PVR’s share many components with desktop computers. With a few parts any spare computer can be turned into a PVR. A computer turned into a PVR can do so much more than what cable, satellite or even Tivo can deliver. The ability to play and burn DVD’s, play downloaded and streamed Internet videos, see digital photos and play downloaded songs display news and weather information on demand to name just a few extra that can be done with a PC based PVR.

The more powerful a computer is the better it is for use as a PVR. The minimum for standard definition recording and playback would have a Pentium 4 processor running at 1.6 GHz with 512 Megabytes of RAM. A P4 running at 2.6 GHz with 2 GB of RAM would be considered to be the minimum requirements for High Definition. Mini desktop PC’s are considered to be the best candidates for use as PVR’s because they fit easily into people’s home entertainment centres but most mini desktops lack a drive bay to mount the required second hard drive for storing the recorded video.

The first thing that a PC needs to become a PVR is some way of getting TV into the computer for recording. The device that does this job is a TV tuner card which tunes into a TV channel and digitizes the audio and video. While there is no shortage of TV tuners that connect to the USB port, a highly bandwidth intense task as handling video will bottleneck through USB. A PCI TV tuner card is a much better choice because the PCI bus can handle the mass of data the TV tuner card will put out.

The choice of a TV tuner card comes down to the source of the programming that will be recorded. Over the air TV signals in the United States now require an ATSC compatible tuner card. An NTSC tuner card can still be used if the main source of standard definition TV signals comes from analog cable. Recording from digital cable or satellite requires a tuner card with a composite or s-video input and an infrared blaster to control the digital cable or satellite box. Many newer tuner cards now feature a clear QAM tuner which will tune in to non-encrypted digital cable channels. Some cable providers send out their bare basic cable line up in clear QAM. Most other cable providers don’t send out any clear QAM channels.

NTSC Tuner cards regardless of the signals they receive fall into two types, hardware encoding and software encoding. Hardware encoding tuner cards compress the video into MPEG format. Software encoding tuner cards require the computer to do the compression. A hardware encoding tuner card is preferable because the tuner card is doing the work of compressing the video not the computer.

With ATSC tuner cards, the work of compressing video is done by broadcasters. USB TV Tuners while popular to viewing TV on computers are generally not considered to be acceptable for use in a PC based PVR because USB will be a bottle neck when it comes to something as bandwidth intense as video.

For recording high definition there are plenty of ATSC tuner cards on the market that support high definition. These cards are for tuning over the air HD broadcasts that can be received with an antenna. For recording HD over cable there are tuner cards that will accept a CableCard, a device that looks like a PCMCIA card for a laptop computer. The tuner card receives the signal, and the CableCard decodes it. Currently Windows Media Centre is the only PVR software that supports CableCard PC TV tuners. Recording HD programming from satellite is somewhat more complicated because there are no Tuner cards for North American satellite services.

Additional capability can be added by adding more than TV tuner card. By having two or more tuner cards in a PC gives a true watch one show while recording another show experience that people know even from the earliest days of VCR’s. Using multiple tuner cards it is also possible to watch and record shows from different television programming providers. For example using an ATSC tuner card and a DVB-S tuner card for free to air (FTA) satellite.

Recording TV shows uses a lot of space on a hard drive so much so in face that just a few shows will fill hard drive on anybody’s spare PC. Adding a large hard drive is an essential investment. The best recording and playback quality comes from having dedicated drive on a controller separate from the boot drive. The normal operations of a PC will read and write to the hard drive that contains the operating system. For standard definition recording any large hard drive will suffice. For high definition recording SATA is preferable. The only external hard drive suitable for use in a PC based PVR are those that use the external SATA or eSATA interface. Just like the TV tuner USB would bottleneck which means that playback would be jerky. Firewire would be a better choice than USB for standard definition use but would still be problematic for high definition recording.

Using a PC based PVR would be nothing short of awkward if it required the keyboard and mouse to control it. That’s why there are remote controls for PC based PVR’s that come on their own or come bundled with TV tuner cards. An infrared receiver that connects to the computer with USB or a special interface on the TV tuner card gets the infrared signals from the remote control and turns it into commands that the PVR software can understand.

The last thing needed to turn a computer into a PVR is of course the software that records the shows and puts a pretty interface on the screen for users to navigate through an interactive program guide, through recorded shows. There are some that are free and some that have to be paid for. Users of Windows Vista (and 7 when it arrives) Home Premium or Ultimate already get Windows Media Center with Windows. For those using Windows 2000 or XP because it’s the operating system that came with an older spare computer still have many PVR programs to choose from.