Tips & Tweaks: Lx3, Lx4, Lx5 modes

NewHome Forums OSSC, OSSC Pro and DExx-vd isl OSSC – Discussion and support Tips & Tweaks: Lx3, Lx4, Lx5 modes

Viewing 15 posts - 16 through 30 (of 168 total)
  • Author
  • #11423

    Oh man! You’re raising the bar of expectations tremendously high πŸ˜‰ Hope you’ve found a magical way to make those modes work with my TV!


    So here’s the story. I had x3 working since before, and managed to get x4 working, as described in the OP. Now I was wondering, why is x5 giving trouble, and why had x2 with 60Hz always had problems (only semi-stable image, that cut in and out)?

    I looked at the horizontal samplerate of x3 and x4. It struck me the samplerate was proportional to the linemode (quite logical perhaps). (this is all generic mode btw, didn’t have time to look into optimized yet)

    1170/3 = 1560/4= 390. So if I extend this to x2 and x5: 780/2 = 1950/5 = 390
    Also, the ratio of samplerate to active was the same in x3 and x4: 1170/960 = 1560/1280 = 1,21875

    So by this logic, x2 & x5 could be 780/640 and 1950/1600= 1,21875, for samplerate/active.

    Previously these had been 858/720 and 2046/1536, respectively.

    Bam! It worked. πŸ™‚

    Well, not quite. For x2 I had to use 781.

    So in practice, I had swapped from 480p (720×480) to VGA, and to 1600×1080 instead of 1536×1080 (inside the full 1920 horizontal, using regular 1920×1080 output mode here). This makes the aspect slightly wide for x5 mode, but I’m willing to make that sacrifice.

    To center the image, I fiddled with sync and backporch only slightly. For the x2 mode I arrived at the nice and even H Sync 50 and H Backporch 70. Scaling these up to the other modes worked very well.

    Here’s my final settings

                  | x2  | x3   | x4   | x5   |
    H Samplerate  | 781 | 1170 | 1560 | 1950 |
    H Active      | 640 |  960 | 1280 | 1600 |
    H Sync        | 50  |   75 |  100 |  125 |
    H Backporch   | 70  |  105 |  140 |  175 |

    @bonzobits Don’t understand why you need to correct the aspect ratio in 320 optimized. 320×4=1280 so should fit nicely in the 1280×1024 frame (1280:960 = 4:3).

    As x3 and x4 didn’t work for you previously, I’m afraid this fix for x2 and x5 probably won’t work for you either. πŸ™

    Bonus tweak: I got PAL 720p generic working by reducing V.Active from 288 to 240, and then increase V.Backporch to 42.


    Just tried this on my Sony KDL-42W653A but sadly could not get a picture, just a black screen with x4 linemode, odd thing was once i went below 5 v.backporch then the TV started to give me a ‘unsupported signal’. Have looked at the manual and the TV supports the following modes….

    640 x 480, 31.5 kHz/60 Hz
    800 x 600, 37.9 kHz/60 Hz
    1024 x 768, 48.4 kHz/60 Hz
    1280 x 768, 47.4 kHz/60 Hz and 47.8 kHz/60 Hz
    1360 x 768, 47.7 kHz/60 Hz
    1280 x 1024, 64.0 kHz/60 Hz (Full HD model only)
    1920 x 1080, 67.5 kHz/60 Hz (Full HD model only)*

    * The 1080p timing, when applied to the HDMI input, will be treated as a video timing and not a PC timing. This will affect the [System Settings] and [Display] settings. To view PC content, set [Scene Select] to [Graphics], [Screen Format]/[Wide Mode] to [Full], and [Display Area] to [Full Pixel]. ([Display Area] is configurable only when [Auto Display Area] is set to [Off].)


    EDIT: corrected info about TV AR settings.


    I’m not sure either. On the VT60, Lx3 modes require the TV to be in 16:9 mode and Lx4 requires 4:3.

    For OSSC optim modes, adjustments to H.samplerate are always necessary to restore horizontal scale and remove the blurred graphics.

    With generic 4:3 modes, the horizontal scale is accurate on the default settings. Some consoles may require tweaks to backporch. All consoles require 256 >> 240 reduction in order that restore AR.

    I’ll take some pics tonight and maybe someone will be able to figure it out. My guess is that it’s due to the TV’s processing of the signal data.

    Congrats on the discovery re H.samplerate. I was tweaking some stuff yesterday, hoping to make some sort of discovery. Based on what you’ve found, I’m going to note down the various tweaker settings for each console and linemulti mode and see if there is not some similar relationship that will work for the VT60.


    Might have gone down the rabbit hole with this one, or will it be a wild goose chase…? Checking VESA timings, making spreadsheets. πŸ™‚

    I’m starting to think display pixel clock tolerance might be one of the most important factors for these picky TVs. When horizontal freq is known, like in @BlockABoots case, the wanted pixelclock can be referenced with VESA timings standards spreadsheet (google CVT1.2Generator).
    Then one can calculate the needed H.Samplerate (given the fixed linecount and H/V. refresh coming from OSSC). However, as this approach is dependent on scanline output and V.Refresh, it could be different from console to console.

    I probably should have put in the above post, I only used my modded 2-chip SNES for the above settings for my TV (outputs 262 lines, V.Refresh around 59.6Hz).

    As I mentioned, working on a spreadsheet. For example, for BlockABoots 1280 x 1024 (64.0kHz, 60Hz), this implies older VESA standard (no reduced blanking), which wants 109MHz pixel clock. So he could try:

    Console lines | 262  | 263  | x4 mode
    H Samplerate  | 1734 | 1727 |
    H Active      | 1280 | 1280 |
    H Sync        |  158 |  156 |
    H Backporch   |  198 |  196 |

    Would link spreadsheet but it’s not finished so just throwing this out as an example. As I said, this might be a wild goose chase… Check back tomorrow.


    @Harrumph, your tweaks haven’t worked for me but they’re giving me hope, so I want to thank you for what you’re doing. I dunno if you can figure out how to get my Samsung 4K to work with anything but 240p passthrough, but the manual is here if you want to give it a shot.


    Great work! This got 3x and 4x working on my panasonic tc-p50-s60! Tested on Genesis, SNES, N64.

    After setting V. Active to 256 I had to turn V. backporch down to 3 before I got picture.

    I’m not happy with the result personally, how do I get the aspect ratio right? It looks way off, especially in 3x. There are also some blurry areas and some not.

    And even then, I’d still be stuck with the borders all the way around without using another scaler in between?

    At this point I’ll be sticking with 2x. The picture in a window is probably too much even if I can tweak out the aspect and pixel sharpness. 2x just works and looks great on my plasma, but I love tweaking and will appreciate any other tips.

    I’ll let you know if I have any luck with your other 5x tips.



    @deltronik This sounds like the same issue I had with VT60. I referred to it as ‘incorrect scale’ but I think this was wrong. Basically, there are columns of blurred graphics going from top to bottom of the screen.

    EDIT: this should be much easier to follow now πŸ™‚
    EDIT: There are some new tips and settings in my first post on page 3. Hope this doesn’t confuse the issue.
    EDIT: correction re AR settings on TV.

    Anyway, the fix:

    – Select the correct aspect ratio for your TV. For mine, Lx3 requires 16:9 and Lx4 requires 4:3.
    – The VT60 enables changing the colour of the sides bars in 4:3 mode, from black to various shades of grey. This is to prevent image retention, your set might not be prone but my VT60 is highly prone so I set to full grey.
    – Load up a game on your console. I’d suggest for your first run, a console which outputs 320 x 240 (IE, not SNES). Pick a game or scene of a game with lots of text on the screen (RPG in-game menu, title screen). Using text makes it easier to tell when all the blurriness has disappeared
    – I would go for 4x first, imo it’s nicer looking than 3x. So go to ‘Output options’ and set ‘240p/288p proc’ to ‘Line4x’.
    – Next, go to ‘Sampling opt’ > ‘Adv.timing > 320 x 240 optim
    – Per Harrumph’s tip, set to 256 and reduce V.backporch until you get a picture
    – Now, increase H.samplerate by 1. This should cause the blurry columns to change position and possibly change number. It should also increase the width of the image by a smidge
    – Keep increasing by 1 until all the blurriness is gone. This is where the text is handy, as all letters should have sharp and distinct edges.
    – Now you can restore the AR by reducing to 240
    – You should now be looking at some super crisp graphics in correct AR

    A few notes:
    – must be at 256 if you want to adjust other tweaker settings. If adjusting H.samplerate, H.synclen, etc with < 256, the TV loses the image and it will only come back once is increased to 256
    – You can use the ‘Generic 4:3’ modes, but this has two key differences with ‘Optim’ modes.
    – Firstly, it is not zoomed in as much, so for Genesis/MD, you can see a lot more of the overscan area.
    – Second, where optim mode has one ‘sweetspot’ for H.samplerate (the point where the blurriness is gone) generic 4:3 gives a clear
    image on every third adjustment (EG @ H.samplerate X, X+3, X+6, etc) so you will only find the correct image width via trial and
    – The same process works for Lx3
    – Although I could only get SNES to work in Lx3, when using the 8:7 AR option (new in firmware 0.76) it looks fricken spectacular. I know there are differing opinions about using this ratio, but imo, there’s simply not other way to SNES πŸ™‚ Give it a try and see what you think.

    Hope that helps. Once you sort out these steps and lay your eyes on some crisp and colourful graphics with correct AR, I think you’ll be amazed at how good the OSSC is with a panny plasma. I’ve been playing through a lot of different games and am continually impressed how new details and image depth are now apparent. It might just be the jump from Lx2 to Lx3/4, but I think the awesome panny black level, motion handling, colour reproduction, etc push the image quality to spectacular heights.



    So I just got home. Turns out I’d forgotten about some settings I’d noted in a spreadsheet last night before bed. Whoops πŸ˜€

    Anyway, I have settings for a few consoles. If your panny handles signals the same way the VT60 does, you might be able to just plug these in.



    WOW! So much information! I am just getting acquainted with the timing tweaks and advanced settings, this is great. Thank You!

    And yes, that does sound like the issue you saw with your VT60 and blurred columns. I’ll try out your fix and let you know!


    Lol. Yeah I’ve fixed up that post, should be much easier to follow now. My brain was a bit fried when I wrote that last night.



    Thanks for posting your findings. I have a Sony TV similar to @BlockABoots and the supported signals are identical. I know that you posted the below on the fly but would you have proper suggestions on what to try for X3 or X4.

    Console lines | 262 | 263 | x4 mode
    H Samplerate | 1734 | 1727 |
    H Active | 1280 | 1280 |
    H Sync | 158 | 156 |
    H Backporch | 198 | 196 |

    As before, thank you for starting this thread and making suggestions.


    @Harrumph how did you get the image to show in this thread? I tried a few methods last night but the best I could do was insert a link to the image host.


    I never inserted image, only used google drive link. I think it should work if it points to an actual file name, like with photobucket etc.?

    Well, I’m still in the rabbit hole but hope to pop up with something useful tomorrow. Right now too tired. πŸ˜‰

    Btw perhaps why your aspect is off, 1280×1024 is a 5:4 format, you should try to use an unscaled mode, if at all possible.


    After all adjustments are done, the image takes up the whole 4:3 window horizontally, give or take one pixel. So horizontal is spot on as far as I can tell. I’m pretty sure that vertical is also, as I’ve measured the rings in Sonic and they have the same measured diameter for vertical and horizontal. Also, I haven’t measured it accurately, but from a rough guess it appears that the graphics are being displayed over roughly 960 vertical lines out of 1080p. The reason I haven’t bothered to measure this, is due to the measurements of the Sonic rings, and it also just looks and feels right. IE, it looks f#@!ing amazing πŸ˜€

Viewing 15 posts - 16 through 30 (of 168 total)
  • You must be logged in to reply to this topic.