Note that this reference documentation is identical to the help that is displayed in MATLAB when you type “help ft_realtime_downsample”.

  FT_REALTIME_DOWNSAMPLE reads realtime data from one buffer and writes it after downsampling
  to another buffer.
  Use as
  with the following configuration options              = cell-array, see FT_CHANNELSELECTION (default = 'all')
    cfg.decimation           = integer, downsampling factor (default = 1, no downsampling)
    cfg.order                = interger, order of butterworth lowpass filter (default = 4)
    cfg.cutoff               = double, cutoff frequency of lowpass filter (default = 0.8*Nyquist-freq.)
  The source of the data is configured as
    cfg.source.dataset       = string
  or alternatively to obtain more low-level control as
    cfg.source.datafile      = string
    cfg.source.headerfile    = string
    cfg.source.eventfile     = string
    cfg.source.dataformat    = string, default is determined automatic
    cfg.source.headerformat  = string, default is determined automatic
    cfg.source.eventformat   = string, default is determined automatic
  The target to write the data to is configured as      = string, target destination for the data (default = 'buffer://localhost:1972')    = string, default is determined automatic
  To stop this realtime function, you have to press Ctrl-C