DVD recorder

China Product


Technical information

Originally, DVD recorders supported one of three standards: DVD-RAM, DVD-RW (using DVD-VR), and DVD+RW (using DVD+VR), none of which are directly compatible. As a general rule, however, most current drives support both the + and - standards, while few support the DVD-RAM standard, which is not directly compatible with standard DVD readers.

Recording speed is generally denoted in values of X (similar to CD-ROM usage), where 1X in DVD usage is equal to 1.321 MB/s, roughly equivalent to a 9X CD-ROM. In practice, this is largely confined to computer-based DVD recorders, since standalone units generally record in real time, that is, 1X speed. fetal doppler

DVD recorders use a laser (usually 650 nm red) to read and write DVDs. The reading laser is usually not stronger than 5 mW, while the writing laser is considerably more powerful. The faster the writing speed is rated, the stronger the laser is. DVD burner lasers often peak at about 100-400 mW in continuous wave (some are pulsed). Some laser hobbyists have discovered ways to extract the laser diode from DVD burners and modify them to create laser apparatus that can cause burning. heartbeat monitor

Computer-based DVD drives test glucose meter

Further information: Optical disc drive

DVD recorder drives have become standard equipment in many, though not all, computer systems currently on the market, after being initially popularized by the Pioneer/Apple SuperDrive; aftermarket drives as of early 2007 can cost as little as $23 . DVD recorder drives can be used in conjunction with DVD authoring software to create DVDs near or equal to commercial quality, and are also widely used for data backup and exchange. As a general rule, computer-based DVD recorders can also handle CD-R and CD-RW media; in fact, a number of standalone DVD recorders actually use drives designed for computers.

Most internal drives are designed with parallel ATA interfaces, with serial ATA becoming more readily available. External drives almost always use USB 2.0 or IEEE 1394, with eSATA becoming an option as well.

DVD recorder drives are required[by whom?]to respect DVD region codes when reading a disc, but do not impose a region code on written discs unless the code has specifically been written into the disc's content.

DVD duplication systems are generally built out of stacks of these drives, connected through a computer-based backplane.

Standalone DVD recorders

When the standalone DVD recorder first appeared on the Japanese consumer market in 1999, these early units were very expensive, costing between $2500 and $4000 USD. However, as of early 2007, DVD recorders from notable brands are selling for US$200 or 150 and less, with even lower "street prices". Early units supported only DVD-RAM and DVD-R discs, but the more recent units can record to all major formats DVD-R, DVD-RW, DVD+R, DVD+RW, DVD-R DL and DVD+R DL. Some models now include mechanical hard disk drive-based digital video recorders (DVRs) to improve ease of use. Standalone DVD recorders generally have basic DVD authoring software built in; however, the appearance of the finished DVD is very basic and usually completely under the control of the unit.

Some believed that DVD recorders would supersede the VCR as the standard television-recording device; however as technology progresses, Panasonic introduced the world's first Blu-ray disc recorder which is capable of recording both DVDs and Blu-ray discs.

DVD recorders have several technical advantages over VCRs, including:

Superior video and audio quality

Easy-to-handle smaller form-factor disc media, and more durable than magnetic tape.

Random access to video chapters without rewinding or fast-forwarding (serial access)

Onscreen multilingual subtitles and labeling not available on VCRs

Reduced playback wear and tear

High-quality digital copying, with little or no generation loss

Improved editing, at least on rewritable media

Playlisting

No risk of accidentally recording over existing content or unexpectedly running out of space during recording

Easy to find recordings due to chapter menus

It does have some disadvantages

Slow initial access/load times due to the optical nature of the disc

Limited rewritability on DVDRW(+RW) discs (typically around 1000). DVD-RAM is better suited for high frequency re-recording (around 100,000 rewrites)

Relatively short life of the laser diodes (average of about 2 years depending on usage).

However, an inconvenience exists in which DVDs recorded with DVD recorders must be finalized to view in other DVD players. (This disadvantage does not apply to DVD-RAM or DVD+RW discs, which require no finalization due to their 'random access' nature.) Also, the implementation of MPEG-2 compression used on most standalone DVD recorders is required to compress the picture data in real time, producing results that may not be up to the standard of professionally rendered DVD video, which can take days to compress.

The United States is converting its over-the-air television broadcasts to digital "ATSC" in June 2009, however this will have very limited impact in ending the need for DVD recorders to perform realtime MPEG-2 encoding or transcoding. The only setup where ATSC could conceivably eliminate MPEG-2 encoding/transcoding in a DVD recorder would be where an antenna is hooked directly into a DVD recorder that has an integrated ATSC tuner. Even then however, the DVD recorder will have to transcode the ATSC MPEG-2 into DVD-Video-legal MPEG-2 if the ATSC MPEG-2 stream isn't already DVD-Video-compatible. This would require transcoding for all high-definition broadcasts and some if not all standard-definition broadcasts. The same general situation applies to digital cable service; only DVD recorders with integrated digital cable ("QAM") tuners can possibly avoid transcoding, and then only if the digital cable system is already sending a DVD-Video-compatible MPEG-2 stream, which again requires transcoding of all HD content and some if not all SD content. All other setups (digital cable box's analog outputs to DVD recorder, satellite box's analog outputs to DVD recorder, DVD recorder tuning and recording analog cable channels which are still permitted after 2/2009, etc.) usually always involve an analog step with MPEG-2 encoding being necessary inside the DVD recorder.

A number of manufacturers have combined DVD recorders with mechanical hard disk drive-based digital video recorders, allowing for recording to large fixed disks, and the ability to view these recordings off the hard disk at a later date.

In Japan, AVCREC recorders, which are able to record MPEG-2 or AVC high definition video from ISDB broadcast with or without re-encoding, get increasingly popular. Initially, AVCREC recorders use DVD recordable discs, but newer models are able to record onto Blu-ray discs as well onto hard disk drives.

ATSC standalone DVD recorders

As a result of the North American digital switchover, tuner-equipped devices manufactured or imported into the United States are now required by the US Federal Communications Commission to include digital tuners.

This has caused most new VHS recorders to be implemented as DVD/VCR combo units, or to be manufactured without tuners. The US requirement of ATSC compatibility forces inclusion of MPEG-2 decoding hardware, which is already part of all DVD players but which otherwise would not have been needed in an analog-only VCR.

An ATSC-capable DVD unit can also serve as a more-powerful alternative to digital television adapters, which allow DTV reception with older NTSC analog televisions. The DVD recorders offer additional capabilities, such as automated VCR-style timeshifting of programming and a variety of output formats, that are deliberately not included in the most common mass-market US ATSC converters.

Unlike the more common digital television adapter boxes, newer DVD recorder units are able to tune both analog and digital signals - an advantage when receiving low-power television and foreign (analogue) signals. Some, however, do suffer from many of the same design limitations as the less costly converter boxes, including poorly-designed signal strength meters, incomplete display of broadcast program information, incompatibility with antenna rotators or CEA-909 smart antennas and inability to add digital channels without wiping out all existing channels and rescanning the entire band.

A DVD recording of an over-the-air HDTV broadcast is at DVD resolution, which is inferior to the original broadcast with 720p or 1080i resolution. Some units also provide limited USB or flash memory interface capability, often only supporting viewing of digital camera still photos or playback of MP3s with no ability to write video to these media.

A small number of DVD recorders are also capable of recording to SVCD, VCD and even Audio CD formats. Recording to DVDs can be done at different speeds giving between 1 and 6 hours on a standard (single sided 12 cm) blank DVD. With some trade off between recording time and video quality.

MiniDVD recorders

8 cm miniDVDs are widely used on some digital camcorders, primarily those meant for a consumer market ("point and shoot"); such discs are usually playable on a full-sized DVD player, but may not record on a full-sized DVD recorder system. Though popular for their convenience (in the manner of VHS-C), DVD camcorders are not considered suitable for more than casual use due to the much higher level of compression used compared to MiniDV and the difficulty of editing MPEG-2 video.

See also

Digital video

Digital video recorder (DVR)

DVD

Optical disc recorder

Videocassette recorder (VCR, video recorder)

Video scaler "Upconverting"

References

^ FCC - DTV enforcement

^ "LITE-ON Black 52X CD-R 32X CD-RW 52X CD-ROM ATAPI/E-IDE CD Burner - CD / DVD Burners". Newegg.com. http://www.newegg.com/Product/Product.aspx?Item=N82E16827106085. Retrieved 2009-11-15. 

v  d  e

Digital television in North America

Digital television

Terrestrial

Digital broadcasting

ATSC tuners  Digital subchannels  Virtual channels  Distributed transmission system  Datacasting (Guide Plus  National Datacast  UpdateLogic)  Metropolitan Television Alliance  Grand Alliance

Digital switchover

All-Channel Receiver Act  SAFER Act  Digital channel election  Set-top boxes  Digital television adapter  U.S. Converter Box Coupon Program (boxes, legislation)  Analog passthrough  DVD recorders  Digital video recorders

Digital standards

ATSC Standards (ATSC  ATSC-M/H  8VSB  A-VSB  E-VSB  PSIP  PMCP  full list)  Standard-definition TV (480i  576i)  Enhanced-definition TV (480p  576p)  High-definition TV (720p  1080i  1080p)  Serial digital interface  Smart antennas (CEA-909)

Digital networks

see Template:American broadcast television

National deployment

List by country  Canada   Mexico   United Kingdom   United States (HDTV  transition  wireless spectrum auction)

Cable

Digital cable

Digital-cable-ready TV (QAM tuners)  Interactive-digital-cable-ready TV (OpenCable Application Platform  Advanced Common Application Platform)  Must-carry  Tru2way

Subscription TV

Encryption  CableCARD  Downloadable Conditional Access System

Satellite TV

DVB-S (Dish Network  GlobeCast World TV  Free-to-air receiver  Bell TV)  DigiCipher 2 (4DTV  Shaw Direct)  Digital Satellite Service/DVB-S2 (DirecTV)

Technical issues

14:9  Active Format Description  Broadcast flag  Channel protection ratios  HDTV blur  Hierarchical modulation  Pirate decryption  Standards conversion  Video on demand

Categories: RecordersHidden categories: Articles lacking sources from June 2009 | All articles lacking sources | All articles with specifically-marked weasel-worded phrases | Articles with specifically-marked weasel-worded phrases from March 2009 | Articles needing cleanup from June 2009 | All pages needing cleanup