How to make sure a continous timecode ?

[Ron Evans]

Well all you guys got me wondering how I haven't seen any of these problems so I just did a DV test ( I will try and render some HDV and try HDV also over the weekend) I have 4 DV pieces of equipment, all Sony. A DHR1000 deck, a PC10 camcorder, TRV50 camcorder and a FX1. I prestriped a Sony Premium ( cheap )tape at LP on the TRV50 on the assumption that this would be the worst of all worlds for an insert test. I then used Premiere 6.5 with my Canopus DVRaptor RT2 to insert a colour matte ( red ) for 4 seconds onto this pre striped tape, and moved the tape between each of the pieces of equipment in turn. NONE of them missed on timecode continuity going from an LP pre strip to an SP record of the red matte. The deck was two frames late on insert point( which I could adjust for and then hit the insert point) but all the camcorders were exactly on the insert point with the export default device control setup. So I prestriped the tape at SP and repeated the test. Exactly the same result. There was no timecode corruption on entry or exit though this was only a 4 second insert and could get much worse over a long period of time resulting in a timecode difference at exit. I quess this explains my input and my assuption that this was the way it was according to spec and practice. Obviously not for everyone!! Apologies if I have misslead anyone.

Ron Evans

[Ron Evans]

Well having posted and then read some of the posts I had missed I though that I should test for a longer insert to see if my camcorders would create an error over a longer insert. So used just the TRV50 this time and striped with red matte for 30 mins. Then went back and inserted a blue matte first 2 mins, then 4 mins, then 6 mins and then 8 mins. all cases were the same as before. No timecode errors on entry or exit. Two of the inserts , the 4 and the 8 min had a frame of mixed blue and red blockies on exit but the timecode was solid on this frame repeatedly single steps forwards and backwards through these changes both on the TRV50 and repeated on the DHR1000.
Clearly there is no real need to stripe but for some continuity in time ( how much time do I have left on this tape?- when on holiday) it may be worth it even if a copy is made afterwards to get clean code for editing. I will still do it for my holiday and family tapes for just this reason.

Regards
Ron Evans

[R Geoff Baker]

I believe you are most likely to have problems if you have created the 'stripe' in a single long recording pass (as you typically would), and subsequently shoot again on that tape with many short shots, over some days of variable temperature ... and you review your material in camera, which was the tape handling habit that suggested this 'solution' in the first place.

The combination of dissimilar tape passes, temperature changes & tape shuttling lead to the problem, in my opinion. The math reveals that it doesn't take very much of tape stretch to generate a single field (or just more than half a single field) change which would cause a timecode skip or repeat .... remember that the key point is that the tape 'stripe' is not preserved, the way it is on a analog edit deck -- it is destructively erased when the tape is reshot. The only purpose of the stripe is to give the camcorder a value to start recording timcode, even if you've cycled past the last shot.

Cheers,
GB

[David Kennett]

GB,

You've got the right idea there. I think the initial idea of "striping" DV was to insure that the TC generator doesn't start at zero again in the middle of a tape. Years ago the term "jam-sync" was used to indicate that a TC generator could read existing time code, and then continue from that count as it went into record. No existing code - start at zero. That is what happens with less than professional DV and HDV. The "pros" give you options. As GB says though, the out point of your last shot will only be close.

When I started with DV, my primitive software did not preserve the original TC. It simply started each capture at zero. If you captured that way, there would be no pre-roll problems. The TC would not match the tape, however. This would only be important for "off-line" editing, or maintaining TC if something must be re-captured. I still capture with new TC. There will not be a pre-roll problem that way. This saves the copying step that was mentioned earlier as a solution to this problem.

[Tyge Floyd]

I striped 20 Sony Premium miniDV tapes before my last assignment in Africa. On several (maybe 4-5) of these tapes there is more than one set of timecodes. It's killing me in the log/capture process with FCP, getting timecode errors. How did this happen? I thought if I striped a tape I would have a continuous timecode.

Shooting on a Sony PD170, never removed a tape until it was no longer going to be used. Did turn the camera on and off several times if that matters.

Is there a way to lay a timecode down that will be continuous? My main concerns are in the batch capture process while in FCP. I was lead to believe that striping tapes would solve my batch capture problems. Guess I was wrong.

[Sean M Lee]

Tyge,
FX1 or Z1U? You can set the Z1 to either free-run or record-run.

[R Geoff Baker]

The simple answer is do nothing and your timecode will be continuous. Striping causes problems, as the stripe is erased on your shoot and doesn't accomplish what you are expecting. The ordinary process of shooting, stopping & shooting again will generate timecode that starts at zero and continues upwards without a break from there -- in the case of the PD170, you can elect to start at something other than zero if shooting DVCam, or shoot 'free run' (which will likely cause your NLE no end of fits) if you want to have timecode that follows the clock and not the 'record run' standard.

Stop striping, it doesn't help.

GB