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Adjusting aspect ratio

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This topic contains 10 replies, has 4 voices, and was last updated by  lavignep 1 month, 4 weeks ago.

Viewing 11 posts - 1 through 11 (of 11 total)
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  • #15126

    lavignep
    Participant

    Hello,
    When setting my wii to 4:3 mode, I also need to set the t.v. In fullscreen mode as well. Unfortunately, I cannot do it on my t.v. and I was wondering if it would be possible to do something about it with the ossc.

    I believe the wii outputs 480×720 in this mode (correct me if I am wrong, I am still trying to wrap my head around this).

    Would it be possible to correct the aspect ratio with the ossc using sampling options, h. Active, sample rate, etc. to address this issue? I have tried multiple combinations but I lack full understanding and cannot predict which settings affects what.

    If that is possible, I would like to know the recipe for 480p and 480i 4:3 aspect ratio on ossc.

    Thank you very much everyone.

    #15150

    BonzoBits
    Participant

    Disclaimer: this may or may not work, but if you don’t mind getting into the menus and making adjustments, it’s worth a shot to at least rule it out.

    On my TV, lx3 mode requires the TV aspect to be 16:9 and lx4 requires the TV aspect to be set to 4:3. This is for Genesis, Saturn, SNES, N64 so I guess it should be the same with other consoles including the Wii.

    If changing the multi mode doesn’t work, try changing h.samplerate. From stuff I’ve read, not all displays are affected by adjustments to h.samplerate, but on mine it changes the width of the displayed image.

    #15181

    lavignep
    Participant

    Thank you BonzoBits for your answer.

    Unfortunately, I did not manage to obtain the result I desire. I have been thinkering with samplerate and other sampling options for the past few days and I believe I have a basic understanding of what each settings is used for but I cannot produce an outcome that is predictable yet. Somewhat I must misunderstand those settings, or my TV does not accept the output. Either that or what I am looking for is not possible.

    My understanding so far is that the wii at 4:3 AR with the ossc outputs 720×480 with a DAC of 858. Of that initial resolution, only 640×480 is active, filling the rest of the horizontal resolution with black border. Since I cannot change AR on my display, this gets stretched to 16:9 which messes the aspect ratio. From my understanding, I should be able to turn on unsamplex2 and double both the h.samplerate and h. active to 1716 and 1440 respectively. That should give me by my understanding a 1440×480 output that “looks” similar (identical??) to passthrough mode but since that is not a standard resolution, my display would not stretch the output to fit the screen. 1440 / 1920 = 0.75 which yields effectively 4:3 AR. Unfortunately, either that does not work like that or I messed something up, I have been playing with these settings quite a bit and although I feel I already tried this, I might be missing something.

    I was also wondering if that was simply possible to achieve a similar effect by cranking the samplerate to produce a 1920 output and using h.active to resize the display area to 4:3 and fill the rest with a black border. I have been reading other threads here about that feature but even though I feel I did everything right, I obviously missed something or I misunderstand the application regarding those settings.

    Does anyone can confirm if I am misreading and what I am trying to achieve is not possible or if indeed, it should be possible but I might be on the wrong track?

    #15185

    Harrumph
    Participant

    This seems similar to the Dreamcast situation. You can set H.Samplerate to 800 and H.Active to 640 for a 4:3 VGA output, possibly your TV will detect this properly without trying to stretch it. Easiest way to do this is to change 480p sampling options from DTV to VGA. However this will undersample the image so you will lose some horizontal details and possibly get aliasing artifacts. So it is not ideal.

    #15205

    lavignep
    Participant

    I believe I have tried that aswell but to no avail. When you mentioned changing sampling options from DTV to VGA, is this the same thing as VESA 640×480 setting or am I missing something else entirely?

    #15210

    Harrumph
    Participant

    Yeah sorry meant VESA.

    #15217

    marqs
    Participant

    Is there a specific reason why keep Wii in 4:3 mode instead of 16:9? Aside from GC games, most content should display in widescreen either natively or via pillarboxing (emulated games, MM9 etc.). In latter case picture quality might take a small hit, though.

    #15225

    lavignep
    Participant

    @harrumph, no need to me sorry, I am still new to all this and I do not know all the terminology.

    @marqs, thanks for checking it out. Like you mentioned, games like MM9 or Konami Rebirth series will work in widescreen but they are a blurry mess. The difference is staggering. From my understandind, the Wii outputs the same amount of pixel in 4:3 than in 16:9 but in order to maintain 4:3 aspect ratio in widescreen, more pixels are dedicated to the black border on both side which causes a severe hit for those games.

    For example, in MM9, it makes objects and bg tiles change width depending on where they are on the horizontal axis. For the Rebirth series, it’s so bad it’s as if a 2xSAI filter was applied in widescreen vs a crisp RGB output. I will try to take pictures to illustrate or you can try it for yourself if you have a Wii. For myself, once I noticed the difference, it was as if I was rediscovering those games for a second time.

    I have yet to be able to correct the aspect ratio with the OSSC (if that is even possible). Maybe a special optimized mode for the Wii in the same vein as the 320×240. If the Wii is outputing 858 dots per line in 4:3, would it be possible to find out how many are used for the black pillars and how many are used for the actual games and only double/digitize those to correct the AR, maybe reducing the h.active to 640 might be needed as well. I am speculating of course, this is all new to me. Like the above poster mentioned, isn’t the Dreamcast doing something similar that gets corrected with one of the OSSC mode? I am hoping that this is at least feasable by tweaking the sampling options on current hardware, of course, a dedicated mode would be even better but I would be very happy to tweak the settings manually and saving a profile.

    It might have gone unnoticed and no more thoughts have been put into this issue since the Wii is basically supported, and most TV will allow to change AR. But for the situation where it is not possible to change AR on the display, I am hoping it is “possible” to correct it through the OSSC on a similar fashion as the Dreamcast.

    One thing to mention is that both MM games are in 480i, but I believe the output of 858 dots per line is the same as for 480p. Speaking of which, my OCD would be very happy to be able to enable line3x for 480i where every two lines gets multiplied by 3, alternating odds and even. That way, MM9 and 10 would look exactly the same as 1-6 in line3x mode. I’m only dreaming 😉

    #15263

    marqs
    Participant

    If your TV only supports 720×480 and 640×480 (active area) 480p modes and stretches them to 16:9, it doesn’t leave many good options for processing 4:3 480i/p input. You’ve probably tried increasing samplerate in passthru mode, but perhaps not in Line2x(480p) or Line3x(480i) modes? If you’re very lucky, your TV accepts 960p / 1440i and tolerates higher samplerate adjustment with those.

    #15270

    lavignep
    Participant

    I believe I have found a solution yet I do not understand exactly what is going on. I will have to investigate a little bit further.

    As it turns out, I only needed to increase h.samplerate from 858 to 889 and adjust backporch by 20 to recenter the image. This gives me a 720×480 that is displayed at correct 4:3 ratio with pillar box. As far as I can tell, these settings produce the exact same result as if I had setted my display in 4:3. I guess could measure everything to see if h.samplerate needs more adjustment because I could not predict or derive that 889 would be the proper value. To me, at this point, it seems very random but I am sure there is some logic behind this that I do not understand yet.

    On my display, 720×480 gets multiplied by 4 (4k tv) in all directions without getting stretched to fill all vertical resolution. I believe I could try a 640×480 using the same method, only increasing samplerate and adjusting the backporch which my display should handle properly and apply stretching to fill the whole vertical space. I will post more info tomorrow about my findings.

    If someone might enlighten me on why increasing only h.samplerate produced the appropriate AR, I would greatly appreciate it. I am sure it could have been predicted or calculated and that these values are not random at all. I will try to predict proper values before trying the the 640×480 experiment tomorrow out of curiosity but if I cannot figure it out, I will try incrementing the values one unit at a time until I get a result (or not) like I did this time.

    Again, thanks everyone and thank you @marqs for creating the OSSC, it trully is a wonderful device!

    #15458

    lavignep
    Participant

    Hello again,

    Unfortunately, I did not manage to produce a satisfying result. I have checked online for Wii specs in 4:3 and here is what I found (not sure if it is true or how to check it). Wii in 4:3 mode has an internal resolution of 640×480 and adds pillarbox of 40px on each side to produce a 720×480 output. I have a few hypothesis on how I should tweak the settings to correct the aspect ratio but so far, I have not produced appropriate result nor do I know if it is even possible. Maybe someone can help me with the right settings if it is indeed possible. So far, I have only tweaked h.active and h.samplerate because I do not know how the other settings work, maybe someone more knowledgeable could help me on what the sampling option does effectively.

    Here are the 3 hypothesis I would like to try.

    1) set h.active to 640 and crop the extra 40px on both side (not sure if it is doable) let the display stretch the 640×480 output as it should. So far, it seems that setting h.active to 640 gets stretched by my display which is weird, maybe I have to change other settings line synclen but I do not understand the relation between each settings yet. Am I wrong in assuming that a similar process is used for the dreamcast? Someone else mentioned it before and to my knowledge, it should be the same no? I have tried h.samplerate of 800 and in 640 h.active and it looks exactly the same as 858/720 on my display. I do not have a dc to test this on so it might be my display or it might be that the wii might need different sampling options.

    2) leave h.active at 720 but shrink the whole horizontal line to 75% and add pillarbox. H.active of 720 is well handled by my display but I am not sure this solution is supported by the ossc hw.

    3) double h.active to 1440 but only apply a 1.5 multiplier on horizontal line, adding pillarbox on both side to fill the 1440 space. Again, not sure if this is doable, I have tried a few combinations using unsamplex2 on and such but I could not produce any significant output.

    I believe I understand how h.active works but maybe someone could explain exactly how h.samplerate and h.synclen works or how it should be used depending on h.active (if these 2 settings are even dependent)

    Thank you for reading through.

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