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DV (and it's related DVCAM and DVCPRO) is a relatively new digital tape format.   it was developed by a consortium of 10 companies as a 'consumer" digital video format.  There are now over 60 companies in the DVC consortium, including Sony, Panasonic, JVC, Philips, and other similar names you've heard before.

DV (also called "mini-DV" in its smallest tape form) was originally known as DVC (Digital Video Cassette).  It uses a 1/4 inch (6.35mm) metal evaporate tape to record very high quality digital video.   The video is sampled at the same rate as D-1, D-5, or Digital Betacam video, although the color information is only half the D-1 rate: 4:1:1 in 525-line (NTSC), and 4:2:0 in 625-line (PAL) formats.  DV images are compressed with a but superior technique to motion-JPEG, allowing for higher-quality 5:1 compression.  DV video information is a constant data-rate of about 36 Mbps (or 3.6 Mbps).  

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• First, to control your DV device, and
• Second, to exchange data between the computer and DV device.

These are related but separate functions, all of which are integrated into one convenient record/play back system. So using FireWire, you can tell your camera to play, pause, fast-forward, rewind and stop, and you can tell the computer to capture what's being sent to it.  You can also tell your camera to record what's being sent to it by the computer.

There are some other systems for control of camcorders and VCRs, which are generally used with older analogue equipment. However, your digital camcorder may have one of these ports so you can more easily integrate it with analogue video systems.

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DV is the actual format of the video and it looks incredible. It is the new super high resolution digital video format that is better quality then S-Video and has many broadcast professionals thinking about scrapping their BetaCam gear. The images are crisp, bright and have excellent depth and contrast. Best off all, the information is stored on the video tape in digital form, so it can be copied over and over without any loss.

FireWire is the jack 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. Not all DV cams have FireWire, and not all DV cams implement the FireWire spec the same way. Worst of all, many PAL (the European television standard) DV cams have the DV input disabled, so that they can be imported at lower duties!

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Most of the high resolution video capture cards on the market use MJPEG compression. The less you compress the video, the better it looks, but the higher the sustained data rate you need. At compression under 6:1 (over 3000 kilobytes/sec) most people will think the video looks as good as the original, but it will be slightly lower quality. The video will have very slight artifacts and image loss.

The DV 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. Unlike MJPEG compressed video, DV video can't be scaled. 

DV in = DV out

This is what makes DV so special. 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. DV is a constant. Every FireWire card we carry delivers the exact same DV quality output. When choosing a FireWire card, there is no video quality debate regardless of what CODEC (compression method) is used.

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Basically the DV CODECs can be split into 2 groups. Hardware and Software.

Software CODECs

The biggest advantage of software based FireWire boards are how affordable they are. They are much less expensive then hardware CODEC based cards because they rely on software compression and the speed and power of your computer to digitize and edit the footage. Software FireWire cards are really just an interface for bringing the DV video in and out of your computer. Everything you do with the video is done by software. The obvious advantage of this is that with computers getting more and more powerful every day, software based systems become faster and faster.

The biggest downside of software based cards is that they are DV only. They don't have S-video or composite video inputs or outputs, just DV. So if you have older analog footage, you have two choices. You can buy a DV deck with analog inputs and make a DV copy of your old footage, or you can run your system with both an analog, MJPEG based, video capture card and a software based FireWire card. You can convert footage from one format to the other by rendering it and creating a new movie using your NLE software. This process can be quite slow. A one minute conversion can take over 15 minutes in a P200MMX system. 

Hardware CODECs

These boards use the same exact DV chips used in your DV cam to handle the DV data. They have both analog and DV inputs and outputs. They can convert from analog to DV and DV to analog in real time. You can create a timeline that includes both analog and DV footage. In addition, these boards have additional chips on board that allow you to view the DV video full screen, full speed on your computer monitor; S-Video or composite video monitor; and through your DV device all the time and at the same time. You can scrub and trim your video while viewing any or all of the output options. This makes the actual editing process much easier and faster.

The biggest downside of Hardware based FireWire boards is the cost. Currently your going to spend around $3000 for a hardware based solution, compared to well under $1000 for a software one. The good news is that prices have dropped, and will continue to drop as more and more DV chips are made and economies of scale start kicking in.

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Remember, DV in = DV out, so the video quality is identical, the only difference is editing features.

A screaming G3 or Pentium II 350+ is going to give you outstanding results. The real difference comes down to the NLE software. We still feel that by far the best application for editing DV footage is Radius EditDV, currently available only for Mac. It is the only NLE software written from the ground up exclusively for editing DV video. As a result it is very stable, renders fast and offers features like Draft DV that put it ahead of Premiere.

That said, if you are going to edit in Premiere, we feel that either platform, as long as you use a new machine, is going to provide you with a stable editing environment that will give you topo notch professional results.

The hardware based solutions are PC only, so if you want one of them, your only choice is between Win98SE and Win2000.

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