Struct CabacDecoder 

pub struct CabacDecoder<'a> { /* private fields */ }

CABAC arithmetic decoder for HEVC (ITU-T H.265, 9.3.3).

Reads a byte-aligned NAL unit payload and exposes methods for context-modelled decisions, bypass bins, and terminating bins.

Implementations

impl<'a> CabacDecoder<'a>

pub fn new(data: &'a [u8]) -> Self

Construct a new CABAC decoder from a NAL payload slice.

The caller is expected to provide the slice data beginning at the first CABAC-coded byte (i.e. immediately after the slice segment header has been consumed by a different reader).

pub fn decode_decision(&mut self, ctx: &mut ContextModel) -> bool

Decode one bin using context-modelled arithmetic coding (spec 9.3.3.2.1).

The context model is read and updated after decoding. Returns true for bin value 1, false for bin value 0.

pub fn decode_bypass(&mut self) -> bool

Decode one bin in bypass (equiprobable) mode (spec 9.3.3.2.3).

No context model is used; the two symbols are equally likely.

pub fn decode_terminate(&mut self) -> bool

Decode the terminating bin (spec 9.3.3.2.4).

Used to detect end-of-slice or end-of-sub-stream. The interval is reduced by 2 first; if the remaining value falls in the upper sub-range the terminating condition is signalled.

pub fn decode_tr( &mut self, ctx: &mut [ContextModel], c_max: u32, c_rice_param: u32, ) -> u32

Decode a truncated Rice (TR) binarized syntax element (spec 9.3.2.2).

• ctx — context model array; the first entry is used for the prefix unary part, subsequent entries for further bins.
• c_max — maximum value (capped by the binarization).
• c_rice_param — Rice parameter controlling the suffix length.

The prefix is decoded as a truncated unary code using context models, and the suffix (if any) is decoded in bypass mode.

pub fn decode_fl(&mut self, n_bits: u32) -> u32

Decode a fixed-length (FL) binarized syntax element using bypass bins (spec 9.3.3.2.3, used via 9.3.2.4).

Reads n_bits bypass bins and returns the resulting value (MSB-first).

pub fn decode_unary(&mut self, ctx: &mut [ContextModel], max: u32) -> u32

Decode a unary (U) binarized syntax element using context models.

Returns the number of 1 bins seen before the first 0 bin, capped at max. Context index for each bin position k is min(k, ctx.len() - 1).

pub fn decode_eg(&mut self, k: u32) -> u32

Decode an Exp-Golomb coded syntax element using bypass bins (spec 9.3.2.5, k-th order).

k is the order parameter. Returns the decoded unsigned value.