If the video is already digital, you don't want to convert it to analog and redigitize. You will only be sacrificing some quality for nothing.

If you can't fit firewire to your laptop then borrow or buy an old one that you can. Any old IBM compatible PC is likely to be fast enough.

Definitely want to use firewire. How about this combination:

http://www.amazon.com/ExpressCard-Adapter-usb-laptops-desktop/dp/B001765PZG/ref=sr_1_21?s=electronics&ie=UTF8&qid=1334763955&sr=1-21
allows you to connect express cards to a USB port, and

http://www.amazon.com/Best-Connectivity-ExpressCard-Controller-SD-EXP30012/dp/B003GAM68U/ref=pd_sim_e_2
an express card adapter for ieee1934.

Camcorder -> 4to6 pin firewire cable -> express card -> usb adapter. The two above items and the cable should run you about $30 including economy shipping.

I would be real surprised if a USB 2 card adapter would allow for the Firewire capture speed. I know USB2 is the same datarate, but you have to allow for the overhead of the adapter.

I would try to get another computer just for the capture or use the blackmagic solution.

Dave T2

DV captures over firewire are only 30Mbps. That leaves an awful lot of extra room for overhead! Even if you lost 90% of the available speed there would still be more than plenty of bandwidth left over.

Chienworks, of course you are correct, but doesn't it make you wonder why nobody makes a USB DV video capture device? Most USB devices capture at DVD speeds, not DV speeds.

Dave T2

The problem isn't the speed, it's the protocol. USB is packet-based (ACK/NAK to you RS-232 ancients) and Firewire is DMA and requires a processor at each end to set up the transfer.

"but doesn't it make you wonder why nobody makes a USB DV video capture device"

I see adapter cables are available that claim to interface between firewire and USB. It wouldn't surprise me if they didn't work properly (or at all) for DV transfer. Anybody tried one?

I know for a fact that when you use a firewire connection, the video data is captured as is without any decoding or encoding, which is why it is so darned efficient. Adding a USB connection to the mix might well cause an extra set of decodes and encodes. Also, Firewire barely touches the CPU in it's housekeeping, whereas USB has the CPU doing lots of work. This would factor into using USB as well. USB 3 is even faster than Firewire, but USB 2 is quite a bit slower.

"Adding a USB connection to the mix might well cause an extra set of decodes and encodes"

What else may happen I am sure that that would not be one of them. Being an all-digital content-ignorant transfer, it would either work well or not at all.

Back in my SD DV codec days, like many here, I used a Canopus Firewire box to preview my video. The way it worked was that any section that would smartrender would play directly through the box with next to no CPU overhead at full resolution regardless of your preview resolution.

I remember well calling up the task manager and watching it while I previewed my video. What you would see is maybe 1 to 2% CPU overhead where the video was playing or across straight cuts, then at any crossfade or place where you added a filter, the CPU usage would go way up and the preview resolution would drop down to "good" or "draft" or whatever you had it set at, at which point the CPU usage would go way up and the quality would go way down. This was with a single core P4 system. As soon as the processed section was done, the preview quality would again be perfect and the cpu usage would drop to nothing.

This was because on unprocessed sections of video, the Firewire interface was actually decoding the video. All that Vegas and the CPU had to do was stream the compressed video data from the hard drive to the Firewire interface. The interface did all it's housekeeping without bothering the CPU.

This was also the big difference between Vegas and competing software of the time. Vegas would give you a low quality (but decent timing-wise) preview of your video without rendering your transitions. Other software including the second version of Final Cut Pro (which I gave up on for this reason) had to render transitions before you could play them. It gave you a full quality low overhead preview, but rendering out transitions was really slow and really interrupted the editing flow. What Vegas allowed you to do was work really quickly with on the fly low resolution transitions. This was bad if you had a producer looking over your shoulder wondering why it looked like crap during the transitions, but great if you were working by yourself and just wanted to get the project done and move on. No the processed parts didn't look full quality, but you could work without constantly taking breaks waiting for transitions to render so it was worth it.

Anyway, the point of all this is that when you are capturing DV video from your mini-DV camcorder over firewire, you are getting a direct digital copy of the data on the tape, and there is next to no overhead on the computer while this is happening. The big issue used to be dropped frames because your hard drive wasn't fast enough. On the old P4 computers, Firewire was way better than USB 2 for capturing video because Firewire didn't burden down your CPU whereas USB 2 did. Also, Firewire could pass data two ways simultaneously (as in playing back a video track and recording an audio track). Way better.

At this point, CPUs are so fast that none of this really matters, but when mini-DV oriented single core editing workstations were the rage, it really did.

Anyway, the point is that capturing SD DV codec footage over firewire takes maybe a hundredth of the power it would take to do this with USB. I'm not saying that it won't work. SD video is pretty light compared to HD and you can get away with murder processing wise these days.

What I would do is just find a computer you can borrow that has firewire to do this capture. Capture to an external USB 2 or USB 3 disk but use Firewire to connect the camera to the computer. Heck, these days you could probably capture DV codec to a 32 gig memory stick and be fine!

Also, if you haven't worked with Firewire video capture before, this is really important:

Connect everything with the power off, then power on when it is all properly connected.

Firewire ports have six connections: four of these are low voltage data and two are much higher voltage power. If by chance you try to plug it in backwards, what will happen is that the current from the power lines will jump across to the control lines and absolutely fry the Firewire circuitry in your camera. I've done this. I'll bet many other "old-timers" here have as well. This is so easy to do. You're fumbling with the connection... no it doesn't fit that way let's try it the other... hmm, it's plugged in but it isn't working... I wonder why ... oh, it's because I tried to plug it in upside down and just like that I fried the circuitry in my camera! How much will it cost? WTF! that's more than twice what these cameras are going for on eBay! You complain to the manufacturer and they ask why you didn't heed the warning in big letters in the manual... like you still have the manual...

You can hot plug the firewire connections if you are ABSOLUTELY CERTAIN of the plug orientation, and if you have the smaller 4 pin connection at both ends, you can't hurt anything, but it is a whole lot easier just to plug it in first and then power up later.

"Adding a USB connection to the mix might well cause an extra set of decodes and encodes."

Nope. Couldn't possibly happen. The final (and only) encode already happened before the data was written to tape. After that, it's pure data transfer.

Then again, we're *ALL* making the assumption this is a DV (or Digital8) camcorder. This wasn't actually stated explicitly in the original question. It might very well be an analog recorder. However, since firewire was mentioned we may be justified in assuming DV.

"I see adapter cables are available that claim to interface between firewire and USB."

*sigh* I looked at the technical descriptions for about 50 different models of these from about 20 different manufacturers today. Every single stinkin' one of them was built for the purpose of allowing a USB cable tester to test firewire cables. Not one single one of them was intended for data transfer. All they do is straight hard wire the four firewire pins to the four USB pins and the shield to the shield. They certainly cannot convert one protocol to the other.

I had a sneaking suspicion that that might be the case, but couldn't see why such an adapter might be useful.

BTW, I asked at my local computer hardware shop today if there is a firewire to USB adapter, but there didn't seem to be one.

[b]"BTW, I asked at my local computer hardware shop today if there is a firewire to USB adapter, but there didn't seem to be one."/b]

You probably will never see one because when you cost the components to change the protocol, you may as well just buy a laptop with Firewire built in. You'll need a processor, memory, and O/S at the very least. Then add the engineering cost including the firmware to handle the different protocols, and the cost could possibly exceed the volume cost of a laptop. All that for two protocols on their last legs. Your best off looking on eBay for a used Vaio laptop with Firewire.