+@item -init_hw_device @var{type}[=@var{name}][:@var{device}[,@var{key=value}...]]
+Initialise a new hardware device of type @var{type} called @var{name}, using the
+given device parameters.
+If no name is specified it will receive a default name of the form "@var{type}%d".
+
+The meaning of @var{device} and the following arguments depends on the
+device type:
+@table @option
+
+@item cuda
+@var{device} is the number of the CUDA device.
+
+@item dxva2
+@var{device} is the number of the Direct3D 9 display adapter.
+
+@item vaapi
+@var{device} is either an X11 display name or a DRM render node.
+If not specified, it will attempt to open the default X11 display (@emph{$DISPLAY})
+and then the first DRM render node (@emph{/dev/dri/renderD128}).
+
+@item vdpau
+@var{device} is an X11 display name.
+If not specified, it will attempt to open the default X11 display (@emph{$DISPLAY}).
+
+@item qsv
+@var{device} selects a value in @samp{MFX_IMPL_*}. Allowed values are:
+@table @option
+@item auto
+@item sw
+@item hw
+@item auto_any
+@item hw_any
+@item hw2
+@item hw3
+@item hw4
+@end table
+If not specified, @samp{auto_any} is used.
+(Note that it may be easier to achieve the desired result for QSV by creating the
+platform-appropriate subdevice (@samp{dxva2} or @samp{vaapi}) and then deriving a
+QSV device from that.)
+
+@end table
+
+@item -init_hw_device @var{type}[=@var{name}]@@@var{source}
+Initialise a new hardware device of type @var{type} called @var{name},
+deriving it from the existing device with the name @var{source}.
+
+@item -init_hw_device list
+List all hardware device types supported in this build of ffmpeg.
+
+@item -filter_hw_device @var{name}
+Pass the hardware device called @var{name} to all filters in any filter graph.
+This can be used to set the device to upload to with the @code{hwupload} filter,
+or the device to map to with the @code{hwmap} filter. Other filters may also
+make use of this parameter when they require a hardware device. Note that this
+is typically only required when the input is not already in hardware frames -
+when it is, filters will derive the device they require from the context of the
+frames they receive as input.
+
+This is a global setting, so all filters will receive the same device.
+