Sonic 2 multiplayer and Scandoubler

cursedverses
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Sonic 2 multiplayer and Scandoubler

Unread post by cursedverses »

I'm playing Sonic 2 on the current Megadrive core, on a Samsung Syncmaster 551s monitor.
I have forced_scandoubler set to 1 and the megadrive core forced to video mode 5 (640x480@60Hz).

Code: Select all

[MiSTer]
key_menu_as_rgui=0     ; set to 1 to make the MENU key map to RGUI in Minimig (e.g. for Right Amiga)
forced_scandoubler=1   ; set to 1 to run scandoubler on VGA output always (depends on core).
ypbpr=0                ; set to 1 for YPbPr on VGA output.
composite_sync=0       ; set to 1 for composite sync on HSync signal of VGA output.
vga_scaler=0           ; set to 1 to connect VGA to scaler output.
hdmi_audio_96k=0       ; set to 1 for 96khz/16bit HDMI audio (48khz/16bit otherwise)
keyrah_mode=0x18d80002 ; VIDPID of keyrah for special code translation (0x23418037 for Arduino Micro)
vscale_mode=1          ; 0 - scale to fit the screen height.
                       ; 1 - use integer scale only.
                       ; 2 - use 0.5 steps of scale.
                       ; 3 - use 0.25 steps of scale.
vscale_border=0        ; set vertical border for TVs cutting the upper/bottom parts of screen (1-399)
bootscreen=0           ; uncomment to disable boot screen of some cores like Minimig. 
;mouse_throttle=10     ; 1-100 mouse speed divider. Useful for very sensitive mice
rbf_hide_datecode=0    ; 1 - hides datecodes from rbf file names. Press F2 for quick temporary toggle
menu_pal=0             ; 1 - PAL mode for menu core
hdmi_limited=0         ; 1 - use limited (16..235) color range over HDMI
                       ; 2 - use limited (16..255) color range over HDMI, for VGA converters.
direct_video=0         ; 1 - enable core video timing over HDMI, use only with VGA converters.
fb_size=0              ; 0 - automatic, 1 - full size, 2 - 1/2 of resolution, 4 - 1/4 of resolution.
fb_terminal=1          ; 1 - enabled (default), 0 - disabled
osd_timeout=30         ; 5-3600 timeout (in seconds) for OSD to disappear in Menu core. 30 seconds if not set.
                       ; Background picture will get darker after double timeout
osd_rotate=0           ; Display OSD menu rotated,  0 - no rotation, 1 - rotate right (+90°), 2 - rotate left (-90°)

; 1 - enables the recent file loaded/mounted.
; WARNING: This option will enable write to SD card on every load/mount which may wear the SD card after many writes to the same place
;          There is also higher chance to corrupt the File System if MiSTer will be reset or powered off while writing.
recents=0

; lastcore - Autoboot the last loaded core (corename autosaved in CONFIG/lastcore.dat) first found on the SD/USB
; lastexactcore - Autoboot the last loaded exact core (corename_yyyymmdd.rbf autosaved in CONFIG/lastcore.dat) first found on the SD/USB
; corename - Autoboot first corename_*.rbf found on the SD/USB
; corename_yyyymmdd.rbf - Autoboot first corename_yyyymmdd.rbf found on the SD/USB
;bootcore=lastcore    ; uncomment to autoboot a core, as the last loaded core.

; 10-30 timeout before autoboot, comment for autoboot without timeout.
bootcore_timeout=10

; Option to load the custom font. Format is plain bitmap 8x8.
; Supported sizes of font:
;   768 bytes - chars 32-127 (only alpha + numeric)
;  1024 bytes - chars 0-127
;  1136 bytes - chars 0-141
;  up to 2048 - only chars 0-141 will be used.
; if first 32 chars are empty (for sizes 1024 bytes and more) then they are skipped.
font=font/myfont.pf

; USER button emulation by keybaord. Usually it's reset button.
; 0 - lctrl+lalt+ralt (lctrl+lgui+rgui on keyrah)
; 1 - lctrl+lgui+rgui
; 2 - lctrl+lalt+del
; 3 - same as 0 (lctrl+lalt+ralt on keyrah)
reset_combo=0

; set to 1 for DVI mode. Audio won't be transmitted through HDMI in DVI mode.
dvi_mode=0

; 0 - 1280x720@60
; 1 - 1024x768@60
; 2 - 720x480@60
; 3 - 720x576@50
; 4 - 1280x1024@60
; 5 - 800x600@60
; 6 - 640x480@60
; 7 - 1280x720@50
; 8 - 1920x1080@60
; 9 - 1920x1080@50
;10 - 1366x768@60
;11 - 1024x600@60
;12 - 1920x1440@60
;13 - 2048x1536@60
;
; custom mode: hact,hfp,hs,hbp,vact,vfp,vs,vbp,Fpix_in_KHz
;   video_mode=1280,110,40,220,720,5,5,20,74250
video_mode=6

; set to 1-10 (seconds) to display video info on startup/change
video_info=0

; Set to 1 for automatic HDMI VSync rate adjust to match original VSync.
; Set to 2 for low latency mode (single buffer).
; This option makes video butter smooth like on original emulated system.
; Adjusting is done by changing pixel clock. Not every display supports variable pixel clock.
; For proper adjusting and to reduce possible out of range pixel clock, use 60Hz HDMI video
; modes as a base even for 50Hz systems. 
vsync_adjust=0

; If you monitor doesn't support either very low (NTSC monitors may not support PAL) or 
; very high (PAL monitors may not support NTSC) then you can set refresh_min and/or refresh_max
; parameters, so vsync_adjust won't be applied for refreshes outside specified.
; These parameters are valid only when vsync_adjust is non-zero.
refresh_min=0
refresh_max=0

; These parameters have the same format as video_mode.
; You need to supply both PAL and NTSC modes if you want vsync_adjust to switch between
; predefined modes as a base. This will reduce the range of pixel clock.
;video_mode_ntsc=2048,40,442,200,240,3,10,8,85909
;video_mode_pal=1920,48,192,240,288,3,10,7,73750

; 1-10 (seconds) to display controller's button map upon first time key press
; 0 - disable
controller_info=6

; JammaSD/J-PAC/I-PAC keys to joysticks translation
; You have to provide correct VID and PID of your input device
; Examples: Legacy J-PAC with Mini-USB or USB capable I-PAC with PS/2 connectors VID=0xD209/PID=0x0301
; USB Capable J-PAC with only PS/2 connectors VID=0x04B4/PID=0x0101
; JammaSD: VID=0x04D8/PID=0xF3AD
;jamma_vid=0x04D8
;jamma_pid=0xF3AD

; Disable merging input devices. Use if only player 1 works.
; Leave no_merge_pid empty to apply this to all devices with the same VID.
;no_merge_vid=0x045E
;no_merge_pid=0x028E

; Same as above but can add multiple devices (one entry per VIDPID). Format is VIDPID in hex number
;no_merge_vidpid=0x12345678
;no_merge_vidpid=0x11112222

; Speeds in sniper/non-sniper modes of mouse emulation by joystick 
; 0 - (default) - faster move in non-sniper mode, slower move in sniper mode.
; 1 - movement speeds are swapped.
sniper_mode=0

; Uncomment following option if you don't want to see a second line for long file names in listing.
;browse_expand=0

; 0 - disable MiSTer logo in Menu core
logo=0

; Custom shared folder for core supporting this feature (currently minimig and ao486 only)
; Can be relative to core's home dir or absolute path.
; Path must exist before core start to use it, or it will fail.
; Make sure USB device is mounted before use shared folder on USB!
shared_folder=./share

; Custom aspect ratio
;custom_aspect_ratio_1=16:10
;custom_aspect_ratio_2=1:1

; use specific (VID/PID) mouse X movement as a spinner and paddle. Use VID=0xFFFF/PID=0xFFFF to use all mice as spinners.
;spinner_vid=0x1BCF
;spinner_pid=0x0005

; spinner_throttle with base value 100 gives one spinner step per one tick. Higher value makes spinner slower.
; Lower than 100 makes spinner faster. Negative value gives opposite direction.
;spinner_throttle=-50

; 0 - X axis, 1 - Y axis.
;spinner_axis=1

; Default filters for video scaler and audio. Paths must be relative to scaler/audio filter folder without leading slash.
;vfilter_default=LCD Effects/LCD_Effect_07.txt
;afilter_default=LPF2000_3tap.txt

; Defines internal joypad mapping from virtual SNES mapping in main to core mapping
; Set to 0 for name mapping (jn) (e.g. A button in SNES core = A button on controller regardless of position on pad)
; Set to 1 for positional mapping (jp) (e.g. A button in SNES core = East button on controller regardless of button name)
gamepad_defaults=0

; Write out file name under the cursor in browser for external integration
; External application or script may parse the info and do some additional actions and/or send info to 3rd party server.
; Warning: it may slowdown the system or add lag while browsing the files in OSD depending on external app/script.
log_file_entry=0

; Automatically disconnect (and shutdown) Bluetooth input device if not use specified amount of time.
; Some controllers have no automatic shutdown built in and will keep connection till battery dry out.
; 0 - don't disconnect automatically, otherwise it's amount of minutes.
bt_auto_disconnect=0

; Reset Bluetooth dongle before pair dialog.
; Some dongles may have problem to pair if not explicitly reset.
; Some dongles (mostly CSR) have problem to pair with BLE if not reset in advance.
; Consequence of reset: some input devices get shutdown after reset.
bt_reset_before_pair=0

;video_mode=640,16,64,120,480,1,3,16,31500 ;	 640x480, 75Hz
;video_mode=640,16,64,120,512,1,3,16,27000 ;	 640x512, 60Hz
;video_mode=640,16,64,120,512,1,3,16,23750 ;	 640x512, 50Hz?
;video_mode=640,56,56,80,480,1,3,25,36000 ;	     640x480, 85Hz
;video_mode=800,56,120,64,600,37,6,23,50000 ; 	 800x600, 72Hz
;video_mode=800,32,64,152,600,1,3,27,56250 ;	 800x600, 85Hz
;video_mode=1 ;					1024x768, 60Hz

[PSX]
video_mode=6
vga_scaler=1

[Spectrum]
video_mode=5

[C64]
video_mode=5

[SMS]
video_mode=6

[Megadrive]
video_mode=5
forced_scandoubler=1

[AO486]
;video_mode=800,56,120,64,600,37,6,23,50000 ; 	 800x600, 72Hz
;video_mode=720,36,72,108,400,1,3,42,30100 ;      720x400, 85Hz
video_mode=720,36,72,108,480,1,3,25,36000 ;      720x400, 85Hz

[AtariST]
video_mode=6


I've noticed when multiplayer starts on Sonic, they switch screenmode from 344x486 60Hz to 344x486i @ 60Hz, causing the monitor to go out of sync.

Outside of setting vga_scaler to 1, is there anything that can be done in the core to counter this?
FoxbatStargazer
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Re: Sonic 2 multiplayer and Scandoubler

Unread post by FoxbatStargazer »

video_mode exclusively refers to the scaler. If you aren't using vga_scaler then it's doing nothing anyway, which is sort of the problem here when the core pushes an interlaced mode. The Genesis and most other interlaced cores have no de-interlacing support for the unscaled analog output. (The arcade core Spy Hunter might actually have this feature built-in.)
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darksakul
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Re: Sonic 2 multiplayer and Scandoubler

Unread post by darksakul »

The Multiplayer mode of Sonic 2 switched from "240p" to 480i to fit the split screen image into a 4:3 frame.
I do notice it causes some issues with some displays, as the Display's built in Deinterlace can do a ugly job of Deinterlacing.
It is my great regret that we live in an age that is proud of machines that think and suspicious of people who try to.
FoxbatStargazer
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Re: Sonic 2 multiplayer and Scandoubler

Unread post by FoxbatStargazer »

I mean this is a 31khz VGA CRT monitor, it doesn't have any de-interlacer nor can it display interlaced content. At present for the Genesis core you basically need to use the de-interlacer in the scalar or some other external device that does the same. But I think the Spy Hunter core shows for example that you could have a core designed to skip interlacing altogether.
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