OSSC PAL Optimal Timings

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WobblingPixels
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OSSC PAL Optimal Timings

Post by WobblingPixels »

Currently working on the OSSC optimal timings for various PAL consoles.
There first one is N64.
Tutorial for OSSC optimal timings 320x288 and 640x288 games (with time stamps), some advices about not getting any picture and loading the correct profile:

https://www.youtube.com/watch?v=vhynfQYNyms

Next console will be PS1:

https://twitter.com/WobblingP/status/14 ... 58/photo/1
DiegoPonga
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Re: OSSC PAL Optimal Timings

Post by DiegoPonga »

I came up with your channel last week and it's great!

Just wondering... Is that N64 video for just raw N64 consoles? In my case, I have a PAL console modded with N64RGB, with a small button in order to toggle the (demonicly awful) default blur.

I guess that there are two standards for the console in terms of resolution, am I right?

Mate, the info in your channel is gold!
Last edited by DiegoPonga on Tue Sep 14, 2021 4:54 pm, edited 1 time in total.
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WobblingPixels
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Re: OSSC PAL Optimal Timings

Post by WobblingPixels »

Thanks. I tested the optimal timings with my N64 rgb modded console without deblur. Just try it out and see if you get same results I would say. :)
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Lux
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Re: OSSC PAL Optimal Timings

Post by Lux »

Interesting project, we PAL players do need attention too !
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WobblingPixels
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Re: OSSC PAL Optimal Timings

Post by WobblingPixels »

OSSC PAL Playstation2 PS2 Optimal Settings/Timings + Tweaks:

https://www.youtube.com/watch?v=ti1JgFVH1uM

The next console is going to be PS1. :)
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NewSchoolBoxer
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Re: OSSC PAL Optimal Timings

Post by NewSchoolBoxer »

I don't have an ADC upscaler to fiddle with but this is interesting to me. Is eyeballing for optimal phase sampling the way? Do we know how RetroTINK automatically finds the optimal phase? It can't be difficult mathematically. Closer to optimal phase gives better picture = higher signal to noise ratio.

What you find optimal for one PS2 or whatever could vary for a different hardware revision or even the same revision from one console that has more aged capacitors and chips versus another. Stored in hot attic for a decade or a smoking home would make a difference. Cable chain could slightly change the optimal timing by the parasitic inductance and capacitance and a low pass filter can significantly subtract the phase near the cutoff frequency. But certainly a narrow range would contain the optimal phase for a large amount of consoles.

At 5:50: In case the image is too bright or too dim, switch between HDMI (RGB) and HDMI (YCbCr 4:4:4)

So you're saying to encode with one of the two possible digital color spaces. Wouldn't the correct setting for all pre-HDMI consoles be RGB and GameCube at least be YCbCr due to utilizing the native video encoding? Maybe isn't straight forward for PAL when games were developed on NTSC monitors. I've found PS2 YPbPr to look wrong on PS1 games compared to any other video output. Would be nice to have RGB vs YPbPr as a comparison for OSSC input.

At 7:50: The hard part is to spot if the game runs in 512x576 or 640x576 resolution or when 480i (60 Hz) is enabled.

Too bad there isn't a spreadsheet of game native resolutions floating around. Well, there kind of is for games that support progressive scan, those that infamously switch between interlaced and progressive scan and some mentions of N64 games with unusual resolutions. I haven't tried PCSX2 to emulate PS2 but DuckStation for PS1 displays the game's resolution on startup and distinguishes between 240/288p and 480/576i.
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WobblingPixels
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Re: OSSC PAL Optimal Timings

Post by WobblingPixels »

NewSchoolBoxer wrote:I don't have an ADC upscaler to fiddle with but this is interesting to me. Is eyeballing for optimal phase sampling the way? Do we know how RetroTINK automatically finds the optimal phase? It can't be difficult mathematically. Closer to optimal phase gives better picture = higher signal to noise ratio.
Retrotink5x has pre-defined optimal timings. You have to select the correct optimal sampling profile for your console and game(s). Its not set automatically. Same with the OSSC except they are not pre-defined.
What you find optimal for one PS2 or whatever could vary for a different hardware revision or even the same revision from one console that has more aged capacitors and chips versus another.
Yep. I put a note in the video to adjust the sampling phase in case the image is to blurry.
So you're saying to encode with one of the two possible digital color spaces. Wouldn't the correct setting for all pre-HDMI consoles be RGB and GameCube at least be YCbCr due to utilizing the native video encoding?
Which setting you use depends in first place on your TV and the support of full or limited range:
https://junkerhq.net/xrgb/index.php/OSSC#TX_mode
I haven't tried PCSX2 to emulate PS2 but DuckStation for PS1 displays the game's resolution on startup and distinguishes between 240/288p and 480/576i.
With PCSX2 you can check the (internal) resolution of games (see my note 8:07min)
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NewSchoolBoxer
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Re: OSSC PAL Optimal Timings

Post by NewSchoolBoxer »

WobblingPixels wrote: Retrotink5x has pre-defined optimal timings. You have to select the correct optimal sampling profile for your console and game(s). Its not set automatically. Same with the OSSC except they are not pre-defined.
Thanks for pointing this out. I did mean the 5x due to the website description:

The first automatic optimal phase algorithm to produce the sharpest image with zero adjustments needed beyond selecting the base mode.

Now I want to post in the 5x thread (again) and say how that's misleading. The LPF on the THS7374 chip used on most SNES mods, for instance, reduces the phase by a significant 135° and adds a 70ns group delay.
WobblingPixels wrote: Which setting you use depends in first place on your TV and the support of full or limited range:
https://junkerhq.net/xrgb/index.php/OSSC#TX_mode
Full or limited range has nothing to do with digital RGB or YCbCr so I'm surprised the OSSC manual gives a suggestion of YCbCr for limited range. I guess I'd like to borrow someone's OSSC for two days and try to prove the optimal setting depends on the console more than the display. If I'm wrong then I have to rectify theory with reality and sometimes that happens in electronics.
WobblingPixels wrote:With PCSX2 you can check the (internal) resolution of games (see my note 8:07min)
Ah thanks again, I saw the video in full and still missed this. I think the captions would useful in the video description or linked in an image or text file. People have short attention spans these days and could miss what to do like I did. You're almost there with the nice timestamps in the description.
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WobblingPixels
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Re: OSSC PAL Optimal Timings

Post by WobblingPixels »

NewSchoolBoxer wrote: Now I want to post in the 5x thread (again) and say how that's misleading. .
The automatic term fits the description but in other way. Just wait for the next R5x firmware update. ;)
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