Dosbox on pi 4, game window is fullscreen but not centered on screen

RussellB

Hi,

I've been working with Hurrican, the Linux port and switched over to the DOS version and came up with the DOSBOX issue on the RPI4. I setup my dosbox.conf per this thread as well as runcommand-onstart and runcommand-onend so it flips to 640x480. The image comes up centered but as you can see it leaves a lot of black border around the image. I assume it's keeping the aspect ratio. Is this expected?

Russ

quicksilver

@RussellB said in Dosbox on pi 4, game window is fullscreen but not centered on screen:

I assume it's keeping the aspect ratio. Is this expected?

If you have aspect=true then yes it will preserve the original aspect ratio.

RussellB

Ok this is weird... using the same setup on another RPi4 a friend has the overscanning issue, and I don't. Using the same executable and the same dosbox-SVN.conf.

Ok... my bad... the TV did not support 640x480 properly. Switched to zoom mode and viola. Time for a new tv!

ecto

I made some quick tests yesterday and wanted to share my findings:

Since SDL1 is patched, dispmanx can be used again with the right aspect ratio (as in not streched across the whole screen) in dosbox.

This is true, and it's nice to see this improvement. Games just ran along nicely. I tested Blood with a resolution up to 640x480.

What didn't work was Ultima 7.2 (Serpent Isle), because there where severe slowdowns whenever the screen faded. I also tried System Shock with the same outcome: screenfading is very slow.

I did not change output=surfacein the dosbox.conf, so that might be another go at it. But so far I would suggest to stick to the workaround quicksilver suggested.

BuZz

@ecto there are some performance issues with dosbox and the sdl1 dispmanx driver, but it's better than the previous overlay config for most things.

I've just committed a change to default to dispmanx on the rpi4 and I removed some previous default configs. It's worth removing the dosbox-SVN.conf from /opt/retropie/configs/pc and reinstalling after updating retropie setup as the old entries could make trouble. But it sounds like your config is probably correct, but just in case.

BuZz

I can confirm the fading issue with system shock. It's likely due to the way the dispmanx driver double buffers and enforces vsync. I will see if there's a workaround in the driver code (but it's an old issue, and I don't think there's a quick fix. Probably better to focus on the libretro cores etc).

It's been a while since I looked at the dosbox modules also, so I will see. Maybe there are alternatives/improvements for the sdl2 core also.

BuZz

I will also look at adding dosbox-staging or replacing current dosbox-sdl2 with it if it works better.

nemo93

@BuZz happy to assist with dosbox-staging if you need. As stated in my other post, it works better (perf wise, no tearing, interesting new features) yet some stuff are still missing like proper fluidsynth (almost done though) or mt32 support. Devs are also looking closely at improving perf on pi platforms too.

BuZz

@nemo93 dosbox staging seems to require fluidsynth 2 which is too new for Debian Buster. But it worked as well as our existing sdl2 dosbox from limited testing.

quicksilver

@ecto I have another solution now for dosbox-svn. It requires running dosbox in an x session but does not require dispmanx for scaling. Performance is better and you don't need to force 640x480 via scripts (like in my previous solution). I'll try to update the thread with details for those who are interested in trying it out.

nemo93

@BuZz said in Dosbox on pi 4, game window is fullscreen but not centered on screen:

@nemo93 dosbox staging seems to require fluidsynth 2 which is too new for Debian Buster. But it worked as well as our existing sdl2 dosbox from limited testing.

That is correct. A discussion is ongoing to backport fluidsynth 1.x. Also there's no mt32 support as we speak. Yet I'm confident both will be added and properly added in the coming weeks/months. Devs are extremly supportive, active and simply kind. If you don't mind I'll keep reviewing the various DOSbox ports/forks and report back in my other thread. I'll give you a nudge should new features or additions are interesting enough to be merged within Retropie.

shavecat

@quicksilver
Works amazing your scripts.
But when i go back to emulationstain its a bit more drak (the screen)
but still amazing thanks ! :)
will love if u have any news of that

realgreg

@quicksilver Can you please post this solution ?

quicksilver

@realgreg sorry for the delay, has been a busy past few weeks. I will try to take a moment to do it this week.

lazd

@quicksilver did you end up posting your solution anywhere? Thanks!

quicksilver

@lazd I did not, sorry keep forgetting. I'll try to get that done.

quicksilver

@lazd @realgreg
sorry for the delay

Below is the best solution I found to get dosbox fullscreen and retain good performance

First we will need to install some dependencies:

sudo apt install xorg xserver-xorg-input-all

Then modify the emulators.cfg located at /opt/retropie/configs/pc/so that its contents look like this:

dosbox = "XINIT:bash /home/pi/RetroPie/roms/pc/+Start\ DOSBox.sh %ROM%"
default = "dosbox"

Next make sure you are launching your DOS games using a .conf file with the right settings for each game, I have included a sample below (make sure to change the launching instructions under the [autoexec] section as needed)

# This is the configuration file for DOSBox SVN. (Please use the latest version of DOSBox)
# Lines starting with a # are comment lines and are ignored by DOSBox.
# They are used to (briefly) document the effect of each option.

[sdl]
#       fullscreen: Start dosbox directly in fullscreen. (Press ALT-Enter to go back)
#       fulldouble: Use double buffering in fullscreen. It can reduce screen flickering, but it can also result in a slow DOSBox.
#   fullresolution: What resolution to use for fullscreen: original, desktop or a fixed size (e.g. 1024x768).
#                     Using your monitor's native resolution with aspect=true might give the best results.
#                     If you end up with small window on a large screen, try an output different from surface.On Windows 10 with display scaling (Scale and layout) set to a value above 100%, it is recommended
#                     to use a lower full/windowresolution, in order to avoid window size problems.
# windowresolution: Scale the window to this size IF the output device supports hardware scaling.
#                     (output=surface does not!)
#           output: What video system to use for output.
#                     Possible values: surface, overlay.
#         autolock: Mouse will automatically lock, if you click on the screen. (Press CTRL-F10 to unlock)
#      sensitivity: Mouse sensitivity. The optional second parameter specifies vertical sensitivity (e.g. 100,-50).
#      waitonerror: Wait before closing the console if dosbox has an error.
#         priority: Priority levels for dosbox. Second entry behind the comma is for when dosbox is not focused/minimized.
#                     pause is only valid for the second entry.
#                     Possible values: lowest, lower, normal, higher, highest, pause.
#       mapperfile: File used to load/save the key/event mappings from. Resetmapper only works with the default value.
#     usescancodes: Avoid usage of symkeys, might not work on all operating systems.

fullscreen = true
fulldouble       = false
fullresolution = original
windowresolution = original
output = surface
autolock         = true
sensitivity      = 100
waitonerror      = true
priority         = higher,normal
mapperfile       = mapper-SVN.map
usescancodes = false

[dosbox]
# language: Select another language file.
#  machine: The type of machine DOSBox tries to emulate.
#             Possible values: hercules, cga, tandy, pcjr, ega, vgaonly, svga_s3, svga_et3000, svga_et4000, svga_paradise, vesa_nolfb, vesa_oldvbe.
# captures: Directory where things like wave, midi, screenshot get captured.
#  memsize: Amount of memory DOSBox has in megabytes.
#             This value is best left at its default to avoid problems with some games,
#             though few games might require a higher value.
#             There is generally no speed advantage when raising this value.

language = 
machine  = svga_s3
captures = capture
memsize  = 16

[render]
# frameskip: How many frames DOSBox skips before drawing one.
#    aspect: Do aspect correction, if your output method doesn't support scaling this can slow things down!
#    scaler: Scaler used to enlarge/enhance low resolution modes. If 'forced' is appended,
#              then the scaler will be used even if the result might not be desired.
#              To fit a scaler in the resolution used at full screen may require a border or side bars,
#              to fill the screen entirely, depending on your hardware, a different scaler/fullresolution might work.
#              Possible values: none, normal2x, normal3x, advmame2x, advmame3x, advinterp2x, advinterp3x, hq2x, hq3x, 2xsai, super2xsai, supereagle, tv2x, tv3x, rgb2x, rgb3x, scan2x, scan3x.

frameskip = 0
aspect    = true
scaler = normal2x

[cpu]
#      core: CPU Core used in emulation. auto will switch to dynamic if available and
#              appropriate.
#              Possible values: auto, dynamic, normal, simple.
#   cputype: CPU Type used in emulation. auto is the fastest choice.
#              Possible values: auto, 386, 386_slow, 486_slow, pentium_slow, 386_prefetch.
#    cycles: Amount of instructions DOSBox tries to emulate each millisecond.
#              Setting this value too high results in sound dropouts and lags.
#              Cycles can be set in 3 ways:
#                'auto'          tries to guess what a game needs.
#                                It usually works, but can fail for certain games.
#                'fixed #number' will set a fixed amount of cycles. This is what you usually
#                                need if 'auto' fails (Example: fixed 4000).
#                'max'           will allocate as much cycles as your computer is able to
#                                handle.
#              Possible values: auto, fixed, max.
#   cycleup: Amount of cycles to decrease/increase with keycombos.(CTRL-F11/CTRL-F12)
# cycledown: Setting it lower than 100 will be a percentage.

core = dynamic
cputype   = auto
cycles = max
cycleup   = 10
cycledown = 20

[mixer]
#   nosound: Enable silent mode, sound is still emulated though.
#      rate: Mixer sample rate, setting any device's rate higher than this will probably lower their sound quality.
#              Possible values: 44100, 48000, 32000, 22050, 16000, 11025, 8000, 49716.
# blocksize: Mixer block size, larger blocks might help sound stuttering but sound will also be more lagged.
#              Possible values: 1024, 2048, 4096, 8192, 512, 256.
# prebuffer: How many milliseconds of data to keep on top of the blocksize.

nosound   = false
rate      = 44100
blocksize = 1024
prebuffer = 25

[midi]
#     mpu401: Type of MPU-401 to emulate.
#               Possible values: intelligent, uart, none.
# mididevice: Device that will receive the MIDI data from MPU-401.
#               Possible values: default, win32, alsa, oss, coreaudio, coremidi, none.
# midiconfig: Special configuration options for the device driver. This is usually the id or part of the name of the device you want to use (find the id/name with mixer/listmidi).
#               Or in the case of coreaudio, you can specify a soundfont here.
#               When using a Roland MT-32 rev. 0 as midi output device, some games may require a delay in order to prevent 'buffer overflow' issues.
#               In that case, add 'delaysysex', for example: midiconfig=2 delaysysex
#               See the README/Manual for more details.

mpu401     = intelligent
mididevice = alsa
midiconfig = 128:0

[sblaster]
#  sbtype: Type of Soundblaster to emulate. gb is Gameblaster.
#            Possible values: sb1, sb2, sbpro1, sbpro2, sb16, gb, none.
#  sbbase: The IO address of the soundblaster.
#            Possible values: 220, 240, 260, 280, 2a0, 2c0, 2e0, 300.
#     irq: The IRQ number of the soundblaster.
#            Possible values: 7, 5, 3, 9, 10, 11, 12.
#     dma: The DMA number of the soundblaster.
#            Possible values: 1, 5, 0, 3, 6, 7.
#    hdma: The High DMA number of the soundblaster.
#            Possible values: 1, 5, 0, 3, 6, 7.
# sbmixer: Allow the soundblaster mixer to modify the DOSBox mixer.
# oplmode: Type of OPL emulation. On 'auto' the mode is determined by sblaster type. All OPL modes are Adlib-compatible, except for 'cms'.
#            Possible values: auto, cms, opl2, dualopl2, opl3, opl3gold, none.
#  oplemu: Provider for the OPL emulation. compat might provide better quality (see oplrate as well).
#            Possible values: default, compat, fast, mame.
# oplrate: Sample rate of OPL music emulation. Use 49716 for highest quality (set the mixer rate accordingly).
#            Possible values: 44100, 49716, 48000, 32000, 22050, 16000, 11025, 8000.

sbtype  = sb16
sbbase  = 220
irq     = 7
dma     = 1
hdma    = 5
sbmixer = true
oplmode = auto
oplemu  = default
oplrate = 44100

[gus]
#      gus: Enable the Gravis Ultrasound emulation.
#  gusrate: Sample rate of Ultrasound emulation.
#             Possible values: 44100, 48000, 32000, 22050, 16000, 11025, 8000, 49716.
#  gusbase: The IO base address of the Gravis Ultrasound.
#             Possible values: 240, 220, 260, 280, 2a0, 2c0, 2e0, 300.
#   gusirq: The IRQ number of the Gravis Ultrasound.
#             Possible values: 5, 3, 7, 9, 10, 11, 12.
#   gusdma: The DMA channel of the Gravis Ultrasound.
#             Possible values: 3, 0, 1, 5, 6, 7.
# ultradir: Path to Ultrasound directory. In this directory
#             there should be a MIDI directory that contains
#             the patch files for GUS playback. Patch sets used
#             with Timidity should work fine.

gus      = false
gusrate  = 44100
gusbase  = 240
gusirq   = 5
gusdma   = 3
ultradir = C:\ULTRASND

[speaker]
# pcspeaker: Enable PC-Speaker emulation.
#    pcrate: Sample rate of the PC-Speaker sound generation.
#              Possible values: 44100, 48000, 32000, 22050, 16000, 11025, 8000, 49716.
#     tandy: Enable Tandy Sound System emulation. For 'auto', emulation is present only if machine is set to 'tandy'.
#              Possible values: auto, on, off.
# tandyrate: Sample rate of the Tandy 3-Voice generation.
#              Possible values: 44100, 48000, 32000, 22050, 16000, 11025, 8000, 49716.
#    disney: Enable Disney Sound Source emulation. (Covox Voice Master and Speech Thing compatible).

pcspeaker = true
pcrate    = 44100
tandy     = auto
tandyrate = 44100
disney    = true

[joystick]
#  joysticktype: Type of joystick to emulate: auto (default), none,
#                  2axis (supports two joysticks),
#                  4axis (supports one joystick, first joystick used),
#                  4axis_2 (supports one joystick, second joystick used),
#                  fcs (Thrustmaster), ch (CH Flightstick).
#                  none disables joystick emulation.
#                  auto chooses emulation depending on real joystick(s).
#                  (Remember to reset dosbox's mapperfile if you saved it earlier)
#                  Possible values: auto, 2axis, 4axis, 4axis_2, fcs, ch, none.
#         timed: enable timed intervals for axis. Experiment with this option, if your joystick drifts (away).
#      autofire: continuously fires as long as you keep the button pressed.
#        swap34: swap the 3rd and the 4th axis. Can be useful for certain joysticks.
#    buttonwrap: enable button wrapping at the number of emulated buttons.
# circularinput: enable translation of circular input to square output.
#                  Try enabling this if your left analog stick can only move in a circle.
#      deadzone: the percentage of motion to ignore. 100 turns the stick into a digital one.

joysticktype  = auto
timed         = true
autofire      = false
swap34        = false
buttonwrap    = false
circularinput = false
deadzone      = 10

[serial]
# serial1: set type of device connected to com port.
#            Can be disabled, dummy, modem, nullmodem, directserial.
#            Additional parameters must be in the same line in the form of
#            parameter:value. Parameter for all types is irq (optional).
#            for directserial: realport (required), rxdelay (optional).
#                             (realport:COM1 realport:ttyS0).
#            for modem: listenport (optional).
#            for nullmodem: server, rxdelay, txdelay, telnet, usedtr,
#                           transparent, port, inhsocket (all optional).
#            Example: serial1=modem listenport:5000
#            Possible values: dummy, disabled, modem, nullmodem, directserial.
# serial2: see serial1
#            Possible values: dummy, disabled, modem, nullmodem, directserial.
# serial3: see serial1
#            Possible values: dummy, disabled, modem, nullmodem, directserial.
# serial4: see serial1
#            Possible values: dummy, disabled, modem, nullmodem, directserial.

serial1 = dummy
serial2 = dummy
serial3 = disabled
serial4 = disabled

[dos]
#            xms: Enable XMS support.
#            ems: Enable EMS support. The default (=true) provides the best
#                   compatibility but certain applications may run better with
#                   other choices, or require EMS support to be disabled (=false)
#                   to work at all.
#                   Possible values: true, emsboard, emm386, false.
#            umb: Enable UMB support.
# keyboardlayout: Language code of the keyboard layout (or none).

xms            = true
ems            = true
umb            = true
keyboardlayout = auto

[ipx]
# ipx: Enable ipx over UDP/IP emulation.

ipx = false

[autoexec]
# Lines in this section will be run at startup.
# You can put your MOUNT lines here.

mount c "/home/pi/RetroPie/roms/pc/.data/arkanoid.pc"
c:
ARKANOID.COM
EXIT

Lastly make sure that dispmanx is DISABLED for dosbox. Dispmanx seriously impacts performance with dosbox on the pi and is not needed if you are using the above method. (Im not entirely sure dispmanx still works when using an x session but it doesnt hurt to turn it off).