DVD Demystified

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Recording Standards in September 1998. It was essentially a combination
of the Chinese government’s original SVCD proposal, the HQ-VCD proposal
from the developers of the original Video CD (Philips, JVC, Sony, and Matsushita),
and C-Cube’s China Video CD (CVD) format. Although the final
SVCD format borrowed from the CVD format, they were incompatible.
Since C-Cube had a head start and widespread manufacturer support,
which threatened the new standard, a new specification called Chao-Ji
VCD (the Chinese equivalent of super) was quickly produced, requiring support
for both formats. Almost all SVCD players are actually Chao-Ji players,
although most discs are now produced in the more capable SVCD
format. SVCD was later standardized as IEC-62107.
In terms of video and audio quality, SVCD is in between Video CD and
DVD, using a 2X CD drive to support 2.2-Mbps variable-bit-rate MPEG-2
video (at 480 � 480 resolution for NTSC and 480 � 567 resolution for PAL),
2-channel MPEG-2 Layer II audio, text and graphic overlays, and other
DVD-like features. Because the data rate is twice as fast, a disc that maximizes
the quality will only play half as long: 37 minutes. Therefore, most
SVCD players are three-disc changers that automatically switch from one
disc to the next to achieve playing times long enough for a feature-length
movie. In 2000 the unofficial DSVCD format appeared, which squeezes the
tracks tighter together to achieve longer playing times. The D stands for
“double,” although typical capacity increases are only 1.5. Table 8.6 also presents
a technical comparison of SVCD and DVD-Video specifications.
Advantages of DVD-Video over SVCD
Chapter 8
Features. The DVD-Video format includes the same basic features as
SVCD (menus, subpictures, pause, search, freeze, slow, fast, scan) and adds
seamless branching, parental control, multiple camera angles, and more.
Capacity. Programs on DVD can be over eight times longer than on
SVCD or even longer at equivalent quality levels. A single-layer DVD-Video
holds over 2 hours of material per side, and a dual-layer disc holds over four
hours. An SVCD holds 35 to 70 minutes and has only one side. Both DVD
and SVCD support still frames with audio, but DVD has the potential for
hundreds more pictures and hours more surround sound.
Convenience. Since SVCDs cannot hold much more than one half hour
at high quality, the disc must be changed one or more times during a movie,
unless the player holds more than one disc at a time. The DSVCD format