Ascii85

From Just Solve the File Format Problem
Jump to: navigation, search
File Format
Name Ascii85
Ontology
Ascii85, ASCII base-85, or Base85, is a binary-to-text encoding originally implemented by Paul Rutter in the 'btoa' program. It is similar in concept to Base64 and Uuencode. A slight modification of it is used in PDF and PostScript files. It is also used in the MkTags Matroska tag editor. There are several varieties of this encoding.

Contents

Identification

In the original uuencoding-like format used by 'btoa', the encoded data is delimited by lines that begin with "xbtoa Begin" and "xbtoa End". In a newer version of the format, the first line begins with "xbtoa5 ".

In PostScript, the "<~" delimiter marks the beginning of an ASCII base-85 string literal. The "~>" EOD marker is added by the ASCII85Encode filter when it is closed, hence it should be regarded as being part of the encoded data. Outside of PostScript, there is no official delimiter to mark the beginning of ASCII base-85 encoded data. In PDF it doesn't matter, since the data (including the EOD marker) is stored in a stream object.

Software

Sample files

Links

Personal tools
Namespaces

Variants
Actions
Navigation
Toolbox