Thursday, August 19, 2010

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 olderNTSC 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 1080iresolution. 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.

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