Sony RDR-GX7 User Manual

What's DVD Recording?

DVD-Video is now the standard. Writable DVD is next.

Worldwide DVD player market

<K>

Units sold

100,000

75,000

50,000

25,000

1997

1998 1999 2000 2001 2002

Since its introduction in 1996, DVD-Video fast became the new world
standard for movie and concert video enjoyment, with extremely high quality
picture and sound reproduction. Not only have DVD players become
commonplace, DVD drives are increasingly employed in computers, game
devices and other electronic equipment. DVD is truly a versatile new storage
medium across a wide spectrum of applications.

Naturally, the time has come for writable DVD. High picture and sound
quality combine with many versatile playback functions to make this the
media of choice. The dream of high-quality digital disc recording in the
home, not only for audio/video entertainment, but also for computer storage, has
now become a reality as a media suitable for the era of broadband
communications.

The total number of DVD playback units, including PCs and game equipment with
DVD drives, is expected to increase greatly in the near future.

There are several different writable DVD format
specifications. Let’s take a look at the common features
and differences of each.

Writable DVD comes in several different formats.

Physical format Logical format

Write-once

Rewritable

Writable DVD formats are a combination of physical and logical formats.

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DVD Compatible type

Video Recording (VR)

type

Digital recording with
high image and sound quality.

Compact with
very large data capacity.

Random access for
superior operation.

Laser pickup for high-quality playback,
time after time, with no disc wear.

Writable DVD has these superior features.

Storage and playback of digitally recorded video
and audio with superior image and sound quality.

Up to 4.7 GB of data can be recorded on a CD-sized 12 cm optical disc.
Quick random access to image and sound without the need for cueing or rewinding.

Non-contact optical reading system is impervious to wear during repeated playback,
and is highly resistant to the effects of dirt and scratches, for superior storage characteristics.

Writable DVD

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Common features of

Compression in field unites.
(The image is digitalized in
field units and compressed.)

Compression on time axis.
(The imaage is compressed by
determining the volume of movement.)

Compressed to

1/40th, on average.

Data volume

Time axis

Impossible

Average
transmission rate

Waste

Average
transmission rate

Variable
compression bit rate

Fixed
compression bit rate

The rate of compression is
varied depending upon data
volume to increase efficiency.

When the transmission rate is fixed,
signal transmission is inefficient,
and portions which cannot be transmitted
result in deterioration of playback quality.

writable DVD

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Just like DVD-Video, writable DVD digitally
records video using the MPEG-2 format,

Digital recording of both image and sound.

video recording

and digitally records audio using Dolby
Digital and other formats. This assures
extremely high quality video and audio
recording, while also ensuring playback
compatibility on conventional DVD players.

How MPEG-2 video compression works

MPEG-2

The primary digital recording formats
used in writable DVD

audio recording

Dolby Digital
Linear PCM
MPEG audio

Fixed bit rate compression & variable bit rate compression

High quality digital recording of
audio and video

MPEG-2 is a highly efficient and effective technology for the compression of video signals at
variable rates. The areas of movement in each scene are determined, and for areas where
there is no change, the volume of data representing those areas can be greatly reduced.

Writable DVD can be recorded at not only fixed transmission rates, but also at variable
transmission rates which enable high image quality recording of complex video images at the
same average transmission rate.

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