Blurry Pixels on 288p (vs extra sharp on 240p)

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  • #40463
    fredpoulpe
    Participant

    Hi,

    I have a RGB modded PAL N64 (NUS-001 (FRA)) :

    (OK) When playing 60HZ NTSC 240p games (on my Everdrive), I get razor sharp pixels with the usual settings (Line4x mode – 320×240 optim)
    (KO) When playing 50HZ PAL 288p Games using recommended settings from this post, pixels are slightly blurry : Lx4 PAL (1080p50) (Generic 4:3 mode), H. Samplerate to 2460 and H. Active to 1920, V.Active to 270.

    I tried everything and I cannot get to have sharp pixels for 288p N64 PAL content on my Samsung 1080p TV. Any recommendation?

    • This topic was modified 1 month, 2 weeks ago by fredpoulpe.
    #40521
    Opaque79
    Participant

    I want to know this as well. Only seems to affect PAL N64. Probably because PAL N64 uses all 288 lines in most cases.

    #40523
    Zacabeb
    Participant

    When in the optimized modes and with optimal sample rate and phase, the OSSC discards samples to effectively keep only those that fall on the center of the pixels in the source. The resulting samples are then repeated to form the output resolution.

    In the generic 4:3 mode however, the OSSC does not discard any samples. This means it captures the transitions between pixels in the source. This result in a softer picture, where the softness is determined by the bandwidth of the source signal.

    #40525
    Opaque79
    Participant

    I only use Generic 4:3 for both NTSC and PAL. PAL still gives a softer image

    #40530
    Zacabeb
    Participant

    Is it set to Line2x or Line4x mode?

    #40532
    Opaque79
    Participant

    Line 4x mode with the Lx4 PAL tweaks.

    H. Samplerate = 2200
    V. Active = 270
    H.Active = 1920

    #40534
    fredpoulpe
    Participant

    In the generic 4:3 mode however, the OSSC does not discard any samples. This means it captures the transitions between pixels in the source. This result in a softer picture, where the softness is determined by the bandwidth of the source signal.

    Thank you ! it makes sense then. Sadly this means I won’t get sharp pixels on PAL games as I see no suitable optimized mode for a 288p output.

    #40546
    Harrumph
    Participant

    I’m not 100% sure with N64, but I think for optimized mode you can just use the same samplerate as for NTSC. On most earlier consoles, there is no difference in dotclock between PAL and NTSC versions. Perhaps you still need to change V.Active to 270 though.

    #40558
    Opaque79
    Participant

    That doesn’t work because using the optimized mode on a PAL console gives a resolution of 320x240LB compared to NTSC 320×240

    #40574
    Harrumph
    Participant

    There’s no inherent difference between those modes afaik, you can set any parameter freely. Of course, the real difference is the line count + refresh rate of the signal, so if it doesn’t work it’s because your display isn’t compatible with the particular pixel clock achieved with the required sample rate (in combination with what it deems acceptable active area/total area). That’s the difference compared to the generic mode, where you can set the samplerate freely until you find a pixel clock range that your display accepts (and gives acceptable aspect ratio). In optimized mode the pixel clocks will be fixed to the integer steps of the optimized samplerate, so it’s less flexible.

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