Physical parameters Of DVD
| Capacity |
| Parameter
| Units
| DVD
| CD |
| max payload
| GBytes
| 4.7 (12 cm SL)
8.54 (12 cm DL)
1.46 (8 cm SL)
2.66 (8 cm DL)
| 0.742 (mode
2)
0.650 (mode 1)
|
| Data rates |
| channel rate
| mbit/sec
| 26.16
| 4.3218
|
| FEC rate
| mbit/sec
| 3.00
| 0.4704
|
| user rate
| mbit/sec
| 11.08
| 1.47
|
| actual data rate
| mbit/sec
| 10.08
| 1.4112
|
| Pits and tracks |
| pit width
| micron
| 0.5???
| 0.5
|
| track pitch
| micron
| 0.74
| 1.6
|
| Min pit length
| micron
| 0.40 (SL)
0.44 (DL)
| 0.833 to 0.972
|
| Max pit length
| micron
| 1.87 (SL)
2.13 (DL)
| 3.054 to 3.560
|
| min pit length
| -
| 2T
| 2T
|
| max pit length
| -
| 10T
| 10T
|
(Note: the minimum pit length for
each layer of the Double layer disc is 10% greater than single layer
disc. Hence the 10% less dense figure for Dual layer discs.)
| Data format |
| sector size
| bytes
| 2048
| 2352 (mode
2)
2048 (mode
1)
|
| Movement |
| Spiral direction
|
| clockwise
| clockwise
|
| max revolutions/sec
| Hz
| 25.5 (12 cm disc)
| 8 (12 cm disc)
|
| min revolutions/sec
| Hz
| 10.5
| 3.5
|
| Reference scanning velocity
| m/s
| 3.49 (SL)
3.84 (DL)
| 1.2 to 1.4
|
| Optics |
| wavelength
| nm
| 650 or 635
| 790
|
| Numerical Aperture of Objective
Lens
| -
| 0.60
| 0.45
|
| refractive index
| -
| 1.55
| 1.55
|
Spot Size
(lambda/NA)
| -
| 0.63
| 1
|
Focus Depth
(Focus Margin, lambda/NA^2)
| -
| 0.47
| 1
|
Chromatic Aberration
(Title margin, lambda/NA^3)
| -
| 0.35
| 1
|
Spherical Aberration
(Thickness Tolerance, lambda/NA^4)
| -
| 0.26
| 1
|
| Reflectivity
| %
| 70 minimum (SL)
25 to 40 (DL)
| 70 minimum
|
| Mass |
| Thickness of substrate
| mm
| 0.6
| 1.2
|
| disc thickness
| mm
| 1.2
| 1.2
|
| disc mass
| grams
| 13 to 20 (12 cm)
6 to 9 ( 8 cm)
| 14
|
| Thickness of spacing layer in Dual Layer
| micron
| 40 to 70
| N/A
|
| FEC |
| Error correction
| method
| RS product code
| CIRC
|
| FEC consumption
| %
| 13
| 25
|
| FEC format
| bytes
| (208,192,17)x(182,172,11)
| (28/32)x(24/28)
|
| Sector constraint length
| -
| 16 (=32 Kbytes)
| 1
|
| correctable burst length
| mm
| 6.0 (SL)
6.5 (DL)
| 2.5
|
| Channel code |
| Channel modulation
| method
| 8/16 (EFM+)
| 8/14 + 3 merge bits
|
| Run length
| bits
| (2,10)
| (3,11)
|
| Diameters |
| outer
| mm
| 120 (12 cm)
80 (8 cm)
| 120
|
| outer lead in
| mm
| 117 (12 cm)
78 (8 cm)
| 117
|
| outer data
| mm
| 116 (12 cm)
76 (8 cm)
| 116
|
| inner data
| mm
| 48 (12 cm)
48 (8 cm)
| 50
|
| inner lead in
| mm
| 45 (12 cm)
45 (8 cm)
| 46
|
| center hole
| mm
| 15 (12 cm)
15 (8 cm)
| 15
|
|