Duplicating a MiniDV?
 

Hello! I was wondering how to duplicate a minidv. Is there a way to transfer it to my computer then transfer it to a blank minidv via the hv20?

Thanks!

The easyest way would be to play the tape on one camcorder and record it with another one connected via firewire, but if you don't have another camcorder, than yes, capturing and exporting back to tape will give you an exact replica.

That only applies to DV AVI. It does not apply to HDV. For HDV the only way to get an exact copy is tape-to-tape.

Note that with DV, typically the timecode will get rewritten unless you have a suitably "pro" camcorder that will preserve the incoming timecode. All the other stuff (time, date, camera settings etc) typically are preserved.

"That only applies to DV AVI. It does not apply to HDV. For HDV the only way to get an exact copy is tape-to-tape." (Gotz)

Why is that?

GB

Keeping in mind that we are in the Premiere forum, and I did not take into account any software that might be smart enough to send clips back to tape without re-encoding, Premiere Pro is not smart enough to do the job.

Why? I don't know. It shouldn't be as hard as they make it out to be.

If you capture DV, put it on a timeline, then put it back to tape, you can do this over and over and over with no loss. It is basically a file transfer.

If you put HDV on a timeline, it gets re-encoded as it is laid back to tape. Just seeing how long the delay is before it starts to write to tape is an indication that something bad is happening.

I wish I knew "why" but I don't.

Thanks for the explanation. I take from this there is no ability to stop recompression for an HDV export from Premiere.

GB

That's my understanding. You would think that the MainConcept plugin would allow it, but I haven't tried it and I haven't heard that many people rave about it. It would be pretty easy to test. If the export started immediately then no re-encoding could be involved. If it took even a little while, then that answers the question.

Is the DV export back to tape re-encoded as DV, or is it just a straight transfer? I.e., is PPro writing back the original bits, or does it re-encode (with the resultant 5:1 encoding ratio) the already-5:1-DV file?

Thanks,
Matt

Premiere does 'smart rendering' for DV, so that only material that has been edited (beyond simple trims) gets recompressed. There's also a 'recompress' checkbox in the Export dialog, if you WANT to recompress the whole thing.

(The recompressed file will be the same size of course - it doesnt get another 5-fold shrink...)

Wouldn't it be better to export your edits to a lossless format, and then export the lossless file to tape? Or does it not make a difference?

Thanks,
Matt

How do you think the camera can handle that? It is a DV (5:1 compressed) flow that it is designed to record, nothing else.

I wasn't clear. Of course you'd compress to DV to go to the camera, but before then--to render all your effects, etc., w/o re-compression, wouldn't it be better to go to a losless codec and then take the final product to DV to tape?

I'm still trying to figure out when things get recompressed and when they don't. Steve G. said that PPro is smart enough to only recompress changed material. But if you apply an effect to the entire movie (e.g., color balance or unsharp mask), then PPro has to re-encode the entire thing, right? For DV, how does that re-encoding the original 5:1 DV to a new 5:1 DV not result in generational loss? On the flip side, because you may want to take the movie back out to DV tape, is there really any gain in going lossless, because you have to re-encode 5:1 anyhow, so you're still encoding original 5:1 footage by an additional 5:1 factor....

I hate math...

I'd really like to know, though, the answers to the above. I get lost in the myriad of codecs sometimes, and in what degrades quality vs. maintains quality, etc. I can see exporting to a lossless codec (some quicktime, blackmagic 10, huffyuv, or just uncompressed) for ingest into a compositing program. I'm still struggling with the back-to-tape issue myself, though, without generational loss due to recompression. What am I missing?

Thanks,
Matt

Matt,

You will gain nothing from using lossless codecs when you still have to convert to DV. It will only cost time and storage. One generation loss for all the rendered parts of your time line can not be avoided, the rest is unaltered as Steven said earlier. The only advise I can give is to finish your editing and then export to tape. Avoid repeating this step if you want to make changes to your project, do that before exporting.

Harm,
Thanks for the confirmation. That's very disappointing but emphasizes what I've been researching...

I still need to output to lossless, though, as I do composite and color correct in AE. It may just be me, but I find the Color Finesse engine in AE to produce better output, and it produces even better output when working on lossless input. I verified that (at least visually) on my HD TV--the original looked crappy so I went back and made sure everything was lossless to final render. Yup, took a lot of space, but the final output is worth it.

I'm really looking forward to that HDMI field unit Stephen Armour is working on--that ought to help with the whole compress-recompress issue, without being tethered to a studio computer. Maybe I'm just getting too snobby since I got an HD TV...

Thanks,
Matt