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 |
 Glossary |
|
| Access Time |
|
| The time needed for the reader to cross the CD gathering
information (between 120 and 600 milliseconds, depending on the reader). |
| A-TIME (Absolute-Time) |
|
| The CD coding system includes a clock which monitors
recording time and predicts a total. |
| A/D (analogic/digital) |
|
| Conversion of an analogue signal to digital. |
| ABERL (Atip Burst Error Length) |
|
| Number of consecutive ATIP errors. The Orange Book specifies
a maximum of 3 (see also, BERL). |
| ADPCM (Adaptive differential pulsation
code modulation) |
|
| Audio file compression format used for CD-I or CD-ROM/XA
to increase listening time or insert more data. By using this format,
up to 16 hours of audio files can be recorded onto one disc (14400
Hertz radio quality). |
| Artwork |
|
| Any design for printing on a CD. |
| ASCII (American Standard Code for Information
Interchange) |
|
| Coding for alphanumeric characters used in computing. |
| ATER (Atip Error Rate) |
|
| Number of CRC errors per second in the ATIP. The Orange
Book specifies a maximum of 10% error, equivalent to a maximum of
7 errors detected every second. |
| ATIP (Absolute Time In Pregroove) |
|
| Marks the spiral length in time. The different areas
have set lengths (The spiral starts at 96:15:00, lead-in area starts
at 97:27:55, data starts at 00:00:00, lead out area starts at 74:05:10
end of spiral beyond 76:05:10). |
| DVD authoring |
|
| The conversion of a high quality digital or analogue
video source to a MPEG-2 file for processing by a DVD reader. |
| BER (Bit Error Rate) |
|
| The number of errors divided by number of correct bits.
The usual rate for a CD-ROM is 1 per 1012 bits. |
| BERL (Burst Error Length) |
|
| This is the measurement of the quantity of blocks containing
type E21 et E31 errors, which generally indicates physical damage.
E22 usually indicates the presence of dust, scratches or handling
errors. This is an important parameter since it indicates the presence
of physical damage with an impact on more than one block of data. |
| Birefringence |
|
| Double light refraction. Certain types of material have
this double refraction. The substrate used for CD-Rs has this property,
and it is caused by the way the molecules are organized and by the
internal tensions created when the disc is molded. Excessive birefringence
can cause interference and read errors. |
| BLER (Block Error Rate) |
|
| A measurement of the integrity of data contained on the
CD. Error type E11, E21, E31 rate is measured over one second using
analysis equipment. An average rate lower than or equal to 220 is
considered acceptable in the Yellow Book and Red Book. |
| Bloc (Block) |
|
| The data is organized into blocks on the CD, containing
a header, the data, error correction and information checks. This
is the minimum logical addressable unit found on a CD, and each one
has a logical block number to enable the data to be found. |
| Books |
|
These summarise the DVD specifications and are marked
from A to E depending on the applications they are intended for :
 |
Book A : DVD-ROM, specifications for
read only. |
|
|
Book B : DVD-Video, contains video specifications
and an Applications specification defining the software and
functions built into video readers. |
|
|
Book C : DVD-Audio, contains audio specifications
and an Applications specification defining the software and
functions built into audio readers. |
|
|
Book D : DVD-R, specifications for one-time
writing and rereading. |
|
|
Book E : DVD-E (erasable or re-recordable)
and DVD-RAM, contains re-recordable specifications. |
|
| Buffer |
|
| A temporary storage area to compensate for the difference
in speed between the peripherals and ensure a smooth flow of data.
A CD CD-Recorder uses from 512 kb to 2 Mb of buffer space. |
|
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