DV, FireWire (or iLink, IEEE1394) Are The Hottest

The latest technology in digital video editing is DV and FireWire.

If you are setting up a new system, go digital right from start. That means, buy a DV camcorder and video capture card with FireWire port.

What is DV?

As you can guess, DV stands for "Digital Video". It is the new high resolution digital video standard.

DV is compressed at the camera, on the tape itself. The camcorder has the DV "codec" built in.

The DV spec is a 720x480 image size with a 5:1 compression. DV video information is carried in a nominal 25 megabit per second data stream. The color information is sampled at 4:1:1 for NTSC, and 4:2:0 for PAL.

Unlike MJPEG compressed video, DV video can't be scaled. You can't lower the screen size, change the screen size or data rate.

DV format is typically reckoned to be equal to or slightly better than Betacam SP or MII in terms of picture quality. Two types of DV camcorders, DVCAM and DVCPRO, are widely used in TV industry today.

However, for most of us, DV often refers to MiniDV actually. MiniDV is just the home level DV format. It is compressed to a constant throughput of 3,600 kilobytes per second. The video quality is not as good as Betacam, but much better than S-video.

What is FireWire?

Technically, it is the high speed, short distance data transfer protocol IEEE1394. Apple didn’t like the numbers and so called it "FireWire". Sony didn’t like it either, and so they called it "iLink". And they are all the same thing.

When the FireWire concept was first announced a few years ago, it was envisioned that it would become a new standard that would replace SCSI and link all our consumer electronics equipment and computers together. Now, the dust has settled and the hype has died down. The only application for FireWire that has actually come to fruition is for transferring digital video (DV) information directly from a camcorder (or VCR) to your hard drive.

What's the difference between DV and FireWire?

DV is the actual format of the video. DV & Firewire

FireWire is the port and protocol that lets you transfer the DV data to your computer. The full FireWire spec includes frame accurate device control and the ability to read and write the digital video.

When the video goes through the 1394 cable, into the capture card, and onto the hard drive, nothing is done to the video. It is a digital copy. It's identical to the original. And this is really nice.

How's the quality of DV?

The DV (MiniDV) spec is a 720x480 image size, at roughly a 5:1 compression. More accurately, it is compressed at a constant throughput of 3600 kilobytes per second which averages out to 5:1 compression.

The images are crisp, bright and have excellent depth and contrast. In general, it's acceptable even in TV stations.

Best of all, the information is stored on the video tape in digital form, so it can be copied over and over without any loss.

DV in = DV out

This is what makes DV so great. When you capture DV footage to your hard drive via FireWire, the DV video on your hard drive is an exact digital copy of the original footage. There is no loss. When choosing a FireWire card, there is no video quality debate regardless of what codec is used.

What are the different DV CODECs?

Don't know what is codec? Check out Getting Started FAQ.

Basically, the DV codecs can be split into 2 groups. Hardware and Software. But remember, the final video quality is not an issue. DV in = DV out.

Software codecs
Software FireWire cards are really just an interface for bringing the DV video in and out of your computer. They rely on software compression and the speed and power of your computer to digitize and edit the footage. The biggest advantage of software based FireWire cards are how affordable they are. Another advantage is that with computers getting more and more powerful every day, software based systems become faster and faster.

OHCI cards
OHCI cards, or "Open Host Controller Interface", use the drivers found in the Windows 98SE, ME & Win2000 operating systems. Since the manufacturers do not have to engineer any software drivers, they are very inexpensive, usually around $100. With these cards you can capture and edit your video, but this can be limited. The only features you get are those that the NLE supports. One of the advantages of the OHCI spec is that it also allows you to attach other cool FireWire devices like hard drives, WebCams, scanners and more.

Hardware codecs
These cards use the same DV chips used in your DV cam to handle the DV data. They have both analog and DV inputs and outputs. Your analog footage is captured and compressed directly into DV in real-time. You can create a timeline that includes both analog and DV footage. Because these cards have analog output (usually through a break out box) you can view your video on a video monitor while you edit. This makes the actual editing process much easier and faster.

Which is better, hardware or software codec?

One thing to keep in mind is that "hard" vs. "soft" doesn't matter when it comes to video quality, both give excellent result when working properly.

Speaking of speed, in early 1998, various vendors claimed a 25% or 30% speed advantage of hard codecs over soft codecs. Too much depends on other factors, like the speed of the computer's CPU, bus and bus interface chipset, to decisively say that one codec will be faster than the other in effects rendering. As CPUs and buses speed up over time, the soft codecs have taken the lead in speed for rendering operations.

However, hardware codes do have some advantages sometimes depending on your requirements. Hardware codec systems usually come with breakout boxes that include analog (composite, Y/C, or even component) connections as well as 1394 connections. You can connect up any VTR format with analog I/O to the box and capture it in real-time or output to it in real-time.

One of the very cool features that many hardware based DV cards now have is real-time features such as transitions, FX, filters, titling and more. Real-Time means you do not have to render, these effects play directly from the timeline. Not everything is in real-time with these cards. Each real-time card comes with its own special selection of real-time features.

Most of the hardware based DV cards also support MPEG2. MPEG2, like DV, is 720 x 480 for NTSC, 720 x 576 for PAL. The big advantage of MPEG2 is that you can lower the data rate and still maintain close to DV quality. MPEG2 compression is what is used by DVD. So these cards usually include DVD authoring software.

What about Digital 8?

Sony's Digital 8 uses DV compression atop the existing Video8/Hi8 technological base and records on Video8 or Hi8 tapes. Both Digital 8 and DV camcorders allow you to transfer video directly to your computer via FireWire, using a DV capture card. The biggest advantage of digital 8, besides the cost, is that you can put an older analog Hi8 tape in the cam, and transfer the video via FireWire.

The only disadvantage is that the video from these cams is simply not as good as what you get with DV. Digital 8 camcorders are aimed at the price sensitive buyers. So they don't get the same quality optics, features and CCDs as DV cams.

Simply put, get a DV camcorder if you can afford. If you can't, a Digital 8 will also do the job.

So, which FireWire card is for me?

To get the best answer, you need to decide what is most important to you.

The flexibility and combination of analog and DV video source?
Are you going to use it in your existing computer, or get a new one?
Do you have adequate storage?
Do you need the NLE software bundled with the card?
Real-Time features?
What is your budget?

Once you have figured this out, it really comes down to the feature combination. That's what separates one FireWire card from another. DV in = DV out, so no matter which card you buy, the final video will look the same.

With our Video Capture Card Features Chart, the task will be much easier!

Or check out our Top 10 Recommendations.

DV Video Editing Software & Hardware - DV & FireWire (iLink, IEEE1394) FAQ