CD-Text

CD-Text is an extension of an audio CD (or more precisely an extension of the Red Book audio CDs), which contains textual information such as title, artist and name of the individual pieces of music. Some CD players can view this text during playback. Playability on devices that do not support CD Text, this in no way impaired.

Technology

The text is always stored in the RW subcodes of CD in the form of the Interactive Text Transmission System ( ITTS ) (which also DAB and MiniDisc used comes ) and can be located at two possible positions: in the lead- in CD or parallel to the music.

In the first case, there are about 5 KB for data. This is the normal location for track information. This area can also be read by most CD -ROM drives, as the MMC specification defines the relevant commands. The necessary extension of the MMC standard is based on a proposal from the company Sony.

CD -Text data that are recorded in parallel with the music are not currently provided. However, there are discs which are within the tracks included in the RW subcode data can be read from a small number of drives, and are therefore more likely not in use. The information presented here 31 MB are used for applications such as CD G ( CD with additional images, such as for Karaoke).

The maximum number of characters that must have CD text is limited. It can be used 64 characters for the title track up to 64 characters, and for the artist as well. For album title and album artist there is no obvious limit. But it must not be more than 3024 characters, the total number of characters in the disc. Otherwise, no CD text is displayed. The same is true if track artist or track title have more than 64 characters; then refuse many CD players to display CD text. The format of the character encoding is specified (for storing the data in the Lead -in) in the Pack Type Indicator ID1 for the album title, singer, songwriter, composer, arranger and provider. Defined values ​​are 0 ( ISO 8859-1 ), 1 ( ISO 646 = 7-bit ASCII), 0x80 (Japanese), 0x81 ( Korean) and 0x82 ( Chinese), in the specification detailed information is lacking, what kind of coding is hide behind the Korean and Chinese version ( "to be defined" ). The default 0 ( ISO 8859-1 ) is used, which is assumed by virtually all burning programs and CD players.

Special characters can be used. Depending on the type of the display during playback ( dot matrix or segmented display), it may happen that the special characters are displayed as spaces. Lowercase letters are always displayed in large segment displays.

Application

Writing: Most burning programs support the writing of CD - Text in the lead-in. Often this has to be specifically activated however. The CD has to be burned in the SAO or DAO mode (recommended ) or in RAW mode. If the RAW mode is used, then the production of CD-Text is also possible to not provided for CD- text devices.

Read: are to display the CD text required special players with appropriate support. By upgrading the firmware ( if possible) would be theoretically possible to retrofit this feature. In conventional CD players but is also the most against the lack of opportunity for display letters. Nahehzu all CD burning tools enable you to add based on the information from CDDB or FreeDB when copying CD Text.

Commercial CDs

Prerecorded CDs rarely have CD text. An exception are CDs from Sony Music, which are partially provided with CD-Text since April 1997.

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