OSSC General Help w/Pixel Perfection

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  • #24736
    NewYears1978
    Participant

    I just started using my OSSC not too long ago. Love this thing and was able to get rid of my huge CRT that was such a nightmare (albeit beautiful) – however I am so confused on how to go about getting perfect pixels with each console.

    I’ve watched FirebrandX videos on YouTube about setting up SNES and NES and those look really nice.

    What confuses me is where to start for each consoles.. for instance on NES and SNES he has said to use 4x or 5x line mode (preference) and then to set it to 320×240 optim – doing that of course gives you massive jaggies and interference which you can correct with phase. What is the difference in using 320×240 optim over just using 4:3 mode?

    When changing to another console how do I know which base level to start at? I am working on my PS1 now and I thought it was 240p just like the NES and SNES but if I use either of my NES and SNES presets with my PS1 it looks awful.

    Also, I am confused on using line 5x mode in 1080p and how it cuts off some lines on the top and bottom – changing to 1920×1200 or 1600×1200 fixes it but then makes things look fuzzier and not sharp anymore.

    Having massive trouble getting my NES, SNES and PS1 to my liking. (gave up on PS2, going to have to use a CRT for that)

    I’ve read various guides and videos but I am just still confused here.

    #24737
    Harrumph
    Participant

    You haven’t read up enough it seems.
    Check the advanced timings and optimal timings sections in the wiki.
    http://junkerhq.net/xrgb/index.php?title=OSSC#Advanced_timing_tweaker
    http://junkerhq.net/xrgb/index.php?title=Optimal_timings

    The other option is to import the profiles FirebrandX has made. Should be on his site. Then you don’t have to think about it much.

    Lastly, 1080/5=216. That’s why x5 1080p mode cannot show all lines.

    #24738
    BlueStinger
    Participant

    Honestly, I don’t get it either. I must have spent 8 hours just trying to understand how to make the PS1 look good in 320×240 mode. When I use my 240p test suite, everything is perfect. I start FF7, everything is perfect. I press “start” to go in the menu and everything is messed up ! Each time, I assumed I did it wrong, each time I tried again, I got the same exact results.

    It’s not too bad as x5 1920×1200 looks perfect anyway, but I don’t get the 320×240 mode at all.

    Also, I’ve read everything I could find on optimal timings, watch every video I could (there are only 2 relevant, the ones FBX made) etc, there is a lack of info out there. Either you get people who are so technical you don’t understand what is their point (I don’t blame them) or you have people who gives you the answer with no further explanations (FBX doesn’t answer comments on his channel for instance, I don’t blame him either). So we’re stuck basically.

    I can watch FBX videos and copy his profiles, but if I want to use a console he did not listed or from another region, there’s no way to know how to setup H synclen or V synclen for instance. On my Xbox, V synclen works from 1 to 7, I’ve seen FBX used 6 for a 480p console so I assumed 6 was the good value, the truth is, I have no idea !

    It’s hard to explain, but basically, we are trying to find the difference between red and blue on the internet but we don’t know the word “color”… I’m willing to do all the research to understand optimal timings, but at least point us in the right direction. Despite all I’ve read, I don’t know how to know IN ADVANCE what the H samplerate should be… From what I gathered, there is a rule to follow like “divide the length of the lines by the number of pixels and you get the perfect samplerate”(I made that up), where does that come from ?! What do I type on Google to get that info ?!

    FBX said “ideally the samplerate should be 857.5” how does he know that ?!!

    Sorry if I sound rude, but you can’t tell us to read more if you don’t tell us what to read. I know you’re going to come back with three links and say something like “see ? It was there all along ! It was easy, I don’t know why you were complaining” but understand that we don’t all have a degree in engineering or electronic. If I don’t know the word “color”, I can’t type it in Google. So, please, just send us the link to those resources and we’ll be happy to read. And as a bonus, we won’t have to ask any more stupid questions and we’ll be able to help the next person to ask.

    And please, don’t tell me those links explain everything, I’ve read those 100 times these past 2 months. They don’t answer any of the questions listed above. Yeah, they make your OSSC work, but they don’t make you understand it, they don’t make you understand what you would need to improve settings. Again, I don’t blame those links, it’s good that they exist but they aren’t the answer to all questions.

    #24739
    NewYears1978
    Participant

    @BlueStinger
    I’m with you – the links I have read 100 times..but to a newb to this stuff it’s a bit overwhelming..I am trying to understand how to get to where I am going so that I can do it on my own and make sense of it.. it’s a bit confusing. I’ve watched tons of videos and guides as well.

    I did solve my PS2 issue though – I just hooked up a Toshiba 20AF45 and man PS2 looks like a dream so I will use that TV soley for 480i (PS2) content. My SNES and NES look great on it too so maybe I don’t even need the OSSC lol (but I know this TV won’t last forever.

    #24751
    BuckoA51
    Keymaster

    Honestly, I don’t get it either. I must have spent 8 hours just trying to understand how to make the PS1 look good in 320×240 mode. When I use my 240p test suite, everything is perfect. I start FF7, everything is perfect. I press “start” to go in the menu and everything is messed up

    Are you sure that game runs at 320×240 all the time? PS1 games change resolutions a lot.

    #24754
    BlueStinger
    Participant

    I assume it was the case, but the game is “advertised” as a running 320x240p on this page http://junkerhq.net/xrgb/index.php?title=Optimal_timings

    I “gave up” anyway and I use the x5 mode in 1920×1200. I have a 240p test suite but it’s not really helpful as I have a 2 issues that persist no matter what I do :

    #1 shimmering on the horizontal Sonic background. No matter what I do, this background displays shimmering (I’ve tried everything) so I assume this background has an “issue” (I’m using a PAL console)

    #2 a wavey line rolling down the screen every 80 frames (or so) when something is scrolling vertically. I assume it’s a sync issue, no matter what I try, I can’t get rid of it.

    As you can see, it’s the best I can do, “assume” things. Because I don’t know how to setup V or H synclen, I don’t understand how samplerate are defined etc. All we have are things like that :

    Horizontal/Vertical sync length
    Sets output sync lengths, which by default are set to match expected input sync lengths. Usually no need to modify.
    Allow TVP HPLL2x
    Controls whether video digitizer H-PLL uses 2x sampling clock internally on supported video modes.
    H-PLL Pre-Coast
    Defines when PLL coast (current freq. freeze) is activated.

    I bet those are helpful for people who know what they mean, but for most people, this is gibberish. No offense, but this is not really noob-friendly. I’m not mad or anything, just frustrated, I have everything I need to get the best video quality from my consoles and all I can do right now is hoping FBX happens to release the optimal timings for consoles I happen to have (which won’t happen anytime soon as he is in USA and I’m in PAL region…)

    #24787
    BuckoA51
    Keymaster

    1) can you more clearly define what you mean by “shimmering” ?

    2) On what console? PAL or NTSC? What game? 50 or 60hz?

    Optimal mode is not a necessity, I rarely use it because I prefer a more analogue look. No CRT was ever that sharp.

    #24788
    BlueStinger
    Participant

    The console is a PS1 PAL (is modded, not sure if it has an impact) and I’m using the 240p test suite from github, the latest build.
    The shimmering issue is pretty weird because it always happens on the same vertical lines of pixels. It’s as if some vertical lines where changing size while scrolling horizontally. Again, it always happens at the same spot no matter where this spot is on the screen (so it affects always the same left portion of a cloud for instance). The higher the scrolling speed, the less noticeable it is. It’s the same no matter the settings I use (and I purposefully messed up the settings to try to figure out where it comes from)

    It really feels like the background is (let’s say) 319.5 pixels wide and screen is 320 pixels, so it’s like certain rows of pixels can’t remain stable. And it happens no matter which mode I’m using.

    #24830
    NewYears1978
    Participant

    I have that same issue trying to use FireBrandX YT method for optimal timings. (Where you set it to 320×240 optim, then adjust the phase and H sample rates)

    Worked perfect on NES and SNES but on PS1 I can never get rid of some shimmering in a corner unless I Just use 4:3 mode instead of 320×240.

    Aside from that I keep dropping sync during gameplay (not menu switches) on several PS1 games (FFT, FF7, Metal Slug X so far)

    Super annoying 🙁

    #24880
    NewYears1978
    Participant

    The thing I can’t figure out is – following FBX guides I was able to get NES and SNES looking nice. When I do the same for PS1 I can NOT get rid of the moving pixels…and if I do on the grid then when I go in games it’s present in menus and some games.

    However, using 4:3 mode instead of 256×240 then the picture is always fine without having to use the phase option.

    So why not just always use 4:3 what is the diff in using that over 256×240 optim etc..?

    #24881
    Steo
    Participant

    The pixels will scale batter using optimal modes and will produce a sharper image when setup correctly, though if 4:3 looks ok to you then you can just stick with that. On some fussy TV’s, you’re lucky to even get 3x generic 4:3. That’s what my old set was like.

    #24883
    Harrumph
    Participant

    I cannot answer your question regarding PS1, I don’t own one and am not very familiar with its peculiarities.

    Regarding the more general question, what is the difference between generic and optimized.
    In generic mode, the analog signal is effectively oversampled. In an analog signal, colour changes between adjacent ”pixels” cannot be instant, there is always a transition. Example go from pure white to pure black, there will be a continuous section of shades of gray because the signal has to drop from maximum to minimum voltage. In generic mode, e.g. in x4 mode there are 1560 samples so for a 341 dot console like NES there are 4.6 samples per dot, thus capturing those transitions.

    In optimized, only one sample per dot is made. This is then horizontally upscaled by the video chip on the OSSC by so-called pixel repetition. Thus, (in x4 mode) the one sample is repeated 4 times (320×240 & 256×240 8:7 mode) or 5 times (256×240 4:3). This gives an ultrasharp appearance that could otherwise only be achieved by digital systems such as an emulator or fpga console.
    This is the reason phase matters for optimized but not generic modes: in generic there is an excess of samples compared to original signal. However, in optimized it’s crucial the sample is taken as close to the center of each dot as possible. Otherwise you see ”unclear” or ”jumping” pixels, due to being taken in/near a transition). Phase basically determines how soon after a line starts that sampling starts.

    I’m sorry I have not been able to adress questions before, I’ve had very limited time recently.

    Edit: I’m sure I saw a picture someone made that pedagogically showed this but now I couldn’t find it unfortunately.

    #24884
    BlueStinger
    Participant

    Those pictures ?

    #24885
    Harrumph
    Participant

    Exactly 🙂

    #24886
    Steo
    Participant

    I wouldn’t have been very good at explaining all of that in detail. 😛

    I have to keep any timings that work for me documented because I prefer optimised modes where possible. I know FirebrandX has some videos, but then some consoles can still slightly vary depending on cables etc. I’ve never been 100% sure on what settings to use for PS1 games with all the weird resolutions they have and even my SNES settings are guesswork at the moment.

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