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Black burst Generator for precise Audio&Video sync in Virtual Dub?

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Cameron Hamill
Black burst Generator for precise Audio&Video sync in Virtual Dub?
on Jan 20, 2013 at 6:36:30 am

Hi Members,

PAL VHS > PC transfer. Significant audio drift / out-of sync on Direct Stream Copy Mode in Virtual Dub. PAL 25.0000fps 240 Minute Tape. Home Video.

I'm using a

JVC S-VHS Hi-Fi VCR (HR-S7600AM) (Has in-built Time Based Correction on this model).

Is it possible to use a Black Burst generator on a consumer grade VHS such as this? I've connected the S-Video out and composite Red/White outputs to a cheap USB2.0 capture card (Conexant Polaris Unused CIR Function).

What I want to do is 'lock it down'. I want to lock the audio and video together and provide a solid feed to Virtual Dub.

Will a black burst generator such as the Horita BSG-50 work for this scenario? Or do I need a VTR / Editing Deck with genlock output or something like that? The Horita has BNC connectors. Do I need to simple buy some S-Video > BNC adapter cables? Where does Genlock come into all of this? It's very confusing.

I already own a DataVideo TBC-1000 (time based corrector)
BlackMagic Design Intensity Shuttle USB3.0 (video capture device-external/outside of the PC device).

I read this on another forum and I'm trying to accomplish exactly what this user is suggesting;

Quote (about audio drift/de-synchronization in Virtual Dub) ;

"I worked on this problem in the late '90s for several years. The core problem is when you have more than one crystal, both trying to give you timing information -- there will always be some rate slew (CPU clock / video clock / sound card crystal / etc).

The only way to really solve this problem is to use a house clock, and make sure your audio and video gear all syncs off the same clock (for more on this, google "blackburst"). Needless to say, cheap consumer hardware won't go through the trouble of implementing this crucial feature, so we'll get wow and flutter from "compensating" software forever to come.

If you actually CARE about your multimedia, you need to get gear that can sync right, but expect an audio+video capture rig to set you back over $1,000. On the bright side, you'll be able to play back OUT with the same sync :-)

Jon - 04 12 05 - 21:55"

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