# Video output devices

## 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. Also, this driver supports adjusting brightness/contrast/hue/etc. (unless you use the old, slow DirectShow DivX codec, which supports it everywhere), see the man page.

In order to make this work, be sure to check the following:

1. You have to use XFree86 4.0.2 or newer (former versions don't have XVideo)

2. Your card actually supports hardware acceleration (modern cards do)

3. X loads the XVideo extension, it's something like this:

       (II) Loading extension XVideo

   in `/var/log/XFree86.0.log`

   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!

4. 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.

5. And finally, check if MPlayer was compiled with 'xv' support. Do a `mplayer -vo help | grep xv` . If 'xv' support was built a line similar to this should appear:

         xv      X11/Xv

## DGA

### PREAMBLE

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).

### 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 executable (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 X server, 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 X server's video driver that controls this chip. So it does not work on every system...

### 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 highly recommended! MPlayer's DGA driver is autodetected by `./configure`, or you can force it with `--enable-dga`.

If the driver couldn't switch to a smaller resolution, experiment with options `-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.

### Security risk

This is a big security risk! Never do this on a server or on a computer that can be accessed by other people because they can gain root privileges through SUID root MPlayer.

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

### 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 honoring aspect ratio) of the video data, but the X server only allows switching to resolutions predefined in `/etc/X11/XF86Config` (`/etc/X11/XF86Config-4` for XFree 4.X.X respectively). Those are defined by so-called modelines and depend on the capabilities of your video hardware. The X server 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`.

These entries are known to work fine with a Riva128 chip, using the nv.o X server driver module.

    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

### DGA & MPLAYER

DGA is used in two places with MPlayer: The SDL driver can be made to make use of it (`-vo sdl:driver=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.

### FEATURES

The DGA driver is invoked by specifying `-vo dga` at the command line. The default behavior is to switch to a resolution matching the original resolution of the video as close as possible. It deliberately ignores the `-vm` and `-fs` options (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 from using additional cycles 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 `XF86Config` 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 double buffering, which results in much smoother movie playback. It will tell you whether double buffering is enabled or not.

Double buffering 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.

Double buffering may be switched on by using the option `-double` and may be disabled with `-nodouble`. Current default option is to disable double buffering. When using the DGA driver, onscreen display (OSD) only works with double buffering enabled. However, enabling double buffering may result in a big speed penalty (on my K6-II+ 525 it used an additional 20% of CPU time!) depending on the implementation of DGA for your hardware.

### 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 16 bit depth since they require only half the memory bandwidth of a 32 bit display.

Using a depth of 24 bit is a good idea even 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 be played back on a Pentium MMX 266. AMD K6-2 CPUs might work at 400 MHZ and above.

### KNOWN BUGS

Well, according to some developers 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 + and 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 double buffering (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 something like that.

- OSD only works with double buffering enabled (else it flickers).

## SVGAlib

### INSTALLATION

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 and monitor.

Be sure not to use the `-fs` switch, since it toggles the usage of the software scaler, and it's slow. If you really need it, use the `-sws 4` option which will produce bad quality, but is somewhat faster.

### EGA (4BPP) SUPPORT

SVGAlib incorporates EGAlib, and MPlayer has the possibility to display any movie in 16 colors, thus usable in the following sets:

- EGA card with EGA monitor: 320x200x4bpp, 640x200x4bpp, 640x350x4bpp

- EGA card with CGA monitor: 320x200x4bpp, 640x200x4bpp

The bpp (bits per pixel) value must be set to 4 by hand: `-bpp 4`

The movie probably must be scaled down to fit in EGA mode:

    -vf scale=640:350

or

    -vf scale=320:200

For that we need fast but bad quality scaling routine:

    -sws 4

Maybe automatic aspect correction has to be shut off:

    -noaspect

According to my experience the best image quality on EGA screens can be achieved by decreasing the brightness a bit: `-vf eq=-20:0`. I also needed to lower the audio samplerate on my box, because the sound was broken on 44kHz: `-srate 22050`.

You can turn on OSD and subtitles only with the `expand` filter, see the man page for exact parameters.

## Framebuffer output (FBdev)

Whether to build the FBdev target is autodetected during `./configure`. Read the framebuffer documentation in the kernel sources (`Documentation/fb/*`) for more information.

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 (default: `/dev/fb0`)

`-fbmode`

  mode name to use (according to `/etc/fb.modes`)

`-fbmodeconfig`

  config file of modes (default: `/etc/fb.modes`)

`-monitor-hfreq`
`-monitor-vfreq`
`-monitor-dotclock`

  important values, see `example.conf`

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

    mplayer -vm -fbmode name_of_mode 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 (use `-vf scale`). You can't use 8bpp (or less) modes.

- You possibly want to turn the cursor off:

      echo -e '\033[?25l'

  or

      setterm -cursor off

  and the screen saver:

      setterm -blank 0

  To turn the cursor back on:

      echo -e '\033[?25h'

  or

      setterm -cursor on

FBdev video mode changing does not work with the VESA framebuffer, and don't ask for it, since it's not an MPlayer limitation.

## Matrox framebuffer (mga_vid)

mga_vid is a combination of a video output driver and a Linux kernel module that utilizes the Matrox G200/G400/G450/G550 video scaler/overlay unit to perform YUV->RGB colorspace conversion and arbitrary video scaling. mga_vid has hardware VSYNC support with triple buffering. It works on both a framebuffer console and under X, but only with Linux 2.4.x.

For a Linux 2.6.x version of this driver check out or have a look at the external Subversion repository of mga_vid which can be checked out via

    svn checkout svn://svn.mplayerhq.hu/mga_vid

### Installation:

1. To use it, you first have to compile `drivers/mga_vid.o`:

       make drivers

2. Then run (as root)

       make install-drivers

   which should install the module and create the device node for you. Load the driver with

       insmod mga_vid.o

3. 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

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

       alias char-major-178 mga_vid

5. 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.

The `/dev/mga_vid` device file can be read for some info, for example by

    cat /dev/mga_vid

and can be written for brightness change:

    echo "brightness=120" > /dev/mga_vid

There is a test application called `mga_vid_test` in the same directory. It should draw 256x256 images on the screen if all is working well.

## 3Dfx YUV support

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

## tdfx_vid

This is a combination of a Linux kernel module and a video output driver, similar to mga_vid. You'll need a 2.4.x kernel with the agpgart driver since tdfx_vid uses AGP. Pass `--enable-tdfxfb` to `configure` to build the video output driver and build the kernel module with the following instructions.

### Installing the tdfx_vid.o kernel module:

1. Compile `drivers/tdfx_vid.o`:

       make drivers

2. Then run (as root)

       make install-drivers

   which should install the module and create the device node for you. Load the driver with

       insmod tdfx_vid.o

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

       alias char-major-178 tdfx_vid

There is a test application called `tdfx_vid_test` in the same directory. It should print out some useful information if all is working well.

## OpenGL output

MPlayer supports displaying movies using OpenGL, but if your platform/driver supports xv as should be the case on a PC with Linux, use xv instead, OpenGL performance is considerably worse. If you have an X11 implementation without xv support, OpenGL is a viable alternative.

Unfortunately not all drivers support this feature. The Utah-GLX drivers (for XFree86 3.3.6) support it for all cards. See for details about how to install it.

XFree86(DRI) 4.0.3 or later supports OpenGL with Matrox and Radeon cards, 4.2.0 or later supports Rage128. See for download and installation instructions.

A hint from one of our users: the GL video output can be used to get vsynced TV output. You'll have to set an environment variable (at least on nVidia):

`export __GL_SYNC_TO_VBLANK=1`

## AAlib – text mode displaying

AAlib is a library for displaying graphics in text mode, using powerful ASCII renderer. There are lots of programs already supporting it, like Doom, Quake, etc. MPlayer contains a very usable driver for it. If `./configure` detects aalib installed, the aalib libvo driver will be built.

You can use some keys in the AA Window to change rendering options:

Key | Action
--- | ---
1 | decrease contrast
2 | increase contrast
3 | decrease brightness
4 | increase brightness
5 | switch fast rendering on/off
6 | set dithering mode (none, error distribution, Floyd Steinberg)
7 | invert image
8 | toggles between aa and MPlayer control

### The following command line options can be used:

`-aaosdcolor=V`

  change OSD color

`-aasubcolor=V`

  Change subtitle color

  where V can be: `0` (normal), `1` (dark), `2` (bold), `3` (bold font), `4` (reverse), `5` (special).

### AAlib itself provides a large sum of options. Here are some important:

`-aadriver`

  Set recommended aa driver (X11, curses, Linux).

`-aaextended`

  Use all 256 characters.

`-aaeight`

  Use eight bit ASCII.

`-aahelp`

  Prints out all aalib options.

The rendering is very CPU intensive, especially when using AA-on-X (using aalib on X), and it's least CPU intensive on standard, non-framebuffer console. Use SVGATextMode to set up a big textmode, then enjoy! (secondary head Hercules cards rock :)) (but IMHO you can use `-vf 1bpp` option to get graphics on hgafb:)

Use the `-framedrop` option if your computer isn't fast enough to render all frames!

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, but vo_aa tries to find the best mode. See for further tuning issues.

## libcaca – Color ASCII Art library

The libcaca library is a graphics library that outputs text instead of pixels, so that it can work on older video cards or text terminals. It is not unlike the famous AAlib library. libcaca needs a terminal to work, thus it should work on all Unix systems (including Mac OS X) using either the slang library or the ncurses library, on DOS using the conio.h library, and on Windows systems using either slang or ncurses (through Cygwin emulation) or conio.h. If `./configure` detects libcaca, the caca libvo driver will be built.

### The differences with AAlib are the following:

- 16 available colors for character output (256 color pairs)

- color image dithering

### But libcaca also has the following limitations:

- no support for brightness, contrast, gamma

You can use some keys in the caca window to change rendering options:

Key | Action
--- | ---
d | Toggle libcaca dithering methods.
a | Toggle libcaca antialiasing.
b | Toggle libcaca background.

### libcaca will also look for certain environment variables:

`CACA_DRIVER`

  Set recommended caca driver. e.g. ncurses, slang, x11.

`CACA_GEOMETRY (X11 only)`

  Specifies the number of rows and columns. e.g. 128x50.

`CACA_FONT (X11 only)`

  Specifies the font to use. e.g. fixed, nexus.

Use the `-framedrop` option if your computer is not fast enough to render all frames.

## VESA - output to VESA BIOS

This driver was designed and introduced as a generic driver for any video card which has VESA VBE 2.0 compatible BIOS. Another advantage of this driver is that it tries to force TV output on. VESA BIOS EXTENSION (VBE) Version 3.0 Date: September 16, 1998 (Page 70) says:

> ### Dual-Controller Designs

> VBE 3.0 supports the dual-controller design by assuming that since both controllers are typically provided by the same OEM, under control of a single BIOS ROM on the same graphics card, it is possible to hide the fact that two controllers are indeed present from the application. This has the limitation of preventing simultaneous use of the independent controllers, but allows applications released before VBE 3.0 to operate normally. The VBE Function 00h (Return Controller Information) returns the combined information of both controllers, including the combined list of available modes. When the application selects a mode, the appropriate controller is activated. Each of the remaining VBE functions then operates on the active controller.

So you have chances to get working TV-out by using this driver. (I guess that TV-out frequently is standalone head or standalone output at least.)

### ADVANTAGES

- You have chances to watch movies if Linux even doesn't know your video hardware.

- You don't need to have installed any graphics' related things on your Linux (like X11 (AKA XFree86), fbdev and so on). This driver can be run from text-mode.

- You have chances to get working TV-out. (It's known at least for ATI's cards).

- This driver calls `int 10h` handler thus it's not an emulator - it calls real things of real BIOS in real-mode (actually in vm86 mode).

- You can use VIDIX with it, thus getting accelerated video display and TV output at the same time! (Recommended for ATI cards.)

- If you have VESA VBE 3.0+, and you had specified `monitor-hfreq, monitor-vfreq, monitor-dotclock` somewhere (config file, or command line) you will get the highest possible refresh rate. (Using General Timing Formula). To enable this feature you have to specify all your monitor options.

### DISADVANTAGES

- It works only on x86 systems.

- It can be used only by root.

- Currently it's available only for Linux.

### COMMAND LINE OPTIONS AVAILABLE FOR VESA

`-vo vesa:opts`

  currently recognized: `dga` to force dga mode and `nodga` to disable dga mode. In dga mode you can enable double buffering via the `-double` option. Note: you may omit these parameters to enable autodetection of dga mode.

### KNOWN PROBLEMS AND WORKAROUNDS

- If you have installed NLS font on your Linux box and run VESA driver from text-mode then after terminating MPlayer you will have ROM font loaded instead of national. You can load national font again by using `setsysfont` utility from the Mandrake/Mandriva distribution for example. (Hint: The same utility is used for localization of fbdev).

- Some Linux graphics drivers don't update active BIOS mode in DOS memory. So if you have such problem - always use VESA driver only from text-mode. Otherwise text-mode (#03) will be activated anyway and you will need restart your computer.

- Often after terminating VESA driver you get black screen. To return your screen to original state - simply switch to other console (by pressing Alt F<x>) then switch to your previous console by the same way.

- To get working TV-out you need have plugged TV-connector in before booting your PC since video BIOS initializes itself only once during POST procedure.

## X11

Avoid if possible. Outputs to X11 (uses shared memory extension), with no hardware acceleration at all. Supports (MMX/3DNow/SSE accelerated, but still slow) software scaling, use the options `-fs -zoom`. Most cards have hardware scaling support, use the `-vo xv` output for them, or `-vo xmga` for Matrox cards.

The problem is that most cards' driver doesn't support hardware acceleration on the second head/TV. In those cases, you see green/blue colored window instead of the movie. This is where this driver comes in handy, but you need powerful CPU to use software scaling. Don't use the SDL driver's software output+scaler, it has worse image quality!

Software scaling is very slow, you better try changing video modes instead. It's very simple. See the DGA section's modelines, and insert them into your `XF86Config`.

- If you have XFree86 4.x.x: use the `-vm` option. It will change to a resolution your movie fits in. If it doesn't:

- With XFree86 3.x.x: you have to cycle through available resolutions with the Ctrl Alt Keypad + and Ctrl Alt Keypad - keys.

If you can't find the modes you inserted, browse XFree86's output. Some drivers can't use low pixelclocks that are needed for low resolution video modes.

## VIDIX

### PREAMBLE

VIDIX is the abbreviation for VIDeo Interface for *niX. VIDIX was designed and introduced as an interface for fast user-space drivers providing such video performance as mga_vid does for Matrox cards. It's also very portable.

This interface was designed as an attempt to fit existing video acceleration interfaces (known as mga_vid, rage128_vid, radeon_vid, pm3_vid) into a fixed scheme. It provides a high level interface to chips which are known as BES (BackEnd scalers) or OV (Video Overlays). It doesn't provide low level interface to things which are known as graphics servers. (I don't want to compete with X11 team in graphics mode switching). I.e. main goal of this interface is to maximize the speed of video playback.

### USAGE

- You can use standalone video output driver: `-vo xvidix`. This driver was developed as X11's front end to VIDIX technology. It requires X server and can work only under X server. Note that, as it directly accesses the hardware and circumvents the X driver, pixmaps cached in the graphics card's memory may be corrupted. You can prevent this by limiting the amount of video memory used by X with the XF86Config option "VideoRam" in the device section. You should set this to the amount of memory installed on your card minus 4MB. If you have less than 8MB of video ram, you can use the option "XaaNoPixmapCache" in the screen section instead.

- There is a console VIDIX driver: `-vo cvidix`. This requires a working and initialized framebuffer for most cards (or else you'll just mess up the screen), and you'll have a similar effect as with `-vo mga` or `-vo fbdev`. nVidia cards however are able to output truly graphical video on a real text console. See the nvidia_vid section for more information. To get rid of text on the borders and the blinking cursor, try something like

      setterm -cursor off > /dev/tty9

  (assuming tty9 is unused so far) and then switch to tty9. On the other hand, `-colorkey 0` should give you a video running in the "background", though this depends on the colorkey functionality to work right.

- You can use VIDIX subdevice which was applied to several video output drivers, such as: `-vo vesa:vidix` (Linux only) and `-vo fbdev:vidix`.

Indeed it doesn't matter which video output driver is used with VIDIX.

### REQUIREMENTS

- Video card should be in graphics mode (except nVidia cards with the `-vo cvidix` output driver).

- MPlayer's video output driver should know active video mode and be able to tell to VIDIX subdevice some video characteristics of server.

### USAGE METHODS

When VIDIX is used as subdevice (`-vo vesa:vidix`) then video mode configuration is performed by video output device (vo_server in short). Therefore you can pass into command line of MPlayer the same keys as for vo_server. In addition it understands `-double` key as globally visible parameter. (I recommend using this key with VIDIX at least for ATI's card). As for `-vo xvidix`, currently it recognizes the following options: `-fs -zoom -x -y -double`.

Also you can specify VIDIX's driver directly as third subargument in command line:

    mplayer -vo xvidix:mga_vid.so -fs -zoom -double file.avi

or

    mplayer -vo vesa:vidix:radeon_vid.so -fs -zoom -double -bpp 32 file.avi

But it's dangerous, and you shouldn't do that. In this case given driver will be forced and result is unpredictable (it may freeze your computer). You should do that ONLY if you are absolutely sure it will work, and MPlayer doesn't do it automatically. Please tell about it to the developers. The right way is to use VIDIX without arguments to enable driver autodetection.

### svgalib_helper

Since VIDIX requires direct hardware access you can either run it as root or set the SUID bit on the MPlayer binary (Warning: This is a security risk!). Alternatively, you can use a special kernel module, like this:

1. Download the development version of svgalib (1.9.x).

2. Compile the module in the `svgalib_helper` directory (it can be found inside the `svgalib-1.9.17/kernel/` directory if you've downloaded the source from the svgalib site) and insmod it.

3. To create the necessary devices in the `/dev` directory, do a

       make device

   in the `svgalib_helper` dir, as root.

4. Then run `configure` again and pass the parameter `--enable-svgalib_helper` as well as `--extra-cflags=/path/to/svgalib_helper/sources/kernel/svgalib_helper`, where /path/to/svgalib_helper/sources/ has to be adjusted to wherever you extracted svgalib_helper sources.

5. Recompile.

### ATI cards

Currently most ATI cards are supported natively, from Mach64 to the newest Radeons.

There are two compiled binaries: `radeon_vid` for Radeon and `rage128_vid` for Rage 128 cards. You may force one or let the VIDIX system autoprobe all available drivers.

### Matrox cards

Matrox G200, G400, G450 and G550 have been reported to work.

The driver supports video equalizers and should be nearly as fast as the Matrox framebuffer

### Trident cards

There is a driver available for the Trident Cyberblade/i1 chipset, which can be found on VIA Epia motherboards.

The driver was written and is maintained by Alastair M. Robinson.

### 3DLabs cards

Although there is a driver for the 3DLabs GLINT R3 and Permedia3 chips, no one has tested it, so reports are welcome.

### nVidia cards

An unique feature of the nvidia_vid driver is its ability to display video on plain, pure, text-only console - with no framebuffer or X magic whatsoever. For this purpose, we'll have to use the `cvidix` video output, as the following example shows:

    mplayer -vo cvidix example.avi

### SiS cards

This is very experimental code, just like nvidia_vid.

It's been tested on SiS 650/651/740 (the most common chipsets used in the SiS versions of the "Shuttle XPC" barebones boxes out there)

Reports awaited!

## DirectFB

> "DirectFB is a graphics library which was designed with embedded systems in mind. It offers maximum hardware accelerated performance at a minimum of resource usage and overhead." - quoted from

I'll exclude DirectFB features from this section.

Though MPlayer is not supported as a "video provider" in DirectFB, this output driver will enable video playback through DirectFB. It will - of course - be accelerated, on my Matrox G400 DirectFB's speed was the same as XVideo.

Always try to use the newest version of DirectFB. You can use DirectFB options on the command line, using the `-dfbopts` option. Layer selection can be done by the subdevice method, e.g.: `-vo directfb:2` (layer -1 is default: autodetect)

## DirectFB/Matrox (dfbmga)

Please read the main DirectFB section for general information.

This video output driver will enable CRTC2 (on the second head) on Matrox G400/G450/G550 cards, displaying video independent of the first head.

Ville Syrjala's has a README and a HOWTO on his homepage that explain how to make DirectFB TV output run on Matrox cards.

the first DirectFB version with which we could get this working was 0.9.17 (it's buggy, needs that surfacemanager patch from the URL above). Porting the CRTC2 code to mga_vid has been planned for years, patches are welcome.

## MPEG decoders

### DVB output and input

MPlayer supports cards with the Siemens DVB chipset from vendors like Siemens, Technotrend, Galaxis or Hauppauge. The latest DVB drivers are available from the Linux TV site. If you want to do software transcoding you should have at least a 1GHz CPU.

Configure should detect your DVB card. If it did not, force detection with

    ./configure --enable-dvb

Then compile and install as usual.

#### USAGE

Hardware decoding of streams containing MPEG-1/2 video and/or MPEG audio can be done with this command:

    mplayer -ao mpegpes -vo mpegpes file.mpg|vob

Decoding of any other type of video stream requires transcoding to MPEG-1, thus it's slow and may not be worth the trouble, especially if your computer is slow. It can be achieved using a command like this:

    mplayer -ao mpegpes -vo mpegpes yourfile.ext
    mplayer -ao mpegpes -vo mpegpes -vf expand yourfile.ext

Note that DVB cards only support heights 288 and 576 for PAL or 240 and 480 for NTSC. You must rescale for other heights by adding `scale=width:height` with the width and height you want to the `-vf` option. DVB cards accept various widths, like 720, 704, 640, 512, 480, 352 etc. and do hardware scaling in horizontal direction, so you do not need to scale horizontally in most cases. For a 512x384 (aspect 4:3) MPEG-4 (DivX) try:

    mplayer -ao mpegpes -vo mpegpes -vf scale=512:576

If you have a widescreen movie and you do not want to scale it to full height, you can use the `expand=w:h` filter to add black bands. To view a 640x384 MPEG-4 (DivX), try:

    mplayer -ao mpegpes -vo mpegpes -vf expand=640:576 file.avi

If your CPU is too slow for a full size 720x576 MPEG-4 (DivX), try downscaling:

    mplayer -ao mpegpes -vo mpegpes -vf scale=352:576 file.avi

If speed does not improve, try vertical downscaling, too:

    mplayer -ao mpegpes -vo mpegpes -vf scale=352:288 file.avi

For OSD and subtitles use the OSD feature of the expand filter. So, instead of `expand=w:h` or `expand=w:h:x:y`, use `expand=w:h:x:y:1` (the 5th parameter `:1` at the end will enable OSD rendering). You may want to move the image up a bit to get a bigger black zone for subtitles. You may also want to move subtitles up, if they are outside your TV screen, use the `-subpos <0-100>` option to adjust this (`-subpos 80` is a good choice).

In order to play non-25fps movies on a PAL TV or with a slow CPU, add the `-framedrop` option.

To keep the aspect ratio of MPEG-4 (DivX) files and get the optimal scaling parameters (hardware horizontal scaling and software vertical scaling while keeping the right aspect ratio), use the new dvbscale filter:

    for a  4:3 TV: -vf dvbscale,scale=-1:0,expand=-1:576:-1:-1:1
    for a 16:9 TV: -vf dvbscale=1024,scale=-1:0,expand=-1:576:-1:-1:1

#### Digital TV (DVB input module)

You can use your DVB card for watching Digital TV.

You should have the programs `scan` and `szap/tzap/czap/azap` installed; they are all included in the drivers package.

Verify that your drivers are working properly with a program such as `dvbstream` (that is the base of the DVB input module).

Now you should compile a `~/.mplayer/channels.conf` file, with the syntax accepted by `szap/tzap/czap/azap`, or have `scan` compile it for you.

If you have more than one card type (e.g. Satellite, Terrestrial, Cable and ATSC) you can save your channels files as `~/.mplayer/channels.conf.sat`, `~/.mplayer/channels.conf.ter`, `~/.mplayer/channels.conf.cbl`, and `~/.mplayer/channels.conf.atsc`, respectively, so as to implicitly hint MPlayer to use these files rather than `~/.mplayer/channels.conf`, and you only need to specify which card to use.

Make sure that you have only Free to Air channels in your `channels.conf` file, or MPlayer will wait for an unencrypted transmission.

In your audio and video fields you can use an extended syntax: `...:pid[+pid]:...` (for a maximum of 6 pids each); in this case MPlayer will include in the stream all the indicated pids, plus pid 0 (that contains the PAT). You should always include in each row the PMT and PCR pids for the corresponding channel (if you know them). You can also specify 8192, this will select all pids on this frequency and you can then switch between the programs with TAB. This might need more bandwidth, though cheap cards always transfer all channels at least to the kernel so it does not make much of a difference for these. Other possible uses are: televideo pid, second audio track, etc.

If MPlayer complains frequently about

    Too many video/audio packets in the buffer

or if you notice a growing desynchronization between audio and video verify the presence of the PCR pid in your stream (needed to comply with the buffering model of the transmitter) and/or try to use the libavformat MPEG-TS demuxer by adding `-demuxer lavf -lavfdopts probesize=128` to your command line.

To show the first of the channels present in your list, run

    mplayer dvb://

If you want to watch a specific channel, such as R1, run

    mplayer dvb://R1

If you have more than one card you also need to specify the number of the card where the channel is visible (e.g. 2) with the syntax:

    mplayer dvb://2@R1

To change channels press the h (next) and k (previous) keys, or use the OSD menu.

To temporarily disable the audio or the video stream copy the following to `~/.mplayer/input.conf`:

    % set_property  switch_video -2
    & step_property switch_video
    ? set_property  switch_audio -2
    ^ step_property switch_audio

(Overriding the action keys as preferred.) When pressing the key corresponding to switch_x -2 the associated stream will be closed; when pressing the key corresponding to step_x the stream will be reopened. Notice that this switching mechanism will not work as expected when there are multiple audio and video streams in the multiplex.

During playback (not during recording), in order to prevent stuttering and error messages such as 'Your system is too slow' it is advisable to add

    -mc 10 -speed 0.97 -af scaletempo

to your command line, adjusting the scaletempo parameters as preferred.

If your `~/.mplayer/menu.conf` contains a `<dvbsel>` entry, such as the one in the example file `etc/dvb-menu.conf` (that you can use to overwrite `~/.mplayer/menu.conf`), the main menu will show a sub-menu entry that will permit you to choose one of the channels present in your `channels.conf`, possibly preceded by a menu with the list of cards available if more than one is usable by MPlayer.

If you want to save a program to disk you can use

    mplayer -dumpfile r1.ts -dumpstream dvb://R1

If you want to record it in a different format (re-encoding it) instead you can run a command such as

    mencoder -o r1.avi -ovc xvid -xvidencopts bitrate=800 \
        -oac mp3lame -lameopts cbr:br=128 -pp=ci dvb://R1

Read the man page for a list of options that you can pass to the DVB input module.

#### FUTURE

If you have questions or want to hear feature announcements and take part in discussions on this subject, join our MPlayer-DVB mailing list. Please remember that the list language is English.

In the future you may expect the ability to display OSD and subtitles using the native OSD feature of DVB cards.

### DXR2

MPlayer supports hardware accelerated playback with the Creative DXR2 card.

First of all you will need properly installed DXR2 drivers. You can find the drivers and installation instructions at the DXR2 Resource Center site.

#### USAGE

`-vo dxr2`

  Enable TV output.

`-vo dxr2:x11` or `-vo dxr2:xv`

  Enable Overlay output in X11.

`-dxr2 <option1:option2:...>`

  This option is used to control the DXR2 driver.

The overlay chipset used on the DXR2 is of pretty bad quality but the default settings should work for everybody. The OSD may be usable with the overlay (not on TV) by drawing it in the colorkey. With the default colorkey settings you may get variable results, usually you will see the colorkey around the characters or some other funny effect. But if you properly adjust the colorkey settings you should be able to get acceptable results.

Please see the man page for available options.

### DXR3/Hollywood+

MPlayer supports hardware accelerated playback with the Creative DXR3 and Sigma Designs Hollywood Plus cards. These cards both use the em8300 MPEG decoder chip from Sigma Designs.

First of all you will need properly installed DXR3/H+ drivers, version 0.12.0 or later. You can find the drivers and installation instructions at the DXR3 & Hollywood Plus for Linux site. `configure` should detect your card automatically, compilation should go without problems.

#### USAGE

`-vo dxr3:prebuf:sync:norm=x:device`

  `overlay` activates the overlay instead of TV-out. It requires that you have a properly configured overlay setup to work right. The easiest way to configure the overlay is to first run autocal. Then run mplayer with dxr3 output and without overlay turned on, run dxr3view. In dxr3view you can tweak the overlay settings and see the effects in realtime, perhaps this feature will be supported by the MPlayer GUI in the future. When overlay is properly set up you will no longer need to use dxr3view. `prebuf` turns on prebuffering. Prebuffering is a feature of the em8300 chip that enables it to hold more than one frame of video at a time. This means that when you are running with prebuffering MPlayer will try to keep the video buffer filled with data at all times. If you are on a slow machine MPlayer will probably use close to, or precisely 100% of CPU. This is especially common if you play pure MPEG streams (like DVDs, SVCDs a.s.o.) since MPlayer will not have to reencode it to MPEG it will fill the buffer very fast. With prebuffering video playback is much less sensitive to other programs hogging the CPU, it will not drop frames unless applications hog the CPU for a long time. When running without prebuffering the em8300 is much more sensitive to CPU load, so it is highly suggested that you turn on MPlayer's `-framedrop` option to avoid further loss of sync. `sync` will turn on the new sync-engine. This is currently an experimental feature. With the sync feature turned on the em8300's internal clock will be monitored at all times, if it starts to deviate from MPlayer's clock it will be reset causing the em8300 to drop any frames that are lagging behind. `norm=x` will set the TV norm of the DXR3 card without the need for external tools like em8300setup. Valid norms are 5 = NTSC, 4 = PAL-60, 3 = PAL. Special norms are 2 (auto-adjust using PAL/PAL-60) and 1 (auto-adjust using PAL/NTSC) because they decide which norm to use by looking at the frame rate of the movie. norm = 0 (default) does not change the current norm. `device` = device number to use if you have more than one em8300 card. Any of these options may be left out. `:prebuf:sync` seems to work great when playing MPEG-4 (DivX) movies. People have reported problems using the prebuf option when playing MPEG-1/2 files. You might want to try running without any options first, if you have sync problems, or DVD subtitle problems, give `:sync` a try.

`-ao oss:/dev/em8300_ma-X`

  For audio output, where X is the device number (0 if one card).

`-af resample=xxxxx`

  The em8300 cannot play back samplerates lower than 44100Hz. If the sample rate is below 44100Hz select either 44100Hz or 48000Hz depending on which one matches closest. I.e. if the movie uses 22050Hz use 44100Hz as 44100 / 2 = 22050, if it is 24000Hz use 48000Hz as 48000 / 2 = 24000 and so on. This does not work with digital audio output (`-ac hwac3`).

`-vf lavc`

  To watch non-MPEG content on the em8300 (i.e. MPEG-4 (DivX) or RealVideo) you have to specify an MPEG-1 video filter such as libavcodec (lavc). See the man page for further info about `-vf lavc`. Currently there is no way of setting the fps of the em8300 which means that it is fixed to 30000/1001 fps. Because of this it is highly recommended that you use `-vf lavc=quality:25` especially if you are using prebuffering. Then why 25 and not 30000/1001? Well, the thing is that when you use 30000/1001 the picture becomes a bit jumpy. The reason for this is unknown to us. If you set it to somewhere between 25 and 27 the picture becomes stable. For now all we can do is accept this for a fact.

`-vf expand=-1:-1:-1:-1:1`

  Although the DXR3 driver can put some OSD onto the MPEG-1/2/4 video, it has much lower quality than MPlayer's traditional OSD, and has several refresh problems as well. The command line above will firstly convert the input video to MPEG-4 (this is mandatory, sorry), then apply an expand filter which won't expand anything (-1: default), but apply the normal OSD onto the picture (that's what the "1" at the end does).

`-ac hwac3`

  The em8300 supports playing back AC-3 audio (surround sound) through the digital audio output of the card. See the `-ao oss` option above, it must be used to specify the DXR3's output instead of a sound card.

## Zr

This is a display-driver (`-vo zr`) for a number of MJPEG capture/playback cards (tested for DC10+ and Buz, and it should work for the LML33, the DC10). The driver works by encoding the frame to JPEG and then sending it to the card. For the JPEG encoding libavcodec is used, and required. With the special cinerama mode, you can watch movies in true wide screen provided that you have two beamers and two MJPEG cards. Depending on resolution and quality settings, this driver may require a lot of CPU power, remember to specify `-framedrop` if your machine is too slow. Note: My AMD K6-2 350MHz is (with `-framedrop`) quite adequate for watching VCD sized material and downscaled movies.

This driver talks to the kernel driver available at , so you must get it working first. The presence of an MJPEG card is autodetected by the `configure` script, if autodetection fails, force detection with

    ./configure --enable-zr

The output can be controlled by several options, a long description of the options can be found in the man page, a short list of options can be viewed by running

    mplayer -zrhelp

Things like scaling and the OSD (on screen display) are not handled by this driver but can be done using the video filters. For example, suppose that you have a movie with a resolution of 512x272 and you want to view it fullscreen on your DC10+. There are three main possibilities, you may scale the movie to a width of 768, 384 or 192. For performance and quality reasons, I would choose to scale the movie to 384x204 using the fast bilinear software scaler. The command line is

    mplayer -vo zr -sws 0 -vf scale=384:204 movie.avi

Cropping can be done by the `crop` filter and by this driver itself. Suppose that a movie is too wide for display on your Buz and that you want to use `-zrcrop` to make the movie less wide, then you would issue the following command

    mplayer -vo zr -zrcrop 720x320+80+0 benhur.avi

if you want to use the `crop` filter, you would do

    mplayer -vo zr -vf crop=720:320:80:0 benhur.avi

Extra occurrences of `-zrcrop` invoke cinerama mode, i.e. you can distribute the movie over several TVs or beamers to create a larger screen. Suppose you have two beamers. The left one is connected to your Buz at `/dev/video1` and the right one is connected to your DC10+ at `/dev/video0`. The movie has a resolution of 704x288. Suppose also that you want the right beamer in black and white and that the left beamer should have JPEG frames at quality 10, then you would issue the following command

    mplayer -vo zr -zrdev /dev/video0 -zrcrop 352x288+352+0 -zrxdoff 0 -zrbw \
        -zrcrop 352x288+0+0 -zrdev /dev/video1 -zrquality 10 \
            movie.avi

You see that the options appearing before the second `-zrcrop` only apply to the DC10+ and that the options after the second `-zrcrop` apply to the Buz. The maximum number of MJPEG cards participating in cinerama is four, so you can build a 2x2 vidiwall.

Finally an important remark: Do not start or stop XawTV on the playback device during playback, it will crash your computer. It is, however, fine to FIRST start XawTV, THEN start MPlayer, wait for MPlayer to finish and THEN stop XawTV.

## Blinkenlights

This driver is capable of playback using the Blinkenlights UDP protocol. If you don't know what Blinkenlights or its successor Arcade are, find it out. Although this is most probably the least used video output driver, without a doubt it is the coolest MPlayer has to offer. Just watch some of the Blinkenlights documentation videos. On the Arcade video you can see the Blinkenlights output driver in action at 00:07:50.

## TV-out support

### Matrox G400 cards

Under Linux you have two methods to get G400 TV out working:

for Matrox G450/G550 TV-out instructions, please see the next section!

XFree86

  Using the driver and the HAL module, available from the Matrox site. This will give you X on the TV.

  This method doesn't give you accelerated playback as under Windows! 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 copy protection enabled (you can "workaround" Macrovision using this Perl script).

Framebuffer

  Using the matroxfb modules in the 2.4 kernels. 2.2 kernels don't have the TV-out feature in them, thus unusable for this. You have to enable ALL matroxfb-specific features during compilation (except MultiHead), and compile them into modules! You'll also need to enable I2C and put the tools matroxset, fbset and con2fb in your path.

  1. Then load the matroxfb_Ti3026, matroxfb_maven, i2c-matroxfb, matroxfb_crtc2 modules into your kernel. Your text-mode console will enter into framebuffer mode (no way back!).

  2. Next, set up your monitor and TV to your liking using the above tools.

  3. 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

     or

         setterm -cursor off
         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'

     or

         setterm -cursor on

  4. 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 `640` and `512` if you set the resolution to other...

  5. Enjoy the ultra-fast ultra-featured Matrox TV output (better than Xv)!

### Matrox G450/G550 cards

TV output support for these cards has only been recently introduced, and is not yet in the mainstream kernel. Currently the mga_vid module can't be used AFAIK, because the G450/G550 driver works only in one configuration: the first CRTC chip (with much more features) on the first display (on monitor), and the second CRTC (no BES - for explanation on BES, please see the G400 section above) on TV. So you can only use MPlayer's fbdev output driver at the present.

The first CRTC can't be routed to the second head currently. The author of the kernel matroxfb driver - Petr Vandrovec - will maybe make support for this, by displaying the first CRTC's output onto both of the heads at once, as currently recommended for G400, see the section above.

The necessary kernel patch and the detailed HOWTO is downloadable from

### Building a Matrox TV-out cable

No one takes any responsibility, nor guarantee for any damage caused by this documentation.

#### Cable for G400

The CRTC2 connector's fourth pin is the composite video signal. The ground are the sixth, seventh and eighth pins. (info contributed from Balázs Rácz)

#### Cable for G450

The CRTC2 connector's first pin is the composite video signal. The ground are the fifth, sixth, seventh, and fifteenth (5, 6, 7, 15) pins. (info contributed from Balázs Kerekes)

### ATI cards

#### PREAMBLE

Currently ATI doesn't want to support any of its TV-out chips under Linux, because of their licensed Macrovision technology.

#### ATI CARDS TV-OUT STATUS ON LINUX

- ATI Mach64: supported by GATOS.

- ASIC Radeon VIVO: supported by GATOS.

- Radeon and Rage128: supported by MPlayer! Check VESA driver and VIDIX sections.

- Rage Mobility P/M, Radeon, Rage 128, Mobility M3/M4: supported by atitvout.

On other cards, just use the VESA driver, without VIDIX. Powerful CPU is needed, though.

Only thing you need to do - Have the TV connector plugged in before booting your PC since video BIOS initializes itself only once during POST procedure.

### nVidia

First, you MUST download the closed-source drivers from . I will not describe the installation and configuration process because it does not cover the scope of this documentation.

After XFree86, XVideo, and 3D acceleration is properly working, edit your card's Device section in the `XF86Config` file, according to the following example (adapt for your card/TV):

    Section "Device"
            Identifier      "GeForce"
            VendorName      "ASUS"
            BoardName       "nVidia GeForce2/MX 400"
            Driver          "nvidia"
            #Option         "NvAGP" "1"
            Option          "NoLogo"
            Option          "CursorShadow"  "on"

            Option          "TwinView"
            Option          "TwinViewOrientation" "Clone"
            Option          "MetaModes" "1024x768,640x480"
            Option          "ConnectedMonitor" "CRT, TV"
            Option          "TVStandard" "PAL-B"
            Option          "TVOutFormat" "Composite"
    EndSection

Of course the important thing is the TwinView part.

### NeoMagic

The NeoMagic chip is found in a variety of laptops, some of them are equipped with a simple analog TV encoder, some have a more advanced one.

- Analog encoder chip: It has been reported that reliable TV out can be obtained by using `-vo fbdev` or `-vo fbdev2`. You need to have vesafb compiled in your kernel and pass the following parameters on the kernel command line: `append="video=vesafb:ywrap,mtrr" vga=791`. You should start X, then switch to console mode with e.g. Ctrl Alt F1. If you fail to start X before running MPlayer from the console, the video becomes slow and choppy (explanations are welcome). Login to your console, then initiate the following command:

      clear; mplayer -vo fbdev -zoom -cache 8192 dvd://

  Now you should see the movie running in console mode filling up about half your laptop's LCD screen. To switch to TV hit Fn F5 three times. Tested on a Tecra 8000, 2.6.15 kernel with vesafb, ALSA v1.0.10.

- Chrontel 70xx encoder chip: Found in IBM Thinkpad 390E and possibly other Thinkpads or notebooks.

  You must use `-vo vesa:neotv_pal` for PAL or `-vo vesa:neotv_ntsc` for NTSC. It will provide TV output function in the following 16 bpp and 8 bpp modes:

  - NTSC 320x240, 640x480 and maybe 800x600 too.

  - PAL 320x240, 400x300, 640x480, 800x600.

  Mode 512x384 is not supported in BIOS. You must scale the image to a different resolution to activate TV out. If you can see an image on the screen in 640x480 or in 800x600 but not in 320x240 or other smaller resolution you need to replace two tables in `vbelib.c`. See the vbeSetTV function for details. Please contact the author in this case.

  Known issues: VESA-only, no other controls such as brightness, contrast, blacklevel, flickfilter are implemented.