Chapter 1

DVD-R 1.0 (12 cm, SS/SL) 3.68 gig (3.95 BB)
DVD-R 2.0 (12 cm, SS/SL) 4.37 gig (4.70 BB)
DVD-R 2.0 (12 cm, DS/SL) 8.75 gig (9.40 BB)
DVD-RW 2.0 (12 cm, SS/SL) 4.37 gig (4.70 BB)
DVD-RW 2.0 (12 cm, DS/SL) 8.75 gig (9.40 BB)
DVD�R 2.0 (12 cm, SS/SL) 4.37 gig (4.70 BB)
DVD�R 2.0 (12 cm, DS/SL) 8.75 gig (9.40 BB)
DVD�RW 2.0 (12 cm, SS/SL) 4.37 gig (4.70 BB)
DVD�RW 2.0 (12 cm, DS/SL) 8.75 gig (9.40 BB)
DVD-RAM 1.0 (12 cm, SS/SL) 2.40 gig (2.58 BB)
DVD-RAM 1.0 (12 cm, DS/SL) 4.80 gig (5.16 BB)
DVD-RAM 2.0 (12 cm, SS/SL) 4.37 gig (4.70 BB)*
DVD-RAM 2.0 (12 cm, DS/SL) 8.75 gig (9.40 BB)*
DVD-RAM 2.0 (8 cm, SS/SL) 1.36 gig (1.46 BB)*
DVD-RAM 2.0 (8 cm, DS/SL) 2.47 gig (2.65 BB)*
CD-ROM (12 cm, SS/SL) 0.635 gig (0.650 BB)
CD-ROM (8 cm, SS/SL) 0.180 gig (0.194 BB)
DDCD-ROM (12 cm, SS/SL) 1.270 gig (1.364 BB)
DDCD-ROM (8 cm, SS/SL) 0.360 gig (0.387 BB)
DVD Technical Details 91
*Formatted DVD-RAM discs have slightly less than the stated capacity. For
example, the contents of a completely full DVD-R will not quite fit on a
DVD-RAM.
TIP: It takes about 2 gigabytes to store 1 hour of average video.
The increase in capacity from CD-ROMs is due to a smaller pit length
(�2.08x), tighter tracks (�2.16x), a slightly larger data area (�1.02x), more
efficient channel bit modulation (�1.06x), more efficient error correction
(�1.32x), and less sector overhead (�1.06x). The total increase for a single
layer is about seven times a standard CD-ROM. A slightly different explanation
can be found at www.mpeg.org/MPEG/DVD/General/Gain.html.
The capacity of a dual-layer disc is slightly less than double that of a single-layer
disc. The laser has to read “through” the outer layer to the inner