+ 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.
+