Sony RDR-GX7 Manual

What's DVD Recording?

DVD-Video is now the standard. Writable DVD is next.
2
Worldwide DVD player market
< K > Units sold
100,000
75,000
50,000
25,000
1997 1998 1999 2000 2001 2002
Writable DVD comes in several different formats.
There are several different writable DVD format
specifications. Let’s take a look at the common features
and differences of each.
Writable DVD formats are a combination of physical and logical formats.
Physical format Logical format
Rewritable
Write-once
DVD Compatible type
Video Recording (VR) type
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.

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.
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.
Quick random access to image and sound without the need for cueing or rewinding.
Up to 4.7 GB of data can be recorded on a CD-sized 12 cm optical disc.
Writable DVD
3

video recording
High quality digital recording of
audio and video
MPEG-2
audio recording
Dolby Digital
Linear PCM
MPEG audio
The primary digital recording formats
used in writable DVD
Just like DVD-Video, writable DVD digitally
records video using the MPEG-2 format,
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.
Digital recording of both image and sound.
Common features of
writable DVD
4
How MPEG-2 video compression works
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.
Fixed bit rate compression & variable bit rate compression
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.
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.
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4.7GB
4.7GB
Image quality
Image quality vs. recording time
10 Mbps
6 Mbps
4 Mbps
2 hours 3 hours 6 hours1 hour
Recording time
High Quality Picture and Sound Recording
2-channel audio
Video
2 hour recording
Linear PCM audio
5.2 Mbps
transmission
rate
Even if the total transmission rates and recording times are the same,
emphasis can be placed on either high sound quality or high picture quality
depending upon the allocation ratio of the audio and video signal portions.
3.554 Mbps
video transmission
rate
1.536 Mbps
audio transmission
rate
2-channel audio
Video
2 hour recording
Dolby Digital audio
4.994 Mbps
video transmission
rate
0.256 Mbps
audio transmission
rate
(bps = bits per second)
Compact optical disc with large data capacity.
The relationship between image quality and recording time.
Recording time on a given disc varies
according to the data transmission rate. If the
rate is high, image quality is better, but
recording time is shorter. If the rate is lowered,
recording time is longer, but at the expense of
image quality. Moreover, even with the same
recording time, image quality can change
depending upon the format for audio recording.
4.7GB per DVD
CD 7
DVD VHS tape
12 cm discs are easy to handle, easy to store.
DVDs are the same size as CDs, just 12 cm and only 1.2 mm thick. Even
a large video collection takes up very little space. Plus, they're easy to
carry and send.
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A DVD in its case is still 1/3 the volume of a VHS tape.
Note: There is also a format specification for an 8 cm DVD which holds 1.46 GB of data.
By varying the transmission
rate, priority can be placed
either on image quality or
on longer recording time.
Common features of
writable DVD 2
A DVD holds seven times as much data as a CD.
One side of a DVD can hold up to 4.7 GB, about seven times a CD
holds. This high data capacity enables longer recording of video
and audio.

Random access for versatile operation
Versatile recording and playback with high reliability.
Confirm recorded content using the menu
function to quickly access and play any
desired sequence.
No need to cue to find blank disc space.
Just press the REC button to start recording on
the remaining blank area. It's quick and easy.
Superior storage characteristics
Since the signal is read by non-contact laser
pickup, there is no wear, even after repeated
playback or cueing operations.
No stretching or print-through as with tape,
just high quality images and sound, always.
Since it is digital, powerful error correction
systems can be used to assure greater
resistance against dirt and scratches for
highly reliable playback.
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Title 1
First recording
Chapter 1 Chapter 2 Chapter 3 Chapter 1 Chapter 1Chapter 2
Title 2
Second recording
Titles and Chapters in Writable DVD
In DVD, content is organized by titles and chapters. In read-only
DVD-Video software, one movie is generally considered one
title, and within the title there are several chapters which can be
accessed through the menu. In writable DVD, one recording is
saved as one title, and within that title different chapters can be
specified. Using this chapter and title data, various playback and
editing functions can be performed from the menu.
Common features of
writable DVD 3

Write-once DVDs can only be recorded once, like photographic film. Rewritable DVDs can be recorded and re-recorded many times, like tape.
Each type has its own advantages, and is chosen depending upon the type of use.
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There are write-once and rewritable DVDs
Write-once
DVD-RW, DVD+RW
DVD-R and DVD+R are "write once" discs,
meaning they can only be recorded once. Since phase change is not permanent, DVD-RW, DVD+RW and DVD-RAM allow data to be written and rewritten over and over.
Merit
There is no danger or mistakenly erasing or
recording over the recorded content.
Rewritable
DVD-R, DVD+R
This type is used for DVD-video
and other playback uses. Data is
represented by the presence or
absence of a pit in the pit lanes
pressed on the disc.
Pit
Read-only
DVD-RAM
DVD-ROM
Organic dye
(groove
recording)
Track pitch: 0.74 microns
Phase
change
material
(groove
recording)
Phase
change
material
(land &
groove
recording)
What is the difference between
DVD-R and DVD+R?
While DVD-R and DVD+R both have the
same basic construction as DVD-ROM,
there are differences in their rotational
control systems and data recording
positions.
What are the differences between DVD-RW,
DVD+RW and DVD-RAM?
While DVD-RW and DVD+RW both have the same basic construction and
performance of DVD-ROM, there are differences in the way their disc
rotational control systems and data recording positions are configured.
DVD-RAM uses a special land and groove recording configuration and
specification which enables data to be rewritten up to 100,000 times,
compared to 1,000 times for DVD-RW and DVD+RW.
Merit
The same disc can be used over and over.
Unwanted sections of the disc can be erased and
rewritten.
Track pitch: 0.74 microns Track pitch: 0.615 microns
Differences in
writable DVD 1
Track pitch: 0.74 microns
Physical format
grooveland

3
During DVD recording, a powerful laser beam, stronger than that used for playback,
heats up the recording material, changing it to represent the data. Write-once DVDs use
chemical change, while rewritableDVDs make use of phase change.
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How Write-once and Rewritable DVDs work.
During recording, a powerful laser beam is focused on the organic dye
recording material, and the heat from the laser changes the chemical
structure of the dye. During playback, the playback laser can sense which
parts of the dye have been changed by heat and which haven’t. Through this
process the [0] and [1] of a digital signal can be represented. However,
changes in the dye structure are permanent, so the disc cannot be rewritten.
In write-once recording,
the organic dye is chemically changed.
Recording material layer
Reflective layer
Playback Recording
Playback of an area
heated by the laser
Laser
Playback of an area
not heated by the laser
Laser pickup Required laser output during
recording and playback
Recording time
Playback
The recording material used is in crystalline form before recording.
When it is heated by the powerful laser, it becomes amorphous and
loses its crystalline structure. However, weaker laser light can be used to
slowly heat it to return it to its original crystalline form. In this way, the disc
can be rewritten over and over.
In rewritable recording,
the phase of the recording material is changed.
Recording time
Recording material layer
(Reflective layer)
Playback Recording Erasing
Amorphous structure Crystalline structure
Laser
Laser pickup Required laser output during
recording and playback
Amorphous and crystalline
structures have different
reflective ratios, so the [0] and
[1] of Through this process
the [0] and [1] of a digital signal
can be represented.
Differences in
writable DVD 11

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Different recording methods are used.
DVD recording methods can basically be divided into two categories, those which place emphasis on
playback equipment compatibility, and those which enable more operation functions. Here, these are
referred to as the DVD compatible type and the Video Recording (VR) type. The DVD compatible type is for
recording DVDs which can be played on DVD-Video players, while the VR type is for taking advantage of
numerous operation functions, playing DVDs primarily with the equipment on which they were recorded.
The DVD-Compatible type has superior playback compatibility.
Discs recorded as the DVD compatible type can be
played on any conventional DVD player. Data is
recorded from the center of the disc outwards.
Recordings made can be played on other players,
and can be given to friends and associates.
Discs which are the DVD Compatible type.
Discs for DVD-R, DVD+R, DVD-RW, DVD+RW all are the DVD Compatible type.
DVD Compatible type discs for DVD+RW have basic editing functions.
What is finalization?
This is a form of final-stage processing that enables the data recorded by writable and
rewritable formats to be played on a conventional DVD-Video player. During finalization, the
menu screen used to operate the convenient playback functions is also created.
DVD Compatible type
Can be played on most DVD-Video players
Basic recording and playback functions can be used. Can only be played on compatible players
Editing and other advanced functions can be used.
Video Recording (VR) type
Differences in
writable DVD Logical format
Logical format-1
2
Differences in
writable DVD 2

The Video Recording (VR) type has many unique functions.
Unwanted scene
The original recording can be changed,
and unwanted scenes can be erased.
Original video recording
The original recording
after editing
AB C
ABC
Editing functions such as erasing scenes in an original video recording can
be performed on the disc itself. Erased scenes can be replaced with
new scenes. In addition, the disc can be “write protected” to prevent
editing and erasing of scenes.
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The VR type is used for DVD-RW and DVD-RAM. The discs can only be played on compatible players,
but they feature quite a number of unique editing functions.
It is possible to record broadcasts which have been specified as “copy once.”
VR type has copy protection system on recording and it is possible to record
not only "copy free" broadcasts but also "copy once" broadcasts which allow recording only once.
Broadcasts with multiplex soundtracks may be recorded.
Stereo and bilingual soundtracks on broadcasts may be recorded, with selection of main,
sub or main + sub (stereo) possible during playback.
The original recording remains as it is.
Playback order can be changed by selecting a pre-set playlist.
Original
Playlist 1 Playlist 2
Creating a playlist and editing
ABC D
DAB DBC
The original video recording can be left as it is, and in place of erasing
scenes and changing the order, a playlist can be created to enable “virtual
editing”for different playback order. Best of all, this does not reduce the
amount of available recording time on the disc.
Recorded video scenes can be edited on the disc itself. Virtual editing is possible by making a playlist
Differences in
writable DVD 2
Note1: Although this information is based on format specifications, there may be cases when playback is not possible on actual equipment purchased.
Note2: Broadcasting stations can add copy generation control signal to programs to protect the rights of copyright holders of the contents.
Recording of "copy once" programs is limited to only once, and "copy never" program is not allowed to be recorded, though "copy free" programs can be recorded over multiple generation.
Logical format-2

Types of Discs and Compatible DVD Players.
There are cases where a recorded DVD disc can not be played back on certain DVD players due to differences in disc type
and recording format. Compatibility by disc type, recording format and type of player is indicated below.
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DVD player
Players which can play back
DVD-RW discs recorded asVR type.
DVD-RW / VR compatible players
Players which can read the recorded
signal on a DVD-RAM disc.
DVD-RAM compatible players
DVD-RW DVD+RW DVD-RAM
DVD-R DVD+R
DVD
compatible
(VR format)
(DVD-Video
format)
Notes:
1. Although this information is based on format specifications for playback and recording formats, there may be cases when playback is not possible on actual equipment purchased.
2.There may be cases where playback is not possible on DVD drives on personal computers or game equipment due to differences in drive type or recording format of the software.
VR (VR format) VR
DVD
compatible
(Video format)
DVD
compatible
(DVD-Video/Video
format)

writable DVD
analog tape
repeated playback
repeated playback
Writable DVD Expands Your Personal Entertainment World.
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Writable DVD represents a quantum leap from the world of analog video tape. It can be used to record and store not only
broadcast programming, but also personally created movie and still video images. Recorded discs can be played back on
a DVD player, a personal computer or even game equipment for an unprecedented level of entertainment versatility.
Writable DVD
DV
Oh, let's see
that part again...
DVD
Recording
Put your video tape collection on
digital DVD for a disc library
you can enjoy over and over.
Put your own digitally recorded
movies and still photos on
Writable DVD for easier enjoyment.
High quality recording and
playback of your favorite TV programs.
Thank you.
Enjoy DVD!
Since recorded DVDs can be played on many
DVD players, car DVD systems, PCs and game
equipments around the world, they can be enjoyed
in many ways. A number of possibilities enable to
create a new style of
communication through DVDs.