
+    print("getUrlFromSubtitles l: %s, item: %s" % (l, item))
+
+    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"),"")
+        if subtitle.get("ext") == subType:
             return subtitle.get("url")
     return None
 
-async def fetchSubtitle(url: str, lang: Optional[str] = 'en', vttType="vtt") -> Optional[str]:
+async def fetchSubtitle(url: str, lang: Optional[str] = 'en', subType: Optional[str] = "vtt") -> Optional[str]:
+    if subType == "srt":
+        subtitle = await fetchSubtitlebyType(url, lang, subType, True)
+        if subtitle:
+            return subtitle
+        subtitle = await fetchSubtitlebyType(url, lang, "xml", True)
+        print(subtitle)
+        return xml_caption_to_srt(subtitle)
+    else:
+        return await fetchSubtitlebyType(url, lang, subType, True)
+
+async def fetchSubtitlebyType(url: str, lang: Optional[str] = 'en', subType="vtt", decode: bool = False) -> Optional[str]:
     ydl_opts = {
         "writesubtitles": True,
         "allsubtitles": True,
@@ -21,19 +56,53 @@ async def fetchSubtitle(url: str, lang: Optional[str] = 'en', vttType="vtt") ->
 
     with yt_dlp.YoutubeDL(ydl_opts) as ydl:
         info_dict = ydl.extract_info(url, download=False)
-        if info_dict.get("subtitles"):
-            # get first available subtitle
-            subtitle_url = getVttUrlFromSubtitles(info_dict.get("subtitles"), lang, vttType)
-            if subtitle_url:
-                with ydl.urlopen(subtitle_url) as subtitle:
-                    return subtitle.read().decode()
-        if info_dict.get("automatic_captions"):
-            subtitle_url = getVttUrlFromSubtitles(info_dict.get("automatic_captions"), lang, vttType)
-            if subtitle_url:
-                with ydl.urlopen(subtitle_url) as subtitle:
-                    return subtitle.read().decode()
+        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:
+                    with ydl.urlopen(subtitle_url) as subtitle:
+                        return subtitle.read().decode() if decode else subtitle.read()
+
     return None
 
+def float_to_srt_time_format(d: float) -> str:
+    """Convert decimal durations into proper srt format.
+    :rtype: str
+    :returns:
+        SubRip Subtitle (str) formatted time duration.
+    float_to_srt_time_format(3.89) -> '00:00:03,890'
+    """
+    fraction, whole = math.modf(d)
+    time_fmt = time.strftime("%H:%M:%S,", time.gmtime(whole))
+    ms = f"{fraction:.3f}".replace("0.", "")
+    return time_fmt + ms
+
+def xml_caption_to_srt( xml_captions: str) -> str:
+    """Convert xml caption tracks to "SubRip Subtitle (srt)".
+    :param str xml_captions:
+        XML formatted caption tracks.
+    """
+    segments = []
+    root = ElementTree.fromstring(xml_captions)
+    for i, child in enumerate(list(root)):
+        text = child.text or ""
+        caption = unescape(text.replace("\n", " ").replace("  ", " "),)
+        try:
+            duration = float(child.attrib["dur"])
+        except KeyError:
+            duration = 0.0
+        start = float(child.attrib["start"])
+        end = start + duration
+        sequence_number = i + 1  # convert from 0-indexed to 1.
+        line = "{seq}\n{start} --> {end}\n{text}\n".format(
+            seq=sequence_number,
+            start=float_to_srt_time_format(start),
+            end=float_to_srt_time_format(end),
+            text=caption,
+        )
+        segments.append(line)
+    return "\n".join(segments).strip()
+
 async def fetchSubtitleUrls(url: str) -> json:
     ydl_opts = {
         "writesubtitles": True,

main.py

@@ -15,8 +15,8 @@ def read_json():
 
 
 @app.get("/subtitle/")
-async def get_subtitle(url: str):
-    subtitle = await fetchSubtitle(url)
+async def get_subtitle(url: str, subtype: str="srt"):
+    subtitle = await fetchSubtitle(url,subType=subtype)
     return JSONResponse(content=subtitle)