2.3.1. Video output devices

NOTE: check the following subsections for details and requirements!

2.3.1.1. Setting up MTRR

It is VERY recommended to check if the MTRR registers are set up properly, because they can give a big performance boost.

Do a 'cat /proc/mtrr' :

--($:~)-- cat /proc/mtrr
reg00: base=0xe4000000 (3648MB), size= 16MB: write-combining, count=9
reg01: base=0xd8000000 (3456MB), size= 128MB: write-combining, count=1


It's right, shows my Matrox G400 with 16Mb memory. I did this from XFree 4.x.x , which sets up MTRR registers automatically.

If nothing worked, you have to do it manually. First, you have to find the base address. You have 3 ways to find it:

• from X11 startup messages, for example:

  (--) SVGA: PCI: Matrox MGA G400 AGP rev 4, Memory @ 0xd8000000, 0xd4000000
(--) SVGA: Linear framebuffer at 0xD8000000

• from /proc/pci (use lspci -v command):

  01:00.0 VGA compatible controller: Matrox Graphics, Inc.: Unknown device 0525 Memory at d8000000 (32-bit, prefetchable)

• from mga_vid kernel driver messages (use dmesg):

  mga_mem_base = d8000000

Then let's find the memory size. This is very easy, just convert video ram size to hexadecimal, or use this table:

You know base address and memory size, let's setup mtrr registers! For example, for the Matrox card above (base=0xd8000000) with 32MB ram (size=0x2000000) just execute:

  echo "base=0xd8000000 size=0x2000000 type=write-combining" >| /proc/mtrr

Not all CPUs support MTRRs. For example older K6-2's [around 266Mhz, stepping 0] doesn't support MTRR, but stepping 12's do ('cat /proc/cpuinfo' to check it').

2.3.1.2. Xv

Under XFree86 4.0.2 or newer, you can use your card's hardware YUV routines using the XVideo extension. This is what the option '-vo xv' uses. In order to make this work, be sure to check the following:

• You have to use XFree86 4.0.2 or newer (former versions don't have XVideo)
• Your card actually supports hardware acceleration (modern cards do)
• X loads the XVideo extension, it's something like this:

    (II) Loading extension XVideo

  in /var/log/XFree86.0.log

  NOTE: this loads only the XFree86's extension. In a good install, this is always loaded, and doesn't mean that the _card's_ XVideo support is loaded!

• Your card has Xv support under Linux. To check, try 'xvinfo', it is the part of the XFree86 distribution. It should display a long text, similar to this:

  	X-Video Extension version 2.2
  	screen #0
  	  Adaptor #0: "Savage Streams Engine"
  	    number of ports: 1
  	    port base: 43
  	    operations supported: PutImage
  	    supported visuals:
  	      depth 16, visualID 0x22
  	      depth 16, visualID 0x23
  	    number of attributes: 5
  	(...)
  	    Number of image formats: 7
  	      id: 0x32595559 (YUY2)
  	        guid: 59555932-0000-0010-8000-00aa00389b71
  	        bits per pixel: 16
  	        number of planes: 1
  	        type: YUV (packed)
  	      id: 0x32315659 (YV12)
  	        guid: 59563132-0000-0010-8000-00aa00389b71
  	        bits per pixel: 12
  	        number of planes: 3
  	        type: YUV (planar)
  	(...etc...)
  

  It must support YUY2 packed, and YV12 planar pixel formats to be usable with MPlayer.

• And finally, check if MPlayer was compiled with 'xv' support. ./configure prints this.

2.3.1.2.1. 3dfx cards

Older 3dfx drivers were known to have problems with XVideo acceleration, it didn't support either YUY2 or YV12, and so. Verify that you have XFree86 version 4.1.0 or greater, it works ok. Alternatively, you can use DRI cvs. If you experience strange effects using -vo xv, try SDL (it has XVideo too) and see if it helps. Check the SDL section for details.

OR, try the NEW -vo tdfxfb driver! See the 2.3.1.9 section!

2.3.1.2.2. S3 cards

S3 Savage3D's should work fine, but for Savage4, use XFree86 version 4.0.3 or greater (in case of image problems, try 16bpp). As for S3 Virge.. sell it.

NOTE: Savage4 has a slow YV12 image displaying capability (it needs to do YV12->YUY2 conversion, because the Savage hardware can't display YV12). So when this documentation says at some point "this has YV12 output use this, it's faster", you shouldn't. Stick to YUY2.

2.3.1.2.3. nVidia cards

nVidia isn't a very good choice under Linux.. You'll have to use the binary nVidia driver, available at nVidia's website. The standard X driver doesn't support XVideo for these cards, due to nVidia's closed sources/specifications.

• Riva128 cards don't have XVideo support even with the nvidia driver :( Complain to NVidia.

2.3.1.2.4. ATI cards

2.3.1.2.5. NeoMagic cards

These cards can be found in many laptops. Under Linux, their peak is only DGA. Unfortunately, the DGA driver in X 4.1.0 doesn't work, you'll have to wait for 4.2.0, or download a modified driver for 4.0.3 or 4.1.0 from here : http://www.mplayerhq.hu/MPlayer/contrib/NeoMagic-driver (there is also the patch to the driver's source).
Drivers provided by Tomek Jarzynka.

2.3.1.3. DGA

2.3.1.3.1. Summary

This document tries to explain in some words what DGA is in general and what the DGA video output driver for mplayer can do (and what it can't).

2.3.1.3.2. What is DGA

DGA is short for Direct Graphics Access and is a means for a program to bypass the X-Server and directly modifying the framebuffer memory. Technically spoken this happens by mapping the framebuffer memory into the memory range of your process. This is allowed by the kernel only if you have superuser privileges. You can get these either by logging in as root or by setting the suid bit on the mplayer excecutable (NOT recommended!).

There are two versions of DGA: DGA1 is used by XFree 3.x.x and DGA2 was introduced with XFree 4.0.1.

DGA1 provides only direct framebuffer access as described above. For switching the resolution of the video signal you have to rely on the XVidMode extension.

DGA2 incorporates the features of XVidMode extension and also allows switching the depth of the display. So you may, although basically running a 32 bit depth XServer, switch to a depth of 15 bits and vice versa.

However DGA has some drawbacks. It seems it is somewhat dependent on the graphics chip you use and on the implementation of the XServer's video driver that controls this chip. So it does not work on every system ...

2.3.1.3.3. Installing DGA support for MPlayer

First make sure X loads the DGA extension, see in /var/log/XFree86.0.log:

    (II) Loading extension XFree86-DGA

See, XFree86 4.0.x or greater is VERY RECOMMENDED! MPlayer's DGA driver is autodetected on ./configure, or you can force it with --enable-dga.

If the driver couldn't switch to a smaller resolution, experiment with switches -vm (only with X 3.3.x), -fs, -bpp, -zoom to find a video mode that the movie fits in. There is no converter right now.. :(

Become ROOT. DGA needs root access to be able to write directly video memory. If you want to run it as user, then install MPlayer SUID root:

    chown root /usr/local/bin/mplayer
    chmod 750 /usr/local/bin/mplayer
    chmod +s /usr/local/bin/mplayer

Now it works as a simple user, too.

!!!! BUT STAY TUNED !!!!
This is a BIG security risk! Never do this on a server or on a computer can be accessed by more people than only you because they can gain root privilegies through suid root mplayer.
!!!! SO YOU HAVE BEEN WARNED ... !!!!

Now use '-vo dga' option, and there you go! (hope so:) You should also try if the '-vo sdl:dga' option works for you! It's much faster!!!

2.3.1.3.4. Resolution switching

The DGA driver allows for switching the resolution of the output signal. This avoids the need for doing (slow) software scaling and at the same time provides a fullscreen image. Ideally it would switch to the exact resolution (except for honouring aspect ratio) of the video data, but the XServer only allows switching to resolutions predefined in /etc/X11/XF86Config (/etc/X11/XF86Config-4 for XFree 4.0.X respectively). Those are defined by so-called modelines and depend on the capabilites of your video hardware. The XServer scans this config file on startup and disables the modelines not suitable for your hardware. You can find out which modes survive with the X11 log file. It can be found at: /var/log/XFree86.0.log.

See appendix A for some sample modeline definitions.

2.3.1.3.5. DGA & MPlayer

DGA is used in two places with MPlayer: The SDL driver can be made to make use of it (-vo sdl:dga) and within the DGA driver (-vo dga). The above said is true for both; in the following sections I'll explain how the DGA driver for MPlayer works.

2.3.1.3.6. Features of the DGA driver

The DGA driver is invoked by specifying -vo dga at the command line. The default behaviour is to switch to a resolution matching the original resolution of the video as close as possible. It deliberately ignores the -vm and -fs switches (enabling of video mode switching and fullscreen) - it always tries to cover as much area of your screen as possible by switching the video mode, thus refraining to use a single additional cycle of your CPU to scale the image. If you don't like the mode it chooses you may force it to choose the mode matching closest the resolution you specify by -x and -y. By providing the -v option, the DGA driver will print, among a lot of other things, a list of all resolutions supported by your current XF86-Config file. Having DGA2 you may also force it to use a certain depth by using the -bpp option. Valid depths are 15, 16, 24 and 32. It depends on your hardware whether these depths are natively supported or if a (possibly slow) conversion has to be done.

If you should be lucky enough to have enough offscreen memory left to put a whole image there, the DGA driver will use doublebuffering, which results in much smoother movie replaying. It will tell you whether double- buffering is enabled or not.

Doublebuffering means that the next frame of your video is being drawn in some offscreen memory while the current frame is being displayed. When the next frame is ready, the graphics chip is just told the location in memory of the new frame and simply fetches the data to be displayed from there. In the meantime the other buffer in memory will be filled again with new video data.

2.3.1.3.7. Speed issues

Generally spoken, DGA framebuffer access should be at least as fast as using the X11 driver with the additional benefit of getting a fullscreen image. The percentage speed values printed by mplayer have to be interpreted with some care, as for example, with the X11 driver they do not include the time used by the X-Server needed for the actual drawing. Hook a terminal to a serial line of your box and start top to see what is really going on in your box ...

Generally spoken, the speedup done by using DGA against 'normal' use of X11 highly depends on your graphics card and how well the X-Server module for it is optimized.

If you have a slow system, better use 15 or 16bit depth since they require only half the memory bandwidth of a 32 bit display.

Using a depth of 24bit is even a good idea if your card natively just supports 32 bit depth since it transfers 25% less data compared to the 32/32 mode.

I've seen some avi files already be replayed on a Pentium MMX 266. AMD K6-2 CPUs might work at 400 MHZ and above.

2.3.1.3.8. Known bugs

Well, according to some developpers of XFree, DGA is quite a beast. They tell you better not to use it. Its implementation is not always flawless with every chipset driver for XFree out there.

• with XFree 4.0.3 and nv.o there is a bug resulting in strange colors
• ATI driver requires to switch mode back more than once after finishing using of DGA
• some drivers simply fail to switch back to normal resolution (use Ctrl-Alt-Keypad +, - to switch back manually)
• some drivers simply display strange colors
• some drivers lie about the amount of memory they map into the process's address space, thus vo_dga won't use doublebuffering (SIS?)
• some drivers seem to fail to report even a single valid mode. In this case the DGA driver will crash telling you about a nonsense mode of 100000x100000 or the like ...
• OSD only works with doublebuffering enabled

2.3.1.3.9. Future work

• use of the new X11 render interface for OSD
• where is my TODO list ???? :-(((

2.3.1.3.A. Some modelines

  Section "Modes"
    Identifier    "Modes[0]"
    Modeline	"800x600"  40     800 840 968 1056  600 601 605 628
    Modeline	"712x600"  35.0   712 740 850 900   400 410 412 425
    Modeline	"640x480"  25.175 640 664 760 800   480 491 493 525
    Modeline 	"400x300"  20     400 416 480 528   300 301 303 314 Doublescan
    Modeline	"352x288"  25.10  352 368 416 432   288 296 290 310
    Modeline	"352x240"  15.750 352 368 416 432   240 244 246 262 Doublescan
    Modeline	"320x240"  12.588 320 336 384 400   240 245 246 262 Doublescan
  EndSection

These entries work fine with my Riva128 chip, using nv.o XServer driver module.

2.3.1.3.B. Bug Reports

If you experience troubles with the DGA driver please feel free to file a bug report to me (e-mail address below). Please start mplayer with the -v option and include all lines in the bug report that start with vo_dga:

Please do also include the version of X11 you are using, the graphics card and your CPU type. The X11 driver module (defined in XF86-Config) might also help. Thanks!

Acki (acki@acki-netz.de, www.acki-netz.de)

2.3.1.4. SDL

Here are some notes about SDL out in MPlayer.

There are several commandline switches for SDL:
	-vo sdl:name		specifies sdl video driver to use (ie. aalib, dga, x11)
	-ao sdl:name		specifies sdl audio driver to use (ie. dsp, esd, arts)
	-noxv		disables Xvideo hardware acceleration
	-forcexv		tries to force Xvideo acceleration
SDL Keys:
	F		toggles fullscreen/windowed mode
	C		cycles available fullscreen modes
	W/S		mappings for * and / (mixer control)

KNOWN BUGS:

• Keys pressed under sdl:aalib console driver repeat forever. (use -vo aa !) It's bug in SDL, I can't change it (tested with SDL 1.2.1).

2.3.1.5. SVGAlib

If you don't have X, you can use the SVGAlib target! Be sure not to use the -fs switch, since it toggles the usage of the software scaler, and it's SLOOOW now, unless you have a real fast CPU (and/or MTRR?). :(

Of course you'll have to install svgalib and its development package in order for MPlayer build its SVGAlib driver (autodetected, but can be forced), and don't forget to edit /etc/vga/libvga.config to suit your card & monitor.

2.3.1.6. Framebuffer output (FBdev)

Whether to build the FBdev target is autodetected during ./configure . Read the framebuffer documentation in the kernel sources (Documentation/fb/*) for info on how to enable it, etc.. !

If your card doesn't support VBE 2.0 standard (older ISA/PCI cards, such as S3 Trio64), only VBE 1.2 (or older?) : Well, VESAfb is still available, but you'll have to load SciTech Display Doctor (formerly UniVBE) before booting Linux. Use a DOS boot disk or whatever. And don't forget to register your UniVBE ;))

The FBdev output takes some additional parameters above the others:

	-fb		specify the framebuffer device to use (/dev/fd0)
	-fbmode		mode name to use (according to /etc/fb.modes)
	-fbmodeconfig		config file of modes (default /etc/fb.modes)
	-monitor_hfreq		IMPORTANT values, see example.conf
	-monitor_vfreq
	-monitor_dotclock

If you want to change to a specific mode, then use

    mplayer -vm -fbmode (NameOfMode) filename

• -vm alone will choose the most suitable mode from /etc/fb.modes . Can be used together with -x and -y options too. The -flip option is supported only if the movie's pixel format matches the video mode's pixel format. Pay attention to the bpp value, fbdev driver tries to use the current, or if you specify the -bpp option, then that.
• -zoom option isn't supported (software scaling is slow). -fs option isn't supported. You can't use 8bpp (or less) modes.
• you possibly want to turn the cursor off : echo -e '\033[?25l'
  and the screen saver: setterm -blank 0
  To turn the cursor back on : echo -e '\033[?25h'

NOTE: FBdev video mode changing _does not work_ with the VESA framebuffer, and don't ask for it, since it's not an MPlayer limitation.

2.3.1.7. Matrox framebuffer (mga_vid)

This section is about the Matrox G200/G400/G450/G550 BES (Back-End Scaler) support, the mga_vid kernel driver. It's active developed by me (A'rpi), and it has hardware VSYNC support with triple buffering. It works on both framebuffer console and under X.

To use it, you first have to compile mga_vid.o:

    cd drivers
    make

Then create /dev/mga_vid device:

    mknod /dev/mga_vid c 178 0

and load the driver with

    insmod mga_vid.o

You should verify the memory size detection using the 'dmesg' command. If it's bad, use the mga_ram_size option (rmmod mga_vid first), specify card's memory size in MB:

    insmod mga_vid.o mga_ram_size=16

To make it load/unload automatically when needed, insert the following line at the end of /etc/modules.conf:

    alias char-major-178 mga_vid

Then run

    depmod -a

Now you have to (re)compile MPlayer, ./configure will detect /dev/mga_vid and build the 'mga' driver. Using it from MPlayer goes by '-vo mga' if you have matroxfb console, or '-vo xmga' under XFree86 3.x.x or 4.x.x.

The mga_vid driver cooperates with Xv.

2.3.1.8. SiS 6326 framebuffer (sis_vid)

SiS 6326 YUV Framebuffer driver -> sis_vid kernel driver

Its interface should be compatible with the mga_vid, but the driver was not updated after the mga_vid changes, so it's outdated now. Volunteers needed to test it and bring the code up-to-date.

2.3.1.9. 3dfx YUV support (tdfxfb)

This driver uses the kernel's tdfx framebuffer driver to play movies with YUV acceleration. You'll need a kernel with tdfxfb support, and recompile with ./configure --enable-tdfxfb

2.3.1.10. OpenGL output

MPlayer support displaying movies using OpenGL. Unfortunately, not all drivers support this ability. For example the Utah-GLX drivers (for XFree86 3.3.6) have it, with all cards. See http://utah-glx.sourceforge.net for details about how to install it.

XFree86(DRI) >= 4.0.3 supports it only with Matrox, and Radeon cards. See http://dri.sourceforge.net for download, and installation instructions.

2.3.1.11. AAlib - text mode displaying

Playing on terminal you'll get better speed and quality using the linux driver, not curses (-aadriver linux). But therefore you need write access on /dev/vcsa<terminal>! That isn't autodetected by aalib, bu vo_aa tries to find the best mode. See http://aa-project.sourceforge.net/tune/ for further tuning issues.

2.3.1.12. VESA - output to VESA BIOS

2.3.1.13. X11

2.3.1.14. Radeon video overlay (radeon_vid)

radeon_vid provides support for the BackEnd Scaler on ATI Radeon chipsets. It was designed and introduced as analog of mga_vid driver, so you can use it in the same way!
But main goal of this driver usage is VESA driver.
Simply because VESA enables TV-out on ATI's card but Backend scaler is used after mode switching. This implementation outputs video stream on both: TV-screen and CRTC display simultaneously. (It slightly degrades quality of video output but it's much better than nothing). Sorry! I couldn't find out any video overlay's related information on ATI pages. (I planned to implement it through int 10h calls). But it was very easy to implement this stuff through reading/writing Radeon ports.
NOTE: XXX_VID technology is perfectly undocumented and maybe in the future this stuff will be fully rewritten. This is the first public release of driver.

Installation

• cd drivers/radeon/radeon
make
  
• install the radeon_vid.o module to your kernelmodules
• execute the following : mknod /dev/radeon_vid c 178 0
• add the following at the end of the /etc/modules.conf file :
    alias char-major-178 radeon_vid
• run depmod -a

Usage:
  mplayer -vo vesa:lvo:/dev/radeon_vid <your options> filename

NOTE: don't use any framebuffers when you plan to use this driver ! Use it only from textmode console.

Limitations: Currently it works only with YUY2 format, so use the DirectShow codec family with it. You should have at least 32MB of video memory.
Conclusion: I know there are lot of lacks and bugs. So if you are able to improve something then simply send me your patches.

2.3.1.A. TV-out support

2.3.1.A.1. Matrox cards

Under Linux you have 2 methods to get TV out working :

• XFree86: using the driver and the HAL module, available from Matrox's site. This will give you X on the TV.
  This method doesn't give you accelerated playback as under Windoze! The second head has only YUV framebuffer, the BES (Back End Scaler, the YUV scaler on G200/G400/G450/G550 cards) doesn't work on it! The windows driver somehow workarounds this, probably by using the 3D engine to zoom, and the YUV framebuffer to display the zoomed image. If you really want to use X, use the -vo x11 -fs -zoom options, but it will be SLOW, and has Macrovision copyprotection enabled.
• Framebuffer: using the matroxfb modules in the 2.4 kernels. 2.2 kernels don't have the TVout feature in them, thus unusable for this. You have to enable ALL matroxfb-specific feature during compilation, and compile them into modules!
  • Enter TVout/matroxset and type make. Install matroxset into somewhere in your PATH.
  • If you don't have fbset installed, enter TVout/fbset and type make. Install fbset into somewhere in your PATH.
  • Then enter into the TVout/ directory in the MPlayer source, and execute ./modules as root. Your text-mode console will enter into framebuffer mode (no way back!).
  • Next, run the ./matroxtv script. This will present you to a very simple menu. Press 2 and ENTER. Now you should have the same picture on your monitor, and TV. The 3. option will turn on independent display, but then you can't use X! If the TV picture has some weird stripes on it, the script wasn't able to set the resolution correctly (to 640x512 by default). Use other menu items randomly and it'll be OK :)

  Yoh. Next task is to make the cursor on tty1 (or whatever) to disappear, and turn off screen blanking. Execute the following commands:

  echo -e '\033[?25l'
setterm -blank 0

  You possibly want to put the above into a script, and also clear the screen.. To turn the cursor back :
  echo -e '\033[?25h'

  Yeah kewl. Start movie playing with mplayer -vo mga -fs -screenw 640 -screenh 512 <filename>
  (if you use X, now change to matroxfb with for example CTRL-ALT-F1 !)
  Change 640x512 if you set the resolution to other..
  Enjoy the ultra-fast ultra-featured Matrox TV output (better than Xv) !

2.3.1.A.2. ATI cards

A few word about ATI's TV-out:
Currently ATI doesn't want to support any of its TV-out chips under Linux. Below is official answer from ATI Inc.:


> Hello!
>
> On your pages you wrote that you support linux developers.
> Currently I participate with mplayer project (www.mplayerhq.hu)
> I'm interesting with enabling TV-out on Radeon VE chips during
> movie playback. I would be glad to add this feature to radeonfb driver
> (which can be found in CVS tree of mplayer project at main/drivers/radeon).
> Do I have a chance to get any official technical documenation?
We will not provide TV out related documents due to macrovision concerns.
Also mpeg2 decoding is something that we MAY consider in the future but not
at this current time. This is again due to proprietary and 3rd party
information.

Pity isn't?

Q:What is Macrovision?
A:It's copy protection mechanism.

It means that if they open any TV-out related information then hackers will be able to disable copy protection on their chips. Therefore we have no chance to get working TV-out on ATI.

What's status of ATI's tv-out chips under Linux: