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VGA Capture Thread

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Reply 860 of 892, by darry

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swaaye wrote on 2020-09-15, 22:01:

I got out the Avermedia C127 (Game Broadcaster HD) that I bought around 8 years ago and found its VGA input is now purple-shifted. I guess there is damage somewhere on the card but I can't see it. I tried different cables, VGA cards, drivers and even different PCs for the capture card (plus Win7 vs 10).

I think HDMI/DVI capture still works though.

That card did have problems with resolutions under 640x480 though. It sounds like the Datapath E1S is the way to go now?

If I was not a perfectionist, I would stay with an OSSC combined with a Cam Link 4K (see samples earlier in thrrad). As it stands, the Datapath E1S, that everybody here seems to love, is on its way to me and will likely be used with OSSC (easier to split/switch HDMI/DVI than VGA and I controlling sampling settings, etc seems easier on the OSSC) .

EDIT : I still really wish there existed a USB 3.0 or 3.1 solution that was both affordable and RGB24 capable . I only have one machine with an available PCIE x4 slot for the E1S .

Reply 861 of 892, by appiah4

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How come this stuff is so obtusely difficult and expensive when virtually every flat panel monitor with a VGA input has this capability built into it? I mean, there HAS TO be a simpler and less expensive way to do this otherwise these panels would not exist? As is, the only setups that apparently work to any satisfaction cost more than what a Dell P line monitor does..

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Reply 862 of 892, by elianda

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AFAIR there are no 4K capture cards that capture RGB. (Correct me if you know one)

Every flat panel screen samples 400p modes as 720, so e.g. 320x200 is displayed wrong since it requires sampling with 640 pixels.

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Reply 863 of 892, by appiah4

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elianda wrote on 2020-09-16, 09:42:

AFAIR there are no 4K capture cards that capture RGB. (Correct me if you know one)

Every flat panel screen samples 400p modes as 720, so e.g. 320x200 is displayed wrong since it requires sampling with 640 pixels.

Assuming for a moment that this sampling method is agreeable (as it is to me, when I use DOS systems on my LCD panels via VGA), why aren't there cheap solutions that do it this way?

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Reply 864 of 892, by vvbee

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appiah4 wrote on 2020-09-16, 10:03:

Assuming for a moment that this sampling method is agreeable (as it is to me, when I use DOS systems on my LCD panels via VGA), why aren't there cheap solutions that do it this way?

How cheap do you need it? I paid like $40 for a VisionRGB-PRO2 and $150 for the VisionRGB-E1S. Someone in the US spent the last couple years selling dozens of VisionRGB-PRO1 for $25 shipped, and that's like pro gear for casual retro capture.

Reply 865 of 892, by darry

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vvbee wrote on 2020-09-21, 14:52:
appiah4 wrote on 2020-09-16, 10:03:

Assuming for a moment that this sampling method is agreeable (as it is to me, when I use DOS systems on my LCD panels via VGA), why aren't there cheap solutions that do it this way?

How cheap do you need it? I paid like $40 for a VisionRGB-PRO2 and $150 for the VisionRGB-E1S. Someone in the US spent the last couple years selling dozens of VisionRGB-PRO1 for $25 shipped, and that's like pro gear for casual retro capture.

And if you mean ultra cheap (direct from China) and new solutions, I would put that down to a lack of market demand and probably the lack of integrated capture chips that can handle 70Hz modes and analogue RGB input (VGA) (somebody correct me if wrong) . Another thing to consider is that capture solutions tend to be video oriented and may not support anything above YUY2 because video is practically always sub-sampled anyway .

In other words, the combination of specific requirements to capture analogue VGA, in RGB24 (no chroma conversion or sub-sampling) at 70Hz and possibly with adjustable horizontal sampling frequency is not something designers of low cost capture chips will likely focus on . Without such cheap chips, you are left with pro-sumer capture cards from the likes of Avermedia that usually do not fulfill all aforementioned requirements anyway or the pro stuff (new or used) .

Reply 866 of 892, by appiah4

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vvbee wrote on 2020-09-21, 14:52:
appiah4 wrote on 2020-09-16, 10:03:

Assuming for a moment that this sampling method is agreeable (as it is to me, when I use DOS systems on my LCD panels via VGA), why aren't there cheap solutions that do it this way?

How cheap do you need it? I paid like $40 for a VisionRGB-PRO2 and $150 for the VisionRGB-E1S. Someone in the US spent the last couple years selling dozens of VisionRGB-PRO1 for $25 shipped, and that's like pro gear for casual retro capture.

$25 is fairly agreeable to me personally, but please do point me to it if anything acceptable can be found for $25 these days..

Regardless, I think I solved my issues by installing a PCI G450 DVI into my Socket 7 PC - now I can get proper DOS output via HDMI. It outputs DOS resolutions as letterboxed 640x480 70Hz. If I can find a cheap-ish DVI capture device I'll be all set.

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Reply 867 of 892, by ruthan

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$25 is fairly agreeable to me personally, but please do point me to it if anything acceptable can be found for $25 these days..

Lets call it vvbees mystery cards, i yeah maybe you can score one for such price, but its not normal price an there is shipping etc. I was glad that i god some Datapath card (Datapath Vision RGB PRO2) from $50 bucks locally in Europe and Epiphan dvi2pcie for 120$ from Russia.

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Reply 868 of 892, by Kordanor

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Uh...I actually thought that with VGA you had much better cards than having like a signal from an old console. Didn't expect it to be that complicated and costly.

So let me summarize and correct me if I am wrong here:

Basically you have VGA->DVI->HDMI, but any of the step can potentially jumped over.

Option A: You have a VGA Output
A: Solution 1:
You have an OSSC (like this OSSC from TANOU) which turns it into HDMI (91€)
Then you put the HDMI into a normal capture device like the Elgato Cam Link 4K (124€)
Total: 215€
Quality: It's okish but has artefacts and isn't 100% (If I understand Darry correctly)

A: Solution 2:
A passive adapter changing VGA to DVI (3€ on Ebay)
DATAPATH VisionRGB-E1S which has a DVI in but also captures VGA via a passive adapter. (Ebay: $99,99 Price+$22,61 Shipping + 31,18$ for customs, making a 153,78$ total = 131,65€)
Total: 134,65€
Quality: Best possible quality

A: Solution 3:
You go super cheap and buy a direct VGA to HDMI converter like this (15€)
Then you put the HDMI into a normal capture device like the Elgato Cam Link 4K (124€)
Total: 139€
Quality: Unknown

A: Solution 4:
You go all out and buy the AV.io HD recorder which plugs into VGA and DVI via included adapter and outputs as USB(400€+23€ Shipping)
Total: 423€
Quality: Excellent (according to LGR)

Option B: You have a DVI Output
(is there actually any graphics card which has DVI and runs fine under DOS 6.22?)
B: Solution 1:
You can record this via the DVI directly using DATAPATH VisionRGB-E1S which has a DVI in. (Ebay: $99,99 Price+$22,61 Shipping + 31,18$ for customs, making a 153,78$ total = 131,65€)
Total: 132€
Quality: Might have resolution issues

B: Solution 2:
You convert the DVI into HDMI using a simple converter like this (7€)
You record this now via a normal capture device like the Elgato Cam Link 4K (124€)
Total: 131€
Quality: Unknown

B: Solution 3 (same as A: Solution 4)
You go all out and buy the AV.io HD recorder which plugs into VGA and DVI via included adapter and outputs as USB(400€+23€ Shipping)
Total: 423€
Quality: Excellent (according to LGR)

Besides of that USB device Epiphan also offers an internal recording tool which takes all signals: Epiphan DVI2PCIe Duo but with 1200€ I guess it's a tad expensive for this list of viable options.

Last edited by Kordanor on 2020-09-23, 18:10. Edited 1 time in total.

Reply 869 of 892, by darry

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Kordanor wrote on 2020-09-23, 17:05:
Uh...I actually thought that with VGA you had much better cards than having like a signal from an old console. Didn't expect it […]
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Uh...I actually thought that with VGA you had much better cards than having like a signal from an old console. Didn't expect it to be that complicated and costly.

So let me summarize and correct me if I am wrong here:

Basically you have VGA->DVI->HDMI, but any of the step can potentially jumped over.

Option A: You have a VGA Output
A: Solution 1:
You have an OSSC (like this OSSC from TANOU) which turns it into HDMI (91€)
Then you put the HDMI into a normal capture device like the Elgato Cam Link 4K (124€)
Total: 215€
Quality: It's okish but has artefacts and isn't 100% (If I understand Darry correctly)

A: Solution 2:
You have an OSSC (like this OSSC from TANOU) which turns it into HDMI (91€)
Because the output is HDMI and you want to record DVI, you would need to convert HDMI down to DVI with an adapter (4€)
Now you capture that DVI signal instead via a DATAPATH VisionRGB-E1S which has a DVI in. (Ebay: $99,99 Price+$22,61 Shipping + 31,18$ for customs, making a 153,78$ total = 131,65€)
Total: 227€
Quality: Best possible quality

A: Solution 3:
You go super cheap and buy a direct VGA to HDMI converter like this (15€)
Then you put the HDMI into a normal capture device like the Elgato Cam Link 4K (124€)
Total: 139€
Quality: Unknown

A: Solution 4:
You go all out and buy the AV.io HD recorder which plugs into VGA and DVI via included adapter and outputs as USB(400€+23€ Shipping)
Total: 423€
Quality: Excellent (according to LGR)

Option B: You have a DVI Output
(is there actually any graphics card which has DVI and runs fine under DOS 6.22?)
You do not need the OSSC step this time because you already got a HDMI/DVI signal
B: Solution 1:
You can record this now via the DVI directly using DATAPATH VisionRGB-E1S which has a DVI in. (Ebay: $99,99 Price+$22,61 Shipping + 31,18$ for customs, making a 153,78$ total = 131,65€)
Total: 132€
Quality: Best possible (I guess?)

B: Solution 2:
You convert the DVI into HDMI using a simple converter like this (7€)
You record this now via a normal capture device like the Elgato Cam Link 4K (124€)
Total: 131€
Quality: Unknown

B: Solution 3 (same as A: Solution 4)
You go all out and buy the AV.io HD recorder which plugs into VGA and DVI via included adapter and outputs as USB(400€+23€ Shipping)
Total: 423€
Quality: Excellent (according to LGR)

Besides of that USB device Epiphan also offers an internal recording tool which takes all signals: Epiphan DVI2PCIe Duo but with 1200€ I guess it's a tad expensive for this list of viable options.

Nice comparison

I would forget about using a card's native DVI or HDMI output of DOS programs for capture purposes. They practically all scale to either what they think is "monitor" native or some arbitrary resolution like 1280x1024@75Hz .

As for VGA capture of DOS software, the Datapath E1S can do direct VGA capture (using a passive DVI-I to VGA adapter), so you do not need a converter like OSSC. I already have an OSSC for feeding my HDMI/DVI monitor, so using it to feed an E1S makes sense in my case, but not necessarily for everyone .

Not all HDMI capture cards handle OSSC's or other digitizer's output . So you need be careful about your combination .

Unless they also explicitly support RGB (some cheaper product docs actually lie about this), all HDMI/capture products are limited to YUY2 capture at best and will have the kind of chroma articacts the Cam Link 4K has, or worse. That being said, those artifacts may not matter that much if the final output is going to be YV12 (worse than YUY2) format lossily compressed video anyway, which will unavoidably cause similar artifacts even on initially RGB captured video. Additionally, the said artifacts will be much less visible if the feed is upsampled (line-doubled) by something like an OSSC before capture .

EDIT : Also, the cheap VGA to HDMI converters often do not handle 70Hz, which is what most DOS stuff runs at (documention for cheap products sometimes lies about this). Many, or at least most, direct VGA capture cards have that limitation too .

Reply 871 of 892, by darry

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The Epiphan AV.io is limited to YUV 4:2:2 , so it will have the same sort of artifacts as a Cam Link 4K . See specs https://www.epiphan.com/products/avio-hd/tech-specs/

EDIT : It also does not seem to support 70Hz input, at least not officially . If memory serves, LGR uses it with an external VGA to DVI digitizer scaler, which likely converts to 60Hz .

EDIT 2: This makes the Epiphan solution both more expensive and worse quality than a Cam Link 4K plus OSSC , because with an OSSC, you can line-double to almost eliminate subsampling artifacts when using a 4:2:2 capture card . 70Hz being not only supported but directly captured by the Cam Link 4K allows you to convert to 60Hz later using software decimation or interpolation, as you prefer, which is another advantage, IMHO .

Reply 872 of 892, by swaaye

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Hey guys. I put the VisionRGB E1S into a PCIe x1 slot. The x1 slots are open-ended on my motherboard and it was the easiest way to go. This appears to be more than adequate bandwidth up to 1024x768. So there is some flexibility there for a lot of retro capturing.

HWInfo says the E1s is a bridged PCI-X 133 to PCIe 1.1 card. If it were PCIe 2.0 the x1 slot would be enough for 1080p 8bpp.

Reply 873 of 892, by darry

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swaaye wrote on 2020-09-25, 00:04:

Hey guys. I put the VisionRGB E1S into a PCIe x1 slot. The x1 slots are open-ended on my motherboard and it was the easiest way to go. This appears to be more than adequate bandwidth up to 1024x768. So there is some flexibility there for a lot of retro capturing.

HWInfo says the E1s is a bridged PCI-X 133 to PCIe 1.1 card. If it were PCIe 2.0 the x1 slot would be enough for 1080p 8bpp.

That depends on if the PC-X 133 to PCI Express bridge on the card is PCI Express 2.0 capable or not .

PCI-X 133 64-bit --> 1.06 GB/s
PCI Express 1.0/1.1 x4 --> 1.000 GB/s
PCI Express 2.0 x1 --> 0.500 GB/s

1920*1080*24*60= 2985984000 bits/second = 355 MB/second , assuming the card only needs to transfer active pixels over the bus .
2200*1125*24*60= 3564000000 bits/second = 424 MB/second , assuming the card needs to transfer all pixels (including inactive ones) over the bus .

Reply 874 of 892, by swaaye

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darry wrote on 2020-09-25, 01:03:

That depends on if the PC-X 133 to PCI Express bridge on the card is PCI Express 2.0 capable or not .

PCI-X 133 64-bit --> 1.06 GB/s
PCI Express 1.0/1.1 x4 --> 1.000 GB/s

No the card/bridge is PCIe 1.1. I meant it's unfortunate it isn't PCIe 2.0.

Reply 875 of 892, by darry

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swaaye wrote on 2020-09-25, 01:19:
darry wrote on 2020-09-25, 01:03:

That depends on if the PC-X 133 to PCI Express bridge on the card is PCI Express 2.0 capable or not .

PCI-X 133 64-bit --> 1.06 GB/s
PCI Express 1.0/1.1 x4 --> 1.000 GB/s

No the card/bridge is PCIe 1.1. I meant it's unfortunate it isn't PCIe 2.0.

Ah, I understand. It is indeed too bad .

That said, it is also too bad that the E1S is not available in a PCI-X 133 variant (or is it?). It would have found a nice place alongside my AJA Kona LH in my Supermicro X8SAX based system .

Reply 876 of 892, by vvbee

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darry wrote on 2020-09-25, 01:43:

That said, it is also too bad that the E1S is not available in a PCI-X 133 variant (or is it?). It would have found a nice place alongside my AJA Kona LH in my Supermicro X8SAX based system .

There's the VisionRGB-X2 for PCI-X. A bunch of them on US ebay right now, not too bad of a price for a dual input card and I don't think it's a common item.

Reply 877 of 892, by darry

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vvbee wrote on 2020-09-25, 02:44:
darry wrote on 2020-09-25, 01:43:

That said, it is also too bad that the E1S is not available in a PCI-X 133 variant (or is it?). It would have found a nice place alongside my AJA Kona LH in my Supermicro X8SAX based system .

There's the VisionRGB-X2 for PCI-X. A bunch of them on US ebay right now, not too bad of a price for a dual input card and I don't think it's a common item.

Thank you. If I did not already have an E1S on the way or if the X2 was significantly cheaper than it is (who still uses PCI-X , 🤣 ?), I would have considered it . I will keep an eye on them, though. If prices go down, they could be an interesting option .

EDIT : The AJA Kona LH (PCI-X native version) was so cheap, it was practically a giveaway (under 40 US$ shipped), compared to the AJA Kona LHE (bridged PCI Express version) (140 US$ shipped). I was "forced" to buy the PCI-X version when my Asus P6X58D Premium kicked the bucket and had to be replaced by a Supermicro X8SAX (only affordable x58 board I could find at the time) .

EDIT2 : The again, a Core i9-9900K is probably a better machine than a Xeon x5675 for capturing losslessly compressed (up to) 2K RGB video anyway .

Reply 878 of 892, by vvbee

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I'd buy the X2 as a curiosity, but the specs aren't bad either.

An interesting thing about bandwidth is that since the Datapath cards have hardware scaling, you can downscale the frames on-card before sending them down the PCI bus, basically increasing bandwidth at the cost of image quality. So I wonder how well AI scaling could now or in the future restore the image if you did like a 2x nearest neighbor downscale on-card and upscaled it back on the host system. I guess you could technically get 1080p at 30-60 FPS on the PCI-based VisionRGB-PRO, since it should be able to capture up to 1920 x 1260 even though the bus can't keep up with that natively.

Reply 879 of 892, by appiah4

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This is still so damn overcomplicated for what it is..

Question: My Matrox G450's DVI port outputs at 640x480@70Hz in DOS and the DOS image is letterboxed as 640x400 with empty pixels at top and bottom, so it is basically upscaled by 2x with no filters. Is this not a perfect way to capture DOS output from a digital source? (Matrox G450's compatibility issues with some really old games aside..)

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