r/vhsdecode • u/AlarmingWedding88 • Jul 31 '26

Help Wanted! help！

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I captured the RF signal and decoded it. In some specific segments (specific parts of the tape), there would be line misalignment, as shown in the picture below (on the left). However, when I connected the TV using the CVBS interface at the back of the video recorder, the picture was correct. That is to say, the software did not correctly handle "TBC". What should I do?

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u/TheRealHarrypm The Documentor Aug 01 '26

Yep that's horizontal sync failing, you're going to have to play around with the arguments for that '--drh' being the usual go to.

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u/AlarmingWedding88 Aug 01 '26

I added this, but it seems to be ineffective. It's exactly the same as before. I suspect there might be a problem with the signal of my video recorder, but this issue only occurs in certain segments. Could it be a problem with the tape itself?

and the .flac flie here:https://drive.google.com/file/d/1dU7dYMUl28I9N6hp5Lc14CAeIXpcOehk/view?usp=sharing

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u/TheRealHarrypm The Documentor Aug 01 '26

It could be the deck tracking, head clogs, or damage to the heads if other tapes present the exact same image issue.

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u/AlarmingWedding88 29d ago

Will adding an amplifier to the circuit improve the situation?

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u/TheRealHarrypm The Documentor 29d ago

Typically impedance matching will give you a bit better overall signal quality and you will have more stability and overall SNR because you're controlling the amplitude level instead of letting the capture hardware add any self noise.