Struct ZpEncoder 

pub struct ZpEncoder { /* private fields */ }

ZP adaptive binary arithmetic encoder.

All internal registers (a, subend) are u32 to match DjVuLibre’s unsigned int types. They hold u16-range values but intermediate arithmetic can exceed 0xFFFF, which is critical for correct carry propagation in zemit.

Implementations

impl ZpEncoder

pub fn new() -> Self

pub fn encode_bit(&mut self, ctx: &mut u8, bit: bool)

Encode one bit using an adaptive probability context.

Matches DjVuLibre’s inline encoder(int bit, BitContext &ctx):

• LPS always calls encode_lps
• MPS with z >= 0x8000 calls encode_mps
• MPS with z < 0x8000 takes fast path (a = z, no shift)

pub fn encode_passthrough_iw44(&mut self, bit: bool)

Encode one bit in IW44 passthrough mode (threshold z = 0x8000 + 3a/8).

Counterpart to [ZpDecoder::decode_passthrough_iw44]; must produce a stream that it correctly decodes.

pub fn encode_passthrough(&mut self, bit: bool)

pub fn finish(self) -> Vec<u8>

Flush the encoder and return the compressed byte stream.

Trait Implementations

impl Default for ZpEncoder

fn default() -> Self

Returns the “default value” for a type.