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Reply 200 of 204, by christal87

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doshea wrote on 2021-12-26, 05:11:
christal87 wrote on 2021-07-27, 18:48:

Note on some "el cheapo" webcam based USB video class (UVC) HDMI capture devices: [...] most of these dongles want to look like USB3, but most are only 2.0 High Speed (HS). This means that uncompressed raw video (e.g. YUYV) will have a limitation either on framerate or maximum resolution, whichever you choose (game capture at 5FPS is not great). You simply can't dunk down like 2.1+MPixels (1920x1080@30...60Hz uncompressed on USB2. It's worth looking for true USB3 capture dongles in the future to avoid this huge limitation.

I also bought a "TenYua" brand "USB 3.0 HDMI Video Grabber" from Amazon - https://www.amazon.com.au/gp/product/B089YMY71Y - since I understood that I needed USB 3 to get good frame rates, but it turned out that it could only capture 640x480 YUYV at 30 FPS, and higher resolutions were much lower frame rates like 5 FPS. On checking lsusb -v in Linux I can see it's really only USB 2.0. I suppose I could probably get my money back on this one too but I'm not sure if I could find a better one that doesn't cost a lot more. Perhaps I could have found a cheaper one that works just as well but doesn't pretend to be USB 3?

Are there any hints that a device isn't really USB 3? This particular device requires a USB A to A cable. I've never seen a USB device/gadget with a USB A socket before, this seems strange to me. I wonder if a blue USB A port is just the cheapest way to make your device look like it's USB 3 when it's not really?

Hey doshea,
Merry Christmas everyone,

Nice to see a fellow linux user. 😀 I've checked the amazon link you have shared. There seems to be no real telltale sign of it not being USB3 if you only look at the title. Because these el cheapo adapters are a pig in a poke, you have to always have some kind of suspicion before buying. If you look carefully the title says USB3, but the third illustration loops HDMI signal through it from a PC to a TV set and states that the third (recording) machine (wich is a notebook) is connected with "USB2.0 output".

Seems to me like Amazon can't really write a good enough product description because the chinese spec was already dubious. There's also a language barrier there and most chinese product manuals are well known for unusable eng/ger/fra/etc translations. I'm hungarian and we're left out of the rain almost every time, but I can tell by the english manuals. At a time there was a domestic meme about a cheap 27MHz wireless keyboard, which the chinese translated directly into hungarian as "wireless telegraph keyboard" (arc telegraph literally in hungarian). I've never seen direct chinese-hungarian translations ever since. 😀 A few years ago I fell for a non-isolated MBUS adapter PCB on aliexpress the same way: title stated it's isolated but the pictures and pricing quickly revealed no isolation whatsoever.

Before you get a refund on this you can try a workaround for the 5FPS limit by a query to it's Video for Linux 2 (V4L2) API representation with v4l2-ctl. Most of these are only a simple USB cam SoC and an HDMI transceiver hanging on the SoCs image sensor input, integrated together. So you may have some registers exposed which configure video format, etc like a webcam would. YUYV is uncompressed and more desirable, but USB2.0 quickly reaches a bandwidth limitation with it. You can try switching to MJPEG to have an adequately high FPS (even 60FPS on lower resolutions is some cases). On the other hand you may not like the compression artefacts, but I had the same issues with my cheap ass USB2.0 grabber and switching to MJPEG was not bad at all. I haven't really noticed degradation. The next thing you can do is tweak the default color setings. USB-A to A plugs aren't standard because you could plug two USB host ports together. Later if it gets broken you may have a hard time replacing the cable, but a lot of chinese stuff do this to cut down costs. I've bought a flash drive style donge which is bulky, so I've added a 30cm (10") long USB extender "pigtail". Try to look for the blue color connector and the Superspeed (SS) logo too. Also the price is at least double of the USB2.0 one.
Example product (which looks good but according to reviews don't expect 4K features to work) : https://www.amazon.com.au/Capture-Recording-A … s/dp/B082XCH1SV
Source: http://ciko.io/posts/cheap_usb_hdmi/

Reply 201 of 204, by doshea

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christal87 wrote on 2021-12-26, 08:28:

Merry Christmas everyone,

Oh yeah, Merry Christmas/Happy Holidays!

but the third illustration loops HDMI signal through it from a PC to a TV set and states that the third (recording) machine (wich is a notebook) is connected with "USB2.0 output".

I would probably discount that as them forgetting to update one of the diagrams when they upgraded the product, or perhaps just not bothering since updating a picture is more effort than updating the words 😀

"wireless telegraph keyboard"

🤣

Before you get a refund on this you can try a workaround for the 5FPS limit by a query to it's Video for Linux 2 (V4L2) API representation with v4l2-ctl. Most of these are only a simple USB cam SoC and an HDMI transceiver hanging on the SoCs image sensor input, integrated together. So you may have some registers exposed which configure video format, etc like a webcam would. YUYV is uncompressed and more desirable, but USB2.0 quickly reaches a bandwidth limitation with it. You can try switching to MJPEG to have an adequately high FPS (even 60FPS on lower resolutions is some cases). On the other hand you may not like the compression artefacts, but I had the same issues with my cheap ass USB2.0 grabber and switching to MJPEG was not bad at all. I haven't really noticed degradation.

Yes, I neglected to mention that the FPS limitations I mentioned were only with YUYV, and much more reasonable rates were available with MJPEG, I just wanted to avoid compression artefacts. Thanks for your advice, I will give MJPEG a try since you didn't find the artefacts to be too bad.

The next thing you can do is tweak the default color setings.

I had a little play with this but didn't spend much time on it. I should try the calibration procedure you linked to at some point!

Thanks for all the info!

Reply 202 of 204, by gen_angry

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gen_angry wrote on 2021-09-24, 20:37:
Hello, […]
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Hello,

I picked up that AIXXCO adapter and it arrived today, have some weird results to share.

I use this for my capture card: https://www.amazon.ca/gp/product/B0813JPLNT/
KVM: https://www.amazon.com/Rosewill-RKV-2P-Deskto … o/dp/B004E2I3YK (from ages ago, works amazingly well btw)
Relevant DOS rig specs: P200MMX, Cardex S3 Trio64 V2/DX 4MB + Diamond Monster3D 4MB, DOS 6.22.
Relevant Win98 rig specs: P4 3.0C, AIW 9800 Pro, Win98SE and WinXP dual boot using XFDISK.
Secondary VGA Monitor is an Asus VP248 using HDMI pass through from the capture card

On the P200 for DOS and simple DOS games, it works and displays decently well on the secondary monitor. No over scan. Off centre by a little bit to the right (2-3 pixels).
Capture card has over scan issues with it and off centre to the left.
ASUS monitor reports displayed resolution at the DOS prompt as 640x416 @ 70hz. "Standard VGA" DOS games like Raptor Call of the Shadows and Duke Nukem 2 are displayed at that resolution as well. Not sure where this resolution comes from but all 80x24 character DOS screens are showing at this res.
VESA games like Duke3D at 800x600 display great on both screens. Off centre to the right by 2-3 pixels, no over scan.
Glide games like Descent II run at 640x480 have no over scan issues but it's off centre to the right on both screens.
Nothing changes if I connect the converter directly to the voodoo, the VGA, or the KVM.

On the P4 in Win98 desktop, there is no over scan anywhere.
At 800x600 on the desktop, it's off to the right considerably on capture card (by at least 20+ pixels). Monitor it's off to the right by like 2-3 pixels
At 1024x768 same issue as above.
At 1280x1024 solves the right shift (2-3 pixels to the right still) but it looks terrible on capture card. Looks great on the monitor.

I connected the KVM directly to the ASUS monitor's VGA in and it shows the proper resolution of 720x400 @ 70hz in DOS but obviously no ability to capture.

This leads me to believe that my capture card is just terrible for 720x400. But here's the strange part. On the P4 at the OS select, resolution displayed is 640x416 @ 70hz so it's the same as the DOS rig. But there's no over scan glitching on either displays. Capture card is shifted to the left a bit but the picture itself looks great.

Would this be an issue with my Trio or is there some kind of setting in OBS that I can use to mimic the P4's result on the DOS rig? I have to issue a debug command on the DOS rig in autoexec to get it to not display blacks too brightly. If it's truly my capture card, any suggestions of good ones that take HDMI in (I have other devices connected to a HDMI switch and would like to be able to use them as well)?

Appreciate any advice or insight. 😀

Update: Replaced the capture card with an evga XR1-Lite (much better card, supports YUY2). Sadly the same issues whether it's plugged in the screen or not. The new capture card cleaned up some of the artifacting but I still get the oddball resolutions, the passthrough is the same, and plugging it directly in the screen doesn't change anything. Everything is as described as above. The image quality is similar to watching a 'cam' rip of a movie (minus the blocking).

Bootleg Aixxco? 🤣 I'll just save up for a proper scaler at some point. Was worth a shot 😀

Reply 203 of 204, by doshea

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My genuine Aixxco arrived and I also had problems with it being off-center like gen_angry reported previously. In addition to the issues with alignment with graphics modes gen_angry reported, in VGA 80x25 text mode it seems like the display is shifted right by about half a character - there is a black band on the left and half of the characters are cut off on the right - which is disappointing! I've only tried it with my "TenYua" brand "USB 3.0" (really USB 2) HDMI capture device so far. I'll try plugging it in to a TV later, but I assume the issue is occurring in the Aixxco VGA to HDMI device, since HDMI is digital and I assume that all display or capture devices would probably align it the same way?

I'm also seeing a lot of noisy waves 🙁

The VGA signal going into the Aixxco is coming from an ATI Mach 8 card, I'm wondering if I can find any tools that will let me change the alignment on the output side. I seem to recall Mach 64 cards having Windows tools that would allow you to do that kind of thing.

Also I had a quick play with using MJPEG encoding and didn't notice much in the way of artifacts, so thanks for the suggestion christal87!

Reply 204 of 204, by christal87

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doshea wrote on 2022-01-10, 10:56:
My genuine Aixxco arrived and I also had problems with it being off-center like gen_angry reported previously. In addition to t […]
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My genuine Aixxco arrived and I also had problems with it being off-center like gen_angry reported previously. In addition to the issues with alignment with graphics modes gen_angry reported, in VGA 80x25 text mode it seems like the display is shifted right by about half a character - there is a black band on the left and half of the characters are cut off on the right - which is disappointing! I've only tried it with my "TenYua" brand "USB 3.0" (really USB 2) HDMI capture device so far. I'll try plugging it in to a TV later, but I assume the issue is occurring in the Aixxco VGA to HDMI device, since HDMI is digital and I assume that all display or capture devices would probably align it the same way?

I'm also seeing a lot of noisy waves 🙁

The VGA signal going into the Aixxco is coming from an ATI Mach 8 card, I'm wondering if I can find any tools that will let me change the alignment on the output side. I seem to recall Mach 64 cards having Windows tools that would allow you to do that kind of thing.

Also I had a quick play with using MJPEG encoding and didn't notice much in the way of artifacts, so thanks for the suggestion christal87!

I haven't noticed much shifting, but I must have missed to see them all and honestly haven't done much capture since I bought the Aixxco.
Drop me a list of problematic modes, resolutions+refresh rates and I'll test them on a Diamond SpeedStar PRO VLB (Cirrus Logic 5428) with it's mode tester utility and compare. I also have a WD90C30 (Paradise) to test with, but don't know a good DOS utility for it to begin with.