Support auto-generated captions

The caption extraction is now entirely in our own hands.

extractors/captions.py

@@ -5,7 +5,10 @@ from urllib.parse import urlencode
 import xml.etree.ElementTree as ET
 
 def extract_captions(id, **kwargs):
-	captions = extract_captions_from_api(id)
+	if "label" in kwargs and "auto-generated" in kwargs["label"]:
+		captions = extract_captions_from_video(id)
+	else:
+		captions = extract_captions_from_api(id)
 	return extract_captions_from_dict(captions, **kwargs)
 
 # Return captions for the language specified,
@@ -19,15 +22,9 @@ def extract_captions_from_dict(captions, *, lang=None, label=None):
 		r.raise_for_status()
 		return r
 
-# Currently unused in favour of extract_captions_from_api.
-def extract_captions_from_video(id):
-	return {
-		"captions": extract_video(id)["captions"]
-	}
-
-# no automatic captions
+# List of captions directly from youtube, but no automatic
 def extract_captions_from_api(id):
-	url = "https://video.google.com/timedtext?hl=en&type=list&v=%s" % id
+	url = "https://video.google.com/timedtext?hl=en&type=list&v={}".format(id)
 	with requests.get(url) as r:
 		if r.status_code == 404:
 			return {
@@ -67,3 +64,9 @@ def extract_captions_from_api(id):
 			})
 
 		return result
+
+# We'll fall back to this function for auto-captions.
+def extract_captions_from_video(id):
+	return {
+		"captions": extract_video(id)["captions"]
+	}

extractors/video.py

@@ -10,6 +10,7 @@ from tools.converters import *
 from tools.extractors import extract_yt_initial_data, extract_yt_initial_player_response
 import tools.files as files
 from math import floor
+from urllib.parse import parse_qs, urlparse, urlencode
 from cachetools import TTLCache
 
 video_cache = TTLCache(maxsize=50, ttl=300)
@@ -165,22 +166,6 @@ def extract_video(id):
 					"second__height": format["height"]
 				})
 
-		if info.get("requested_subtitles"):
-			for language_code, subtitle in info["requested_subtitles"].items():
-				if language_code == "live_chat":
-					continue
-
-				subtitle_url = subtitle["url"]
-				label = get_language_label_from_url(subtitle_url)
-				subtitle_api_url = get_subtitle_api_url(id, label, language_code)
-				result["captions"].append({
-					"label": label if label != "" else language_code,
-					"languageCode": language_code,
-					"url": subtitle_api_url,
-					"second__subtitleUrl": subtitle_url # Direct YouTube url
-				})
-
-
 		result = get_more_stuff_from_file(info["id"], result)
 
 		return result
@@ -300,6 +285,27 @@ def get_more_stuff_from_file(id, result):
 							f["qualityLabel"] = label
 						f["second__order"] = format_order(f)
 
+				for track in player_response["captions"]["playerCaptionsTracklistRenderer"]["captionTracks"]:
+					# safely editing the track format by taking apart the url...
+					url = track["baseUrl"]
+					parts = urlparse(url)
+					qs = parse_qs(parts.query)
+					qs["format"] = ["vtt"]
+					qs = urlencode(qs, doseq=True)
+					# ...and putting it back together...
+					parts = parts._replace(query=qs)
+					url = parts.geturl()
+					# now make the caption object
+					label = combine_runs(track["name"])
+					language_code = track["languageCode"]
+					subtitle_api_url = get_subtitle_api_url(id, label, language_code)
+					result["captions"].append({
+						"label": label,
+						"languageCode": language_code,
+						"url": subtitle_api_url,
+						"second__remoteUrl": url
+					})
+
 	except Exception:
 		print("messed up extracting recommendations.")
 		traceback.print_exc()

tools/converters.py

@@ -217,7 +217,7 @@ def get_subtitle_api_url(id, label, language_code):
 	subtitle_api_url = "/api/v1/captions/{}?".format(id)
 	params = {}
 
-	if label:
+	if label and "auto-generated" in label:
 		params["label"] = label
 	else:
 		params["lang"] = language_code