Information technology — SEDRIS —
Part 2: Abstract transmittal format
This annex describes guidelines that may assist in developing encoding formats that conform to this part of ISO/IEC 18023.
Table A.1 lists the topics for this annex:
This annex contains guidelines that may ease development efforts. Guidelines are provided for:
Each of these topics is discussed below.
An encoding element is encoding-specific and will depend on the type of encoding being developed. Encoding elements are defined in 5.2.2 ENCODING ELEMENT grammar.
For a character-based encoding (e.g., a clear text encoding), an ENCODING ELEMENT is also character-based. The purposes served by an ENCODING ELEMENT in a character-based encoding include, but are not limited to:
For a binary encoding, an ENCODING ELEMENT consists of a specific set of bits assigned a meaning. The purposes served by an ENCODING ELEMENT in a binary encoding include, but are not limited to:
An encoding may specify how compression techniques apply. All compression should ensure that the initial uncompressed data is recreated after decompression. Thus, only lossless compression should be supported (see 4.4 Compression).
Compression may be applied in many different ways. The entire transmittal may be compressed using external compression techniques, subset of data within a transmittal may be defined for compression purposes, and/or individual <DRM OBJECT>s within the transmittal may be individually compressed.
An encoding may use <ENCODING ELEMENT>s to enable more efficient access to portions of a transmittal. It should be possible to remove all <ENCODING ELEMENT>s used for access efficiency without impacting the meaning of the environmental data.