Struct PrefixCodeGroup 

pub struct PrefixCodeGroup {
    pub green: PrefixCode,
    pub red: PrefixCode,
    pub blue: PrefixCode,
    pub alpha: PrefixCode,
    pub distance: PrefixCode,
}

The five prefix codes that make up one §6.2 “prefix code group”.

In bitstream order: green-channel + backref-length + color-cache (channel 1), red (2), blue (3), alpha (4), backref-distance (5). Each pixel is decoded with exactly one group; which group applies to which pixel block is selected by the §6.2.2 meta-prefix layer.

Fields

green: PrefixCode

Prefix code #1: green channel + length-prefix + color-cache. Alphabet size is 256 + 24 + color_cache_size per §6.2.3.

red: PrefixCode

Prefix code #2: red channel, alphabet 256.

blue: PrefixCode

Prefix code #3: blue channel, alphabet 256.

alpha: PrefixCode

Prefix code #4: alpha channel, alphabet 256.

distance: PrefixCode

Prefix code #5: backref distance, alphabet 40.

Implementations

impl PrefixCodeGroup

pub fn green_alphabet_size(color_cache_size: usize) -> usize

The size-of-alphabet for prefix code #1 (green / length / color-cache) for a stream whose color-cache holds color_cache_size entries (0 when the cache is disabled, 1 << color_cache_code_bits when it is enabled). Per §6.2.3: 256 + 24 + color_cache_size.

pub fn read( reader: &mut BitReader<'_>, color_cache_size: usize, ) -> Result<Self, MetaPrefixError>

Read one prefix-code group (five canonical prefix codes) from the bitstream in §6.2 order.

Trait Implementations

impl Clone for PrefixCodeGroup

fn clone(&self) -> PrefixCodeGroup

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for PrefixCodeGroup

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for PrefixCodeGroup

impl PartialEq for PrefixCodeGroup

fn eq(&self, other: &PrefixCodeGroup) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for PrefixCodeGroup