add option to use different youtube-dl modules (fixes #1330)

by setting the 'downloader.ytdl.module' value. For example

{
    "downloader": {
        "ytdl": {
            "module": "yt_dlp"
        }
    }
}

or '-o module=yt_dlp'

docs/configuration.rst

@@ -1943,6 +1943,16 @@ Description
     `downloader.ytdl.raw-options`_ to ``true`` to suppress all output.
 
 
+downloader.ytdl.module
+----------------------
+Type
+    ``string``
+Default
+    ``"youtube_dl"``
+Description
+    Name of the youtube-dl Python module to import.
+
+
 downloader.ytdl.outtmpl
 -----------------------
 Type

gallery_dl/downloader/ytdl.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2018-2020 Mike Fährmann
+# Copyright 2018-2021 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -8,7 +8,6 @@
 
 """Downloader module for URLs requiring youtube-dl support"""
 
-from youtube_dl import YoutubeDL, DEFAULT_OUTTMPL
 from .common import DownloaderBase
 from .. import text
 import os
@@ -16,8 +15,14 @@ import os
 
 class YoutubeDLDownloader(DownloaderBase):
     scheme = "ytdl"
+    module = None
 
     def __init__(self, job):
+        module = self.module
+        if not module:
+            module_name = self.config("module") or "youtube_dl"
+            module = YoutubeDLDownloader.module = __import__(module_name)
+
         DownloaderBase.__init__(self, job)
         extractor = job.extractor
 
@@ -42,10 +47,11 @@ class YoutubeDLDownloader(DownloaderBase):
             options["logger"] = self.log
         self.forward_cookies = self.config("forward-cookies", False)
 
-        outtmpl = self.config("outtmpl")
+        self.outtmpl = self.config("outtmpl")
-        self.outtmpl = DEFAULT_OUTTMPL if outtmpl == "default" else outtmpl
+        if self.outtmpl == "default":
+            self.outtmpl = module.DEFAULT_OUTTMPL
 
-        self.ytdl = YoutubeDL(options)
+        self.ytdl = module.YoutubeDL(options)
 
     def download(self, url, pathfmt):
         if self.forward_cookies:

scripts/hook-gallery_dl.py

@@ -7,3 +7,5 @@ hiddenimports = [
     for package in (extractor, downloader, postprocessor)
     for module in package.modules
 ]
+
+hiddenimports.append("youtube_dl")