OSSC (DIY video digitizer & scandoubler)

[citrus3000psi]

What would the OSSC do with something like a 1080i/720p VGA signal

[atheistgod1999]

Can this thing sample at the horizontal output resolution, so 960 samples per line in line triple for example?

[marqs]

Does anyone think that 480i could work with the option to cancel odd or even fields to replicate the way certain extron boards downscale to 240p?

You mean displaying the fields on top of each other without any offset? Adjustable field offset is on the wishlist but it needs memory that's on quite short supply. Maybe a customized fw which cuts some other feature(s) to make spece for additional line buffers.

Hey Marqs? When you tested the Dreamcast, did you just stick with the Garo/Kuro vga boxes, or have you tried testing them with the official one and other 3rd party?

I have only tested Kuro - changing H-PLL values did not make any difference even if phase was preset to an unoptimal value that showed flicker.

What would the OSSC do with something like a 1080i/720p VGA signal

720p and 1080p are only digitized. 1080i is also passed through as is, but for some reason it doesn't work at the moment.

Can this thing sample at the horizontal output resolution, so 960 samples per line in line triple for example?

By default Line3x Generic 4:3 mode takes 1170 samples per line (960 assumed active), and multiplies that by 4/3 to output 1560 pixels per line (1280 active but with content on original 960 only).

[AndehX]

any news on the availability of these?

[BuckoA51]

Narrowly missed out on an OSSC last year? If you are number 1736 to 1749 check your inbox NOW! We have a small number of units.

[AndehX]

I literally have the money to buy one now too

[wildchild22]

I know people will think this is crazy. But I would like an option to treat 240p as 480i as an option. This way for games like killer instinct gold and other 240p games with 480i menus there will be no drop outs during switches. I think this would be great if it could be implemented.

[Galgomite]

I know people will think this is crazy. But I would like an option to treat 240p as 480i as an option. This way for games like killer instinct gold and other 240p games with 480i menus there will be no drop outs during switches. I think this would be great if it could be implemented.

I had thought about this also. It would be cool if you could lock in a format so it gets displayed regardless of input. Even if it resulted in more flicker or whatever on 480i menus, it could be worth it in the right situations. Could this work?

[BuckoA51]

Most of the issues with switching are due to the fact the refresh rate changes slightly when the console goes from 480i to 240p, so that wouldn't help.

[wildchild22]

The cheap ebay gbs scaler does not loose sync with killer instinct gold so it may in fact help the n64. Not sure if it will help all consoles though.

Most of the issues with switching are due to the fact the refresh rate changes slightly when the console goes from 480i to 240p, so that wouldn't help.

[AndehX]

yeah the GBS never loses sync regardless of 480i/240p. Maybe implement into the OSSC whatever it is the GBS does?

[MetalMilitia]

The reason it does this is because the GBS is interpreting the 240p signal incorrectly. It reads that signal as 480i and then de-interlaces it, as opposed to reading it as a progressive image like it should. I wouldn't want the OSSC to do anything like that.

[Galdelico]

The reason it does this is because the GBS is interpreting the 240p signal incorrectly. It reads that signal as 480i and then de-interlaces it, as opposed to reading it as a progressive image like it should. I wouldn't want the OSSC to do anything like that.

Yeah, that doesn't seem like anything you need, in order to improve the actual experience with the OSSC. Also - if I'm not mistaken - I remember an old CRT of mine (Thomson?) doing pretty much the same thing, with those games... 'Jumping'/blinking and going black for a second, during the resolution switch, with the AV channel indicator popping up on screen every time.

Speaking of the OSSC, Marqs/Matt, do you guys have any idea about when to expect the firmware update that will bring the profiles feature? I can't wait to be finally able to save all the settings, with all my systems, and then just forget about it.

[BuckoA51]

The cheap ebay gbs scaler does not loose sync with killer instinct gold so it may in fact help the n64. Not sure if it will help all consoles though.

I think that scaler converts everything to standard 59.94 refresh rate though. You'd need a frame buffer to do that.

Speaking of the OSSC, Marqs/Matt, do you guys have any idea about when to expect the firmware update that will bring the profiles feature?

I'm actually going to be beta testing that firmware tonight.

[Galdelico]

I'm actually going to be beta testing that firmware tonight.

Awesome!
Thanks! ^_-

[AndehX]

The reason it does this is because the GBS is interpreting the 240p signal incorrectly. It reads that signal as 480i and then de-interlaces it, as opposed to reading it as a progressive image like it should. I wouldn't want the OSSC to do anything like that.

If it eliminates the 240p/480i sync drop, then I would totally want that as an option. Yes it may be reading the signal incorrectly, but if that's the only way to get rid of the delay, then why not have it as an option? It's an option that would only be used on a very small handful of games anyway...

[Galgomite]

For anyone interested: I tried out the DVDO Micro with the OSSC on my HDTV this evening. Just a few minutes mind you but the result was disappointing. In 480p, the picture was upscaled to 1080p but had a constant vertical jitter. At 720p, the picture was stable but received no upscaling to 1080p at all. Test game was Ninja Gaiden on PC Engine.

[Guspaz]

The reason it does this is because the GBS is interpreting the 240p signal incorrectly. It reads that signal as 480i and then de-interlaces it, as opposed to reading it as a progressive image like it should. I wouldn't want the OSSC to do anything like that.

If it eliminates the 240p/480i sync drop, then I would totally want that as an option. Yes it may be reading the signal incorrectly, but if that's the only way to get rid of the delay, then why not have it as an option? It's an option that would only be used on a very small handful of games anyway...

The GBS is a scaler, not a line doubler. It can (and does) alter timing by buffering frames, meaning that the timing differences between 240p and 480i (however they're handled) can be masked.

The OSSC is a line doubler, not a scaler. It can only alter timing inasmuch as it has enough memory to buffer a handful of scanlines. From what Marqs has said, there's nothing that can be done.

[AndehX]

The reason it does this is because the GBS is interpreting the 240p signal incorrectly. It reads that signal as 480i and then de-interlaces it, as opposed to reading it as a progressive image like it should. I wouldn't want the OSSC to do anything like that.

If it eliminates the 240p/480i sync drop, then I would totally want that as an option. Yes it may be reading the signal incorrectly, but if that's the only way to get rid of the delay, then why not have it as an option? It's an option that would only be used on a very small handful of games anyway...

The GBS is a scaler, not a line doubler. It can (and does) alter timing by buffering frames, meaning that the timing differences between 240p and 480i (however they're handled) can be masked.

The OSSC is a line doubler, not a scaler. It can only alter timing inasmuch as it has enough memory to buffer a handful of scanlines. From what Marqs has said, there's nothing that can be done.

ahh that sucks. Oh well, nothing is perfect I guess ^_^

[BuckoA51]

Small number of OSSC order invitations just went out. If your number is between 1751 and 1771, check your inbox.

[paulb_nl]

The timing difference between 240p/480i is only 0.5 scanline with the N64 (263 vs 262.5). If the OSSC can run slightly out of sync and output an extra line (526 vs 525) then it only needs to buffer 1 line.

But the big question is can the OSSC keep the pixelclock going during the transition from 240p to 480i?

[marqs]

The timing difference between 240p/480i is only 0.5 scanline with the N64 (263 vs 262.5). If the OSSC can run slightly out of sync and output an extra line (526 vs 525) then it only needs to buffer 1 line.

But the big question is can the OSSC keep the pixelclock going during the transition from 240p to 480i?

That would only solve mismatch of line counts - a fixed single refresh rate output from 2 different source refresh rates still requires a framebuffer so that one source frame can be periodically dropped/duplicated when input&output refresh rates do not match.

[orange808]

Yep. Can't be done without a frame buffer.

I have a Panasonic DMR-ES10 that can accept 240p and convert it to 480i. It sucks.

(Nice for true 480i composite video sources, though.)

[marqs]

Yep. Can't be done without a frame buffer.

Refresh rate transitioning without sync loss should be possible with Freesync, but implementation would be still far from trivial. Freesync also has its own issues, including being DP only and unsuitable for low-persistence displays (brightness fluctuations in this case would be unnoticeable though, as rate changes would be tiny and infrequent).

[Guspaz]

Freesync over HDMI is a thing:

https://www.amd.com/Documents/freesync-hdmi.pdf

That PDF is from 2015, so I believe all those monitors have shipped by now. It's also reported to work over DVI in some cases, and sometimes even on monitors that don't advertise FreeSync support.

[BuckoA51]

This looks VERY interesting - http://www.eurogamer.net/articles/digit ... s-revealed

[Nrg]

Yep, upcoming HDMI 2.1 adds Adaptive Sync / FreeSync! So Variable Refresh Rates are possible with HDMI 2.1. It's called "Game Mode VRR features variable refresh rate".

"HDMI FORUM ANNOUNCES VERSION 2.1 OF THE HDMI SPECIFICATION":
http://www.hdmi.org/press/press_release.aspx?prid=145

[Galdelico]

This looks VERY interesting - http://www.eurogamer.net/articles/digit ... s-revealed

Which leads me to a question (honest curiosity, from someone who has zero technical education and expertise on this subject).

If they'll ever come, how do you guys plan do manage major hardware/software improvements to the current OSSC? Something like an HDMI 2.1 integration, new features that get past actual memory limitations, etc. Would it be possible to provide additional boards/components to attach to the unit, in order to make it more compatible and/or powerful?

I'm probably just looking too forward, but the whole project has been exciting to follow since the very beginning, for me, so it comes quite natural to wonder if the idea behind it is to reach the limits of what it can do at this stage - and then move on to the OSSC2, or whatever its successor will be named - or to expand it beyond its current capabilities, and have a device that basically grows up along with the technology it's meant to support.

[borti4938]

Just a quick note to marqs:

Speaking of the OSSC, Marqs/Matt, do you guys have any idea about when to expect the firmware update that will bring the profiles feature?

I'm actually going to be beta testing that firmware tonight.

I've took a look on the profile support Great work on that marqs!

But what I don't like is that the OSSC always loads profile 0 on each power cycle. It's a bit user-unfriendly. If I use profile 4 and switch off the OSSC, I expect that profile 4 is loaded again on the next power cycle.

So what I did is: I kept away profile 0 from the user selection and use this slot as a copy of the latest loaded/saved profile. If you like, marqs, I can send you the code changes

BR

[jarp]

Btw. does anybody know if there is PCB mounted female HDMI connectors in existence which would have DVI connector's footprint? I am of course thinking about replacing DVI connector of the OSSC with HDMI connector as adapter adds bulkiness a lot. I think there are none as Googling did not reveal anything... Yeah I should've had bought DIY kit but did not have time back then to do the assembly.