Ascii85
From Just Solve the File Format Problem
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== Identification == | == Identification == | ||
| − | In PostScript, the "<code><~</code>" token marks the beginning of an ASCII base-85 string literal, hence it is not part of the encoded data. The "<code>~></code>" EOD marker, on the other hand, should be regarded as part of the encoded data, since it is added by the ASCII85Encode filter when it is closed. | + | In PostScript, the "<code><~</code>" token marks the beginning of an ASCII base-85 string literal, hence it is not part of the encoded data. The "<code>~></code>" EOD marker, on the other hand, should be regarded as being part of the encoded data, since it is added by the ASCII85Encode filter when it is closed. |
There is also a [[uuencoding]]-like format, delimited by lines that begin with "<code>xbtoa Begin</code>" and "<code>xbtoa End</code>". | There is also a [[uuencoding]]-like format, delimited by lines that begin with "<code>xbtoa Begin</code>" and "<code>xbtoa End</code>". | ||
Revision as of 11:43, 22 June 2015
Ascii85, or Base85, is a binary-to-text encoding. It is similar in concept to Base64 and Uuencode. It is often used in PDF and PostScript files, and rarely anywhere else. There are several varieties of it.Identification
In PostScript, the "<~" token marks the beginning of an ASCII base-85 string literal, hence it is not part of the encoded data. The "~>" EOD marker, on the other hand, should be regarded as being part of the encoded data, since it is added by the ASCII85Encode filter when it is closed.
There is also a uuencoding-like format, delimited by lines that begin with "xbtoa Begin" and "xbtoa End".
Software
- ascii85.tgz
- btoa-5.2.tar.gz
- Ascii85 libraries are readily available for most popular programming languages.
Links
- Wikipedia article
- Online ASCII85 encoder
- Online ASCII85 decoder
- RFC 1924: A Compact Representation of IPv6 Addresses
