[downloader:ytdl] add 'outtmpl' option (#395)

docs/configuration.rst

@@ -1171,6 +1171,25 @@ Description | Route youtube-dl's output through gallery-dl's logging system.
 =========== =====
 
 
+downloader.ytdl.outtmpl
+-----------------------
+=========== =====
+Type        ``string``
+Default     ``null``
+Description The `Output Template <https://github.com/ytdl-org/youtube-dl#output-template>`__
+            used to generate filenames for files downloaded with youtube-dl.
+
+            Special values:
+
+            * ``null``: generate filenames with `extractor.*.filename`_
+            * ``"default"``: use youtube-dl's default, currently ``"%(title)s-%(id)s.%(ext)s"``
+
+            Note: An output template other than ``null`` might
+            cause unexpected results in combination with other options
+            (e.g. ``"skip": "enumerate"``)
+=========== =====
+
+
 downloader.ytdl.raw-options
 ---------------------------
 =========== =====

docs/gallery-dl.conf

@@ -169,6 +169,7 @@
             "format": null,
             "forward-cookies": true,
             "mtime": true,
+            "outtmpl": null,
             "rate": null,
             "retries": 4,
             "timeout": 30.0,

gallery_dl/downloader/ytdl.py

@@ -8,7 +8,7 @@
 
 """Downloader module for URLs requiring youtube-dl support"""
 
-from youtube_dl import YoutubeDL
+from youtube_dl import YoutubeDL, DEFAULT_OUTTMPL
 from .common import DownloaderBase
 from .. import text
 import os
@@ -36,6 +36,9 @@ def __init__(self, extractor, output):
             options["logger"] = self.log
         self.forward_cookies = self.config("forward-cookies", True)
 
+        outtmpl = self.config("outtmpl")
+        self.outtmpl = DEFAULT_OUTTMPL if outtmpl == "default" else outtmpl
+
         self.ytdl = YoutubeDL(options)
 
     def download(self, url, pathfmt):
@@ -60,7 +63,17 @@ def download(self, url, pathfmt):
     def _download_video(self, pathfmt, info_dict):
         if "url" in info_dict:
             text.nameext_from_url(info_dict["url"], pathfmt.kwdict)
-        pathfmt.set_extension(info_dict["ext"])
+
+        if self.outtmpl:
+            self.ytdl.params["outtmpl"] = self.outtmpl
+            pathfmt.filename = filename = self.ytdl.prepare_filename(info_dict)
+            pathfmt.extension = info_dict["ext"]
+            pathfmt.path = pathfmt.directory + filename
+            pathfmt.realpath = pathfmt.temppath = (
+                pathfmt.realdirectory + filename)
+        else:
+            pathfmt.set_extension(info_dict["ext"])
+
         if pathfmt.exists():
             pathfmt.temppath = ""
             return True