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Introduction

Capturing video demands a lot of processing power from the CPU. This is where the video capture card comes in. The card takes most of the burden of the processing and turns the signal into binary data and stores it onto a hard drive.

The human eye needs around 25 frames per second (fps) to see moving images without "jerks." For a full screen capture of 704x576 pixels you can imagine the amount of data that has to be written to the hard disk in every second. That's:

704x576 pixels
24 bits of data per pixel
25 fps. (If you are a good number cruncher then you can E-mail the figures)

And that's just the video data! What about the audio. With some more expensive cards you can capture the audio and ensure the best audio and video sync. The cheaper ones use your existing sound card which can result in bad sync. When you use a cheaper card there are ways around that using the video editor package that will come with your capture card.

The capture card uses a compression format to perform this task more efficiently, there is little degradation in quality and takes a lot less space on your hard drive. The compression used is called MJPEG Encoding, if you are familiar with the JPEG image format then, as you can surmise, the M simply stands for Moving. Even with a compression of 16.5:1, the hard drive's speed is essential. I use a DiamondMax 3400/13.6Gb EIDE/Ultra ATA 3.5in 5400rpm which gives me a formatted disk size of 13 Gb and over 12.17 Mb/sec write and 12.40 Mb/sec read at a compression ratio of only 3.0:1. However, there are now faster EIDE models on sale now and getting cheaper by the minute. I set this hard drive up with 1 partition using a formatting program called Maxblast.exe. This can be downloaded at the Maxtor website

The card I use is a Marox Rainbow Runner bolt on card to a Matrox Mystique 220, 4 Mb video card. I have found this to be adequate for the projects I am doing and is an excellent beginner's and intermediate's card, not just for an easy to understand interface but for the value for money. The prices are always coming down and are now beginning to change in design and concept due to public demand for "ease of use" hardware.

To describe how to set up your system for video editing, I thought it would be best to describe the set up that I have built and then you can decide on your own "studio" design.

First of all I did my research into what kind of card would be best to buy. I only have a VHSC non stereo camcorder, at the moment, so I opted for a Mystique with Rainbow Runner bolt-on. This card can capture at 704x576 and at 25 fps with CD quality audio and TV out capability. It occupies one of my PCI slots. It is also one of the cheaper cards on the market and is adequate for my purposes (ie. Home video projects, presentations and learning the basics of digital video editing).
I then bought the hard drive. It is very important to get as fast a drive as possible so that there is less chance of dropped frames when it comes to capturing your project. Dropped frames = jerky footage. The higher the data transfer rate the better.
Next, I bought a VCR and portable TV. The VCR so that I can capture the AV signal via the Rainbow Runner and its "video in" cables. The TV so that I can see what the finished project will look like when it is written back to tape. When you play an AVI file on the computer the movie is displayed on the TV via the Rainbow Runner's video cables.
The last thing is also important, that is taking the time to de-fragment your hard drive as often as you can to ensure that your system is optimised for video editing and speed of access. When you buy a large capacity hard drive you can find yourself waiting hours the de-fragmenter to do its job, so find something to do while you're waiting.