[webtoons] download episode background music (#8733)

add 'bgm' option

docs/configuration.rst

@@ -6745,13 +6745,24 @@ Note
     This requires 1 additional HTTP request per submission.
 
 
+extractor.webtoons.bgm
+----------------------
+Type
+    ``bool``
+Default
+    ``true``
+Description
+    Download an episode's `background music` if available.
+Note
+    Requires |ytdl|
+
+
 extractor.webtoons.quality
 --------------------------
 Type
     * ``integer``
     * ``string``
     * ``object`` (`ext` → `type`)
-
 Default
     ``"original"``
 Example

docs/gallery-dl.conf

@@ -943,6 +943,7 @@
         {
             "sleep-request": "0.5-1.5",
 
+            "bgm"       : true,
             "quality"   : "original",
             "banners"   : false,
             "thumbnails": false

gallery_dl/extractor/webtoons.py

@@ -130,10 +130,53 @@ class WebtoonsEpisodeExtractor(WebtoonsBase, GalleryExtractor):
         return results
 
     def assets(self, page):
+        assets = []
+
         if self.config("thumbnails", False):
             active = text.extr(page, 'class="on', '</a>')
             url = _url(text.extr(active, 'data-url="', '"'))
-            return ({"url": url, "type": "thumbnail"},)
+            assets.append({"url": url, "type": "thumbnail"})
+
+        if self.config("bgm", True):
+            if bgm := text.extr(page, "episodeBgmList:", ",\n"):
+                self._asset_bgm(assets, util.json_loads(bgm))
+
+        return assets
+
+    def _asset_bgm(self, assets, bgm_list):
+        import binascii
+        params = {
+            #  "quality"     : "MIDDLE",
+            "quality"     : "HIGH",  # no difference to 'MIDDLE'
+            "acceptCodecs": "AAC,MP3",
+        }
+        headers = {
+            "Accept"        : "application/json",
+            "Content-Type"  : "application/json",
+            "Origin"        : self.root,
+            "Referer"       : self.root + "/",
+            "Sec-Fetch-Dest": "empty",
+            "Sec-Fetch-Mode": "cors",
+            "Sec-Fetch-Site": "cross-site",
+        }
+
+        for bgm in bgm_list:
+            url = (f"https://apis.naver.com/audiocweb/audiocplayogwweb/play"
+                   f"/audio/{bgm['audioId']}/hls/token")
+            data = self.request_json(
+                url, params=params, headers=headers, interval=False)
+            token = data["result"]["playToken"]
+            data = util.json_loads(binascii.a2b_base64(token).decode())
+            audio = data["audioInfo"]
+
+            assets.append({
+                **bgm,
+                **audio,
+                "type": "bgm",
+                "url" : "ytdl:" + audio["url"],
+                "_ytdl_manifest": audio["type"].lower(),
+                "extension": "mp3",
+            })
 
 
 class WebtoonsComicExtractor(WebtoonsBase, Extractor):

test/results/webtoons.py

@@ -129,6 +129,51 @@ __tests__ = (
     "author_name" : "spin.ani",
 },
 
+{
+    "#url"     : "https://www.webtoons.com/en/super-hero/unordinary/episode-20/viewer?title_no=679&episode_no=21",
+    "#comment" : "background music (#8733)",
+    "#class"   : webtoons.WebtoonsEpisodeExtractor,
+    "#options" : {"bgm": True},
+    "#range"   : "1",
+    "#pattern" : r"ytdl:https://apis.naver.com/audioc/audiocplay/play/audio/4A10DDE1B92388DA164C48B0356AA442/hls/manifest\.m3u8\?apigw-routing-key=KR&codec=AAC&kbps=64&tt=\d+&tv=.+",
+
+    "audioId"         : "4A10DDE1B92388DA164C48B0356AA442",
+    "author_name"     : "uru-chan",
+    "codec"           : "AAC",
+    "comic"           : "unordinary",
+    "comic_name"      : "unOrdinary",
+    "count"           : 63,
+    "cpContentId"     : None,
+    "cpNo"            : 5,
+    "description"     : "Nobody paid much attention to John – just a normal teenager at a high school where the social elite happen to possess unthinkable powers and abilities. But John’s got a secret past that threatens to bring down the school’s whole social order – and much more. Fulfilling his destiny won’t be easy though, because there are battles, frenemies and deadly conspiracies around every corner.",
+    "duration"        : 90.096692,
+    "encodingTargetYn": False,
+    "episode"         : "21",
+    "episodeNo"       : 21,
+    "episode_name"    : "Episode 20",
+    "episode_no"      : "21",
+    "expireTime"      : int,
+    "extension"       : "mp3",
+    "filePath"        : "679_21/1475723621351drama7.mp3",
+    "genre"           : "super-hero",
+    "kbps"            : 64,
+    "lang"            : "en",
+    "language"        : "English",
+    "num"             : 0,
+    "objectType"      : "mp4a.40.2",
+    "originalFileSize": 0,
+    "playImageUrl"    : "/20161006_271/1475724249957QlGUF_JPEG/1475724249934679214.jpg",
+    "region"          : "KR",
+    "registerYmdt"    : "2016-10-06 12:25:09",
+    "sortOrder"       : 1,
+    "stopImageUrl"    : "",
+    "title"           : "unOrdinary - Episode 20",
+    "titleNo"         : 679,
+    "title_no"        : "679",
+    "type"            : "bgm",
+    "username"        : "62610",
+},
+
 {
     "#url"     : "https://www.webtoons.com/en/comedy/live-with-yourself/list?title_no=919",
     "#comment" : "english",