When did the DEFLATE compressed data format specification come out?
Deutsch Informational [Page 4] RFC 1951 DEFLATE Compressed Data Format Specification May 1996 3. Detailed specification 3.1.
Where can I find the RFC 1951 specification?
A pointer to the latest version of this and related documentation in HTML format can be found at the URL .
How are the blocks of a compressed data set compressed?
Compressed representation overview A compressed data set consists of a series of blocks, corresponding to successive blocks of input data. The block sizes are arbitrary, except that non-compressible blocks are limited to 65,535 bytes. Each block is compressed using a combination of the LZ77 algorithm and Huffman coding.
How big is a block in deflate format?
The representation used in the “deflate” format limits distances to 32K bytes and lengths to 258 bytes, but does not limit the size of a block, except for uncompressible blocks, which are limited as noted above.
What was the purpose of the RFC 1951?
If you are intent on doing it yourself, then you can look at puff.c, also in the zlib distribution, which was written with the purpose of supplementing RFC 1951 with an unambiguous definition of the deflate format by virtue of being a heavily commented working deflate decoder. RFC 1951 does in fact explain the format with exactitude.
Is there a free library for DEFLATE compression?
First off, you don’t need to do what you’re doing, since it has already been done for you in zlib, a free compression library that permits commercial use. zlib provides implementations of deflate compression and inflate decompression, per RFC 1951.
What does rfc1951 say about extra bits?
RFC1951 says the following about the representation of extra bits: The extra bits should be interpreted as a machine integer stored with the most-significant bit first, e.g., bits 1110 represent the value 14.