04 Nov 2015

The DV Revolution (and the birth of modern video) Featured

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Remeber DV? Remeber DV? Sony / RedShark News

It's easy to forget that perhaps the biggest leap forward in recent video history was a tape-based format in Standard Definition called Digital Video.

Things haven't exactly been quiet in the field of digital video over the last ten years or so. We've moved to HD, been wowed by the look of large-sensor video cameras and now we're at the point where we're surprised if a new camcorder doesn't shoot and record in 4K.

It's easy to forget that perhaps the biggest leap forward in recent history was a tape-based format in Standard Definition. It was the DV format, the first consumer digital format, and it introduced the concept of a digital video codec to most users for the very first time.

Pre-DV

Prior to DV, if you were a video professional or a high-end consumer, your choice for higher-than-VHS quality video was somewhat limited. S-VHS competed with Hi-8, then there was U-Matic and, at the higher end, Betacam. None of these formats were digital and, consequently, they suffered from degradation whenever a copy was made.

This meant that what we take for granted today with NLEs was impossible: tape-to-tape editing was slow and generation losses meant it was hard to make a really good looking final edit.

The struggles of early NLEs

Around the time that DV first appeared, users were starting to experiment with computer-based editing. This was a huge challenge with the level of performance available around the end of the '90s.

Products like Fast's AV Master and DPS's Perception card digitised incoming video so that it could be edited on a computer. But, at best it, was a struggle. Virtually nothing worked in real time. You had to render dissolves, transitions, titles; it was an exercise in  patience and frustration. You could get good results but you had to wait for them.

Just to put this in perspective, I remember waiting for a 10 second dissolve to render. It took 45 minutes!

Soon after this, some "dual stream" cards came along that could process a dissolve in real time in hardware.

The DV revolution

Analogue capture was never going to be the future. When DV came along, it was a revelation. All the disadvantages of analogue video seemed to disappear almost overnight.

With DV, you could copy as many generations as you liked without loss. And it simply looked better. There was no tape noise, very little dropout (except that when there was a dropout, it was total and severe), and the pictures were sharper than anything we'd seen from a consumer camera.

Of course, the fact that DV used tape for capture seems old fashioned to us now. However, these were tiny tapes. The small size of the cassettes meant that cameras, like the seminal Sony VX1000, could be small, functional and stylish.

The move to digital video meant that, for the first time, consumers were exposed to the idea of a codec. And what a codec it was! It was ideal for editing.

DV is an intra-frame codec, which means that every frame is encoded, completely independently of any other frame. Effectively, each frame is a stand-alone still picture. This means it was perfect for editing and makes it easy to process (because the computer's processor only has to consider one frame at a time in order to display an image).

The DV format was a great example of a product that was well conceived and cleverly designed. And it appeared at just the right point in the growth of computer technology to be able to take full advantage of it. Perhaps the best example of this was Firewire.

Firewire (known generically as IEEE 1394, and, peculiarly  by Sony as I-Link) was, for the time, a pretty advanced connection that was ideal for transferring video from a camera to a computer. It was fast and, in one of its two main modes, dedicated to carrying video. It was also able to carry tape transport commands as well.

DV - entirely because it only had to work with Standard Definition - had a very manageable data rate of only 25 Mbit/s, although that might seem rather high for SD, (you can record HD at lower data rates than that, but at much higher levels of compression), yet this was a relatively mild codec and it didn't use Long GOP encoding.

To get video from your DV camera to a computer, all you needed (in theory) was a Firewire interface card. In practice, you also had to have a hardware DV decoder, because most computers weren't up to decoding DV in real time on their CPU.

Fast produced the DV Master card, which had an on-board hardware DV codec. It worked well, but for a long time, setting up NLEs to work with DV could be a chore. Drivers had to be exactly right or the simple act of plugging in a DV cable could crash the computer.

Bridge to modernity

As the technology matured, we started to see a glimpse of the modern era of digital video editing and post production.

DV brought high quality video to the masses, as well as professionals. The format itself was very capable. I remember seeing the output from one of Sony's professional DV CAM cameras on a good monitor and I would say that it could approach the look and quality of Betacam SP, Sony's professional and much more expensive analogue format.

DV not only raised the quality of video recordings, but it raised expectations, too. It was, quite possibly, the last tape format. Probably because, once video became digital, it was no longer tied to the medium it was delivered on. It could live on computers, hard disks and anywhere that could store a file.

Soon, that came to include cameras themselves. As solid state memory came down in price, cameras were able to shed the complexity of a tape drive and become lighter and more robust as a result.

For me, DV was the point when the modern era of video started.


David Shapton

David is the Editor In Chief of RedShark Publications. He's been a professional columnist and author since 1998, when he started writing for the European Music Technology magazine Sound on Sound. David has worked with professional digital audio and video for the last 25 years.

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