Slashdot Mirror
Cheap Tapeless DV Capture?
K'thardin asks: "Recently I've been chafing under the limitations of mini-DV tapes, as I attend various conventions throughout the year and record certain events and information panels. These limitations include dropped frames, gummed up tape heads (especially prevalent when you spend more than fifteen minutes at a time on pause), and most importantly, time constraints as the largest mini-DV tapes can only hold 83 minutes on SP (a little over 2 hours on EP, with a loss in quality and larger possibility of dropped frames). Several events I attend can run for 4 hours or more, so the time constraint is one of the worst, as it requires me to change tapes several times, thus loosing vital footage." Are there video acquisition devices out there that can record to high density media as well as (or instead of) DV Tapes? If not, how difficult would it be to build a portable one?
"There are several tapeless acquisition systems out there, such as the Firestore FS-4, the QuickStream, and the ADS Pyro drive. The advantages to these solutions are generally longer recording time, elimination of dropped frames, and the ability to record natively in several video formats, removing the need for time-consuming tape capture. The problem with most of these is that they are prohibitively expensive for the larger capacities, require user-built portable power solutions for long duration recording times, are not upgradeable, and have been reported to be buggy by several users.
Considering these devices are little more than specialized computers, I've been considering what sort of devices would be a cheap and more reliable alternative to commercial offerings. An article on DVInfoNet details the creation of a relatively cheap and upgradeable tapeless acquisition system that uses a tablet PC. The problem with this is power and space constraints. There are several existing and upcoming Linux-based devices out there (as well as those that can be made to be Linux devices) that can be made to do what I wish with the capacities I need. The problem there is that none of the ones I've found come with a Firewire port, which is vital for tapeless acquisition on current DV based cameras. Also is the problem that many of these acquisition systems do not have the capability of being upgraded, or simply lack the ability for one to swap out hard drives should it become necessary (such as recording two 4-hour events back to back ... I've done this). The only possible solution I've seen containing a needed Firewire port is the Apple iPod, and it doesn't seem to have the ability to process the information coming in from a camcorder fast enough to prevent jittery video; nor is it upgradeable.
Does anyone else have this complaint? Are there any devices I've overlooked that fit the criteria of small, relatively powerful, cheap, power-efficient, Firewire-enabled devices with upgradeable/swappable hard drives that are able to run Linux?"
Considering these devices are little more than specialized computers, I've been considering what sort of devices would be a cheap and more reliable alternative to commercial offerings. An article on DVInfoNet details the creation of a relatively cheap and upgradeable tapeless acquisition system that uses a tablet PC. The problem with this is power and space constraints. There are several existing and upcoming Linux-based devices out there (as well as those that can be made to be Linux devices) that can be made to do what I wish with the capacities I need. The problem there is that none of the ones I've found come with a Firewire port, which is vital for tapeless acquisition on current DV based cameras. Also is the problem that many of these acquisition systems do not have the capability of being upgraded, or simply lack the ability for one to swap out hard drives should it become necessary (such as recording two 4-hour events back to back ... I've done this). The only possible solution I've seen containing a needed Firewire port is the Apple iPod, and it doesn't seem to have the ability to process the information coming in from a camcorder fast enough to prevent jittery video; nor is it upgradeable.
Does anyone else have this complaint? Are there any devices I've overlooked that fit the criteria of small, relatively powerful, cheap, power-efficient, Firewire-enabled devices with upgradeable/swappable hard drives that are able to run Linux?"
Why not stop recording?
FWIW, I do video / film production for a living.. this just doesn't make sense. Consumer DV camcorders switch off automatically after a few minutes for a reason - not to save battery life *tho that's a benefit* but because of the exact 'gumming' thing mentioned. The drum spins and creates a magnetic effect which pulls tiny metallic particles off of the tape. Too much of this and your drum/heads/tape gets messed up.
It seems like the person posting the topic doesn't really understand what they are doing - or rather, they don't have a good foundation on which to improve their problems. So instead they are looking for a product (that's not prohibitively expensive) that caters to the way they think things 'should be done'.
Learn to work how the gear is designed to work. Then start experimenting.
I actually have a similar issue as the root poster and found this solution myself. I hook my laptop up to my DV camers, turn it on and it stays on becuase the firewire is hooked up. Normally it turns off after 15 minutes but I tested it on Friday and captured 3 1/2 hours before the camcorder batter strted running down. This is perfect for long events. On a side note My laptop's HD is 60GB of which 40 are free (I cleared it out for this test) Just for fun, I setup Vegas' capture to use my 40GB USB drive (it's the drive that came in my laptop, only 4200RPM - in a little enclosure it's powerd off the USB) and it worked perfectly, not a dropped frame. Provided your batteried last long enough or you have a power port this should be able to go for 8 or more hours, just get more HD space. Sony Vegas (which is what I was using) can add a dozen or more drives and use them in sequence as they fill up. You can get a bunch of laptop crives and enclosures if you want to use the host battery - or 3.5" enclosures and regular 250-300GB drives if you're doing it with AC.
To get less dropped frames, use DVCAM tape in your miniDV camera, not cheap miniDV tape. DVCAM has a much stronger backing, better lubrication and is generally worth the extra money.
Wooooooah there. Are you a Sony dealer? You sound like one.
For one thing, using DVCAM tapes in your non-Sony camera will cause *more* dropouts as the "better lubrication" gets mixed up with the lubricants from whatever tapes you were using before and basically creates a big mess. Notably, sticking Sony tapes in a Panasonic camera is asking for trouble.
Better advice would be: Use one brand of tapes, and never, ever, switch.
Better yet, use a Sony DVCAM camera with the DVCAM tape...
You *are* a Sony dealer!
Check out the Panasonic P2 cameras
Ok, maybe you're not a Sony dealer...
Don't become a regular here -- you will become retarded.
Bottom line is that if you're getting clogged heads after pausing for 15 minutes, you are either using A. the cheapest, crappiest, oldest, most unbelievably shedding tape in the known universe or B. the worst camcorder ever manufactured. Figure out which of these is the case and replace the defective part in question. If you're having enough problems with DV tape to warrant this sort of complaining, there's something seriously wrong.
Don't get me wrong, I'd love to see something like an iPod repurposed using a Linux-based firmware to do DV capture. It's something somebody could probably hack together in a few hours, given that Linux already runs on the things (or at least some models thereof). However, the reason I'd like to see it is not because tapes aren't a good archival medium, but because for the purposes of video production work, it would be a tremendous time savings if you could skip the capture part entirely and just copy a file across.
Check out my sci-fi/humor trilogy at PatriotsBooks.
The posters problem is that he has been mixing brands of tape in his camera. The different formulations react against each other and cause the heads to gum up with debris.
You should stick to one brand of tape and that is it. That is the advice most video professionals give from a vast amount of experience (me being one of those people).
If the recording is critical consider using mini DV-CAM tapes. These look like standard DV tapes but have a different formulation and are designed for the higher quality professional DV-CAM format. But there is nothing stopping you using them in a standard DV camera. OK so you loose the benefits of the DV-CAM codec, but the tape will be far more robust.
But whatever you do, stick to one brand of tapes only!