MiST VGA upscaling experiments

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Re: MiST VGA upscaling experiments

Postby DrOG » Mon Jan 09, 2017 5:51 pm

Thanks for the schematics!

Yes, the BK0011M is the only core that's 31kHz video output can not be handled by my old LG L1734S monitor: it says 'out of range 49Hz'. Perhaps any of the other three USSR models would give more compatible result: their 720x576@50Hz would be acceptable by your capture card!

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Re: MiST VGA upscaling experiments

Postby Sorgelig » Mon Jan 09, 2017 10:33 pm

There are several cores with 320 lines per frame. For example ZX core with Pentagon timings also has 320 lines and probably won't work (Only ULA-48/128 will work). That's why using scaler with wider video parameters support is a good thing. Otherwise you will have to find a lot of time and money to find a monitor supporting everything. And at the end you will probably won't be satisfied by monitor itself.

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Re: MiST VGA upscaling experiments

Postby Newsdee » Tue Jan 10, 2017 11:41 am

Does it need many changes per core?

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Re: MiST VGA upscaling experiments

Postby Sorgelig » Tue Jan 10, 2017 12:41 pm

Very minor change. I've made separate module which does all mixing inside. NES and Minimig (in my repository) are already with YPbPr support. I will update all my cores with YPbPr support probably at the end of this week or beginning of next. I'm just waiting for one scaler to test before release.
I can upload some cores here is somebody is willing to test YPbPr.

YPbPr cable info is on WiKi already.
Also, i've discovered, the same cable can be used for RGsB (Sync-On-Green) connection and it doesn't require any change in core. Since transistor does H+V mixing, both RGBS and RGBHV will turn into RGsB signal with this cable.

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Re: MiST VGA upscaling experiments

Postby Doozer » Tue Jan 10, 2017 3:30 pm

Sorgelig wrote:V
Also, i've discovered, the same cable can be used for RGsB (Sync-On-Green) connection and it doesn't require any change in core. Since transistor does H+V mixing, both RGBS and RGBHV will turn into RGsB signal with this cable.


Hi Sorgelig,

Thank you very much for the work. Is it possible to include a 15KHz RGBHV mode? This is required by some arcade CRT or modified TV sets.

Cheers,

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Re: MiST VGA upscaling experiments

Postby Sorgelig » Tue Jan 10, 2017 3:51 pm

Video signal is done inside FPGA core. So, adding a new video format is not automatic. Every core has to be modified for a new video format. I suggest to use some external HVSync extractor from CSync since 15KHz RGBHV is exotic.

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Re: MiST VGA upscaling experiments

Postby Sorgelig » Wed Jan 11, 2017 12:48 pm

Ok. I've got the first scaler from my queue ;)
It's Crestron HD-Scaler. It's not actually consumer product, but it can be found on eBay for very good price. I've got it for 33USD only (unfortunately shipping cost was another 35USD). According to description, this scaler supports many different signals (RGBHV, RGBS, YPbPr, RGsB) with wide sync freqs from 576i50 to 1080p60 with the same connection unlike chinese scalers where you have to plug either to SCART or VGA even if it's the same scaler.
And it really recognizes all RGB/YUV formats. Unfortunately it's very picky to progressive scans and cannot display scandoubler video of 320 lines (BK0011M, ZX with Pentagon timings), although interlaced 320 lines video works well. Also i couldn't make work DBLPAL/DBLNTSC/HD720/HighGFX video modes of Amiga (actually, even on real Amiga i couldn't these modes work with this scaler).
Those cores generating 312 lines with scandoubler works just fine. So, it most likely just Firmware problem. Unfortunately Crestron has strange policy of FW update and doesn't allow to update by anyone but only authorized dealers and partners. So, i cannot update it. For those 320 lines scandoubler modes the scaler recognizes the video format and displays 576p50 in info, but video stays black.
Besides picky to progressive modes, it works really good. Has a lot of video modes to output. A lot of setting of picture scale, position, color adjusments and so on..
There is another model on the way to me - Crestron HD-Scaler-VGA-E - this newer model replaces HD-Scaler in production line. I've got it on eBay as well for the same 30USD. I hope it will be less picky for progressive modes.

Also i will get Atlona AT-HD500 scaler. I've saw this scaler mentioned in this thread and that user stated it supports just everything from MiST he tried. Well, i will see :)

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Re: MiST VGA upscaling experiments

Postby Sorgelig » Wed Jan 11, 2017 5:56 pm

Scandoubler mode never been my default display mode for several reasons. Just now i've tried scandoubler in Amiga core and found it as awful. In interlaced video resolutions scandoubler just adds flicker while originally it should remove the flicker.
And it's impossible to remove the flicker from interlace video because it will require frame buffer, and Minimig core occupies almost all FPGA/SDRAM resources already.
So, i still think scandoubler in current implementation in MiST is mostly useless. Either external scaler with resolution and framerate fixing required, or monitor supporting 15KHz and some fluctuations from standard.

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Re: MiST VGA upscaling experiments

Postby Sorgelig » Thu Jan 12, 2017 7:50 am

There is a big progress! After contacting Crestron Taiwan i've managed to update HD-Scaler to latest firmware, and now all modes including 320 scandoubled (which not worked before) work!
The only problem now i see is Amiga core with higher resolutions DBLPAL/DBLNTSC/HD720/HighGFX don't work, but i need to investigate it since it possible core problem, not scaler's.

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Re: MiST VGA upscaling experiments

Postby ericgus » Thu Jan 12, 2017 8:27 am

Sorgelig wrote:There is a big progress! After contacting Crestron Taiwan i've managed to update HD-Scaler to latest firmware, and now all modes including 320 scandoubled (which not worked before) work!
The only problem now i see is Amiga core with higher resolutions DBLPAL/DBLNTSC/HD720/HighGFX don't work, but i need to investigate it since it possible core problem, not scaler's.


Thanks for the update.. im silently watching with great interest.. (as I am sure a lot of others are) .. please keep posting your results..

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Re: MiST VGA upscaling experiments

Postby Sorgelig » Thu Jan 12, 2017 11:21 am

Tested another scaler - LKV353.
With YPbPr connection it works well with scandoubled video. For some strange reason it doesn't work with interlaced 312 lines video while 320 lines interlaced video works well. So, basically this scaler can be used with scandoubled videos. It even supports Amiga high resolution modes, but they look overscaned.

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Re: MiST VGA upscaling experiments

Postby SuperBabyHix » Thu Jan 12, 2017 4:18 pm

Sorgelig wrote:The only problem now i see is Amiga core with higher resolutions DBLPAL/DBLNTSC/HD720/HighGFX don't work, but i need to investigate it since it possible core problem, not scaler's.


I can double check if you need, but I was never able to get any of those modes to work on my 15/31Khz CRT monitor.

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Re: MiST VGA upscaling experiments

Postby Sorgelig » Thu Jan 12, 2017 11:20 pm

SuperBabyHix wrote:
Sorgelig wrote:The only problem now i see is Amiga core with higher resolutions DBLPAL/DBLNTSC/HD720/HighGFX don't work, but i need to investigate it since it possible core problem, not scaler's.


I can double check if you need, but I was never able to get any of those modes to work on my 15/31Khz CRT monitor.

It looks like core is OK with these modes. It's a scaler which doesn't like these modes. Another scaler LKV353(LKV356) shows At least HD720/HighGFX modes but too overscanned (and Amiga doesn't provide overscan control for these modes). I have real Amiga 1200 and behavior of both scalers are same for MiST and real A1200.

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Re: MiST VGA upscaling experiments

Postby Sorgelig » Fri Jan 13, 2017 10:09 am

LKV353 accepts scandoubled RGBHV (48Hz/50Hz) video through VGA input. Although sometimes it's not well centered.

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Re: MiST VGA upscaling experiments

Postby Sorgelig » Tue Jan 17, 2017 4:59 am

Tested AT-HD500 (FW 6.45A) - results aren't impressive at all. Scaler is very picky to video format. It displays 576i from Minimig core, but refuses to display 576i from Menu core, but displays 576p from Menu. Doesn't display neither 576i nor 576p from BK0011M core. None of extended video modes from Minimig are displayed. Basically this scaler is worse than cheap chinese scalers. LKV353 looks more advanced comparing to AT-HD500.
Surprisingly AT-HD500 accepts YPbPr video, although it's not listed as supported. Probably it shares the same firmware core with AT-HD510 where YPbPr officially supported. Originally i've though to buy AT-HD510 as well, but looking at AT-HD510 and how it's picky to video.. From other side, AT-HD500 is not supposed to support any MiST video due to it's VGA only. So... it's hard decision whether i want to get AT-HD510 as well..

Waiting for Crestron HD-SCALER-VGA-E to arrive.

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Re: MiST VGA upscaling experiments

Postby Sorgelig » Tue Jan 17, 2017 6:31 am

Those who have XRGBMini (or other scaler from this company) - does it support hi resolution modes from Minimig core? DBLPAL/DBLNTSC/HIGHGFX/HD720/SUPERPLUS?

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Re: MiST VGA upscaling experiments

Postby Sorgelig » Wed Jan 18, 2017 9:07 am

Tested Crestron HD-SCALER-VGA-E. It's supposed to be a replacement to discontinued model HD-SCALER.
Very bad support of non standard resolutions.. 320 lines video is not supported neither as 576i nor as 576p. Currently it has firmware 1.01. I hope i will update it to latest 1.04 and it will start to support more video modes.
It's very frustrating because i've tested Minimig core with resolution 1396x562 (Super HighRes Interlaced PAL) and i must say - I NEVER saw such crispy video where text is so clear, so you can easily use this resolution as main resolution to work in Workbench! Really amazing!
I've disassembled both HD-SCALER and HD-SCALER-VGA-E - they are completely different inside. Different main chipsets. Main chip of HD-SCALER-VGA-E is under heatsink but it looks like same chip on GBS8220 ;) It also because i see similar SDRAM chip connected to it and overall this chip handles everything from VGA input to color digital output with HDMI converter chip on the output. Overall schematics of HD-SCALER-VGA-E is much simpler than HD-SCALER.
So, i don't expect it will start to support more resolutions like HD-SCALER after FW update.. Will see..

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Re: MiST VGA upscaling experiments

Postby Sorgelig » Fri Feb 03, 2017 1:06 am

Tested Kramer VP-425. While it's supposed to be a professional scaler, it's one of the worst scaler i've tried. It supports only exact 576i resolution only, so many cores aren't supported. This is the only scaler which failed even on Minimig PAL resolution. It wrongly detects fields order, so picture looks scrambled. Engineers from Israel company still have a long way to go. Even chinese cheap scalers work better.

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Re: MiST VGA upscaling experiments

Postby Sorgelig » Fri Feb 03, 2017 1:29 am

Today there are 2 clear favorites in scalers:

1) Crestron HD-SCALER (don't mess it with HD-SCALER-VGA-E!) - it supports all close to TV standard modes with latest scaler firmware. It also supports all possible connections from MiST: RGBHV/RGBS/RGsB/YPbPr. This scaler is definitely the bests for developers who want to try different resolutions, syncs and color spaces.
2) Lenkeng LKV353 - it suports all scandoubled TV modes (through YPbPr) from cores i've tried. It doesn't support 15KHz modes from most cores, but 15KHz from Minimig works(!). So setting scandoubler disable for Minimig and scandoubler enable for all other cores making this scaler support all cores using TV resolutions.

Both scalers have video quality at 4 (from 5) points. Before i could say 5, but after looking at quality of Crestron HD-SCALER-VGA-E (which unfortunately is very picky for supported resolutions) i cannot give 5 anymore. HD-SCALER-VGA-E video quality is simply outstanding! I can clearly read text in Minimig's Super Hi-Res PAL mode (1280x512) while it's barely readable on those 2 favorites.

There are some cores having highly specific resolutions with >70Hz. These cores most likely won't work with these scalers (although need more tests). But this issue should be addressed to such cores, not to scalers. I believe all cores emulating retro system can be coded to support standard TV output.

I think i will stop here since i've tried almost every brand including professional ones. Such tests cost a lot of my money since i have to buy these scalers. It's good that i can grab some of them by a fraction of price on ebay. I don't see any other brand which may provide a real high quality scalers. I'm coming to my original idea to make my own scaler which will take video from MiST's digital output and thus eliminate ADC conversion which is most critical part.

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Re: MiST VGA upscaling experiments

Postby goran » Fri Feb 03, 2017 10:01 pm

Thanks for the info. :)

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Re: MiST VGA upscaling experiments

Postby Newsdee » Sat Feb 04, 2017 12:09 am

Great work on testing, Sorgelig. Upscalers are a bit of a minefield, I bought a few random ones that turned out to be the same thing with slightly different connectors. I should add though that the HD-SCALER seems to be discontinued... so grab one while you can :)

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Re: MiST VGA upscaling experiments

Postby Sorgelig » Sat Feb 04, 2017 2:59 am

Newsdee wrote:I should add though that the HD-SCALER seems to be discontinued... so grab one while you can :)

Yes. I've mentioned about it above. HD-SCALER-VGA-E/HD-SCALER-HD-E are supposed to be a direct replacements (depend on input you need). Unfortunately these new scalers are too picky for video formats.

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Re: MiST VGA upscaling experiments

Postby Newsdee » Sat Feb 04, 2017 6:44 am

Sorgelig wrote:Yes. I've mentioned about it above. HD-SCALER-VGA-E/HD-SCALER-HD-E are supposed to be a direct replacements (depend on input you need). Unfortunately these new scalers are too picky for video formats.

It's a sign of the times... old formats are left behind. Now the wave of USB-C has started to rise as well...

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Re: MiST VGA upscaling experiments

Postby SuperBabyHix » Fri Feb 24, 2017 4:32 am

Hey Sorgelig, I found a good deal on the Crestron HD-Scaler (also around $30) so I decided to try it. Image quality is excellent as you said, but I am having another issue that I am hoping is fixed with the newer firmware (mine is definitely on the old as, as you said, it does not play well with the 320 line modes). It seems to be dropping frames no matter what I set the output to (576p@50, 720p@50, or 1080p@50). At least I think that is the issue, or is it that the various PAL cores output at a slightly different rate than the scaler puts out, and this stutter is due to frame rate conversion? I suspect this is the case, but would love your input. Thanks.

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Re: MiST VGA upscaling experiments

Postby Sorgelig » Sat Feb 25, 2017 2:13 am

SuperBabyHix,
It's true that many (if not all) cores output slightly out of TV standard freqs. Real PAL resolution is 312.5lines per field. I don't remember any core providing exactly 312.5lines(may be only Minimig - but i didn't check its code as it's too complicated). So if core provides only 312lines or even 320lines - the vertical frequency is already doesn't match to standard PAL. So, you will have stutter issue if you will output to PAL. I suggest to set scaler output to 60Hz(NTSC). Stutter will be less noticeable.


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