This file describes SDL-specific usage information about MAME. It is
intended to cover aspects of using and configuring the program that are
specific to running MAME from the command line on any system which is
supported by SDL (including Windows).

In addition to the keys described in config.txt, the following additional
keys are defined for SDL-specific versions of MAME:



Debugging options
-----------------

-[no]oslog

	Outputs the error.log data to the stderr TTY channel (usually the 
	command line window MAME was started in). This can be used at
	the same time as -log to output the log data to both targets as well.
	Default is OFF (-nooslog).

-watchdog <duration> / -wdog <duration>

	Enables an internal watchdog timer that will automatically kill the MAME
	process if more than <duration> seconds passes without a frame update.
	Keep in mind that some games sit for a while during load time without
	updating the screen, so <duration> should be long enough to cover that.
	10-30 seconds on a modern system should be plenty in general. By default
	there is no watchdog.



Performance options
-------------------

-[no]multithreading / -[no]mt

	Enables multithreading for the final drawing operation.  This can help 
	performance on multicore/hyperthreaded systems with slow video cards,
	but may cause undesired behavior in some games.
	Note that some drivers in MAME and MESS will use multiple threads even
	when this is set to OFF, assuming -numprocessors allows it.
	The default is OFF (-nomultithreading).
	

-numprocessors <auto|value> / -np <auto|value>

	Specify the number of processors to use for work queues. Specifying
	"auto" will use the value reported by the system or environment 
	variable OSDPROCESSORS. To avoid abuse, this value is internally limited
	to 4 times the number of processors reported by the system. 
	The default is "auto".

-sdlvideofps

        Enable output of benchmark data on the SDL video subsystem, including
		your system's video driver, X server (if applicable), and OpenGL stack
		in -video opengl mode.

-bench [n]

        Benchmark for [n] number of emulated seconds; implies the command string:
        -str [n] -video none -sound none -nothrottle. Default is OFF (-nobench)



Video options
-------------

-video <soft|opengl|none>

	Specifies which video subsystem to use for drawing.  The default for 
	Mac OS X is 'opengl' because OS X is guaranteed to have a compliant 
	OpenGL stack.  The default on all other systems is 'soft'.

-numscreens <count>

	Tells MAME how many output windows to create. For most games, a single
	output window is all you need, but some games originally used multiple
	screens. Each screen (up to 4) has its own independent settings for
	physical monitor, aspect ratio, resolution, and view, which can be
	set using the options below. The default is 1.  SDL currently has a
	limit of 1 with the expectation of increasing this when SDL 2.0 is
	released.

-[no]window / -[no]w

	Run MAME in either a window or full screen. The default is OFF
	(-nowindow).

-[no]maximize / -[no]max

	Controls initial window size in windowed mode. If it is set on, the
	window will initially be set to the maximum supported size when you
	start MAME. If it is turned off, the window will start out at the
	smallest supported size. This option only has an effect when the
	-window option is used. The default is ON (-maximize).

-[no]keepaspect / -[no]ka

	Enables aspect ratio enforcement. When this option is on, the game's
	proper aspect ratio (generally 4:3 or 3:4) is enforced, so you get the
	game looking like it should. When running in a window with this option
	on, you can only resize the window to the proper aspect ratio, unless
	you are holding down the CONTROL key. By turning the option off, the
	aspect ratio is allowed to float. In full screen mode, this means that
	all games will stretch to the full screen size (even vertical games).
	In window mode, it means that you can freely resize the window without
	any constraints. The default is ON (-keepaspect).

-[no]unevenstretch

	Allow non-integer stretch factors allowing for great window sizing
	flexability.  The default is ON. (-unevenstretch)

-[no]centerh

        Center horizontally within the view area. Default is ON (-centerh).

-[no]centerv

        Center vertically within the view area. Default is ON (-centerv).

-[no]waitvsync

	Waits for the refresh period on your computer's monitor to finish
	before starting to draw video to your screen. If this option is off,
	MAME will just draw to the screen at any old time, even in the middle
	of a refresh cycle. This can cause "tearing" artifacts, where the top
	portion of the screen is out of sync with the bottom portion. Tearing
	is not noticeable on all games, and some people hate it more than
	others. However, if you turn this option on, you will waste more of
	your CPU cycles waiting for the proper time to draw, so you will see a
	performance hit. You should only need to turn this on in windowed mode.
	In full screen mode, it is only needed if -triplebuffer does not
	remove the tearing, in which case you should use -notriplebuffer
	-waitvsync. Note that support for this option depends entirely on your
	operating system and video drivers; in general it will not work in
	windowed mode so -video opengl and fullscreen give the greatest chance
	of success.
	The default is OFF (-nowaitvsync).

-[no]syncrefresh

	Enables speed throttling only to the refresh of your monitor. This
	means that the game's actual refresh rate is ignored; however, the
	sound code still attempts to keep up with the game's original refresh
	rate, so you may encounter sound problems. This option is intended
	mainly for those who have tweaked their video card's settings to
	provide carefully matched refresh rate options. Note that this option
	does not work with -video gdi mode.The default is OFF (-nosyncrefresh).



Video soft-specific options
---------------------------

-scalemode

        Scale mode: none, async, yv12, yuy2, yv12x2, yuy2x2 (-video soft only)
        Default is 'none'.



Video OpenGL-specific options
-----------------------------

-[no]filter / -[no]flt

	Enable bilinear filtering on the game screen graphics. When disabled,
	point filtering is applied, which is crisper but leads to scaling
	artifacts. If you don't like the filtered look, you are probably better
	off increasing the -prescale value rather than turning off filtering
	altogether. The default is ON (-filter).

-prescale <amount>

	Controls the size of the screen images when they are passed off to the
	graphics system for scaling. At the minimum setting of 1, the screen
	is rendered at its original resolution before being scaled. At higher
	settings, the screen is expanded by a factor of <amount> before being
	scaled. This produces a less blurry image at the expense of some speed
        and also increases the effective resolution of non-screen elements such
        as artwork and fonts. The default is 1.

-[no]gl_forcepow2texture Always use only power-of-2 sized textures (default off)
-[no]gl_notexturerect    Don't use OpenGL GL_ARB_texture_rectangle (default on)
-[no]gl_vbo              Enable OpenGL VBO,  if available (default on)
-[no]gl_pbo              Enable OpenGL PBO,  if available (default on)

	These 4 options are for compatibility in -video opengl.  If you report
	rendering artifacts you may be asked to try messing with them by the 
	devs, but normally they should be left at their defaults which results
	in the best possible video performance.

-gl_glsl             Enable OpenGL GLSL, if available (default off)
-gl_glsl_filter      Enable OpenGL GLSL filtering instead of FF filtering 0-plain,
                     1-bilinear (default)
-glsl_shader_mame0   Custom OpenGL GLSL shader set mame bitmap 0
-glsl_shader_mame1   Custom OpenGL GLSL shader set mame bitmap 1
-glsl_shader_mame2   Custom OpenGL GLSL shader set mame bitmap 2
-glsl_shader_mame3   Custom OpenGL GLSL shader set mame bitmap 3
-glsl_shader_mame4   Custom OpenGL GLSL shader set mame bitmap 4
-glsl_shader_mame5   Custom OpenGL GLSL shader set mame bitmap 5
-glsl_shader_mame6   Custom OpenGL GLSL shader set mame bitmap 6
-glsl_shader_mame7   Custom OpenGL GLSL shader set mame bitmap 7
-glsl_shader_mame8   Custom OpenGL GLSL shader set mame bitmap 8
-glsl_shader_mame9   Custom OpenGL GLSL shader set mame bitmap 9
-glsl_shader_screen0 Custom OpenGL GLSL shader screen bitmap 0
-glsl_shader_screen1 Custom OpenGL GLSL shader screen bitmap 1
-glsl_shader_screen2 Custom OpenGL GLSL shader screen bitmap 2
-glsl_shader_screen3 Custom OpenGL GLSL shader screen bitmap 3
-glsl_shader_screen4 Custom OpenGL GLSL shader screen bitmap 4
-glsl_shader_screen5 Custom OpenGL GLSL shader screen bitmap 5
-glsl_shader_screen6 Custom OpenGL GLSL shader screen bitmap 6
-glsl_shader_screen7 Custom OpenGL GLSL shader screen bitmap 7
-glsl_shader_screen8 Custom OpenGL GLSL shader screen bitmap 8
-glsl_shader_screen9 Custom OpenGL GLSL shader screen bitmap 9
-gl_glsl_vid_attr    Enable OpenGL GLSL handling of brightness and contrast.
                     Better RGB game performance.  Default is on.



Per-window options
------------------

NOTE:  Multiple Screens are limited to 1 until SDL 2.0 is released.

-screen <display>
-screen0 <display>
-screen1 <display>
-screen2 <display>
-screen3 <display>

	Specifies which physical monitor on your system you wish to have each
	window use by default. In order to use multiple windows, you must have
	increased the value of the -numscreens option. The name of each
	display in your system can be determined by running MAME with the
	-verbose option. The display names are typically in the format of:
	\\.\DISPLAYn, where 'n' is a number from 1 to the number of connected
	monitors. The default value for these options is 'auto', which means
	that the first window is placed on the first display, the second
	window on the second display, etc.

	The -screen0, -screen1, -screen2, -screen3 parameters apply to the
	specific window. The -screen parameter applies to all windows. The
	window-specific options override values from the all window option.

-aspect <width:height> / -screen_aspect <num:den>
-aspect0 <width:height>
-aspect1 <width:height>
-aspect2 <width:height>
-aspect3 <width:height>

	Specifies the physical aspect ratio of the physical monitor for each
	window. In order to use multiple windows, you must have increased the
	value of the -numscreens option. The physical aspect ratio can be
	determined by measuring the width and height of the visible screen
	image and specifying them separated by a colon. The default value for
	these options is 'auto', which means that MAME assumes the aspect
	ratio is proportional to the number of pixels in the desktop video
	mode for each monitor.

	The -aspect0, -aspect1, -aspect2, -aspect3 parameters apply to the
	specific window. The -aspect parameter applies to all windows. The
	window-specific options override values from the all window option.

-resolution <widthxheight[@refresh]> / -r <widthxheight[@refresh]>
-resolution0 <widthxheight[@refresh]> / -r0 <widthxheight[@refresh]>
-resolution1 <widthxheight[@refresh]> / -r1 <widthxheight[@refresh]>
-resolution2 <widthxheight[@refresh]> / -r2 <widthxheight[@refresh]>
-resolution3 <widthxheight[@refresh]> / -r3 <widthxheight[@refresh]>

	Specifies an exact resolution to run in. In full screen mode, MAME
	will try to use the specific resolution you request. The width and
	height are required; the refresh rate is optional. If omitted or
	set to 0, MAME will determine the mode auomatically. For example,
	-resolution 640x480 will force 640x480 resolution, but MAME is free to
	choose the refresh rate. Similarly, -resolution 0x0@60 will force a
	60Hz refresh rate, but allows MAME to choose the resolution. The
	string "auto" is also supported, and is equivalent to 0x0@0. In window
	mode, this resolution is used as a maximum size for the window. This
	option requires the -switchres option as well in order to actually
	Enable resolution switching.

	The -resolution0, -resolution1, -resolution2, -resolution3 parameters
	apply to the specific window. The -resolution parameter applies to all
	windows. The window-specific options override values from the all
	window option.

-view <viewname>
-view0 <viewname>
-view1 <viewname>
-view2 <viewname>
-view3 <viewname>

	Specifies the initial view setting for each window. The <viewname>
	does not need to be a perfect match; rather, it will select the first
	view whose name matches all the characters specified by <viewname>.
	For example, -view native will match the "Native (15:14)" view even
	though it is not a perfect match. The value 'auto' is also supported,
	and requests that MAME perform a default selection. The default value
	for these options is 'auto'.

	The -view0, -view1, -view2, -view3 parameters apply to the
	specific window. The -view parameter applies to all windows. The
	window-specific options override values from the all window option.



Full screen options
-------------------

-[no]switchres

	Enables resolution switching. This option is required for the
	-resolution* options to switch resolutions in full screen mode. On
	modern video cards, there is little reason to switch resolutions unless
	you are trying to achieve the "exact" pixel resolutions of the original
	games, which requires significant tweaking. This option is also useful
	on LCD displays, since they run with a fixed resolution and switching
	resolutions on them is just silly.
	The default is OFF (-noswitchres).



Sound options
-------------

-sound <sdl|none>

	Specifies which sound subsystem to use. 'none' disables sound altogether.
	The default is sdl.

-audio_latency <value>

	This controls the amount of latency built into the audio streaming. By
	default MAME tries to keep the audio buffer between 1/5 and 2/5 full.
        On some systems, this is pushing it too close to the edge,  and you get
        poor sound sometimes. The latency parameter controls the lower threshold.
        The default is 2 (meaning lower=2/5 and upper=3/5). Set it to 3
        (-audio_latency 3) to keep the sound buffer between 3/5 and 4/5 full.
        If you crank it up to 4, you can definitely notice the lag.



SDL Keyboard Mapping
--------------------

-keymap              Enable keymap. Default is OFF (-nokeymap)
-keymap_file         Keymap Filename. Default is 'keymap.dat'.
-uimodekey           Key to toggle keyboard mode. Default is 'SCRLOCK'



SDL Joystick Mapping
--------------------

-joy_idx1            Name of joystick mapped to joystick #1, default is auto.
-joy_idx2            Name of joystick mapped to joystick #2, default is auto.
-joy_idx3            Name of joystick mapped to joystick #3, default is auto.
-joy_idx4            Name of joystick mapped to joystick #4, default is auto.
-joy_idx5            Name of joystick mapped to joystick #5, default is auto.
-joy_idx6            Name of joystick mapped to joystick #6, default is auto.
-joy_idx7            Name of joystick mapped to joystick #7, default is auto.
-joy_idx8            Name of joystick mapped to joystick #8, default is auto.
-sixaxis             Use special handling for PS3 Sixaxis controllers. 
                     Default is OFF (-nosixaxis)



SDL Lowlevel driver options
---------------------------

-videodriver         SDL video driver to use ('x11', 'directfb', ... or 'auto' for SDL default
-audiodriver         SDL audio driver to use ('alsa', 'arts', ... or 'auto' for SDL default
-gl_lib              Alternative libGL.so to use; 'auto' for system default

