Again there is confusion between physical and logical structure. A CD can
contain a maximum number of "channel bits" that store both user information
CD-DA as defined by the Red Book and IEC 908 is a fixed physical and logical
structure. Audio information is stored in addressable subcode blocks, each
containing 98 frames. Each frame contains 24 bytes of 16-bit 44.1 kHz
sampled stereo audio plus overhead. After processing, each frame contains
588 channel bits that are physically represented by pits (marks) and lands
in the information layer of the disc.
CD-ROM as defined by the Yellow Book and ISO/IEC 10149 added three types of
addressable sectors on top of the CD-DA structure. Each sector contains 98
frames. Subcode blocks are still present. Each 2352 byte sector stores
variable amounts of both user information and overhead. User information can
be computer data, raw or compressed video and/or audio files, or anything
else that the receiving system knows how to process. With limited bandwidth,
19.2 hours of single channel audio using 4-bit, 18.9 kHz sampling can be
stored on a CD-I (e.g. elevator music.) Various compression methods, such as
MPEG-x, can also store large amounts of audio or video information in CD-ROM
CD-R and CD-RW are physical structures that support recording and rewriting
respectively. They can contain a CD-DA, CD-ROM, or other logical structures.
I hope that this clarifies the confusion over disc capacity.
Media Sciences, Inc.
> -----Original Message-----
> From: Association for Recorded Sound Discussion List
> [mailto:[log in to unmask]] On Behalf Of Howard Friedman
> Sent: Friday, January 04, 2008 11:56 PM
> To: [log in to unmask]
> Subject: Re: [ARSCLIST] CD-R question
> To all,
> There is such a thing as a JukeDisc, which can store as much as 151
> minutes. In fact, I have a CD that holds the complete 32 Beethoven
> Sonatas, for a total playing time of 538 minutes and 56 seconds.
> Howard Friedman