Buying guide for Digital Video recorders / Players - DVD, hard disk PVR and Blu-ray

In digital video recording (DVR), the signal is stored in digital form on digital storage media such as DVDs, Blu-ray or hard disks. If the original material is in analogue form (e.g. standard TV), it has to be digitized by the recorder in order to be stored. For HDTV or standard digital TV, the original signal is already in digital form and is best recorded before it is converted into analogue to preserve its high quality. A recorder usually requires an internal digital tuner or a HDMI input to get access to the digital signal level.

What types of digital video recording and playback units are available?

• Standalone DVD players and recorders

• Digital video recorders (DVR) or personal video recorders (PVR)

• Blu-ray players and recorders

Standalone DVD players and recorders

DVD recorders are similar to VHS decks but record the information digitally to a DVD instead of a tape. Some units can upscale the output to produce a HD signal with selectable resolutions when playing a standard DVD and feed this via HDMI or DVI port to a HDTV set. This can be quite impressive but is definitely inferior to proper HD material (you will need blue ray or hard disk to get the real thing). It still allows you to enjoy your old DVDs in HD enhancement on your new HD flat panel TV.

DVD recorder are also available with integrated digital tuners. These provide you with two main advantages: you don't need a separate digital tuner to receive digital television and the recorder has access to the high quality digital signal for recordings. To get the best of both worlds you can go for a combination of DVD and hard disk drive with an inbuilt digital tuner (for multi tuners see below).

Digital video recorders (DVR) or personal video recorders (PVR)

Digital Video Recorders (DVR) or Personal Video Recorders (PVR) use computer style hard disk drives HDD for recording. PVRs usually include digital tuner(s) and an always up-to-date electronic program guide (EPG) that makes it much more convenient to select your programs for recording.

These devices can have extremely high storage capacities (depending on size of hard disc) allowing you to record a large number of movies and other programs. They can be erased, edited and re-recorded and are extremely fast. The channel that the PVR is tuned to can be constantly recorded, which allows for rewinding and pausing of live programs. Some come in combination with DVD or even Blu-ray drives (e.g. Panasonic) to allow you to make permanent copies of your recordings (see above).

A PVR with inbuilt digital TV tuner acts as a digital TV set-top box and allows you to record the programs at the same time. It records the digital signal directly before it is converted into analogue for output to standard TV and will therefore provide better quality of digital TV recording than DVD recorders without digital tuners. You should at least have two internal tuners (some have more) to be able to watch one program while recording another (or more). They are available in the Sky+HD box, numerous Freeview versions and digital cable versions.

The new HDTV tuners such as the sky+HD box and the HD TVDrive box from TeleWest in the UK are fully functional PVRs with sizable hard disk drives. They allow you to record and play-back HDTV programs and standard digital TV at high quality. If you have been thinking of joining Sky Digital anyway, you can now get a free sky+ box or sky+HD box when you subscribe to the relevant package online.

Blu-ray players and recorders

The Blu-ray discs used in blu-ray players are optical storage media similar to DVDs (4.7 GB) but with much higher storage capacities (up to 50 GB) and can accommodate the larger data requirements of HD videos and PlayStation video games. This is achieved by using blue-violet laser to read and write data. The shorter wavelength of those lasers allows for almost 10 times more data storage than on DVDs.

The players and recorders are geared towards high definition television with HDMI connection, etc. Blu-ray is also used in some of the new games consoles such as PlayStation 3. Read more about Blu-ray players ...