OSSC (DIY video digitizer & scandoubler)

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makar1
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Re: OSSC (DIY video digitizer & scandoubler)

Post by makar1 »

Harrumph wrote:To (perhaps) clarify, one single profile can contain a separate setting for each input video mode, i.e. 240p/360p/384p/480i/480p etc. In the case of Gamecube/GBP (using GBI) and Wii, a single profile slot can actually be used, at least if you are satisfied with generic modes. 480i and 480p output is identical for Gamecube and Wii. There would be a potential conflict however between GBI 240p and Wii VC 240p, if you want to use optimized mode for GBI.
There's no reason to use any output other than 360p for GBI if you own an OSSC. Image quality is greatly improved over 240p/480p.
Chris230291
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Re: OSSC (DIY video digitizer & scandoubler)

Post by Chris230291 »

Hi. I have a audio issue with my SNES when in line multi 3,4,5. In 2x mode it sounds perfect.
Picture looks spot on in all modes, except 1x "out of range" on monitor.
Its a NTSC-J mini. I remember modding it for RGB years ago. Almost certain that I didn't use a fancy board.
Any suggestions?
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Harrumph
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Re: OSSC (DIY video digitizer & scandoubler)

Post by Harrumph »

makar1 wrote: There's no reason to use any output other than 360p for GBI if you own an OSSC. Image quality is greatly improved over 240p/480p.
There is. 360p is normalized to 60Hz, so you will get frame stutter because of duplicated frame roughly every 4 seconds. Depending on how much scrolling is used in a game, that can be a bit too distracting for me. So I tend to go back and forth between modes depending on game. IIRC, the frame stutter can be removed in 360p by increasing the frame buffer (I never tried actually). So costs some additional lag.
paulb_nl
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Re: OSSC (DIY video digitizer & scandoubler)

Post by paulb_nl »

You can set format to hdcustom instead of hd60 for 360p 604x374@59.76Hz. There is far less stutter that way.

https://www.gc-forever.com/wiki/index.p ... _Converter
thebigcheese
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Re: OSSC (DIY video digitizer & scandoubler)

Post by thebigcheese »

Chris230291 wrote:Hi. I have a audio issue with my SNES when in line multi 3,4,5. In 2x mode it sounds perfect.
Picture looks spot on in all modes, except 1x "out of range" on monitor.
Its a NTSC-J mini. I remember modding it for RGB years ago. Almost certain that I didn't use a fancy board.
Any suggestions?
Try audio downsampling if you haven't already. If that still doesn't work, you'll need to install a dejitter mod.
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Harrumph
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Re: OSSC (DIY video digitizer & scandoubler)

Post by Harrumph »

paulb_nl wrote:You can set format to hdcustom instead of hd60 for 360p 604x374@59.76Hz. There is far less stutter that way.

https://www.gc-forever.com/wiki/index.p ... _Converter
Thanks for the tip, will try that! According to my calculations, that would be approx one duplicate frame per 33 seconds?
Chris230291
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Re: OSSC (DIY video digitizer & scandoubler)

Post by Chris230291 »

thebigcheese wrote:
Chris230291 wrote:Hi. I have a audio issue with my SNES when in line multi 3,4,5. In 2x mode it sounds perfect.
Picture looks spot on in all modes, except 1x "out of range" on monitor.
Its a NTSC-J mini. I remember modding it for RGB years ago. Almost certain that I didn't use a fancy board.
Any suggestions?
Try audio downsampling if you haven't already. If that still doesn't work, you'll need to install a dejitter mod.
Thanks for the reply.Yes I already tried that but it didnt help.
Can you explain why I need the dejitter please? I thought it would not have worked at all if I needed it?
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Guspaz
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Re: OSSC (DIY video digitizer & scandoubler)

Post by Guspaz »

makar1 wrote:
Harrumph wrote:To (perhaps) clarify, one single profile can contain a separate setting for each input video mode, i.e. 240p/360p/384p/480i/480p etc. In the case of Gamecube/GBP (using GBI) and Wii, a single profile slot can actually be used, at least if you are satisfied with generic modes. 480i and 480p output is identical for Gamecube and Wii. There would be a potential conflict however between GBI 240p and Wii VC 240p, if you want to use optimized mode for GBI.
There's no reason to use any output other than 360p for GBI if you own an OSSC. Image quality is greatly improved over 240p/480p.
The reason not to use 360p is poor display compatibility.
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Harrumph
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Re: OSSC (DIY video digitizer & scandoubler)

Post by Harrumph »

Not particularly poor when linedoubled/tripled by the OSSC.
Edit: realised it’s a 4:3 signal, so yeah I guess YMMV.
Edit2: scratch that edit, see below
Last edited by Harrumph on Wed Sep 11, 2019 10:10 am, edited 2 times in total.
paulb_nl
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Re: OSSC (DIY video digitizer & scandoubler)

Post by paulb_nl »

Harrumph wrote:Thanks for the tip, will try that! According to my calculations, that would be approx one duplicate frame per 33 seconds?
Yeah close to that number. I think I timed it at 29 seconds.
nmalinoski
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Re: OSSC (DIY video digitizer & scandoubler)

Post by nmalinoski »

Chris230291 wrote:
thebigcheese wrote:
Chris230291 wrote:Hi. I have a audio issue with my SNES when in line multi 3,4,5. In 2x mode it sounds perfect.
Picture looks spot on in all modes, except 1x "out of range" on monitor.
Its a NTSC-J mini. I remember modding it for RGB years ago. Almost certain that I didn't use a fancy board.
Any suggestions?
Try audio downsampling if you haven't already. If that still doesn't work, you'll need to install a dejitter mod.
Thanks for the reply.Yes I already tried that but it didnt help.
Can you explain why I need the dejitter please? I thought it would not have worked at all if I needed it?
In a nutshell, the problem with the NES and SNES is that the last non-visible scanline, right before the visible scanlines, gets cut short, meaning that the horizontal sync cadence doesn't stay the same. CRTs don't give a care, but digital hardware often expects a perfect sync cadence and tends to choke when it doesn't get it. A dejitter mod would correct that janky sync, which would make it acceptable to digital displays that would normally choke on it.
thebigcheese
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Re: OSSC (DIY video digitizer & scandoubler)

Post by thebigcheese »

And to clarify, that can manifest differently depending on the display. You might get just video, as in your case, or you might get nothing at all. In either case, dejitter should fix it. I also had to turn on audio downsampling to get my capture card to cooperate, but now that I think about it, I might not have needed it for my TV/receiver.
paulb_nl
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Re: OSSC (DIY video digitizer & scandoubler)

Post by paulb_nl »

Harrumph wrote:Not particularly poor when linedoubled/tripled by the OSSC.
Edit: realised it’s a 4:3 signal, so yeah I guess YMMV.
If you use the Line2x 240x360 or Line3x 240x360 modes then the output is 1280x720 and 1920x1080. The output is much closer to standard line counts than Line3x/5x 240p.
Chris230291
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Re: OSSC (DIY video digitizer & scandoubler)

Post by Chris230291 »

The sound always works but its all glitchy and garbled in 3x,4x and 5x modes.
Perfect in 2x mode.
This is over HDMI.
From the 3.5mm jack on the OSSC its always perfect.
My NES is fine. But I recently fitted Tims RGB mod which I think have dejitter built in?

Definitely sounding like I need a dejitter?
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Guspaz
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Re: OSSC (DIY video digitizer & scandoubler)

Post by Guspaz »

paulb_nl wrote:
Harrumph wrote:Not particularly poor when linedoubled/tripled by the OSSC.
Edit: realised it’s a 4:3 signal, so yeah I guess YMMV.
If you use the Line2x 240x360 or Line3x 240x360 modes then the output is 1280x720 and 1920x1080. The output is much closer to standard line counts than Line3x/5x 240p.
Neither 360x1 nor 360x2 nor 360x3 nor 240x3 nor 240x5 work on my display. 240x1, 240x2, and 240x4 all work.
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Harrumph
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Re: OSSC (DIY video digitizer & scandoubler)

Post by Harrumph »

paulb_nl wrote: If you use the Line2x 240x360 or Line3x 240x360 modes then the output is 1280x720 and 1920x1080. The output is much closer to standard line counts than Line3x/5x 240p.
Yeah seems I did remember correctly after all. :) I suppose it works similarly to 240p lx3 mode where total and actual video is multiplied by different factors?
Guspaz wrote: Neither 360x1 nor 360x2 nor 360x3 nor 240x3 nor 240x5 work on my display. 240x1, 240x2, and 240x4 all work.
Well that’s a shame, but it doesn’t oppose that HD60 360p modes should be more compatible in general than 240p x3/x5 as paulb_nl pointed out just now (h freq and line count is exactly on spec for 720p/1080p). Hdcustom might be less so, but fortunately for me, it also works on my TV.
paulb_nl
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Re: OSSC (DIY video digitizer & scandoubler)

Post by paulb_nl »

Harrumph wrote: I suppose it works similarly to 240p lx3 mode where total and actual video is multiplied by different factors?
Sort of. They are just optimized modes so for example Line2x 240x360 samples at 5x sample rate and duplicates every 1/5th sample at 4x.
https://github.com/marqs85/ossc/blob/1d ... des.c#L161
https://github.com/marqs85/ossc/blob/1d ... ler.c#L465

This results in 1500x750 output with 960 actual video. Well 1024 actual video because H.active is set to 256 but of course GBA is only 240x160 resolution.
thebigcheese
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Re: OSSC (DIY video digitizer & scandoubler)

Post by thebigcheese »

Chris230291 wrote:The sound always works but its all glitchy and garbled in 3x,4x and 5x modes.
Perfect in 2x mode.
This is over HDMI.
From the 3.5mm jack on the OSSC its always perfect.
My NES is fine. But I recently fitted Tims RGB mod which I think have dejitter built in?

Definitely sounding like I need a dejitter?
Yes. Recent NESRGB kits do have dejitter, so that would certainly explain why that's working fine
Chris230291
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Re: OSSC (DIY video digitizer & scandoubler)

Post by Chris230291 »

OK thanks guys.
Can you get dejitter combined with RGB amps?
My SNES picture is a little dark.
I think I just connected the RGB pins from a chip to the multiout.
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Harrumph
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Re: OSSC (DIY video digitizer & scandoubler)

Post by Harrumph »

Chris230291 wrote: Can you get dejitter combined with RGB amps?
Yes, shmups user Arthrimus designed this combined board.
https://arthrimus.com/product/snes-rgb- ... itter-mod/
Chris230291
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Re: OSSC (DIY video digitizer & scandoubler)

Post by Chris230291 »

Sweet thanks
SavagePencil
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Re: OSSC (DIY video digitizer & scandoubler)

Post by SavagePencil »

If I wanted to determine optimal timings for a McWill-powered Atari Lynx, what would be the best approach? There's no 240p test suite to validate individual pixels like a checkerboard pattern. It's also put into a frame so it's not fullscreen.
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nullifer
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Re: OSSC (DIY video digitizer & scandoubler)

Post by nullifer »

When playing PS2 games I'm getting these black borders at the top and bottom of the image, i thought this only happens on pal consoles? can I get rid of them?
Image
on the same ps2 running ps1 games the black borders at the top and bottom are not there.



Also is there anyway for me to adjust 480i settings so that i don't need to change my monitor to 4:3 to correct the aspect ratio?
For example when I play ps1 games at line 3x it outputs 1280x720 making it so i do not need to change my monitor from widescreen to 4:3 to unstretch the image.
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Galdelico
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Re: OSSC (DIY video digitizer & scandoubler)

Post by Galdelico »

Correct me if I'm wrong, isn't NTSC FFX supposed to have black bars at the top/bottom? I remember noticing how the game didn't show the same level of overscan, on my CRT TV, compared to other NTSC PS2 titles, even back in the days.

And btw, a good number of Japanese/American console games didn't use the full vertical screen space, on different platforms: take a look at Daytona USA on the Saturn, just to name the first one that comes to my mind.
nmalinoski
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Re: OSSC (DIY video digitizer & scandoubler)

Post by nmalinoski »

nullifer wrote:Also is there anyway for me to adjust 480i settings so that i don't need to change my monitor to 4:3 to correct the aspect ratio?
For example when I play ps1 games at line 3x it outputs 1280x720 making it so i do not need to change my monitor from widescreen to 4:3 to unstretch the image.
Aside from using line3x or line5x, I don't think so.

Aside from that, always forcing 4:3 doesn't really make sense to me. 480i and 480p can be either 4:3 frames or anamorphic widescreen frames, and the OSSC, as far as I've seen, does not support any kind of detection of PAR; so, if someone wanted to use the widescreen mode available in a lot of games for, say, the PS2 or Xbox, then the OSSC would force that 16:9 image to only be displayed in 4:3.

If, however, the OSSC hardware is capable of detecting PAR, then it should be possible to add support to the firmware for automatically applying windowboxing, or automatically enlarge the frame size to the matching aspect ratio, or, at the very least, passing that PAR along to the display in the hope that the display will know what to do with it.

(Somewhat related, if the OSSC could read EDID info from the connected display and determine its native aspect ratio, it might be possible for the OSSC to automatically apply or omit pillarboxing; I'm not sure windowboxing is possible with just a line buffer.)
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James-F
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Re: OSSC (DIY video digitizer & scandoubler)

Post by James-F »

Most PS2 games use only 448 lines out of the 480, that's what you are seeing.
PS1 games on the other hand mostly use all the 240 lines.
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nullifer
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Re: OSSC (DIY video digitizer & scandoubler)

Post by nullifer »

Alright thanks guys.

Is there anyway for me to modify the image in sampling options to get it to show 4:3 without switching my monitor to 4:3 mode like I was mentioning before?
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Harrumph
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Re: OSSC (DIY video digitizer & scandoubler)

Post by Harrumph »

nullifer wrote: Is there anyway for me to modify the image in sampling options to get it to show 4:3 without switching my monitor to 4:3 mode like I was mentioning before?
No, not possible
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Galdelico
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Re: OSSC (DIY video digitizer & scandoubler)

Post by Galdelico »

nullifer wrote:Alright thanks guys.

Is there anyway for me to modify the image in sampling options to get it to show 4:3 without switching my monitor to 4:3 mode like I was mentioning before?
Any chance your monitor supports multiple user profiles? If so, you could just set one identical to your current configuration, only 4:3 instead of 16:9. This way, you'd probably have to flick only one button, instead of going through the OSD every single time.
nmalinoski
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Re: OSSC (DIY video digitizer & scandoubler)

Post by nmalinoski »

Galdelico wrote:
nullifer wrote:Alright thanks guys.

Is there anyway for me to modify the image in sampling options to get it to show 4:3 without switching my monitor to 4:3 mode like I was mentioning before?
Any chance your monitor supports multiple user profiles? If so, you could just set one identical to your current configuration, only 4:3 instead of 16:9. This way, you'd probably have to flick only one button, instead of going through the OSD every single time.
My TV has a button for toggling aspect ratios on the remote control; I thought that was a pretty standard feature on consumer televisions.
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