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DVD FAQ
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Luna Verde
Technologies, Inc.
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DVD Frequently-Asked Questions
What is DVD?
DVD or Digital Versatile Disc is a new optical disc format with
similarities to audio CDs and CD-ROMs. It will be made available
initially in a 12cm size (the same as an audio CD) with a possible
introduction of an 8cm size at a later date. The DVD format is
supported by the majority of the largest consumer electronics
companies in the world.
What are the properties of a DVD?
DVD is unique in that it can have two layers of data on each of the
two sides of the disc. The DVD format is capable of 4.7GB (4,700
Megabytes) of storage in one layer on each side, and 8.5GB in dual
layers on each side. This gives a 12cm DVD a total capacity of 17GB
or 17,000 Megabytes, or roughly 11,800 3.5" floppy disks.
The dual layer capability is accomplished by using a special optical
pickup device that can focus on either of the two layers of data
bonded to the substrate. The top layer of data is sufficiently
transparent to allow access to the bottom layer by the pickup device.
How is a DVD different from a CD-ROM?
A CD-ROM is specified as a single layer, single side disc with a
maximum capacity of 650 Megabytes. It would take more than 7 CD-ROMs
to equal the capacity of one side, one layer of a DVD. When DVD takes
on dual layer dual sides one 12 cm DVD can hold the equivalent of 26
standard CD-ROMs.
What is DVD-ROM?
The DVD-ROM (Read Only Memory) is a data storage application of DVD
similar to CD-ROM but with differences in the format. The DVD
utilizes a disc format known as Micro UDF (Universal Disc Format)
Bridge. Micro UDF Bridge along with the ISO-9660 directory structure
and path table permit the DVD-ROM to act just like a CD-ROM with
vastly higher data capacity and allow cross platform compatability.
What will the DVD-ROM be used for?
Because the DVD-ROM acts just like a CD-ROM, it will used to
distribute software programs, interactive games, Digital video, data
archives (such as telephone directories), and reference works. The
enormous market for corporate training can be realized with the
storage of DVD-ROM, for an interactive full motion training experience.
What is DVD Video?
DVD Video is a significantly more complex and structured application
of DVD. The basic Micro UDF Bridge file system of the DVD points to
a Video Manager which in turn can enable selection of Video Title Sets.
Video Title Sets contain the information necessary to playback video
and its companion audio on a DVD player system.
DVD Video can utilize either MPEG-1 or MPEG-2 compressed video, and
LPCM audio, Dolby AC-3 audio, or MPEG-2 audio. The DVD Video format
allows for up to 8 discrete audio channels, 32 data channels (or
sub-pictures) that can be used for foreign language sub-titles or
other sorts of captioning. The DVD Video format also supports closed
captioning that may already exist in the master video tape.
Other unique features of DVD Video enable parental controls of content,
world region controls of playback, anti-piracy encoding, and even
selection of up to seven different camera angles of the same scene.
Multiple aspect ratios are supported including 4:3 pan/scan, letterbox
and anamorphic for the new breed of widescreen 16:9 receivers.
What will DVD Video be used for?
By far the greatest utilization of DVD Video will be for movies and
similar forms of entertainment. Because of the huge data capacity of
the DVD, a full length up to 133 minute movie can be placed on one
side/one layer of the disc allowing for uninterrupted playback.
DVD Video players emulate typical VCR functions such as fast forward,
fast reverse, still frame, frame advance and slow motion but with far
better quality.
The superb audio capabilities, particularly Dolby AC-3 5.1 and
MPEG-2 5.1, will produce a theater quality digital surround sound
experience in the home environment.
Due to the interactive and branching capability of DVD Video, training
will likely be another extensive application.
What is MPEG video?
MPEG video is a group of video compression standards sanctioned by an
organization known as the Moving Pictures Experts Group. It is a
method of reducing the amount of data required to store video in a
digital form by taking advantage of human perception of moving pictures.
It basically involves removing redundancies that occur from frame to
frame in a video sequence. Full bandwidth, uncompressed CCIR 601
digital video of the highest quality would need 21 Megabytes for
each second of video. MPEG-1 video at the nominal bit rate of 1.15
Megabits/sec. requires only 144 kilobytes of storage space. The
compression ratio is approximately 145:1.
While MPEG-1 is a reasonably good compression standard, it lacks
certain refinements that are useful for applications such as
real-time transmission of streaming video. Likewise, the standard
for MPEG-1 video does not support field rate compression or the
standard video resolution of 720x480 pixels (720x576 PAL). MPEG-1
is limited to 352x240 pixels (352x288 PAL) and frame rate encoding
only.
MPEG-2 is the true enabler of DVD Video technology even though DVD
Video also supports MPEG-1. The quality of MPEG-2 DVD is best
described as broadcast quality vs. MPEG-1's VHS quality. MPEG-2 as
specified for DVD can have Variable Bit Rates (VBR) of up to about
9.8 Megabits/sec depending on the other audio and/or sub-picture
streams that are running at the same time. The nominal MPEG-2 bit
rate is about 5Mb/sec, which produces a video picture that is
subjectively 5 times better than MPEG-1 at 1.15Mb/sec. This is
partially due to a lower compression ratio (less is thrown away)
and partially due to the higher resolution of MPEG-2 - 345,600 pixels
per frame vs. MPEG-1's 84,480 pixels per frame.
VBR allows the DVD Video "compressionist" to apply more or less
compression to picture scenes depending on the difficulty of the
scene. For instance, a scene with very little movement may require
only a 3Mb/sec rate for highest quality, whereas a scene of an auto
race might require 8Mb/sec.
What is Dolby AC-3 Audio?
Dolby AC-3 audio is a compression method that allows either stereo
sound (with embedded surround) or 5.1 which is a theater type
surround sound that, when decoded provides speaker feeds to front
left and right, front center, rear left and right and .1, which is
the sub-woofer. Dolby AC-3 is intended for use in countries that
employ the NTSC television standard. AC-3 has a sampling frequency
of 48kHz compared to 44.1khz for compact audio discs.
What is MPEG-2 Audio?
MPEG-2 Audio is similar to Dolby AC-3 audio, but is primarily
intended for use in countries that use the PAL TV standard. The
sampling frequency for MPEG-2 Audio is 48kHz.
What is LPCM audio?
Linear Pulse Code Modulation - which is the current standard for
audio CDs. LPCM is an uncompressed digital audio sampling process
that has a large appetite for storage space. Sampling frequencies
can be either 48 or 96kHz with up to eight channels on a DVD.
Alternately, LPCM could be used for a new audio "Super CD" boasting
either a larger capacity than existing audio CDs, or a quantum leap
in audio quality by utilizing the 96kHz sampling rate.
What can I play a DVD on?
A number of major electronics manufacturers including Toshiba,
Thompson, Philips, Matsushita, Sony and others have promised players
for North America by early 1997. Players have been shipping in Japan
since 4th quarter 1996. The "set-top" players will not play DVD-ROMs,
only DVD-Video.
Some computer manufacturers have also promised DVD drives and
applications for new systems available in 4st quarter 1997.
Can I upgrade my computer to play DVDs?
Yes, assuming your IBM compatible computer has a Pentium class
processor with a PCI slot, and adequate memory and a scaling display
card.
Where can I get more DVD-ROMs?
A number of companies are already producing DVD-ROM titles including
Activision, Creative Multimedia, SoftKey, Tsunami, Xiphias,
Mechadeus and Electronic Arts. DVD-ROMs should be available through
the normal CD-ROM distribution channels by October 1998.
Where can I get more DVD Videos?
DVD Videos are starting to come to market as well. Some of the
first offerings are from Warner already released in Japan and should
likewise turn up in the large North American electronic stores about
the same time as the consumer DVD Video players.
Can I play my old CD-ROMs on my new DVD enabled PC?
Yes, with one exception! All CD-ROMs are fully compatible with and
can be played on your new DVD system. Unfortunately most CD R discs
are not compatible with the new DVD drives due to a dye color
incompatibility with the new DVD lasers. This will all change when
"generation 2" drives are released in November 1997. Generation 2
drives offer faster speeds and a new laser technology to allow
reading of CD-Rs. You can also play your audio CDs on your new DVD
system with the appropriate software driver.
I am an OEM, is there a solution for my company's branded PCs?
Yes, Luna Verde Technologies manufacturers Revolution-DVD(tm)
Mpact(tm).
What is Revolution-DVD Mpact?
Revolution-DVD Mpact is a state-of-the-art DVD acceleration
technology that delivers true home theater-quality for all kinds of
DVD content. Revolution-DVD Mpact is powered by a new kind of
flexible, high-performance multimedia chip: the Mpact/3600 media
processor. Developed by Chromatic Research in partnership with
Toshiba, SGS-Thompson, and LG Semicon. Like a low-cost supercomputer
on a single chip, the Mpact media processor works together with the
PC's Pentium-class chip with MMX technology to process and display
DVD's digital audio and video.
Why is Revolution-DVD Mpact Better Than Other Solutions?
Better video quality: Revolution-DVD Mpact video is crisper,
brighter and more colorful, without the jerky motion and digital
"artifacts" of lower quality solutions.
Better audio: Audio is more realistic and immersive. Using SRS
TruSurround(tm), Revolution-DVD Mpact can deliver realistic Dolby
Digital surround sound from just two speakers. Or, Revolution-DVD
Mpact can connect to Dolby Digital and ProLogic receivers for true
6-speaker digital surround sound.
Cost-effective: The unique architecture of the Mpact media processor
delivers more bang for the buck than other multimedia acceleration
technologies, delivering the highest-quality DVD at an affordable
cost.
Upgradable: Revolution-DVD Mpact is software-upgradable, making it
possible to add new DVD features through simple software downloads
in the future.
How does Revolution-DVD Mpact improve quality?
Unlike many PC DVD solutions which take many shortcuts due to lack
of available processing power, Revolution-DVD Mpact is a
no-compromises, no-shortcuts solution for all the video and audio
requirements of DVD.
In addition, Mpact technology has horsepower to spare to go beyond
the DVD specification and add features that enhance the user's DVD
experience. For example, Mpact Chromabright and Chromadjust
technologies - real-time digital brightness and color adjustment -
overcome previous limitations of computer monitors to ensure the
best, brightest, most colorful picture quality possible.
Revolution-DVD Mpact, via Avsync Technology, is the only DVD
solution to guarantee exact synchronization of audio and video,
regardless of the number and type of other PC functions running
simultaneously with movie playback.
What makes Mpact technology so powerful?
First, Mpact technology is powered by the Mpact Media Processor, a
breakthrough in chip design that allows a single chip to execute
many multimedia tasks simultaneously. For example, the Mpact/3600
contains 4.50 "arithmetic logic units" (each like a little processor)
that work together to multitask at 3.6 billion operations/second,
performing 48 different tasks at every tick of the processor's
internal clock. This multitasking approach is a more efficient use
of silicon than traditional chips, giving the Mpact media processor
unprecedented multimedia processing power per dollar.
Second, Mpact technology taps into the ever-growing power of the PC's
own X86/MMX CPU.
This unique approach gives Mpact technology the extraordinary ability
to simultaneously manage combinations of full motion video, 3D and 2D
graphics, digital audio, video conferencing, video editing, fax/modem
and more on a single chip, with better performance and at a lower cost
than combinations of traditional multimedia chips.
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Copyright © 1998 Luna Verde Technologies, Inc.