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?"
How about... analog? Is digital a requirement? A good quality VHS camcorder (like an old professional model) shoudl be able to tape for quite a long time and give you a great picture. Maybe even beta or VHS-C or 8mm or something. If you go out of the digital realm, you may have better luck. And there must be special VCR type things that can take those tapes and have FireWire to take the video off for you easily.
My other suggestion is more decidedly low tech: 2+ camcorders. Switch one on when the other is about to run out of tape.
Comment forecast: Bits of genius surrounded by a sea of mediocrity.
JVC recently announced a new HDD-based digital camcorder, with storage of 20 or 30GB that is good for over 10 hours of video.
D =1 e s-Four-Hard-Drive-Based-Everio-Camcorders.htm
http://www.jvc.com/press/index.jsp?item=461&pageI
http://www.camcorderinfo.com/content/JVC-Introduc
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.
Slight correction to a common misconeption about MiniDV tape and the DV format:
There is no loss in quality going to LP recording mode compared to SP mode. It is still 25 Mb/sec.
Switching to LP you give up reliable insert editing, recording/playback compatibility with other cameras, and audio dubbing. And you are more likely to have dropouts. But aside from these things, SP and LP produce identical quality video.
And Digital-8 has the same quality as well. Same 25 MB/sec recording rate. The reason Digital 8 is perceived as an inferior format is because it appears on relatively lower quality cameras. You can dub DV digitally to a Digital 8 deck and you will end up with a perfect copy.
iSight is a fun toy, and good for confrencing and maybe seeing a girl naked on the other side of the country, I don't think it'd be that great for recording your favorite stripper's 4 hour set.
DV Rack (http://www.dvrack.com/ by Serious Magic runs on a laptop and was made to do exactly this plus it has automatic quality monitoring that watches video and audio levels in real-time alerting you when thresholds are exceeded. It also turns your laptop screen into a field monitor that lets you compare live camera to recorded clips in split screen (good for checking continuity/framing).
There's an express version that lists for $149.
Disclaimer: Yes, I work at the company but hey someone finally asked a question on Slashdot that requests exactly what a product that I worked on does.
miniDV EP is the same quality as SP. The only difference is the tape speed. The data packets are the same.
Dropouts? I've been using miniDV for years in an industrial environment and I never have dropouts. Your camera is gummed up as you've already explained.
Always use fresh tapes for important events and record them, completely, with the lens cap on then rewind to retension and create a proper timecode on the entire tape. Don't reuse tapes, keep your camcorder clean and stick to one tape manufacturer.
Pause for 15 minutes while recording? Huh?!?! Most camcorders shut themselves off. There's no good reason to be on pause for 15 minutes. Turn it off then back on.
You don't need a HD. What you need is attention to detail and, it seems, a second camcorder and tripod. Record overlapping segments and do post-editing.