VHS Stop Recording

[ES Steelman]

Greetings. Hope this isn't such a newb question, but I picked up a vhs capture gig because I wasn't smart enough to say no. I have searched high and low but it seems everytime there is unrecorded space on the tape it actually stops recording . It seems as if it may be tied to a scene detection setting but I can't seem to figure it out. My goal is to set the tape length timer, hit record and then walk away. Maybe I missed something very obvious. The actual capture up to that point is working fine. Is this normal expected behavior?
Thanks!

 

[DayGeckoArt]

I'm curious about this because it's something I want to try... What capture device do you use? Does it stop providing data when the VCR feed goes black?

 

[ES Steelman]

August VGB 300. Typical USB 2.0. That may be the case though causing OBS to just stop recording. I assumed even though there was a blank area that it would continue to record. Can't seem to find a way to get it keep going. I definitely don't want to sit through this many tapes and start and stop the record again every time there is a break. Just wanted to capture all (blank spots and all) and do all of the post work cleanup in DaVinci Studio and possibly some uprez in Topaz. If this fails, I may just run them through my firewire cam and use something like Scenalyzer to capture. I'm brand new to OBS so there may be something very obvious that I am missing.

 

[DayGeckoArt]

I don't think there's anything in OBS. I've tried to find a way to get OBS to stop recording when the video stops, but the best I've found is the built in timer

 

[ES Steelman]

That was my plan to just set the timer and walk away. LOL! 30+ tapes to capture.

 

[WP1]

Perhaps try to find an old school time base corrector, common gear back in the analog days. With one between the VCR and your capture device the capture device should still get a clean NTSC video signal even when the recording runs out.

 

[koala]

There is an output timer in OBS you can set to the total runtime of one tape, but there is no auto-detection for "unrecorded space" at the end of a tape. It's an analog medium that doesn't carry any information about what is recorded on the tape. For OBS, it's just a continuous input from a capture device. Not even the end of a tape can be signaled.
You need to cut the video after recording with some postprocessing tool. A very simple tool is Avidemux.

 

[ES Steelman]

"It's an analog medium that doesn't carry any information about what is recorded on the tape. For OBS, it's just a continuous input from a capture device. Not even the end of a tape can be signaled. "
That is what made me think it shouldn't stop recording between scene breaks or unrecorded space but continue recording. Hard drive space is not an issue. I will be doing the post work in Davinci Resolve Studio so no problem chopping heads and tails and dead space.
Haven't tried the timer yet to see if it fixes the problem.
May look at the time base corrector. Thanks for the replies!

 

[WP1]

Scene breaks on an analog tape = no NTSC video signal to the capture card as a VCR only can provide signal when there is one on the tape. A time base corrector will provide a clean NTSC video signal on its output regardless of whether there is one on its input. This is the only way you are likely to be able to overcome the capture card / OBS dropping when there is no video on the tape. A time base corrector also essentially re-clocks the signal from tape for better stability, and in the analog days it also provided a way to lock multiple video signals in sync (genlock).

 

[FerretBomb]

There is no reason OBS should stop recording on its own, just because a video capture device is sending a blank signal. It should just keep going forever until you stop it, or it runs out of disk space.

If it IS stopping, my immediate suspicion would be that you may have set a 'stop recording' hotkey in the Settings->Hotkeys codex. OBS uses hotkeys, not shortcuts, which many people are not familiar with. In OBS, if that button (combo) is pressed for any reason, the function will activate.
Many newbies will set their spacebar as start/stop recording, then wonder why they have a hundred one or two second video files on their disk... because they were typing and hitting the space bar to put spaces between words. Likewise, having something bound to F12 will also trigger at the same time something bound to CTRL+F12... because F12 was hit for any reason.

I'd recommend setting one up and burning the hour to sit with it and wait until it stops.
Failing that, post a logfile from a session where it occurred. Worst-case, it'll say that the user requested the recording to stop. Best case, it will list which process stopped the recording and why.

 

[WP1]

I suspect the capture device is sending an error on loss of input signal, rather than "blank". A gap in recording on a video tape is *not* a blank signal i.e black with sync, it is no signal at all. On analog videotape the video signal comes directly from the tape and is as stable as the gyroscopic stability of the spinning video read heads, there are no electronics buffering, stabilizing,etc. that is why time base correctors existed for broadcast applications.

 

[ES Steelman]

Thanks everyone for the responses and Happy New Year. I got sidetracked with this when the power supply went out on my main editing machine. I replaced it and now that is out of the way, I will pick up tomorrow trying the suggestions of setting a record timer and a couple of other options . BTW there were no hotkeys enabled. I also suspect it is hardware related in terms of the actual capture device itself. These are all pretty cheap pieces of hardware but some people seem to get good results. If this doesn't work with this device I will probably route the SVHS deck through my mini dv cam and capture via firewire.
Thanks again and I will let you know what I came up with.