ecorder) A device that records video from up to a dozen or more surveillance cameras onto a hard disk. The frame rate can be switched from real time to time lapse in order to save storage space. Digital recorders are more flexible than earlier analog VHS tape systems, and the video can be easily transmitted over a computer network. See CCTV
ecorder) Also known as a "personal video recorder" (PVR) or "hard disk recorder," a DVR is a consumer device that allows the viewer to pause and rewind any broadcast, cable or satellite TV program as well as record and play back selected programs (see live pause
). An order of magnitude more flexible than earlier videocassette tape recorders (VCRs), an entire season of programs from one or more favorite series can be recorded.
DVRs may be built into the set-top box or replace the box using plug-in modules (see CableCARD
). They store incoming digital TV signals on the hard disk as well as digitize analog TV into the MPEG-2 format. The video may be compressed to maximize storage space.
Part of the Service or Stand-Alone
The DVR periodically downloads channel program guide updates as well as software updates for the unit itself. When the DVR is integrated into the cable or satellite set-top box, the downloads ride the same medium as the TV service. When the DVR is stand-alone, the downloads come in via the home network.
Before the Turn of the Century
DVRs first came on the market in 1999 with products from ReplayTV and TiVo (www.tivo.com). They quickly made the VCR obsolete for timeshifting TV programs, and Tivo became the DVR leader. ReplayTV was later acquired by SONICblue, D&M Holdings and eventually the DirecTV satellite TV service (www.directv.com). See cloud DVR
, multi-room DVR sharing
, live pause
, DVD recorder
and networked DVR
. Contrast with NVR
This earlier DVR from ReplayTV appears in front of the Find Shows screen, which enables a viewer to search for programming throughout the week by keyword. (Image courtesy of ReplayTV.)