How to tell if full frame TBC is working?

[aramkolt]

I've read a lot on this forum about certain TBCs not working well for consumer grade video content with "choking issues" (assuming that technically means lots of dropped frames) depending on the source, but I've also read how some of the known "good" units can degrade or develop other issues with age (capacitors needing replacement etc).

My question is if there's a guide out there or general principles in how to test a TBC that you just bought to make sure that it is actually functioning as intended in your setup?

I presume this involves looking for dropped frames in statistics, but how do you know if any dropped frames are due to the capture card/host computer limitations versus the fault of the TBC?

I did see an old post from Lordsmurf discussing checking to see if it removes VHS macrovision which I'd like to go a bit beyond in testing. I could see it being possible that a TBCs could remove macrovision, but then drop frames randomly that you may not be able to perceive at the time of capture and may then run into issues later in the processing chain.

If it is as simple as just looking for dropped frames, is it reasonable to expect that a proper TBC with have ZERO dropped frames?

[lordsmurf]

Verify drops, including in frame-by-frame scrub. Tedious.

Actual frame TBCs (in the context of consumer analog format usage) RAM buffer to prevent any drops, but truly awful footage doesn't contain enough complete field/frame data to stop drop. TBCs are chip sets, not just single chips, and RAM is part of the set. Furthermore, the programming matters, which is why some TBCs are flawed, some are crap, some are marginal.

Non-source drops are somewhat easy to locate in comparative analysis Avisynth scripting. Not flawless, but detection less tedious than manual scrub.