how does optical media technology work? by wayne heperiod 2
Post on 17-Jan-2016
220 Views
Preview:
TRANSCRIPT
How Does Optical Media How Does Optical Media Technology Work?Technology Work?
By Wayne He Period 2
Common File Systems Common File Systems for CDs and DVDsfor CDs and DVDs
High SierraHigh Sierra In 1985, representatives from several
companies met at High Sierra Hotel at Lake Tahoe, Nevada. Created a logical format and file structured
for CD-ROMs.Was later submitted to the International
Organization for Standardization (ISO).
ISO 9660ISO 9660 Adapted from the High
Sierra format. Level 1 Interchange:
Filenames may only have uppercase letters, digits, and underscores ( _ ).
8 characters max. for filenames and 3 chars max for extensions.
Directory names may only have 8 characters maximum.
Directories are limited to 8 levels deep.
Files must be contiguous.
Level 2 Interchange: Allowed the filename
and extension to have a total of 30 characters maximum.
Level 3 Interchange: “Files must be
contiguous” restriction removed.
JolietJoliet Extension of ISO 9660 CDs can be recorded with filenames with 64
characters max. Specifications:
Filenames and directories can have 64 characters maximum (as stated above)
Directories may have extensions. Directories can be deeper than eight levels. Supports multisession recording.
Universal Disk Format (UDF)Allows an operating system to read,
write, and modify dataDVDs are based on this format.
Lands and Pits on CDs Lands and Pits on CDs and DVDsand DVDs
A land is a layer that reflects light.Pits look like bumps.
Data Bits and Channel BitsLand – 1 data bitPit – 0 data bitChannel bits:
A “1” refers to a change from a land to a pit, or from pit to land.
A “0” refers to no change between a land and a pit.
CLV and CAV
Circular Angular VelocityAccesses data off
of rotating disksUsed by disk
drivesDisk motor does
not need to change speed
Constant Linear Velocity Used by older CD-
ROM players Rotational speed
changes depending on the data’s location
Ensures constant data rate regardless of the data’s location
Speeds of different optical media technologies
CD-ROM CD-ROM CD-i/XA CD-i/XA
Mode 1 Mode 2 Form 1 Form 2
Speed (CLV)
(2,352 Bytes/Block)
(2,048 Bytes/Block)
(2,336 Bytes/Block)
(2,048 Bytes/Block)
(2,324 Bytes/Block)
1x 176,000 153,600 175,200 153,600 174,300
2x 352,800 307,200 350,400 307,200 348,600
4x 705,600 614,400 700,800 614,400 697,200
6x 1,058,400 921,600 1,051,200 921,600 1,045,800
8x 1,411,200 1,228,800 1,401,600 1,228,800 1,394,400
12x 2,112,000 1,843,200 2,102,400 1,843,200 2,091,600
16x 2,816,000 2,457,600 2,803,200 2,457,600 2,788,800
20x 3,520,000 3,072,000 3,504,000 3,072,000 3,486,000
Read/Write Audio
Color Books
(not to be confused with children’s coloring books)
RedRed books define CD-Audio “father” of all CD-formatsCompact Disc-Digital Audio (CD-DA)
defined by Philips N.V. and Sony in 1980
Yellow “mother” of all CD formatsDefines CD-ROMsDeveloped by Philips N.V. and Sony in
1983Allows storing of digitalized content
OrangeCD-Recordable (CD-R)Created by Philips N.V. and Sony in
1988Can now record (as where the name
“CD-Recordable” came from)
GreenCompact Disc Interactive (CD-i)Stores an entire hardware and software
systemStores special compression methods for
audio and visual data Interleaves audio, video, and text data
BlueCD PlusMultisession disc with two sessions
Music Data
WhiteVideo CDDeveloped by JVC, Philips, Sony, and
Matsushita in July 1993Stores MPEG-1 (Motion Picture Experts
Group) videos (maximum of 74 minutes)Playable on a personal computer (PC)
or a DVD player
top related