DVR with built-in DVD recorder.
A DVD recorder is an optical disc recorder that records video onto blank writable DVD media. Such devices are available as either installable drives for computers or as standalone components for use in studios or home theater systems. Currently in the U.S. DVD recorders are undergoing a transformation, adding a digital ATSC tuner if it has a tuner as mandated by the FCC.
Technical information
Originally, DVD recorders supported one of three standards: DVD-RAM, DVD-RW, and DVD+RW, 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 an issue confined to computer-based DVD recorders, since standalone units generally record in real time, that is, 1X speed.
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. [1]
Computer-based DVD drives
- 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 [2]. 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.
DVD recorder drives are required 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, and DVD+R DL. Some models now include hard disk-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, with the rise of DVR's and competing media formats like Blu-ray, the DVD recorder's future seems limited.
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
- 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
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.
A number of manufacturers have combined DVD recorders with hard disk-based digital video recorders, allowing for simple recording to large fixed disks, and the ability to spool these recordings off the DVD at a later date.
8cm 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
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