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

quicksilver

@mitu that make sense why it isn't working then. I'll have to stick with using my pi3 for dos games for now in that case. Thanks again for the help.

quicksilver

Just an update for anyone following this thread. ~~I was able to get decent performance using dosbox-sdl2 by turning vsync off and using a lower resolution video mode in the runcommand menu. So it is a viable alternative for some games,~~ (see post below)however it doesnt seem to support .mp3/.ogg audio format which quite a number of GOG games utilize. This results in a CD-ROM not inserted error.

nemo93

hey @quicksilver perhaps you could give dosbox-staging a try? SDL2 as well as MP3/OGG are supported features. Devs are nice and eager to add more features like autotype or bundling DOS/32A directly - like Dosbox-X iirc. As of typing there's no support for MT-32 or Fluidsynth but it's being discussed.

I've created a (too long) thread to discuss this. Dosbox-staging is the version I'm now using as default along with dos32a extender, it provides nice compatibility, decent performance, no/less tearing (eg. Rayman, Raptor especially) and joypad support out-of-the-box on my Pi3B+.

quicksilver

I wanted to give another update about dosbox performance on the pi 4. I must have been mistaken about dosbox-sdl2, I cannot get decent performance using it. It's usable for undemanding titles but for late release dos titles it's not really up to the task. Currently I'm using dosbox-svn for all my games. The problem I have been having is that using output=overlay provides proper scaling but gives pretty poor performance. Output=surface is much more performant but doesn't support scaling, which means you end up with a nice fast dosbox but in a tiny little window. However I discovered that if I enable dispmanx, set output=surface and use windowed mode set to the resolution of my display I get a fullscreen image (albeit stretched) and much improved performance. Unfortunately dispmanx does hinder performance a little bit but it's still better than using output=overlay.

@nemo93 I had trouble building dosbox-staging. During the compilation process I kept getting an error saying it couldn't find "opusfile".

mitu

@quicksilver What games are you using as a benchmark ?

For the dosbox-staging compilation, you probably need libopus-dev and libopusfile-dev installed.

quicksilver

@mitu I'm mainly using tie fighter collectors CD-rom version. That game has an option to run 640x480 res during missions and it's very demanding. It's especially noticable when large ships and space stations are on screen. With output=overlay and tie fighter set to 640x480, the game can become a slide show if many ships/large ships are on screen. With output=surface performance is massively improved. I have also tested using Amazon Trail windows 3.1 version. There is a dissolve effect when the main menu comes up that seems to be really taxing. When output=overlay the dissolve effect takes a long time to finish. Output=surface and it's nearly instantaneous. Dispmanx does slow it down a little but it seems to be the only way to get output=surface fullscreen.

Glaglachel

@quicksilver I have exactly the same issue with the last 4.6 version on my RPI4 : with dispmanx enabled, the aspect parameter from the conf files is completely ignored.

I can also achieve a correct scale centered display when specifying the windowresolution but it means I have to configure output = overlay instead of output = surface and the final aspect is not really good, texts on games are readable but not as smooth as it is with my RPI3B+ with Retropie 4.4 (without any particular configuration compared to the default conf file).

I'm doing my test with my CD version of Heroes of Might & Magic.

quicksilver

@Glaglachel yes unfortunately dosbox doesn't behave the same way on the pi 4. Performance is actually better on my pi 3. Hopefully that can be fixed at some point because for now I cant find a perfect solution via the settings.

Glaglachel

@quicksilver Let's hope so :) I've just rebuilt one RPI3B+ with the last retropie 4.6 and everything is working as expected with no need to use dispmanx and parameters in my conf file are the same than previous versions :

fullscreen=false
fulldouble=false
fullresolution=original
windowresolution=original
output=surface

aspect=false
scaler=none

RetroJoe

@Glaglachel

I'm using original Dosbox on my pi4
Same as I used on pi3
And all games I've tested so far approx 25 I had on pi3 are working great
I do have the screen of center but no issues
I tried the sdl2 version that was sluggish

quicksilver

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

And all games I've tested so far approx 25 I had on pi3 are working great

I do have the screen of center but no issues

You can change to fullscreen=false in the dosbox.conf file and it will center the display. Most undemanding games do work just fine on the pi 4, it's just the more demanding games that the difference is noticable.

RetroJoe

@quicksilver
That makes
the screen tiny when loading and playing a dos game.

I put back to true.

Any other suggestions?
Thanks

quicksilver

@RetroJoe if you set it to fullscreen=false make sure that the window resolution setting is set to the resolution of your display.

RetroJoe

@quicksilver thanks that fixed it 👍😁

Glaglachel

@RetroJoe Indeed, all my games are running too but not as good as on my RPI3. If I can have a good centered fullscreen ratio and keep output = surface, I will be happy

RetroJoe

@Glaglachel makes sense I'm sure it will get improved in time. I'm just happy to play them still on pi4 for now.

Glaglachel

I finally tested with dosbox-sdl2 and graphic result is quite good with default parameters in .conf file. Performance is maybe a little under dosbox but for now it is a good compromise :-) Need to be tested on longer game sessions.

RetroJoe

dosbox-sdl2 gave me poor performance, even with games like arkanoid.

ParadoxGBB

Just wanted to chime in with my findings as well. Since setting up my pi4 I noticed the same thing --- the defaults overwrote dosbox-SVN.conf but overlay no longer seeems to respect placement, resolution, or scaling compared to the 3B.

I had success with the following settings for now:

fullscreen=false
windowresolution=1920x1080
frameskip=1

I noticed particularly bad performance for fade in/out sequences --- the baseline testing program I was focused on tuning was Zoop. The frameskip in particular helped thread the needle between the resolution/scale and performance for me.

Anyone try experimenting with config.txt settings in the boot folder to see if anything in there is causing a problem?

quicksilver

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

Anyone try experimenting with config.txt settings in the boot folder to see if anything in there is causing a problem?

The issue is that the pi 4 uses different display drivers compared to previous pi models. If you scroll up a ways you'll see that mitu provided a basic explanation of the issue. At the moment there isn't anything we can do about it. I've tried every combination of settings to try to get past the scaling issue and unfortunately they all involve using output=overlay, which is just too demanding for 3d dos games. So for now I'm just playing those dos games on my pi 3.