OSSC (DIY video digitizer & scandoubler)

[blizzz]

marqs, which driver version are you using? When I tested the custom 720p modeline with linux with my SC-500N1 I got the same horizontal shift as in your video. But on my card the colors were all messed up. I wonder if that's a driver issue, a difference between the SC-500N1 and SC-512N1, or maybe the video output of my linux machine is still a bit different than the scaler.

[marqs]

Wow. So...clean !

Thanks to the LPF chip added on the latest prototype - there's quite a bit of noise if LPF iis bypassed.

marqs, which driver version are you using? When I tested the custom 720p modeline with linux with my SC-500N1 I got the same horizontal shift as in your video. But on my card the colors were all messed up. I wonder if that's a driver issue, a difference between the SC-500N1 and SC-512N1, or maybe the video output of my linux machine is still a bit different than the scaler.

The driver version is 1.1.0.140. I've also noticed inverted colors on some configurations plus some other bugs e.g. upside-down video with RGB32 surface. There seems to be also some vertical banding in basic 480p mode (easily seen in gradients) - I should check if that also happens with PC input.

[Fudoh]

After some debugging, the problem was traced to TVP7002 chip which randomly reported no sync even when everything was working. A small workaround (there's now quite a few for TVP7002 bugs) was added which pretty much fixed this issue

would you share a little more details on that workaround ?

The video looks stunning. I hope the LPF is up to considerably worse sources like PS2 as well. But I'm glad already that all the PSU induced noise seems to be gone as well.

[rtw]

A few days ago I finally had a chance to personally test some arcade boards (Armed Police Batrider, Brave Blade, Gaplus, Raiden, Raiden 2 DX, R-Type Leo, Super Mario Bros, Super Space Invaders, Truxton, Viper Phase 1). As expected, they were a lot trickier than consoles, with wildly different refresh rates and line counts. Initially many of those failed to sync reliably with OSSC. After some debugging, the problem was traced to TVP7002 chip which randomly reported no sync even when everything was working. A small workaround (there's now quite a few for TVP7002 bugs) was added which pretty much fixed this issue. In the end, only Super Space Invaders out of the 10 boards couldn't sync - I'll have to examine its signal to find out if there's something strange.

Saturn looks very nice, could you please share with us what kind of setup you are using for the arcade PCBs ?

I.e. the complete chain from JAMMA board to DVI/HDMI output.

SSI/Majestic 12 is known to have bad/unconventional sync, you need a composite sync regenerator i.e. an LM1881.

[marqs]

After some debugging, the problem was traced to TVP7002 chip which randomly reported no sync even when everything was working. A small workaround (there's now quite a few for TVP7002 bugs) was added which pretty much fixed this issue

would you share a little more details on that workaround ?

I'm reading status (sync, linecount etc.) from TVP7002 every 20ms, and normally I disable output immediately when no sync is reported. This has worked well so far with consoles but now there are these random false sync loss events with many arcade boards. Perhaps TVP7002's sync detection doesn't work reliably with refresh rates like 55Hz, but as these events are random and not too frequent (once per second or less), it's easy to fix by not disabling output immediately but only after N consecutive "no sync" reads.

[marqs]

Saturn looks very nice, could you please share with us what kind of setup you are using for the arcade PCBs ?

I.e. the complete chain from JAMMA board to DVI/HDMI output.

SSI/Majestic 12 is known to have bad/unconventional sync, you need a composite sync regenerator i.e. an LM1881.

I'm using Arcade Supergun MK IV. I checked that it has 470ohm resistor on the sync like to drop it to normal analog sync level. Just checked Super Space Invaders with a scope but didn't find anything very unusual there. Video trigger mode on my scope doesn't work well though - I had to use normal edge/pulse trigger so I may have missed some irregularities.

[rtw]

Supergun MK IV. I checked that it has 470ohm resistor on the sync like to drop it to normal analog sync level. Just checked Super Space Invaders with a scope but didn't find anything very unusual there. Video trigger mode on my scope doesn't work well though - I had to use normal edge/pulse trigger so I may have missed some irregularities.

Thank you for the info

I use a HAS, so I would need a mini-din to scart male adapter. Then I would need some kind of DVI+Audio combiner to get HDMI out of it.

There has been quite a few discussions on cables, can anyone tell me where the best place would be to buy them ?

Majestic 12 (Taito F2) is known to have bad sync, I am guessing that the other F2 based games have the same issue. F3 has issues as well. The solution is a sync regenerator.

[Fudoh]

Then I would need some kind of DVI+Audio combiner to get HDMI out of it.

before everyone starts looking for those external DVI+Audio to HDMI combiners, *many* TVs actually have an audio input that can be associated with one of the HDMI inputs. So check this first before throwing money at something you don't need.

[AndehX]

Then I would need some kind of DVI+Audio combiner to get HDMI out of it.

before everyone starts looking for those external DVI+Audio to HDMI combiners, *many* TVs actually have an audio input that can be associated with one of the HDMI inputs. So check this first before throwing money at something you don't need.

Really? I thought it was only the VGA input that had an external audio input?

[rtw]

Then I would need some kind of DVI+Audio combiner to get HDMI out of it.

before everyone starts looking for those external DVI+Audio to HDMI combiners, *many* TVs actually have an audio input that can be associated with one of the HDMI inputs. So check this first before throwing money at something you don't need.

I am aware of that but I have an 8 input HDMI switcher so it has to be HDMI

[Fudoh]

Really? I thought it was only the VGA input that had an external audio input?

no, to support audio-less DVI from PCs, usually at least one HDMI port can use external audio as well.... Might have gotten rarer in the recent past, but many TVs still offer this.

[Mantrox]

Pretty amazing results! *claps*
Razor sharp, clean image.

[Xyga]

Then I would need some kind of DVI+Audio combiner to get HDMI out of it.

before everyone starts looking for those external DVI+Audio to HDMI combiners, *many* TVs actually have an audio input that can be associated with one of the HDMI inputs. So check this first before throwing money at something you don't need.

I have personally never seen one, this must be a thing specific to some particular brands and series, or I've missed something.

[Das Muel]

You can assign analogue audio (from the component input) to any of the three HDMI ports on my 2014 Panasonic LED. I use the feature all the time with my XPC-4.

[Galgomite]

Wow. That output looks amazing.

[ZellSF]

Then I would need some kind of DVI+Audio combiner to get HDMI out of it.

before everyone starts looking for those external DVI+Audio to HDMI combiners, *many* TVs actually have an audio input that can be associated with one of the HDMI inputs. So check this first before throwing money at something you don't need.

I have personally never seen one, this must be a thing specific to some particular brands and series, or I've missed something.

Most TVs I've run into has had either audio ports dedicated to one of the HDMI inputs or one that could be assigned to it.

Mostly Panasonic and Sony panels.

Definitely something worth checking for. Or you know, get a decent audio setup.

[Xyga]

Well I've had only LG (x2) and Sony (x2) these past years, also talked to more than one Samsung owners who had that problem.

None of the sets I've used/'met'/inquired about featured that. It must really be brand/series specific.

[ZellSF]

Well I've had only LG (x2) and Sony (x2) these past years, also talked to more than one Samsung owners who had that problem.

None of the sets I've used/'met'/inquired about featured that. It must really be brand/series specific.

I looked up a random LG, Samsung and Sony manual just now. They all feature separate audio inputs that could be assigned to DVI/HDMI. I'm not saying there aren't brands/series that do not have the feature, but it definitely isn't uncommon.

[Xyga]

Really are you really sure about the Sony ?
I went to check the manual of a current W7 model and it's no diffrent from my 2013's: no option to assign audio input to HDMI.

Checked a random LG 650 and although the manual didn't specify it, the specs show a dedicated 'PC Audio' input, so it must be okay.
(my old LG had one too but only working with VGA)

A random series Samsung (series 5), didn't have any analogue input other than the one going with composante, and from what I could read in the manual no option to reassign it to other inputs.

Maybe it's not uncommon but definitely not that common either, because it's not something that's supposed to be needed by a huge majority of users, so there's no obligation for manufacturers to implement it.

[blizzz]

Are you sure? The 2012 model (Sony KDL-40EX650) has an option for HDMI audio source. It's a bit hidden in the system menu and not the normal input options.

Sound > HDMI/DVI Audio Source > ○ Auto / ○ HDMI Audio / ○ PC Audio

[Xyga]

Nope, nothing like that anywhere. Probably a lot of things changed with the W series.

When there's only one audio input on a set and it's the one that goes with component, it's quite unlikely that kind of feature will be available anyway.

[bobrocks95]

No separate audio input on the 2015 Sony W700B and it didn't look like there was any option to use the component input's analog audio... manufacturers may be removing this on newer models.

[BazookaBen]

manufacturers may be removing this on newer models.

Very possible. Many PC's are including HDMI instead of DVI nowadays.

Which brings me to this:

Or you know, get a decent audio setup.

Seriously guys, if you're so worried about getting great video, why are you totally ignoring audio? These consoles, especially from the 16-bit era, only truly shine once you hook them up to a decent set of speakers or headphones.

Spending $2,000 on a video setup then running audio to your TV speakers is a travesty.

[Mantrox]

manufacturers may be removing this on newer models.

Very possible. Many PC's are including HDMI instead of DVI nowadays.

Which brings me to this:

Or you know, get a decent audio setup.

Seriously guys, if you're so worried about getting great video, why are you totally ignoring audio? These consoles, especially from the 16-bit era, only truly shine once you hook them up to a decent set of speakers or headphones.

Spending $2,000 on a video setup then running audio to your TV speakers is a travesty.

Thats why i will run the audio to my stereo amp.
But i can understand that not everyboby can have both, at same at the same time.
If i had to choose, i would go with the image 100%.

[BazookaBen]

All you really need are a nice set of headphones and maybe a headphone amp if your TV doesn't have headphone out. So good sound should be within reach of everybody.

[Ji-L87]

Not to hijack this thread but, if the TV has a headphone out, a cheap and easy way to improve TV audio is hooking up a powered PC 2.1 speaker system or an old stereo kit or boombox with aux inputs.
Like the ones you can find super cheap used. Not the most elegant solution but it tends to work well. Cheap 2.1 setups usually have very small satellite speakers that are easy to hide and the subs are usually not that big either, still they perform (much) better than flat panel built-in speakers.

[Das Muel]

I just run audio from my Panasonic's headphone out to a large pair of powered studio monitors. No separate amp or sub needed. Fantastic sound.

[Guspaz]

Or you know, get a decent audio setup.

Seriously guys, if you're so worried about getting great video, why are you totally ignoring audio? These consoles, especially from the 16-bit era, only truly shine once you hook them up to a decent set of speakers or headphones.

Spending $2,000 on a video setup then running audio to your TV speakers is a travesty.

Existing home theatres are going to typically be pulling audio off the HDMI, because that's the only way to get support for higher bitrate surround sound. Many AV receivers don't support mixing HDMI video with analog audio, and so if the audio isn't present on the HDMI cable, you need to resort to additional trickery to get audio into the home theatre system, such as HDMI audio injectors. What does TV speakers have to do with any of this?

[BazookaBen]

Well, we're really only dealing with old systems in this thread, so you can connect their audio out's directly to your receiver

People wondering about getting audio on HDMI are generally trying to get audio on their TV speakers, to which I say f-that get a real stereo system. You can usually get a decent receiver on craigslist or at goodwill for pretty cheap.

[bobrocks95]

Well, we're really only dealing with old systems in this thread, so you can connect their audio out's directly to your receiver

People wondering about getting audio on HDMI are generally trying to get audio on their TV speakers, to which I say f-that get a real stereo system. You can usually get a decent receiver on craigslist or at goodwill for pretty cheap.

What he's saying is what if you have everything HDMI plugged into your receiver and then the receiver to the television? How do you avoid adding a mixing device for audio when your receiver is only looking for digital audio over HDMI?