Capture 2 mini-dv at the same time

[Ferggue]

I have 2 Mini-DV cameras with Firewire output and an internal PCI Firewire board with 3 6-pin Firewire inputs.
My question is whether it is possible to capture 2 Mini-DV at the same time using both cameras over Firewire. If possible, can it be done with the Scenalizer software?

Thank you!

[dellsam34]

If you have two firewire ports try it, Open two windows of Sclive and select the right camcorder name for each window and see how it goes.

[DB83]

I never fail to understand why people have to do everything 'yesterday'


Surely it is better to get a proper transfer of one tape than risk crapping out on both - which you then end up doing again.

[dellsam34]

Not to mention that the data bandwith is devided in half so it would brobably takes twice the time of transfering one tape at a time, So besides the risks there is really no benifit.

[Alwyn]

If a computer can handle capturing uncompressed at what 1gb per second, I'm sure it could handle two lots of 13gb per hour.

As for rushing, if I had 50 tapes to do, I know what I'd rather!

[dellsam34]

DV is around 25MB/s, Two streams are about 50MB/s, Firewire is 400MB/s theorically, Practically is around 25MB/s, So as soon as you connect another DV streaming device that number approximatly drops in half. But the only way to find out for sure is to try.

[Ferggue]

DV is around 25MB/s, Two streams are about 50MB/s, Firewire is 400MB/s theorically, Practically is around 25MB/s, So as soon as you connect another DV streaming device that number approximatly drops in half. But the only way to find out for sure is to try.

I have 600 tapes to transfer so I am looking to increase the transfer rate. I will try to connect the two cameras as soon as I have another firewire cable and I will tell you about my experience.

[dellsam34]

For that many tapes you need about 15TB of storage to store the captures if you want to leave them in DV format (assuming 2hr tape is about 25GB), A cheaper way is to use BD-R DL 50GB discs and burn as data, they are like a $1/disc, Each disc can approximatly hold 2 tapes, so you would need 300 discs. BDXL discs are 100GB each so only 150 discs are needed but they are little bit pricier.

Offcourse you can convert to h.264 after each capture for less storage but converting that many files requires months if not years to finish.

[Alwyn]

I'd be buying two 8tb drives and see how you go. Yes, they're more expensive, but far more convenient. Make sure you make a backup (that could be on BD). The future/present is having instant access to your videos on your PC or TV. I couldn't think of anything worse than having 150 BDs to sort through to access my videos.

Smart Rendering DV with Scenealyzer after rough editing is a cinch and fast, and any decent computer should render DV to H264 in real time.

assuming 2hr tape is about 25GB

I was under the impression that the tape length and therefore the amount of storage was fixed at 13gb. My camera can record in "LP" mode, but I assume that would reduce quality. I have never heard of a "2 hour/25gb" MiniDV tape.

[Cornucopia]

I think what @dellsam34 means is that 25Mbps for 2 Hrs = ~22-26GB (rule of thumb = 13GB/hr). So though the most common tapes only hold 60 minutes' worth (or 90 if using LP), there are some larger cassettes available for some prosumer cams, which can give you up to 2 hrs (perhaps beyond). Those aren't likely though, in this scenario.

Also, perhaps the association of VHS SP speed recording of 2hrs to fill a tape was carried over here.

I'd say, if each tape is full, and recorded at SP speed, the OP would end up with 13GB * 600 = 7800GB or ~7.5TB. If one were wanting to do editing and/or archiving using HDs (as opposed to cloud, tape, optical disc, etc), then yes 2 8TB drives would be a good idea.
Personally, I would think for archiving, BDR is an excellent inexpensive alternative, or maybe additional backup option. And a simple catalogging app that logs discs's files is a no brainer. I already have had such a setup for a decade, and I've got about 850 CDRs, 200 DVDRs and a couple scores of BDRs and various RE/Ws. Takes all of a few seconds to do a search through the catalog tool and then go get and insert the disc.

Scott

[Ferggue]

I have another firewire cable. I will tell you about my experience transferring 2 Mini-DV tapes at the same time.

I'm already doing 150 Mini-DVs with a single camera and I still have 600 left, so I need to work with more than one camera at a time. Context: it is a work for a Public Archive for the Conservation of Memory on the crimes against humanity that occurred during the last military dictatorship in Argentina (1976-1983). This file are videos of the judgments initiated in 2001.

I connected the two cameras at the same time, opened two Scenalizer windows and correctly in each one I was able to select each camera separately and started the transfer with both cameras. There was no problem, the capture was successful in both cases.
The only strange thing is that in one of the two windows the vumeter does not work during capture nor does it emit sound even though the mute option is unchecked, but then in the final .AVI file it does have sound.

I save the files directly on 2TB USB External Hard Drives, the DV file in .AVI and also a compression in H264 .MP4, which I do with Adobe Encoder, a very practical program because I load all the files together and do the process in one row. (takes 25 minutes for every hour of DV video).

It should also work with 3 cameras, right? I have another Digital8 camera that I could plug in when I get another Firewire cable to do the experiment.

Hardware:
2 Sony Mini-DV Handycam
2 Firewire cables 6 - 4 pins
1 PCI Firewire 6-pin 3-input board
PC: Windows 10, AMD FX-6300, 16GB DDR3 RAM and 2GB gtx 950 GPU

[Alwyn]

Well there you go. Never say never.

Your Digital 8 camera won't play MiniDV tapes; the tape cassettes are different sizes.

[Ferggue]

Well there you go. Never say never.

Your Digital 8 camera won't play MiniDV tapes; the tape cassettes are different sizes.

Yes, I know that. What I propose with the Digital8 camera is capturing 3 cameras at the same time through a single computer and a single firewire board.

[Cornucopia]

I guess it doesn't hurt to try. But each thing you add to the overhead takes you steps closer to something crashing/freezing/skipping. Calculate your individual and cumulative bandwidths and capacities. That port controller may have some underlying combined throughput limit.

In fact, I strongly recommend that you take time to do a couple of realtime checks throughout the length on BOTH clips of pairs of captures (or all three of triplets, if possible) - maybe not all of them obviously, but enough regularly, because there is the likelihood of data dropouts, which may not be evident enough to stop capture, but might still be there. And tapes of such important gravity deserve premium treatment. It would be a shame if a dropout occurred right at a climactic moment, and then was not reviewed soon enough and then was left through to distribution.

Personally, for piece of mind, I would suggest you just purchase 2 more cards & computers. Clone the existing setup if you have to. Then capture each, singly-dedicated, together (or staggered, so one's downtime is another's re-setup time). It is still the same overall amount of capture throughput but it is inherently safer.

Btw, the thing with the audio probably has to do with the fact that the soundcard is partly being used for the metering, and a hardware resource like that cannot be shared. Just like you cannot use a single mic & cam on both Zoom and Teams at the same time. Exclusive use.


Scott

[Cornucopia]

Also, please make sure those external USB drives are USB 3.0 (or better) not USB 2.0. You'd quickly hit a wall of bandwidth limitation with the latter. And externals are prone to file copy/transfer glitches, so make sure you create MD5 hashes of the files. Oh, and use dedicated power supplies on the drives, NOT usb power!


Scott

[rrats]

compression in H264 .MP4, which I do with Adobe Encoder, a very practical program because I load all the files together and do the process in one row. (takes 25 minutes for every hour of DV video).

You should reecode with ffmpeg in the interlaced format

ffmpeg \
 -y \
 -hide_banner \
 -i "${INPUT_FILE}" \
 \
 [... audio ...]\
 \
 -vf tinterlace=interleave_top,fieldorder=tff \
 -crf 20\
 -preset medium \
 [... more video ...]\
 -codec:v libx264 \
 \
 -f mp4 \
 -flags +ildct+ilme \
 [... more muxing ...]\
 \
 "${OUTPUT_FILE}"