Codec reference

compress accepts --codec NAME; without it, the CLI uses huffman. decompress chooses a decoder from the archive header, so it takes no codec name. The table lists the primary names printed by Codec::name; Codec::parse also accepts some aliases.

CLI name	What it models or writes	Magic	Source
`huffman`	One byte Huffman tree per block, adapted between blocks	`AHF0`	`block_huffman.rs`
`huffman-o1`	Previous-byte Huffman contexts, adapted per byte	`AHF1`	`adaptive_huffman.rs`
`lz77`	Literal and back-reference tokens	`LZ77`	`lz77.rs`
`ppm-o1`	Byte PPM, max context 1 byte	`PP11`	`byte_ppm.rs`
`ppm-o2`	Byte PPM, max context 2 bytes	`PP12`	`byte_ppm.rs`
`ppm`	Byte PPM, max context 3 bytes	`PP13`	`byte_ppm.rs`
`ppm-o4`	Byte PPM, max context 4 bytes	`PP14`	`byte_ppm.rs`
`ppm-o5`	Byte PPM, max context 5 bytes	`PP15`	`byte_ppm.rs`
`ppm-o6`	Byte PPM, max context 6 bytes	`PP16`	`byte_ppm.rs`
`ppm-byte-mix`	Adaptive mix of byte PPM orders	`PPMX`	`byte_ppm.rs`
`ppm-bit`	Bit PPM, max context 8 bits	`PB08`	`ppm.rs`
`ppm-bit-o16`	Bit PPM, max context 16 bits	`PB16`	`ppm.rs`
`ppm-bit-o32`	Bit PPM, max context 32 bits	`PB32`	`ppm.rs`
`ppm-bit-o64`	Bit PPM, max context 64 bits	`PB64`	`ppm.rs`
`ppm-bit-mix`	Adaptive mix of bit PPM orders	`PBMX`	`ppm.rs`
`ppmd`	Exclusion-based byte PPMD-style model	`PPMD`	`ppmd.rs`
`ppmd-bit`	PPMD byte distribution converted to bit probabilities	`PDBT`	`ppmd_bit.rs`
`ppmd-mix`	PPMD byte and bit-history predictions mixed	`PDMX`	`ppmd_mix.rs`
`ppm-mix`	Byte and bit PPM predictions mixed	`PMIX`	`hybrid_ppm.rs`
`match`	Hashed next-byte match predictor	`PMAT`	`ppm_match_mix.rs`
`ppm-match-mix`	Byte PPM plus match predictor	`PMM3`	`ppm_match_mix.rs`
`wikimix5`	Five wiki-oriented next-byte predictors	`WMX5`	`wikimix.rs`

PMAT and PMM3 decoders also accept older payload forms (PMAT without the MBY1 marker and PMM2, respectively). See archive formats for the wire layout and source map for links to each file.

Command shape

cargo run --release -- compress [--no-progress] [--codec NAME] INPUT ARCHIVE
cargo run --release -- decompress [--no-progress] ARCHIVE OUTPUT
cargo run --release -- stats [--no-progress] INPUT ARCHIVE
cargo run --release -- profile [--no-progress] INPUT

Square brackets here mean “optional”; do not type them literally. profile runs only the internal match-mix configurations. --no-progress is useful when saving command output or following a lesson.

For a first run, use the quickstart.

Command shape​

Command shape