The following options determine which downloader is picked:
external_downloader: Executable of the external downloader to call.
None or unset for standard (built-in) downloader.
- hls_prefer_native: Use the native HLS downloader instead of ffmpeg/avconv.
+ hls_prefer_native: Use the native HLS downloader instead of ffmpeg/avconv
+ if True, otherwise use ffmpeg/avconv if False, otherwise
+ use downloader suggested by extractor if None.
The following parameters are not used by YoutubeDL itself, they are used by
the downloader (see youtube_dl/downloader/common.py):