How to make sure a continous timecode ?

[Douglas Spotted Eagle]

When you black a tape, you are also laying down time code, or striping, if you're working with DV. (and most other formats)

[R Geoff Baker]

What he said. Unfortunately, you also erase your previous black/stripe when you shoot again on the same tape, so all is for nought.

GB

[Khoi Pham]

"It seems to work fine with the end-search function. But thats useless, if you wand to recor from a prerecorded spot or when removing tapes and so on."

This always work for me, if you remove the tape or checking the tape in VTR mode, then play/pause it 16 frames before where you want the camera to record again, then switch to camera mode and record, it always record 16 frames after your pause point when you are in vtr mode, so if you want continous timecode then always make sure you have atleast 1 second of video after your pause point.

[Marc Fairorth]

Now I understand something about when timecodes are laid down.

But I've not heard a clear voice yet concerning if the practice of striping the tape prior to shooting is really necessary. Specifically this: if I never take the tape out of my FX1 until its done, only record and stop, do I risk any breaks in the timecode? I'd been striping my DV tapes for years, but I've basically gone away from ever rewinding and checking my shots (I'm not a pro, I'm usually just shooting candid shots of my kids at play, so it can't be recreated anyhow).

Should I stripe my tapes in my FX1?

Thanks!

[Dylan Pank]

Marc,

Striping is irrelevant in your case. The only people I ever came across striping their tapes were my students when I taught in Turkey. Basically we criticised them if they ever had gaps/resets in their timecode. Pretty much what was happening was, as you said, they were reviewing their shots. A few of the more savvy ones figured out that striping their tapes was a way to avoid this, but I do remember it caused as many problems as it solved, as there were timecode breaks where the footage dropped back to the blacked sections. This caused problems with tape pre-rolls either in capturing or when being used in linear tape to tape suites. So I can absolutely guarantee from personal experience that DV DOES erase the old timecode.

However, I've also found breaks in TC in my PD150 footage (and I never stripe my tapes) when stopping and starting, but striping wouldn't have made any difference.

[R Geoff Baker]

"But I've not heard a clear voice yet concerning if the practice of striping the tape prior to shooting is really necessary"

Hey, I'll be as clear as I can: Striping a DV tape doesn't do what you think it is doing, your stripe will be entirely erased when you record again on that tape, and the practice of 'striping' a DV tape before shooting can cause problems with duplicated/skipped timecode values that are hard to spot ...

You stripe an analog tape you intend to use as an edit master so you can insert video and audio on top during the edit. Period. You never stripe a tape you are using in a camcorder for shooting -- no camcorder will use or preserve the stripe, so you are at best wasting your time.

If the goal is to avoid gaps and resets in your timecode, don't ever shuttle past the end of your last shot into blank tape, or if you do, backwind a frame or two into the last shot before shooting. This is how DV camcorders are designed to work, and this will eliminate completely any timecode gaps/restarts.

I expect the HDV world will be the same ...

HTH

GB

[Dominic Jones]

Same thing - it's an expression, I think, based on the fact that the frames are black but it has the timecode "stripe" running along it - hence "Black and Stripe"...

[Ron Evans]

All pre striping a tape does is ensure that there are NO sections on the tape that there is no timecode. At least all consumer and Prosumer camcorders search for the timecode when a tape is inserted and use this timecode to continue from when record is started. The timecode is embeded in a particular area of the tape and is re-writen when recording is started. Correctly adjusted camcorders will not miss, and will maintain continuous timecode. Care must be taken to ensure that pre striping was done at the tape speed of the recording. Its no good striping at LP and then recording at SP for instance or vis versa. Timecode will be writen at the correct speed but the start point will be wrong. That is starting half way through an LP tape ( 45 mins) and record to the end at SP will leave an end time of 01:15:00 in SP!!! Cameras pre roll before starting to record so it is possible to re insert a tape on the last value of timecode on tape and then have a recording with a timecode break since the roll will go to a blank section before recording starts and the camcorder will think it is blank tape and start timecode at zero again. IF you never remove or view the tape untill full the camera will back roll each time to ensure this doesn't happen.
I actually miss the timecode re-write feature on Hi8. Timecode is writen on Hi8 tape in much the same way by the rotating heads but all my Sony Hi8 equipment has the ability to re-write timecode which of course solved all these problems of timecode breaks.
Vertical interval timecode on analogue equipment like SVHS has the same problem as DV, once writen your stuck with it. Control track timecode was not on all VHS/SVHS equipment ( there was always a linear control track but not always any code just pulses for the record/playback head timing) I think some of the JVC SVHS machines had control track time code that could be re-writen.
The bottom line is pre striping tape wil result in a continuous timecode but the recording will be on a tape that has already had a previous recording of black. Since there is no fine cue/review control to back up just a few frames with HDV like most DV cameras, either shoot a long tail on all shots if you are going to remove tape and view, so that you can stop way before the end of the shot to start the next shot and avoid camera going over end of timecode.
For my holiday and family tapes I prestripe since everyone wants to watch all the time!!!! For the event projects I do I use new tape and don't view tape untill editing.

Ron Evans

[R Geoff Baker]

Ron, I'm happy that your 'prestriping' has never given you grief, but I have been given tapes to edit where the combination of prestriping and advancing before the last shot has created duplicated or skipped timecode values -- this is typical of tapes that were 'striped' in a single long pass, but are later used for mulitple short shots, particularly when temperature changes typical of an Ottawa winter are also affecting the tape ... the result crashes a batch capture attempt, or most Premiere attempts at capture.

If you have a tape with timecode problems, make a Firewire dub of the tape. The new tape will have new, continuous timecode & the video and audio will be an unchanged 'clone' of the original -- every bit the result of your old 'rewrite the timecode' solution. And given that you will only ever have to do this to tapes where your advancing/reviewing resulted in timecode breaks, you'll probably save time and effort as you won't have to waste a pass on every one of your tapes, just dub the problem ones.

Cheers,
GB
Ottawa, Canada

[Ron Evans]

GB
The one time I had a problem was with my Sony PC10 that was continuously causing timecode problems and was a result of a defective chip. This was evident in that while shooting I could see the timecode reset to zero in the viewfinder!!! Not had problem since. I only prestripe when I know its going to be a case of shoot look, shoot look etc. You are correct in that a copy with 1394 will give a nice fresh timecode that can be relied on for batch capture. The timecode faults you see could also be a problem with LP and SP recording on the same tape which could lead to big discontinuities by recording short clips in SP over an LP encoded tape.

Ron Evans

[Mike Teutsch]

Hi everyone,

Maybe this will put this issue to rest!

I too was advised to “stripe” my tapes, to prevent gaps in the time code and thereby prevent problems with gaps when batch capturing etc. I fact, it was recommended that you should stripe with color bars.

After reading this entire post today, I decided to conduct an experiment.

I put a new tape into my XL1s and recorded a short shot, and then fast forwarded a little and recorded another shot. As all would expect, I had two short shots each with the time code starting from zero.

Next I put in a striped tape. I fast-forwarded to a black striped section with time code but no image. I recorded again, for about 15 seconds. Upon playing back the footage, it looked fine with no apparent problems with time code changes.

To verify this, I put the same tape into my CH-VF1 deck, where I could control the playback better. Playing at normal speed it appeared again to be fine, and it appeared to be fine when using a slow playback.

Then I played the footage using my remote, which allows me to play it at about a half frame per button push, IE it takes two presses of the slow forward button to move forward one frame. When I did it this way, it moved from blank area time-code to the footage time-code without missing a beat—No Problem. But, when exiting the shot and returning to the striped area of the tape, it did have a problem. The time code stepped --:--:15, --:--:16, --:--:20. In other words it dropped 4 frames. This of course would probably cause some capture problems at times.

So what this proves is that you can’t maintain the correct time-code when you stripe a tape. It may work at times, but it obviously will not work all the time. I guess, from now on, I will skip striping and just use care in recording. I hope that this information will help in this post.

Mike

[Dylan Pank]

Mike,

This is great, it's a duplication of the faults we used to see with my students who would prestripe. They would get into difficulties when pre-rolling for batch capture or on linear machines. The deck would re-wind over that skip and then fail to find the pre-roll point, in some cases rewinding to the previous section and playting ad infinitum.

In another situation students would capture whole tapes in one long pass for offline, and set up the NLEs to ignore TC breaks, which meant after a few timecode skips, their TC would be right off by the end of the tape, by up to a second or two, so when they re-captured at online quality just their sequence clips the edits were often very wrong.

Ron, our experience with this issue took place with VX1000s, which have no LP mode, only SP.

[Marco Wagner]

Some from what I gather a good practice would be to:


1. Fast forward and rewind your fresh tape to loosen dust and tention the tape.

2. Record a few seconds/minute before and after a shot.

3. Start recording the next shot in the duration of time recorded AFTER the last shot (before the time code breaks).


Is that correct?

[R Geoff Baker]

Yes Marco, I think you describe the best tape handling habits. Pack the tape once, roll tape at the top, maybe to bars and tone, and for all shots afterwards let the tape run a second or two long. If you watch what you've shot, cue for the next shot with the heads parked on the extra material you shot before -- if you don't review your material, you shouldn't have to do anything, though I have found that if you power up and start shooting with no pause or time at all between power on and shooting, you might cause a timecode reset to zero. If a reset causes you grief, make a lossless dub via Firewire and get a new tape with continuous timecode.

GB

[Marco Wagner]

Thanks a bunch. My main concern is dropped frames and dropped audio. I never really seem to have issues with time code. I usually capture just the scenes I need, manually. I wouldn't know what to do with batch capture. Once in a while I would get a scene that would lock for a frame or two and then continue, very frustrating. Packing the tape seems to have help a lot.