Developing a analogue capture card with in built tbc

[Sharc]

There is only one (hardware version) of the IOData GV-USB2. I bought the last one (out of many,) 2 months ago.

It does not feature any significant time base correction, just some more resilience to unstable signal, compared to USB-Live 2 for instance.

Thanks. This confirms my doubts. Miracles are still rare

[aramkolt]

Can confirm now after some testing that the GV-USB2/HQ version doesn't appear to have line TBC properties. It does have a different part number in the lower right of the label on the device, so I was thinking perhaps that meant a different hardware version - though interestingly the box does only list XP and Win7 for compatibility. I do have one of the "Win11" versions on the way, but other's that are testing those are likely to arrive before mine. Seems odd not to have all versions state support XP through Win11 if they are all the same hardware version though? Could be the included software is what Windows 10/11 may or may not support?

[VWestlife]

The "HQ" version just sounds like a different included software bundle; no changes in hardware, unless someone can crack it open and prove otherwise.

[aramkolt]

[Attachment 92063 - Click to enlarge]

Saw this post by Video Capture Guide on YouTube. He seems to suggest that his GV-USB2 does better with horizontal stabilization than the ATI600. While neither is a true line TBC, the ATI600 in his other tests did demonstrate significant horizontal stabilization, so it's pretty interesting to see him post that the GV-USB2 does better than the ATI600 at that. He mentions in the post that he's working on a full video about it, so it's just a matter of time that we'll see the results he's seeing.

Just for reference, this is a comparison he did in the past with his ATI600 that showed significant flagging improvement compared to others:
https://www.youtube.com/watch?v=3SRoGgJZbwc

This again suggests that there are at least two hardware versions of the GV-USB2. Video Capture Guide was one of the first to post about wanting to test the supposedly newer hardware version of the GV-USB2 with line-tbc-like abilities, so I'm sure that's what he was able to get and is using for this test.

[Sharc]

The "HQ" version just sounds like a different included software bundle; no changes in hardware, unless someone can crack it open and prove otherwise.

Yes. See post#89 with quotes from the manufacturer, and @lollo's experience with a recently purchased device in post#90.

[Darryl In Canada]

There is only one (hardware version) of the IOData GV-USB2. I bought the last one (out of many,) 2 months ago.

I wrote to I-O Data in Japan and this was their reply in April 2026:

This product has been tested and confirmed to work with Windows 11, so it is compatible with that operating system.
*Our products are intended for the domestic market and are compatible only with Japanese versions of operating systems.

The GV-USB2 is a product that has been in production since before the release of Windows 11, and the design of the outer box is changed each time it is sold. Depending on market inventory, the previous design may still be available for purchase.

However, since only the design of the outer box is different, the specifications of the product itself have not been changed. Even products labeled "Windows 10 compatible" can be used with Windows 11.

Furthermore, this product requires the installation of dedicated drivers and software before use. The latest version is available for download from our website.

[Darryl In Canada]

Just for reference, this is a comparison he did in the past with his ATI600 that showed significant flagging improvement compared to others:
https://www.youtube.com/watch?v=3SRoGgJZbwc

This again suggests that there are at least two hardware versions of the GV-USB2. Video Capture Guide was one of the first to post about wanting to test the supposedly newer hardware version of the GV-USB2 with line-tbc-like abilities, so I'm sure that's what he was able to get and is using for this test.

According to the reply in April 2026 I received from I-O Data in Japan, the GV-USB has just one hardware version. This assumes that the tech support has the correct info. Regarding the comparison to the ATI600, it is slightly better on my stress test St. Elsewhere test. But slightly better doesn't mean it solves the problem of waviness/flaginess. It does not.

To try to unscientifically quantify it:
- ATI AIW 9600XT: 1/10
- ATI TV Wonder 600: 4/10
- I-O Data GVUSB2: 5/10

So, all three fail the bad tape test.

The only digitization devices I've used that get 10/10 on overcoming waviness are my Sony MiniDV camcorder (DV-25) and the ClonerAlliance ViewLiteAV.

So, just to make it clear for newbies trying to make sense of all this:

• Expensive VCR with a LineTBC feature to I-O Data GVUSB2 is better than expensive VCR with a LineTBC feature to DV-25 device.
• Cheap VCR to I-O Data GVUSB2 is worse than VCR with a LineTBC feature to DV-25 device.

Why? Because the blockiness one tends to see in digitization with the DV-25 device is less noticeable than the waviness one tends to see (on some tapes) in digitization with the I-O Data GVUSB (and the ATI 600, etc.).

[Sharc]

[/I]Furthermore, this product requires the installation of dedicated drivers and software before use. The latest version is available for download from our website.[/I]

..... and one has to enter the serial number of the device to initiate the download of the driver. This is basically positive IMO as one will get the suitable driver instead of selecting from a pletora of HW versions and a pletora of driver versions to find out yourself which combination eventually works on your system.

[lordsmurf]

The original TW9910 chip has always claimed
- Digital Horizontal PLL for synchronization processing and pixel sampling
- Advanced synchronization processing and sync detection for handling non-standard and weak signal
Maybe that gives a certain advantage which may be experienced as "line TBC like" or similar.

To be blunt -- and not at all in reference to you Sharc -- marketing statements regarding PLL, synchronization, processing, horizontal, etc. Those are statements that are intended for people that are easily bamboozled by bullshit. To a degree, ignorant consumers. Suckers. Chumps. Morons even.

In recent years, PLL has become another lose term, that marketers conflate with TBC. To some degree, the marketing copywriters are ignorant themselves on these topics. PLL is not TBC.

There are some truly ignorant comments online lately, in the past year, regarding the GV-USB2 particularly, as it pertains to "having TBC" (it doesn't whatsoever).

This is correct, and needs to be repeated, and repeated, and repeated:

It does not feature any significant time base correction, just some more resilience to unstable signal, compared to USB-Live 2 for instance.

There are many cards less resilient, and some more resilient. Resiliency is not presence of TBC.

As "Video Capture Guide" aka "Darryl In Canada" has stated:

. Regarding the comparison to the ATI600, it is slightly better on my stress test St. Elsewhere test. But slightly better doesn't mean it solves the problem of waviness/flaginess. It does not.

So, clearly, no TBC of any kind.

I also want to clarify some. ATI 600 USB has one of the best images of any USB capture card. But not the stability. It was never intended to be used without line+frame TBCs in the workflow. ATI, a Canadian company, was also very much pressured to enforce strict anti-copy by Macrovision and the Canadian government in the 2000s. As such, it easily see false anti-copy, which many people don't seem to recognize anymore, as most of us did at that time.

So if you're trying to "bareback" your captures (no TBCs = no protection), then that quality card won't work. It's not supposed to be used that way.

So, just to make it clear for newbies trying to make sense of all this:
- Expensive VCR with a LineTBC feature

I hate it when people refer to these pro/hobby video tools (the VCRs with line TBCs) as "expensive". It's just not. These VCRs were the same price, or more, when new 20-30 years ago. Add in inflation, and these excellent VCRs are now half-price to historical. I bought decks new at the time, and it was a hobby expense. Videos is one of the cheapest hobbies, and cheapest business capex, or any around.

As long as people continue to piss away $1k+ on phones, $1k+ on "gamer" computers, etc -- BS on these quality VCRs being "expensive". No worse than anything else these days.

All that referring to VCRs as "expensive" does is psych-out would-be buyers. So they end up in a much worse capture reality.

This again suggests that there are at least two hardware versions of the GV-USB2.

It's to be expected with long-lived devices, where you have decade-old models. Semiconductors (chips) are not made forever. This is the exact reason that TBCs degraded from the '00s to the '10s, chips stopped being fabbed (largely due to '08-09 recession), forcing the TBCs manufacturers to use lesser alternatives. The R&D was designed around a chipset, and then that was broken in later iterations. Capture cards are not special here. Chip fabs end runs, and almost never restart.

[Sharc]

The original TW9910 chip has always claimed
- Digital Horizontal PLL for synchronization processing and pixel sampling
- Advanced synchronization processing and sync detection for handling non-standard and weak signal
Maybe that gives a certain advantage which may be experienced as "line TBC like" or similar.

... marketing statements regarding PLL, synchronization, processing, horizontal, etc. Those are statements that are intended for people that are easily bamboozled by bullshit. To a degree, ignorant consumers. Suckers. Chumps. Morons even.

In recent years, PLL has become another lose term, that marketers conflate with TBC. To some degree, the marketing copywriters are ignorant themselves on these topics. PLL is not TBC.

Sure, PLL is not TBC, but a PLL (Phase Locked Loop) can indeed significantly reduce the jitter of the lousy sync pulses coming out of a VCR by generating re-timed low-jitter sync pulses (a basic application of a PLL). This alone does not make it a TBC though, but it is an essential building block of wiggle/line jitter suppression. In other words, a capture device with a PLL will outperform a capture device based on simple threshold slicing/gating of the VCR's line sync pulses only, and this may explain why the GV-USB2 performs somewhat better/more resilient than other capture dongles with respect to line wiggle/jitter and make people believe (misinterprete) that it "has TBC".

P.S. I can't imagine that these days any company will redesign their capture device and spend millions to include a TBC in their capture dongles - just because a few freaks would like to have it. For what market, for whom?

[lordsmurf]

Sure, PLL is not TBC, but a PLL (Phase Locked Loop) can indeed significantly reduce the jitter of the lousy sync pulses coming out of a VCR by generating re-timed low-jitter sync pulses (a basic application of a PLL).

But then it gets into questions of the quality of the PLL, how effective? And once again, the claim always falls apart with capture cards.

P.S. I can't imagine that these days any company will redesign their capture device and spend millions to include a TBC in their capture dongles - just because a few freaks would like to have it. For what market, for whom?

Correct. In long-lived devices, no new R&D is done. But "patch" attention is given when needed, mostly for supply chain issues. When chip fab ends (most common issue), new chips are located, quickly drop-in tested, and "good enough" is the mantra. When it fails, such as Cypress TBCs, products is just ended. It can't be milked anymore, product is done/obsoleted. Hauppauge, Pinnacle, even Easycaps, are guilty of this. In fact, not just capture cards, but SSDs, hand drives, pretty much anything in a computer. Any former reputation tends to tank, new good reputation for formerly-bad product is rare to never.

Driver support adds another wrinkle, OS to OS, and tends to get worse over time, not better. This is why so many of us maintain legacy WinXP and Win7 systems. We care about the video, not the OS being "new" (which doesn't matter).

There's a decay curve over time.

[Alwyn]

There are some truly ignorant comments online lately, in the past year, regarding the GV-USB2 particularly, as it pertains to "having TBC"

Apart from the aforementioned YT video, give us some examples.

[The 14th Doctor]

In the context of "does it have a TBC" then here is my test

Between it and a Pinnacle 510, results are exactly the same in terms of wiggling mess. The IO-Data does not do any further correction.

[johnmeyer]

I don't know the context of some of the previous posts, but I'm pretty sure that you cannot make a time base corrector without using a phase lock loop chip. The entire concept of synchronizing the timing of the various horizontal and vertical sync signals coming from your VCR with what was created by the TV camera, pretty much requires that you create an error signal and then use that to adjust the phase of sync signals. That is the basic definition of what a phase lock loop circuit does.

I am an electrical engineer by training, and my first job out of college in the early 1970s was at HP working in their microwave test equipment division on the 8660 synthesized signal generator. It was filled with phase lock loop circuitry, so while I didn't design those circuits, I sure spent a lot of time working with the results and learning how they work.

So, if something is labeled as "PLL" and it doesn't work, then it is because it is badly designed, and NOT because it uses a PLL.

I hesitate to quote ChatGPT as an authority on anything, but this was it's response to my query: "Do most video Time Base Corrector (TBC) circuits use a Phase Lock Loop (PLL)?"

ChatGPT: "Short answer: yes—almost all TBCs use one or more PLLs, but a PLL alone is not sufficient to perform time base correction."

The idea that a PLL alone is not sufficient is obvious to anyone who has designed circuitry because you also must have lots of filtering and you obviously need to have a way to generate the actual timing waveforms and merge them into the video signal.

[lordsmurf]

There's too many recent threads right now, same topic.

It started here with a 2026 bump on pg3:
https://forum.videohelp.com/threads/418238-Developing-a-analogue-capture-card-with-in-...e3#post2794924

Then these posts popped up:
https://forum.videohelp.com/threads/420384-Comparing-I-O-Data-GV-USB2-vs-ATI-600-Flagg...nd-Frame-Drops
https://forum.videohelp.com/threads/420443-4-different-IODATA-GV-USB2-s-tested-with-sa...-Like-Activity
https://forum.videohelp.com/threads/420448-GV-USB2-vs-ATI-TV-Wonder-600-USB

I debunked the TBC claims here:
https://forum.videohelp.com/threads/420443-4-different-IODATA-GV-USB2-s-tested-with-sa...ty#post2796088
and in the follow-up post.

[lordsmurf]

I'm pretty sure that you cannot make a time base corrector without using a phase lock loop chip.

Correct.

ChatGPT: "Short answer: yes—almost all TBCs use one or more PLLs, but a PLL alone is not sufficient to perform time base correction."

Correct.
Amazingly. (Hint: ChatGPT sucks, too many hallucinations. Use Claude or Gemini -- or both.)

So, if something is labeled as "PLL" and it doesn't work, then it is because it is badly designed, and NOT because it uses a PLL.
The idea that a PLL alone is not sufficient is obvious to anyone who has designed circuitry because you also must have lots of filtering and you obviously need to have a way to generate the actual timing waveforms and merge them into the video signal.

I would imagine that a capture card uses a cheap chip, and whatever memory is on the PLL chip is all you get. It likely stores some edge information, and then releases/renews in a GOP-like fashion. Very primordial. In some ways, worse than just letting the wiggle pass. It depends on how bad, how frequent.

As an engineer, concur?

BTW -- Would you believe that you and I have been having discussions online for 20 years now? In emails, in PMs, on forums.
It's really been nice knowing you all these years.

[johnmeyer]

BTW -- Would you believe that you and I have been having discussions online for 20 years now? In emails, in PMs, on forums.
It's really been nice knowing you all these years.

Ditto! I hope we have both helped a few people along the way.