Revision based on latest comments from Thomas
This commit is contained in:
R. Bernstein
@@ -58,16 +58,16 @@ to decode and encode it.
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@chapter Encoding and Decoding CD Text
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@menu
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* CD Text Categories (Pack Types)::
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* Text Pack Types:: Text Pack Types (0x80-0x85, 0x8e)
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* Other Pack Types:: Other Pack Types (0x86, 0x87, 0x8d)
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* TOC Pack Types:: TOC Pack Types (0x88, 0x89)
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* Block Pack Type (0x8f)::
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* Top-Level CD Text Categories (Pack Types)::
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* Pack Contents::
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* Text Pack Types::
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* Other Pack Types::
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* TOC Pack Types::
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* Block Pack Type (0x8f)::
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@end menu
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@node CD Text Categories (Pack Types)
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@section CD Text Categories (Pack Types)
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@node Top-Level CD Text Categories (Pack Types)
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@section Top-Level CD Text Categories (Pack Types)
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CD Text information is grouped into @emph{blocks}, each one in a particular
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language. Up to 8 languages (or blocks) can be stored.
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@@ -97,7 +97,7 @@ The CD Text categories are identified by a single-byte code.
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@caption{CD Text Categories}
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@end float
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Some additional information regarding specific pack types:
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Additional notes regarding Pack Types:
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@itemize
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@item Pack Types @kbd{0x8a} to @kbd{0x8c} although not specified are reserved for potential future use.
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@@ -117,6 +117,83 @@ next section. A shortcut for repeated identical track texts is
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provided, so that a text that is identical to the one of the previous
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track occupies only 2 or 4 bytes.
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@node Pack Contents
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@section Pack Contents
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Text Packs are stored in CD in the sub-channel of the Lead-in of the
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disc. The file @file{doc/cookbook.txt} of the
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@url{http://libburnia-project.org/,libburnia} distribution describes
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how to write the CD Text pack array to CD, and how to read CD Text
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packs from CD. If you are just interested in a more high-level access
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CD Text information without having to understand the internal
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structure, you can use libcdio's CD Text API for getting and setting
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fields.
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The format is explained in part in Annex J of (@ref{mmc3r10g.pdf,,
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MMC-3}), and in part by Sony's documentation
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@ref{cdtext.zip,,cdtext.zip}.
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Each pack consists of a 4-byte header, 12 bytes of payload, and 2 bytes
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of CRC.
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The first byte of each pack tells the pack type. See above for a list of
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types.
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The second byte tells the track number to which the first text piece
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in a pack is associated. Number 0 means the whole album. Higher
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numbers are valid for types @kbd{0x80} to @kbd{0x85}, and
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@kbd{0x8e}. With these types, there should be one text for the disc
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and one for each track. With types @kbd{0x88} and @kbd{0x89}, the
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second byte bears a track number, too. With type @kbd{0x8f}, the
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second byte counts the record parts from 0 to 2.
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The third byte is a sequential counter.
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The fourth byte is the Block Number and Character Position Indicator.
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It consists of three bit fields:
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@table @dfn
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@item bits 0-3
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Character position. Either the number of characters which the current
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text inherited from the previous pack, or 15 if the current
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text started before the previous pack.
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@item bits 4-6
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Block Number (groups text packs in language blocks)
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@item bit 7
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Is 0 if single byte characters, 1 if double-byte characters.
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@end table
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The 12 payload bytes contain pieces of zero terminated data. When
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double-byte text is used the zero is a double byte, otherwise it is a
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single ASCII NUL.
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A text may span over several packs. Unused characters in
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a pack are used for the next text of the same pack type. If no text of
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the same type follows, then the remaining text bytes are set to 0.
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The CRC algorithm uses divisor @kbd{0x11021}. The resulting 16-bit
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residue of the polynomial division is inverted (xor-ed with
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@kbd{0xffff}) and written as Big-endian number in bytes 16 and 17 of
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the pack.
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The text packs are grouped in up to 8 blocks of at most 256 packs. Each
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block pertains to one language. Sequence numbers of each block are
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counted separately. All packs of block 0 come before the packs of block
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1.
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The limitation of block number and sequence numbers imply that there are
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at most 2048 text packs possible.
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If a text of a track (pack types @kbd{0x80} to @kbd{0x85} and
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@kbd{0x8e}) repeats identically for the next track, then it may be
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represented by a TAB character (ASCII 9) for single byte texts,
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resp. two TAB characters for double byte texts. (This should be used
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because 256 * 12 bytes is few space for 99 tracks.)
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The two binary bytes of pack type @kbd{0x87} are written to the first
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@kbd{0x87} pack of a block. They may or may not be repeated at the start
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of the follow-up packs of type @kbd{0x87}.
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@node Text Pack Types
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@section Text Packs (@kbd{0x80}--@kbd{0x85}, @kbd{0x8e})
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@@ -198,14 +275,17 @@ the Genre Code, such as ``USA Rock music in the 60's''.}
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This information is always ASCII encoded.
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Pack type @kbd{0x8d} Sony documents says:
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Pack type @kbd{0x8d} Sony documents say:
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@quotation
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@emph{Closed Information: (use 8859-1 Code) Any information can
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be recorded on disc as memorandum. Information in this field will not
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be read by CD TEXT players available to the public.}
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be read by CD-TEXT players available to the public.}
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@end quotation
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It is always ISO-8859-1 encoded.
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One can however read this information with an MMC READ TOC/PMA/ATP
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command. (See Section 5.23 of @ref{mmc3r10g.pdf}).
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This field is always ISO-8859-1 encoded.
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@node TOC Pack Types
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@section TOC Pack Types (@kbd{0x88}, @kbd{0x89})
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@@ -213,6 +293,9 @@ Pack type @kbd{0x88} records information from the CD's Table of
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Contents, as of READ PMA/TOC/ATIP Format @kbd{0010b}. See Table 237 TOC
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Track Descriptor Format, Q Sub-channel of @ref{mmc3r10g.pdf,, MMC-3}.
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This information duplicates information stored elsewhere and that can
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be obtained by an MMC READ TOC/PMA/ATP command.
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The first pack of type @kbd{0x88} (Table of Contents) records in its
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payload bytes as follows:
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@@ -231,7 +314,7 @@ POINTs between the lowest track number (1 or @code{01h}) and the highest
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track number (99 or @code{63h}). The payload of the last pack is padded
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by zeros.
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Using the @kbd{.TOC} example from Sony documents as an example:
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Using the @kbd{.TOC} from Sony documents as an example:
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@smallexample
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A0 01
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A1 14
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@@ -256,8 +339,7 @@ Encoding the above gives:
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Pack type @kbd{0x89} (Second Table of Contents) is not yet clear. It
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might be a representation of Playback Skip Interval, Mode-5 Q
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sub-channel, POINT 01 to 40 See Section 4.2.6.3 of @ref{mmc3r10g.pdf,, MMC-3}.
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If so, then this seems not to apply to write type SAO, because the CUE
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SHEET format offers no way to express Mode-5 Q.
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The time points in the Sony example are in the time range of the
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tracks numbers that are given before the time points:
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@@ -415,82 +497,6 @@ Byte :Value Meaning
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29 : 00 00 00 00 00 00 00 = language codes for block 1..7 (none)
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@end smallexample
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@node Pack Contents
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@section Pack Contents
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The attributes are represented on CD as Text Packs in the sub-channel
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of the Lead-in of the disc. The file @file{doc/cookbook.txt} of the
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@url{http://libburnia-project.org/,libburnia} distribution describes
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how to write the CD Text pack array to CD, and how to read CD Text
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packs from CD. If you are just interested in a more high-level access
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CD Text information without having to understand the internal
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structure can use libcdio's CD Text API for getting and setting
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fields.
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The format is explained in part in Annex J of (@ref{mmc3r10g.pdf,,
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MMC-3}), and in part by Sony's documentation
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@ref{cdtext.zip,,cdtext.zip}.
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Each pack consists of a 4-byte header, 12 bytes of payload, and 2 bytes
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of CRC.
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The first byte of each pack tells the pack type. See above for a list of
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types.
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The second byte tells the track number to which the first text piece
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in a pack is associated. Number 0 means the whole album. Higher
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numbers are valid for types @kbd{0x80} to @kbd{0x85}, and
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@kbd{0x8e}. With these types, there should be one text for the disc
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and one for each track. With types @kbd{0x88} and @kbd{0x89}, the
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second byte bears a track number, too. With type @kbd{0x8f}, the
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second byte counts the record parts from 0 to 2.
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The third byte is a sequential counter.
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The fourth byte is the Block Number and Character Position Indicator.
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It consists of three bit fields:
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@table @dfn
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@item bits 0-3
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Character position. Either the number of characters which the current
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text inherited from the previous pack, or 15 if the current
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text started before the previous pack.
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@item bits 4-6
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Block Number (groups text packs in language blocks)
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@item bit 7
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Is Double Byte Character? Is 0 if single byte characters, 1 if double-byte
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characters.
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@end table
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The 12 payload bytes contain pieces of ASCII NUL-terminated texts or
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binary data. A text may span over several packs. Unused characters in
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a pack are used for the next text of the same pack type. If no text of
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the same type follows, then the remaining text bytes are set to 0.
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The CRC algorithm uses divisor @kbd{0x11021}. The resulting 16-bit
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residue of the polynomial division is inverted (xor-ed with
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@kbd{0xffff}) and written as Big-endian number in bytes 16 and 17 of
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the pack.
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The text packs are grouped in up to 8 blocks of at most 256 packs. Each
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block is in charge for one language. Sequence numbers of each block are
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counted separately. All packs of block 0 come before the packs of block
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1.
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The limitation of block number and sequence numbers imply that there are
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at most 2048 text packs possible. (READ TOC/PMS/ATIP could retrieve 3640
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packs, as it is limited to 64 KB - 2.)
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If a text of a track (pack types @kbd{0x80} to @kbd{0x85} and
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@kbd{0x8e}) repeats identically for the next track, then it may be
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represented by a TAB character (ASCII 9) for single byte texts,
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resp. two TAB characters for double byte texts. (This should be used
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because 256 * 12 bytes is few space for 99 tracks.)
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The two binary bytes of pack type @kbd{0x87} are written to the first
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@kbd{0x87} pack of a block. They may or may not be repeated at the start
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of the follow-up packs of type @kbd{0x87}.
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@node Higher-Level Encoding
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@chapter Higher-Level Encoding
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@@ -558,44 +564,6 @@ The following purpose specifiers have no effect on CD Text:
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Input Sheet Version = "0.7T"
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@end smallexample
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Purposes specifiers Text Code, Language Code, Genre Code, and Text Data
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Copy Protection are two hexidecimal digits.
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For example, to indicate MS-JIS character code (of which the exact
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name is unknown) enter:
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@smallexample
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Text Code = 0x80
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@end smallexample
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Genre Code is settable by a 4-hexidecimal digit number, or by 2
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two-digit hexidecimal numbers. For example:
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@smallexample
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Genre Code = 0x001b
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Genre Code = 0x00 0x1b
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@end smallexample
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Purpose specifiers which have the meaning ``Content of pack type 0xXY''
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may be replaced by the pack type codes. For example:
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@smallexample
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0x80 = Session content of pack type 0x80
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Track 02 0x80 = Track content of pack type 0x80 for track 2.
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@end smallexample
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Applicable are pack types @kbd{0x80} to @kbd{0x86}, @kbd{0x8d},
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@kbd{0x8e}.
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Text Code may be specified only once. It gets specified ISO-8850-1
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automatically as soon as content is defined which depends on the text
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encoding of the block, that is, with pack types @kbd{0x80} to @kbd{0x85}.
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If a track attribute is set, but the corresponding session attribute is not
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defined or defined with empty text, then the session attribute gets attached
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as empty test. Normally, empty content is ignored.
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An example @code{cdrskin} run with three tracks:
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@smallexample
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@@ -661,7 +629,7 @@ page for defining the corresponding CD Text attributes: @kbd{ARRANGER},
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An Example of a CDRWIN cue sheet file:
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@smallexample
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CATALOG 1234567890123
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FILE "cdtext.bin" BINARY
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FILE "audiodata.bin" BINARY
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TITLE "Joyful Nights"
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TRACK 01 AUDIO
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FLAGS DCP
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@@ -705,7 +673,8 @@ in @email{libcdio-devel@@gnu.org}, December 2011. @* Mail archives at
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@item @emph{SCSI Multimedia Commands --- 3 (MMC-3)},@anchor{mmc3r10g.pdf} @*
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Revision 10g, November 12. 2011
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@url{http://www.t10.org/cgi-bin/ac.pl?t=f&f=mmc3r10g.pdf} In
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particular, see Table 237 (TOC Track Descriptor Format, Q
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particular, Section 5.23 (READ TOC/PMA/ATIP Command),
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see Table 237 (TOC Track Descriptor Format, Q
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Sub-channel), Annex J (CD Text format in the Lead-in Area) and
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Sections 4.2.5.3 (Mode-5 Q).
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@@ -715,6 +684,9 @@ Sections 4.2.5.3 (Mode-5 Q).
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@item Cue-Sheet Syntax
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@url{http://digitalx.org/cue-sheet/syntax}
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@item @emph{libburnia} project @url{http://libburnia-project.org}
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See @file{doc} directory in that project.
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@item @emph{libcdio} source code @url{http://www.gnu.org/s/libcdio}
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@item @emph{cdrecord} source code @url{ftp://ftp.berlios.de/pub/cdrecord/alpha}
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