[gelbooru] rewrite mp4 video URLs (fixes #1048)

gallery_dl/extractor/booru.py

@@ -51,7 +51,7 @@ class BooruExtractor(SharedConfigMixin, Extractor):
 
             for image in images:
                 try:
-                    url = image["file_url"]
+                    url = self.get_file_url(image)
                 except KeyError:
                     continue
                 if url.startswith("/"):
@@ -86,6 +86,10 @@ class BooruExtractor(SharedConfigMixin, Extractor):
         """Collect metadata for extractor-job"""
         return {}
 
+    @staticmethod
+    def get_file_url(image):
+        return image["file_url"]
+
     def extended_tags(self, image, page=None):
         """Retrieve extended tag information"""
         if not page:

gallery_dl/extractor/gelbooru.py

@@ -33,6 +33,15 @@ class GelbooruExtractor(booru.XmlParserMixin,
             self.session.cookies["fringeBenefits"] = "yup"
             self.per_page = 42
 
+    @staticmethod
+    def get_file_url(image):
+        url = image["file_url"]
+        if url.startswith("https://mp4.gelbooru.com/"):
+            ihash = image["md5"]
+            return "https://img2.gelbooru.com/images/{}/{}/{}.webm".format(
+                ihash[0:2], ihash[2:4], ihash)
+        return url
+
     def items_noapi(self):
         yield Message.Version, 1
         data = self.get_metadata()