GBS 8200/8220 CFW Project

The place for all discussion on gaming hardware
rama
Posts: 1373
Joined: Wed Mar 08, 2017 3:15 pm

Re: GBS 8200/8220 CFW Project

Post by rama »

Fantastic results, awesome! I didn't realize it was that fast :)

I lack the equipment here to do meaningful lag tests, but the progressive modes always felt fast, and deinterlacing mode felt similar, if not the same.
Now we know it's really 2 frames, or 33ms. I think 33ms is at the boundary where some people start noticing delays.
16ms though, that's well within what anyone should be able to compensate for. So this is definitely a Mega Man / Dance Dance Revolution ready device :D
NoAffinity wrote:So, then is there really any benefit to be had by including the GBS in the chain for VGA sources?

I thought "okay well maybe just convenience, to have a VGA input connected and either an RGB or component input, connected, but as we've found when having both RGB and component connected simultaneously, there is a negative effect on the image quality.
Just for convenience, I think.
The GBS can act as a variable adapter that allows sources to be 240p or 480i, but also jump up to EDTV or HD resolutions without all the usual headache.
It's okay to have one Component source and either one RGBS or one VGA source, by the way. These 2 channels are separated and don't affect each other.
What's not okay is the mixing of VGA and RGBs.
I recommend a SCART switcher on the RGBs line, so when there's a VGA source, the SCART switcher can be set to an empty channel.

The main point of the device is still good quality upscaling of 240p, of course :)

By the way, Dreamcast *may* work better now.
I noticed that the device has weird issues with higher than 60Hz refresh sources.
I don't understand what the problem is yet, but Dreamcast is most likely 60Hz anyway.
User avatar
maxtherabbit
Posts: 1763
Joined: Mon Mar 05, 2018 4:03 pm

Re: GBS 8200/8220 CFW Project

Post by maxtherabbit »

NoAffinity wrote:And, to backup the belief that GBS w/ GBS-Control CFW is indeed a low-lag solution and fast deinterlacer, I thought I'd do some lag testing. I think I've sampled enough comparisons here to definitely say that the processing time of the GBS w/ GBS-Control CFW is on par with the OSSC.

GBS CFW Lag Testing

Testing component input @ GBS, VGA vs. CRT
Process chain: SNES SCART output ->SB-2840->C2G 6x2 Component Matrix->Simultaneous component output to
->GBS-8200->Sync Master 930b VGA monitor
->Sony Trintron KV-27FV16 (240p/480i support only)

GBS CFW @ 1280x1024 (supported resolution for SM930b)

240p test suite @ 240p, 1 frame of delay on the GBS side:
Spoiler
Image
240p test suite @ 480i, 2 frames of delay on the GBS side:
Spoiler
Image

Testing component input @ GBS, LCD vs. CRT
Process chain: SNES SCART output ->SB-2840->C2G 6x2 Component Matrix->Simultaneous component output to
->GBS-8200-> OSSC Pass thru->HDMI output through various HDMI switches/splitters->TCL 49s405 LCD @ Game Mode
-> Sony Trintron KV-27FV16 (240p/480i support only)

GBS CFW @ 1280x1024

240p test suite @ 240p, 3 (2.5?) frames of delay on the GBS side:
Spoiler
Image
240p test suite @ 480i, 3 (2.5?) frames of delay on the GBS side:
Spoiler
Image

Testing component input @ GBS, VGA vs. CRT vs. LCD
Process chain: SNES SCART output ->SB-2840->C2G 6x2 Component Matrix->Simultaneous component output to
-> Sony Trintron KV-27FV16 (240p/480i support only)
->Powered VGA splitter (1 in, 2 out)
->GBS-8200-> OSSC Pass thru->HDMI output through various HDMI switches/splitters->TCL 49s405 LCD @ Game Mode
->Sync Master 930b VGA monitor

GBS CFW @ 1280x1024 (supported resolution for SM930b)

240p test suite @ 240p, 1 frame of delay on the GBS side:
Spoiler
Image
240p test suite @ 480i, 2 frames of delay on the GBS side:
Spoiler
Image

Testing SCART-direct input @ GBS, VGA vs. LCD
Process chain: SNES SCART output ->GBS-8200->Powered VGA splitter (1 in, 2 out)->Simultaneous ouput to
->OSSC Pass thru->HDMI output through various HDMI switches/splitters->TCL 49s405 LCD @ Game Mode
->Sync Master 930b VGA monitor

GBS CFW @ 1280x1024 (supported resolution for SM930b)

240p test suite @ 240p, no verifiable difference:
Spoiler
Image
240p test suite @ 480i, no verifiable difference:
Spoiler
Image
Lastly, GBS-8200 CFW output set to 640x480 mode (supported resolution for SM930b). The same process chain as immediately above, but with the 480p line doubling and upsample2x enabled at the OSSC. No verifiable difference:
Spoiler
Image
do you have a VGA CRT? seems like that would be a much more accurate comparison since we don't know the input lag of that samsung display

also, I'm having trouble figuring out how to explain that one test where it was showing 3 frames. it seems inconsistent with the other tests
User avatar
NoAffinity
Posts: 1019
Joined: Mon May 07, 2018 5:27 pm
Location: Escondido, CA, USA

Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

ah yes, of course, "resolution-switch smoothing" is also a significant benefit. I'm thinking my next compilation will be of some GBS CFW outputting through the DVDO VP30, upscaling to 1080p. I personally prefer native pixel ratios, to the maximum extent possible, but there are plenty of folks out there that just want 1080p out of their old consoles.

The resolution-switching smoothing at the GBS shifts the paradigm a bit. The approach historically has been to use something like a VP30 or a chinese SCART-to-HDMI scaler to do the resolution-switching smoothing, and a byproduct of that was of course scaling. But, now with the GBS doing the resolution-switching smoothing, I think that opens up a realm of possibilities for post-process scaling with the least possible disruption when resolution switching occurs.
Ryoandr
Posts: 269
Joined: Mon Jun 12, 2017 4:12 am

Re: GBS 8200/8220 CFW Project

Post by Ryoandr »

Just did some pics for the curious.
Right is a JVC 15khz on Svideo
Left is Sony VGA CRT with latest GBSC
https://imgur.com/a/42BBIWW

Taken at 1/60s, you can even see the delay between the 2 beams.
User avatar
maxtherabbit
Posts: 1763
Joined: Mon Mar 05, 2018 4:03 pm

Re: GBS 8200/8220 CFW Project

Post by maxtherabbit »

Ryoandr wrote:Just did some pics for the curious.
Right is a JVC 15khz on Svideo
Left is Sony VGA CRT with latest GBSC
https://imgur.com/a/42BBIWW

Taken at 1/60s, you can even see the delay between the 2 beams.
wow! this thing is fast
User avatar
NoAffinity
Posts: 1019
Joined: Mon May 07, 2018 5:27 pm
Location: Escondido, CA, USA

Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

maxtherabbit wrote: do you have a VGA CRT? seems like that would be a much more accurate comparison since we don't know the input lag of that samsung display

also, I'm having trouble figuring out how to explain that one test where it was showing 3 frames. it seems inconsistent with the other tests
I don't have a VGA CRT. Yes, presumably there is some delay at the VGA monitor, which we don't know, but given that there likely is some delay, the results are potentially more impressive. On the flip side of that, VGA CRT's are expected to introduce some delay, so I think going SCART->component->CRT route compared to the processing via the GBS route, is more telling than the results would be from adding delay at a VGA CRT.

I was also having trouble explaining the 3 frame delay (possibly around 2.5 frames, as you can see the next number half displaying on the counter), and was hoping maybe somebody else would see something that would account for that anomaly.
Last edited by NoAffinity on Sun Jan 20, 2019 8:16 pm, edited 1 time in total.
User avatar
maxtherabbit
Posts: 1763
Joined: Mon Mar 05, 2018 4:03 pm

Re: GBS 8200/8220 CFW Project

Post by maxtherabbit »

NoAffinity wrote:On the flip side of that, VGA CRT's are expected to introduce some delay
I don't believe that is correct

also, see the post above with the imgur link - someone did a test with VGA CRT through GBS vs a 15kHz TV - it's only a few scanlines
Ryoandr
Posts: 269
Joined: Mon Jun 12, 2017 4:12 am

Re: GBS 8200/8220 CFW Project

Post by Ryoandr »

CRT PC monitors will have absolutely no lag added.
CRT TV with a VGA port will have added processing lag.
User avatar
NoAffinity
Posts: 1019
Joined: Mon May 07, 2018 5:27 pm
Location: Escondido, CA, USA

Re: GBS 8200/8220 CFW Project

Post by NoAffinity »

maxtherabbit wrote:
NoAffinity wrote:On the flip side of that, VGA CRT's are expected to introduce some delay
I don't believe that is correct

also, see the post above with the imgur link - someone did a test with VGA CRT through GBS vs a 15kHz TV - it's only a few scanlines
Sorry I think I misunderstood your question. I was thinking a CRT TV w/ VGA port (thanks for clarifying Ryoandr). But, no I don't have either CRT TV w/ VGA port or a CRT VGA monitor. Agreed, CRT VGA monitor would add no delay. Wish I still had that Dell 20" CRT VGA monitor that I took the recycler 3 or 4 years ago before I knew I would one day want it again. :oops:
Ryoandr
Posts: 269
Joined: Mon Jun 12, 2017 4:12 am

Re: GBS 8200/8220 CFW Project

Post by Ryoandr »

You can still find some really fine 19/21"s for next to nothing.
Iiyama, Mitsubishi, Sony (including Dell and Gateway rebadges), Lacie, LG, all good brands for a PC CRT.
User avatar
maxtherabbit
Posts: 1763
Joined: Mon Mar 05, 2018 4:03 pm

Re: GBS 8200/8220 CFW Project

Post by maxtherabbit »

I think I'm finally ready to grab one of these and jump in

I see on the wiki it addresses issues with the V5 model as well as discusses the V3, however almost all of the listings I see on ebay now are for V4. Anything to be aware of with the version 4s? Given the option should I get a 4 or 5?
User avatar
AndehX
Posts: 790
Joined: Sun Oct 18, 2015 11:37 pm

Re: GBS 8200/8220 CFW Project

Post by AndehX »

Not sure about the v4's but in a couple of days, I'll be building one for my friend to replace his crappy "SCART to HDMI" converter. It's the HDMI model, so if I encounter any bumps in the road while building it, I shall post here.
User avatar
maxtherabbit
Posts: 1763
Joined: Mon Mar 05, 2018 4:03 pm

Re: GBS 8200/8220 CFW Project

Post by maxtherabbit »

I remember reading many pages ago that dot clock optimized sampling was not working that well. So does that mean that everything is just being greatly oversampled? What are the default sampling rates?
rama
Posts: 1373
Joined: Wed Mar 08, 2017 3:15 pm

Re: GBS 8200/8220 CFW Project

Post by rama »

Hmm, so basically when given optimal conditions, the delay is sub-frame?
It'd make sense, as there's just a single buffer and the read/write timings are synchronized as close as possible.
Most processing is done on single line delay buffers.

maxtherabbit:
The most common design is the "V4.0" and there's simply nothing special about it.
It's good out of the box, with a slightly beefier power supply than the yellow button type.
Direct DAC video driver, as opposed to first edition buffered one. I think this works better anyway.

The sampling clock issue is related to VGA bypass mode and a software thing.
I haven't figured out a universal method to determine good sampling clocks for that mode.

Scaling mode is greatly oversampled, yes. This is what delivers the sharp look in the 1280 presets.
There are several multipliers and dividers in the ADC and then digital stages.
I haven't worked out what the ratios are, so I can't really tell by how much it oversamples.
It's a lot though :)

Edit:
If it's any indication, the ADC is specified to ~160Mhz maximum, and I maximized it whenever possible.
PerplexedApe
Posts: 3
Joined: Sat Jan 19, 2019 1:00 pm

Re: GBS 8200/8220 CFW Project

Post by PerplexedApe »

I'm stumped on making this work, this is the dump of the compiling log and serial watcher after boot.
https://pastebin.com/5N2iZ143
Any ideas on what I could try?
rama
Posts: 1373
Joined: Wed Mar 08, 2017 3:15 pm

Re: GBS 8200/8220 CFW Project

Post by rama »

maxtherabbit wrote: I see on the wiki it addresses issues with the V5 model as well as discusses the V3, however almost all of the listings I see on ebay now are for V4. Anything to be aware of with the version 4s? Given the option should I get a 4 or 5?
I've now seen a "V5.0" that is actually the "V4.0" design.
I guess the model numbers are just fashion at this point.
There are basically 3 regular / VGA output designs and 2 HDMI output designs that I'm aware of.
They're all so similar though that it's enough to verify a model by picture, and they mostly need the same set of small fixes anyway.

Dunno if you noticed, but the deinterlacer method can be selected now. 2 options are available, with a 3rd coming some other day :)
User avatar
maxtherabbit
Posts: 1763
Joined: Mon Mar 05, 2018 4:03 pm

Re: GBS 8200/8220 CFW Project

Post by maxtherabbit »

rama wrote:
maxtherabbit wrote: I see on the wiki it addresses issues with the V5 model as well as discusses the V3, however almost all of the listings I see on ebay now are for V4. Anything to be aware of with the version 4s? Given the option should I get a 4 or 5?
I've now seen a "V5.0" that is actually the "V4.0" design.
I guess the model numbers are just fashion at this point.
There are basically 3 regular / VGA output designs and 2 HDMI output designs that I'm aware of.
They're all so similar though that it's enough to verify a model by picture, and they mostly need the same set of small fixes anyway.

Dunno if you noticed, but the deinterlacer method can be selected now. 2 options are available, with a 3rd coming some other day :)
most of the V4s I'm seeing on ebay have the following layout, that is distinct from both the V3 and V5 pics you have on the wiki

Image
Higgy
Posts: 54
Joined: Thu Mar 15, 2018 1:29 pm

Re: GBS 8200/8220 CFW Project

Post by Higgy »

My version 8200 'V' or 5.1 is basically a 2-VGA port board with only 1 VGA-out populated. And it has the later (V4) power setup.
It does not have Samsung or Hynix (?) memory but still seems to function well. I added the 4x 10uF caps on last night but did not have time to power it up.

My 8220 V3 has more interference, so I will try and do a 'before' and 'after' fitting the 4x 10uF caps. I got my PLCC bits last night so i will build up another ESP8266 plug-on module.
Then I will have 2 setups, ok different GBS- boards but I will have one with a Sync Stripper and one without (both boards do have the 1nF cap mod though).
rama
Posts: 1373
Joined: Wed Mar 08, 2017 3:15 pm

Re: GBS 8200/8220 CFW Project

Post by rama »

maxtherabbit:
Yep, your picture shows the most common design. "Beefy" power supply, no second output buffer, no weird 1MOhm input DC bypassing.
Not much to say about them. They work well out of the box, but can be tuned as well.

The predecessor is the first revision GBS8220 (I only see those with 2 populated and working VGA outputs).
That one has a linear power supply that gets very hot, a second output buffer (that one with the charge pump, causing some video noise), and otherwise regular stuff.
I don't recommend them, mainly because the charge pump noise isn't easy to fix. Also I wonder if that hot power supply is fine.
One would think that the linear supply solution would have less noise, but at least on my 60Mhz scope, it's actually noisier.

The most recent design often has the yellow buttons, the power supply is weaker (330uH coil), it is prepared to use the charge pump output buffer (but I never see it populated), and has an odd input DC bypass.
These recent ones need the modifications (extra caps, removal of c11, etc) more than the others.
Once everything is tuned up, they're working well.

For all the models, the SDRAM manufacturer doesn't seem to matter. It's kind of a good sign if they used a known brand there.
It may hint at good quality assembly as well, which *is* important, of course.
rama
Posts: 1373
Joined: Wed Mar 08, 2017 3:15 pm

Re: GBS 8200/8220 CFW Project

Post by rama »

PerplexedApe:
We talked on reddit ;p

Basically, PerplexedApe has an ESP8266 board variant where it looks like the SCL / SCA pins have extra circuitry.
It seems to prevent proper I2C operation. The software only reads garbage back.

A dedicated tinkerer could find 2 useful pins and probably make it work, but doing this over some forum posts is tricky :p
Better to just go and buy a common NodeMCU clone.
(Though his variant annoyingly calls itself "NodeMCU" as well, just with an extra "32Mb" tacked on ><)
Higgy
Posts: 54
Joined: Thu Mar 15, 2018 1:29 pm

Re: GBS 8200/8220 CFW Project

Post by Higgy »

rama - I got my 2nd ESP8266 soldered up.
How can I run 2 ESP modules at once (on separate GBS and screens) ? On one do I change SSID 'gbscontrol' and on WiFi tab 'gbscontrol-local' to say 'gbscontrol_2' and 'gbscontrol_2-local' ?

I don't know if having the 'same' wifi setting was causing issues last night but using firmware from 9PM last night 'few fixes' I see the new settings you added in the UI, but I could not use the UI to make any changes and the communication box at the bottom of the UI was empty.

I was probably using one ESP while programming (or waiting to compile) the other, so maybe having duplicate WiFi settings was causing communication issues, as while plugged into my PC and waiting for compiling to finish I guess the ESP will be broadcasting.

Thanks
glac81
Posts: 12
Joined: Mon Aug 13, 2018 3:45 am

Re: GBS 8200/8220 CFW Project

Post by glac81 »

rama wrote:Quick question to anyone reading:

Is your gbs producing a very red'ish hue on the output?
It would show up in dark gray / near black, which would look almost red tinted.

I just came across one that does this, and for some reason the DAC blanking level is skewed on it.
It must be the chip or some passive components since the software is the same, but it's hard to explain how.
I have had one with this exact problem. I have returned it for another one. For reference, before the return, the image shifted to green interference and the blacks were right again.
rama
Posts: 1373
Joined: Wed Mar 08, 2017 3:15 pm

Re: GBS 8200/8220 CFW Project

Post by rama »

Higgy:
I've found more bugs and ironed them out. Maybe it works better now.
Particularly, the scan for networks option was broken badly. It left the device in a state where it wouldn't update anymore.

I also made it so that the device name can be changed in a single place, not all over the code.

Code: Select all

const char* device_hostname_full = "gbscontrol.local"; // change to gbscontrol1.local
const char* device_hostname_partial = "gbscontrol"; // change to gbscontrol1
glac81:
Not sure this is the same, but if your replacement works, all the better :)
rama
Posts: 1373
Joined: Wed Mar 08, 2017 3:15 pm

Re: GBS 8200/8220 CFW Project

Post by rama »

Also, in case anyone wonders, the preset selection and some (not all yet) options are saved instantly now.
So, selecting 1280x720 will switch to the preset and also make it the bootup default.
This is more intuitive and saves a few extra buttons on the ui.

One new enhancement option is available: The line blur filter can now be turned off (default is enabled).
It increases vertical sharpness to razor, but the look can be a bit weird, imo. It's a matter of taste (and scanline use!).
User avatar
maxtherabbit
Posts: 1763
Joined: Mon Mar 05, 2018 4:03 pm

Re: GBS 8200/8220 CFW Project

Post by maxtherabbit »

rama wrote:Specifically, I bypass anything also that's pure VGA (H+V Sync). True that it can be 480p and I could scale it, but there's no need to.
Bypass mode looks great already and I don't think messing around with the image is a benefit :p

So yeah, full processing only for PAL, NTSC and their true progressive modes (EDTV).
Anything above EDTV (ie 720p) is bypassed and looks great, imo.
my primary interest in a use case for this thing out of the box is to use it to scale dreamcast - will it be possible for me to force the VGA 480p input into scaling mode?

I would like to use the GBS to defeat this:
Image

concept being: greatly oversampling the input, using the scaler to stretch the inner, active 640px of the 858px line to fill the active area of the output resolution's line, resulting in a scaled output at 1280x720 or 640x480 where the dreamcast image completely fills the 4:3 area
rama
Posts: 1373
Joined: Wed Mar 08, 2017 3:15 pm

Re: GBS 8200/8220 CFW Project

Post by rama »

It's not currently possible.
Knowing which sync type can appear on which input, and what actual video formats to expect there, is a foundation for my automatization stuff.
I'll have to rewrite this and think of a way to allow some VGA sources on the scaling path.

I can see that there's a need for it though, and I can limit the scope to 640x480 and maybe some DOS resolutions.
One annoying factor is that for PC sources, the vertical refresh rate can vary so much.
60Hz or 72Hz is no problem in bypass mode, but it makes a huge difference to the processing data path.
As such, please don't count on every refresh working right away ;p

So yeah, I'll look into it, but I've no idea how long it takes.
User avatar
maxtherabbit
Posts: 1763
Joined: Mon Mar 05, 2018 4:03 pm

Re: GBS 8200/8220 CFW Project

Post by maxtherabbit »

rama wrote:It's not currently possible.
Knowing which sync type can appear on which input, and what actual video formats to expect there, is a foundation for my automatization stuff.
I'll have to rewrite this and think of a way to allow some VGA sources on the scaling path.

I can see that there's a need for it though, and I can limit the scope to 640x480 and maybe some DOS resolutions.
One annoying factor is that for PC sources, the vertical refresh rate can vary so much.
60Hz or 72Hz is no problem in bypass mode, but it makes a huge difference to the processing data path.
As such, please don't count on every refresh working right away ;p

So yeah, I'll look into it, but I've no idea how long it takes.
thank you! please keep in mind that the dreamcast is also capable of outputting 240p (and 480i, but who cares about that lol) in RGBHV as well, so include that in the scope if possible

dreamcast only does 60Hz on VGA though, 480p or 240p
User avatar
maxtherabbit
Posts: 1763
Joined: Mon Mar 05, 2018 4:03 pm

Re: GBS 8200/8220 CFW Project

Post by maxtherabbit »

this board should work for the controller?
Image
Image
Higgy
Posts: 54
Joined: Thu Mar 15, 2018 1:29 pm

Re: GBS 8200/8220 CFW Project

Post by Higgy »

rama - thanks for looking into having 2 ESP/GBS running.
Unfortunately I've hit a hurdle I am now getting this error message out of the blue within Arduino IDE:

Error downloading http://arduino.esp8266.com/stable/packa ... index.json

I've spent a good couple hours on it, time to hit the whisky and bed. :cry:
User avatar
AndehX
Posts: 790
Joined: Sun Oct 18, 2015 11:37 pm

Re: GBS 8200/8220 CFW Project

Post by AndehX »

Should do. I have 2 of them here ready to install when my HDMI board comes.
Post Reply