Screen tearing – OSSC Pro (Scaler mode) – PS1 – Spyro

[Dumpling]

Hi all,

I’m having an issue with screen tearing along the bottom of the screen while playing Spyro the Dragon on a PAL PlayStation 1 using the OSSC Pro (firmware up to date). I’m running the OSSC Pro strictly in Scaler mode — I haven’t tested line multiplier modes yet.

Setup:

Console: PlayStation 1 (PAL)
Cable: PlayStation 1 PS1 RGB SCART PACKAPUNCH sync-on-luma cable
Display: Samsung UE49MU8000 4K TV
OSSC Pro output: 1080p (50–120)
Display settings: Scanlines + Shadowmask enabled
Scaler mode only
Game mode: On (issue seems related)
Framelock: Initially caused tearing/rolling, partially fixed by setting it to 50 and turning Framelock off

The tearing shows up when rotating the camera in-game, and it’s most noticeable along the bottom edge of the screen. When I tested the same setup on my parents’ Panasonic HDTV, the issue didn’t occur — which makes me think it’s specific to how the Samsung handles OSSC Pro output.

I tried turning Game Mode off on the Samsung and that seemed to eliminate the tearing, but ideally I’d like to keep Game Mode on to benefit from the lower latency.

Also, are certain scaler algorithms known to handle this sort of thing better than others? I’d like full access to them so I can tweak image sharpness for dithering accuracy.

Has anyone else seen this with Samsung 4K TVs (especially the MU8000)? Any advice on settings or known workarounds would be hugely appreciated.

Thanks in advance!

• This topic was modified 9 months, 1 week ago by Dumpling.

[BuckoA51]

This is likely caused by a miss-match between the frame rate of the game (PAL PS1 doesn’t run bang on 50hz) and what your TV natively supports. By turning frame lock off you’re outputting a slightly different frame rate, usually this results in a stutter rather than a tear though. By turning game mode off you prevent the TV double or triple buffering the image.

Does the MU8000 support VRR or similar? You could try turning VRR flag on, on the OSSC Pro, this has been known to solve the issue on some TVs.

[Dumpling]

Cool, thanks for your response. I’ll check later. I’m pretty sure my TV doesn’t have VRR, I could be wrong.
Are there any other settings in the OSSC Pro I could try? The issue seems present with Framelock both on and off, and I would like Game Mode on on the TV.

[marqs]

Have you tested its game mode with any other 1080p50 source? You can also try fine-tuning refresh rate with “Off (preset Hz)” and via “Output opt -> Adv. disp timing” if that makes a difference, but overall it sounds like a TV issue (especially if you can replicate it in A-LM mode).

[Dumpling]

Sorry for the late reply, I haven’t chance to check another 50 source, I have a PS2? Not sure what hz that is.

It seems to work fine though.

I do have a MegaDrive but only a RF connector and one of those Retrotink MegaDrive to HDMI cables.

I’ll have more of a play around and report back.

[Dumpling]

Hi @marqs last night I tried these settings of 49.92 which Google gave me from somewhere and so far so good. No screen tearing.
I also had no screen tearing setting the frame lock off to 60, but I thought because the console is outputting 50 that mismatch may be too much even though it worked.

Funnily enough this screen tearing has only started happening when I use S-Video and the Playstation SCART sync-on-luma inputs.
When I used component it didn’t happen – I don’t know why that would make a difference. The screen tearing has happened on both PS1 and PS2.
Do you know why that could be? The screen tearing doesn’t happen immediately, it can take a good half hour of playing then starts about 1cm from the bottom of screen and slowly gets bigger.

I’m happy to change the timings as that seems to work – I’m just interested why it happens on some inputs and not others.

What do I do if it’s a game that switches resolution quite often like Silent Hill? Does that require two custom timings?

Also is there any documentation about what all the AV expansion options do? I had a search but could find much. The only setting I see make a difference is the Shaping Filter Y.

Thanks!

[marqs]

It looks like 49.76Hz is too much away from 50Hz for the TV to handle it correctly. No idea why component (presumably via OSSC and not directly to TV) worked without artefacts since PS2 should output same rate as with SCART-RGB. Anyway, I would just use “Framelock off 50Hz” setting instead of playing with presets.

Legacy AV options are not well documented but the ones which are not self-explanatory or related to RF addon control various filters which are generally not something that need further adjustment.

[Dumpling]

@marqs unfortunately I get screen tearing after a while with frame lock off 50. Maybe my TV is very picky.

It’s a Samsung from 2017 so quite old now.

Either way I don’t mind fiddling with the timings 🙂

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