Re:Understanding Deflate
by userbinator on Thursday September 18, 2025 @02:09AM
(#45286058)
but I think the bits must be the opposite "endian" here, ie 2 instead of one
I remember asking the zlib developers many years ago why DEFLATE's bit order was unusual in that it made table-based decoding slightly more complex than necessary, and was told that only Phil Katz knew.
Also of note is that LHA/LZH uses an extremely similar data format where Huffman is also used to encode both literals and lengths in one "alphabet": http://justsolve.archiveteam.org/wiki/LHA Given that LHA very slightly predated ZIP, I suspect the latter was developed based on the former's algorithms.
I remember asking the zlib developers many years ago why DEFLATE's bit order was unusual in that it made table-based decoding slightly more complex than necessary, and was told that only Phil Katz knew.
Also of note is that LHA/LZH uses an extremely similar data format where Huffman is also used to encode both literals and lengths in one "alphabet": http://justsolve.archiveteam.org/wiki/LHA Given that LHA very slightly predated ZIP, I suspect the latter was developed based on the former's algorithms.