nuttx/graphics/vnc/server/Kconfig

#
# For a description of the syntax of this configuration file,
# see the file kconfig-language.txt in the NuttX tools repository.
#

menuconfig VNCSERVER
	bool "VNC server"
	default n
	depends on NET_TCP && !NX_LCDDRIVER
	select FB_UPDATE
	---help---
		Enable support for a VNC Remote Frame Buffer (RFB) server.

if VNCSERVER

choice
	prompt "VNC server protocol"
	default VNCSERVER_PROTO3p8

config VNCSERVER_PROTO3p3
	bool "Version 3.3"
	depends on EXPERIMENTAL

config VNCSERVER_PROTO3p8
	bool "Version 3.8"

endchoice # VNC server protocol

config VNCSERVER_NDISPLAYS
	int "Number of displays"
	default 1
	range 1 99
	---help---
		Specifies the number of RFB displays supported by the server.
		Normally this should be one.

config VNCSERVER_NAME
	string "VNC display name"
	default "NuttX"

config VNCSERVER_PRIO
	int "VNC server task priority"
	default 100

config VNCSERVER_STACKSIZE
	int "VNC server stack size"
	default DEFAULT_TASK_STACKSIZE

config VNCSERVER_UPDATER_PRIO
	int "VNC updater thread priority"
	default 100

config VNCSERVER_UPDATER_STACKSIZE
	int "VNC updater thread stack size"
	default DEFAULT_TASK_STACKSIZE

choice
	prompt "VNC color format"
	default VNCSERVER_COLORFMT_RGB16

config VNCSERVER_COLORFMT_RGB8
	bool "RGB8 3:3:2"

config VNCSERVER_COLORFMT_RGB16
	bool "RGB16 5:6:5"

config VNCSERVER_COLORFMT_RGB32
	bool "RGB32 8:8:8"

endchoice # VNC color format

config VNCSERVER_SCREENWIDTH
	int "Framebuffer width (pixels)"
	default 320
	---help---
		This setting defines the width in pixels of the local framebuffer.

			Memory usage: PixelWidth * ScreenWidth * ScreenHeight

		So, for example, a 320x240 screen with RGB16 pixels would require
		2x320x240 = 150 KB of RAM.

config VNCSERVER_SCREENHEIGHT
	int "Framebuffer height (rows)"
	default 240
	---help---
		This setting defines the height in rows of the local framebuffer.

			Memory usage: PixelWidth * ScreenWidth * ScreenHeight

		So, for example, a 320x240 screen with RGB16 pixels would require
		2x320x240 = 150 KB of RAM.

config VNCSERVER_NUPDATES
	int "Number of pre-allocate update structures"
	default 48
	---help---
		This setting provides the number of pre-allocated update structures
		that will be used.  Dynamic memory allocations are never made.  In
		the likely event that we run out of update structures, the graphics
		subsystem will pause and wait for the next structures to be released.

		Overhead is 12-bytes per update structure.

config VNCSERVER_UPDATE_BUFSIZE
	int "Max update buffer size (bytes)"
	default 1024
	---help---
		A single buffer is pre-allocated for rendering updates.  This
		setting specifies the maximum in bytes of that update buffer.  For
		example, an update buffers of 32 pixels at 8-bits per pixel and
		32-rows would yield a buffer size of 1024!

		There is a very strong interaction with this setting and the network MTU.
		Ideally, this buffer should fit in one network packet to avoid accessive
		re-assembly of partial TCP packets.

		REVISIT:  In fact, if the buffer does not fit in one network packet,
		then there appears to be reliability issues in the connection.  I am
		not sure why that is; TCP is a stream so it should not matter how
		many packets are in a transfer.

		Example:  Negotiated pixel depth = 8 BPP, window width = 800 pixels.
		CONFIG_VNCSERVER_UPDATE_BUFSIZE needs to be the payload size (MSS)
		of the transfer or 800 bytes.  The MTU is then:

		  MSS = MTU - sizeof(IP Header) - sizeof(VNC FramebufferUpdate Header)

		For IPv4, the IP Header is 20 bytes; 40 bytes for IPv6.  The
		FramebufferUpdate header is 16 bytes so.  The desired MSS is 800 bytes
		so MTU = 836 or 856.  For Ethernet, this is a total packet size of 870
		bytes.

config VNCSERVER_KBDENCODE
	bool "Encode keyboard input"
	default n
	depends on LIBC_KBDCODEC
	---help---
		Use a special encoding of keyboard characters as defined in
		include/nuttx/input/kbd_coded.h.

config VNCSERVER_INBUFFER_SIZE
	int "Input buffer size"
	default 80

config VNCSERVER_DEBUG
	bool "VNC Server debug"
	default n
	depends on DEBUG_FEATURES && !DEBUG_GRAPHICS
	---help---
		Normally VNC debug output is selected with DEBUG_GRAPHICS.  The
		VNC server support this special option to enable GRAPHICS debug
		output for the VNC server while GRAPHICS debug is disabled.  This
		provides an cleaner, less cluttered output when you only wish to
		debug the VNC server versus enabling DEBUG_GRAPHICS globally.

config VNCSERVER_UPDATE_DEBUG
	bool "Detailed updater debug"
	default n
	depends on DEBUG_GRAPHICS || VNCSERVER_DEBUG

endif # VNCSERVER