Enum SignalRange 

#[non_exhaustive]
#[repr(u8)]
pub enum SignalRange {
    Full = 0,
    Narrow = 1,
}

Signal (quantization) range of the encoded channel values.

Narrow is the single ITU convention variously called limited, video, studio swing, MPEG, or TV range (BT.601 / BT.709 / BT.2100 — the aliases do not differ in meaning). Its anchor values scale with bit depth as anchor × 2^(N−8) — a bit shift, not a full-scale stretch:

depth	luma / R’G’B’	chroma (Cb/Cr)
8-bit	16–235	16–240
10-bit	64–940	64–960
12-bit	256–3760	256–3840

For the RGB and gray layouts this crate describes, narrow means studio-swing R’G’B’ / Y′: the luma span applies to every channel. The wider chroma span would matter only for YCbCr layouts (none exist here).

Values outside the anchors are legal in a narrow signal — sub-blacks (1–15·2^(N−8)), super-whites (236–254·2^(N−8)), and xvYCC’s deliberate gamut excursions. Any future expand-to-full conversion must choose clamp-vs-preserve for them explicitly.

Maps 1:1 to CICP’s video_full_range_flag and AV1’s color_range (Full = full-range flag set, Narrow = limited).

There are no Narrow↔Full conversion kernels yet. zenpixels-convert refuses range-crossing conversions rather than relabeling (relabeling without rescaling lifts or crushes blacks); narrow data must be preserved verbatim end-to-end. Caveat while that holds: cross-depth conversion of narrow data uses full-scale rescaling (×(2^M−1)/(2^N−1)), which maps ITU anchors only approximately (8-bit 235 widens to 60 395 where the ITU 16-bit anchor is 235·256 = 60 160, ≈0.36 % of full scale); exact anchor remapping is the future range kernels’ job.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Full = 0

Full range: 0 – 2^N−1 (0–255 for 8-bit, 0–65535 for 16-bit).

Narrow = 1

Narrow (limited/studio) range: 16–235 luma applied to all RGB/gray channels, scaled by 2^(N−8) at higher depths — see the type-level docs for the full table, excursion semantics, and conversion rules.

Trait Implementations

impl Clone for SignalRange

fn clone(&self) -> SignalRange

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for SignalRange

impl Debug for SignalRange

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

Formats the value using the given formatter.

impl Default for SignalRange

fn default() -> SignalRange

Returns the “default value” for a type.

impl Display for SignalRange

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

Formats the value using the given formatter.

impl Eq for SignalRange

impl Hash for SignalRange

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for SignalRange

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for SignalRange