Monday, May 28, 2007
Basically, a digital video recorder consists of a TV tuner, a computer processor, some Random Access Memory, an operating system (most often Linux), and a hard drive. This array of software and components- when combined with an on screen program guide- provides a powerful way to record TV programming directly off of the satellite signal, cable, or airwaves and then access those recordings for playback. If this description makes the digital video recorder sound like a VCR, at least from the standpoint of its function, then that is a correct assessment of what a DVR is capable of. There are a couple of major differences between a VCR and a DVR though. For one thing, unlike a VCR, a DVR cannot be used to play rental videos. (Some of the more advanced DVR's come with DVD drives and are capable of displaying video from a DVD, but that capability is an extra feature that goes far beyond the basics of what a DVR can do.) The more important difference between a VCR and a digital video recorder is the fact that a digital video recorder is actually easy to program. Rather than having to use an abstract and esoteric numeric interface to set the time and the channel of the program that you want to record, digital video recorders let you use the intuitive interface of an on screen program guide to select the programming that you want to record. The software then does the rest. Most DVR's are also perfectly capable of recording more than one channel at a time because they have more than one TV tuner. Some can even record four channels at a time, but that's rare.
One of the consequences of the popularity of digital video recorders is fear among advertisers that people will avoid watching TV commercials by recording all of their programming and then fast forwarding through the ads while watching the playback. One high end DVR will even detect and tag the beginnings and ends of commercial breaks so that it can automatically skip over them during playback. While these fears are well founded- after all, a lot of people do record TV just so they can skip over the commercials later- there are still enough people watching commercials so that the economy (or at least TV sponsorship) is in no danger of collapsing any time soon!
DVR's themselves take on a variety of forms. For example, there are some pretty basic set top boxes that are provided by TV service providers to their customers. These are essentially extensions of the receivers. There are also a variety of portable devices that can record video and then play it back on built in miniature LCD screens. At the other end of the extreme are media center computers that not only act as digital video recorders, but serve as the hub of multimedia entertainment systems that are capable of playing music as well as video and displaying a variety of computer functions on the TV screen. Many of these devices can even record video off of TV broadcasts and then burn it onto DVD's.
With all of this functionality and all of these options, DVR's provide a degree of control over TV viewing that puts other devices and technologies to shame.