1.14 Can DVD record from VCR/TV/etc?
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This article is from the DVD Formats FAQ, by jtfrog@usa.net (Jim Taylor) with numerous contributions by others.
1.14 Can DVD record from VCR/TV/etc?
Short Answer: Not yet, but soon. Pioneer and Philips have announced DVD
home video recorders. (See 4.3.)
Long answer: Recording analog video to DVD is a very tricky process. The
minimum requirement for reproducing audio and video on DVD is an MPEG video
stream and a PCM audio track. (Other streams such as Dolby Digital audio,
MPEG audio, and subpicture are not necessary for the simplest case.) Basic
DVD control codes are also needed. It's difficult in real time to encode
the video and audio, combine them with DVD-Video info, and write the whole
thing to a recordable DVD disc, especially in a form that's compatible with
standard DVD-Video players. This is still extremely expensive for a home
recorder, even though prices for DVD production systems have dropped over
the space of three years from millions of dollars to thousands of dollars
to hundreds of dollars for the simplest packages.
Other obstacles: Price of blank discs initially will be $30 and up.
Real-time compression requires higher bit rates for decent quality,
lowering capacity. MPEG-2 compression works much better with high-quality
source, so recording from VHS or broadcast/cable may not give very good
results (unless the DVD recorder has special prefilters, which increases
the cost).
Don't be confused by DVD-R drives, DVD-RAM drives, or other recordable
variations of DVD (see 4.3). These existing recorders can store data, but
to create full-featured DVD-Videos requires additional hardware and
software to do video encoding (MPEG), audio encoding (Dolby Digital, MPEG,
or PCM), subpicture encoding (run-length-compressed bitmaps), still frame
encoding (MPEG), navigation and control data generation, and multiplexing.
In spite of all the difficulties, many of the major DVD manufacturers are
working on recordable DVD for the home. We will see various DVD video
recorders in the year 2000. Early units, especially those that can record
from analog video sources such as TV, will be expensive: probably $2,000
and up. There will also be cheaper units that can record only from a source
of already-compressed digital audio and video, such as satellite, DTV, or
digital cable. At some point, DVD recorder/players will be built into
satellite and cable receivers.
Some people believe that recordable DVD-Video will never be practical for
consumers to record TV shows or home videos, since digital tape is more
cost effective. On the other hand, digital tape lacks many of the
advantages of DVD such as seamless branching, instant rewind/fast forward,
instant search, and durability, not to mention the coolness of small shiny
discs. Once the encoding technology is fast and cheap enough, and blank
discs are cheap enough, recordable DVD will reach the mainstream.
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