Options

'background': Set background color. Black is a default.
'no_window': Disables default SDL window when set to non-zero value. Application must provide OpenGL context and both window_size_cb and window_swap_buffers_cb callbacks when set.
'window_title': Set the SDL window title, if not specified default to the filename specified for the output device. Ignored when 'no_window' is set.
'window_size': Set preferred window size, can be a string of the form widthxheight or a video size abbreviation. If not specified it defaults to the size of the input video, downscaled according to the aspect ratio. Mostly usable when 'no_window' is not set.