Direct-to-disk recording (DDR) refers to methods by which analog signals and digital signals such as digital audio and digital video are digitally recorded to optical disc recording technologies such as DVDs, and CD optical discs. Magnetic storage includes hard drives (HDD), magnetic tape such as videotape and is different from flash memory.
Generally these devices have the ability to convert analog signals into computer files.
Direct to disk can involve permanent or semi-permanent non-volatile memory recording media. Computer hard disk drives are random access, erasable and rewritable non-volatile recording devices but have been referred to as "permanent" by some manufacturers of direct to disk systems.
In 1982, New England Digital offered an optional hard disk recorder package for their Synclavier which allowed digital recording of monophonic 16-bit 50 kHz audio direct to a hard drive; this was the first digital direct to disk audio recorder available commercially. Stereo audio was not immediately available due to data input and output limitations on hard drives of that time.
Today, a majority of digital audio recording is preserved on hard disk drives.
Types:
Consumer: From camcorders to digital video recorder (DVR) and set top box models like TiVo to personal computer based recorders.
High-end consumer – Pro: non-linear editing (NLE) systems like Avid Technology video editing systems, to high-end tapeless camcorders
Professional portable: For recording television productions/filmmaking in the field with professional video cameras in digital cinematography for digital cinema productions.
Professional television studio: From small systems able to record 2 hours to Large multi port playout systems with a 100 hours of rec/play time
Miniaturization of recording and storage technology for consumer video already allows the non-professional user to directly record home movies to a permanent storage medium like DVD.
DDRs are slowly replacing Consumer: Magnetic tape based DV, Digital8, 8mm Video Format, VHS and MicroMV video tape recorders.
Professional recording equipment using DtD transfers is beginning to appear. In April 2006, Seagate announced the first professional Direct-To-Disc cinematic camera aimed at the independent filmmaker (using their disc drives).
Infinity Series by Grass Valley
Infinity Digital Media Camcorder – Infinity Digital Media Recorder
REV PRO Digital Media Drive-REV PRO Removable Media
Professional television studio DDRs video servers are being used to replace video tape recorders (VTR)s and VTR Cart machines, that playout television commercials and TV shows. Digital audio workstations (DAW) are used in professional audio recording studios
AJA Video Systems' Ki Pro family of direct-to-disk (solid-state disk/HDD/Compact Flash) professional DVRs (http://www.aja.com/en/family/ki-pro)
Blackmagic Design's HyperDeck Studio line of professional SSD DVRs (http://www.blackmagic-design.com/products/hyperdeckstudio)
The Media Pool (1994)- Disk Recorder by Broadcast Television Systems Inc. (BTS) was the first Professional Studio DDR. Received the Outstanding Achievement in Technical/Engineering Development Awards from National Academy Of Television Arts And Sciences in 2000–2001 for Pioneering developments in shared video-data storage systems for use in television video servers - Philips/Thomson.
Profile from Tektronix Models: PDR200-(1996), PDR300, PDR400
Quantel:
sQ Class of Servers and sQ Clients
Grande Vitesse Systems (GVS):
Profile GVS9000 2XU Pro, GVS9000 1XU Pro, GVS90000 7XU and other models of DDRs
Nomadic 1U 12xPro 24 hrs Uncompressed 10-bit 1080p Media Storage
Metropolis Media Servers
9000CTR Dual Uncompressed HD Controller
Grass Valley:
Profile PVS3000, PVS3500 and other models of DDRs
K2 Media Servers and Media Clients
Profile XP Video Servers
Profile XP Open SAN System
M-Series intelligent video digital recorder (iVDR)
Turbo intelligent digital disk recorders (iDDRs)
Rave/SpectSoft
RaveHD
Rave2K
Digitale Videosysteme (DVS):
DVS Clipster DDR
DVS 2K Pronto DDR
CarbonHD digital disk recorder
The Digital video is stored on a storage area network (SAN) hard disk array.
Each year hard disk storage capacity gets larger and is able to hold hours of movies on Tera Byte systems.
Quicker into the non-linear editing systems: no need to digitise
The hard disks can store more than most video tapes
Tapes and VTRs are expensive to maintain for the higher video data rates
Hard disks are more expensive than video tapes
Hard disks fail more frequently than video tapes
Not practical to store a bank of hard drives for long term video storage.
