+    postprocessors:    A list of dictionaries, each with an entry
+                       * key:  The name of the postprocessor. See
+                               youtube_dl/postprocessor/__init__.py for a list.
+                       as well as any further keyword arguments for the
+                       postprocessor.
+    progress_hooks:    A list of functions that get called on download
+                       progress, with a dictionary with the entries
+                       * filename: The final filename
+                       * status: One of "downloading" and "finished"
+
+                       The dict may also have some of the following entries:
+
+                       * downloaded_bytes: Bytes on disk
+                       * total_bytes: Size of the whole file, None if unknown
+                       * tmpfilename: The filename we're currently writing to
+                       * eta: The estimated time in seconds, None if unknown
+                       * speed: The download speed in bytes/second, None if
+                                unknown
+
+                       Progress hooks are guaranteed to be called at least once
+                       (with status "finished") if the download is successful.
+    merge_output_format: Extension to use when merging formats.
+    fixup:             Automatically correct known faults of the file.
+                       One of:
+                       - "never": do nothing
+                       - "warn": only emit a warning
+                       - "detect_or_warn": check whether we can do anything
+                                           about it, warn otherwise
+    source_address:    (Experimental) Client-side IP address to bind to.
+    call_home:         Boolean, true iff we are allowed to contact the
+                       youtube-dl servers for debugging.
+