Enum Strictness 

#[non_exhaustive]
pub enum Strictness {
    Lenient,
    Strict,
}

How much the decoder tolerates from a stream that violates the AV1 specification.

AV1 leaves the handling of non-conforming streams to the decoder. dav1d conceals what it can and keeps going — a video player would rather show a damaged frame than stop — and that is what this port did unconditionally before 0.6.0. A still-image pipeline usually wants the opposite: a corrupt AVIF should fail instead of yielding garbage pixels, and an encoder bug that desynchronises the symbol stream must not sail through an encode→decode round trip (imazen/rav1d-safe#422 was exactly that).

Every check behind Strict is a comparison at a point the decoder already evaluates, or a once-per-OBU / once-per-tile header check. None of them is in a per-pixel loop.

The variants are ordered: Lenient < Strict.

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.

Lenient

dav1d’s library default (strict_std_compliance = 0): conceal and continue.

Non-conforming values are clamped or reset exactly as dav1d does, so output stays bit-exact with dav1d even on corrupt input. Use this when a best-effort frame beats an error, or to reproduce dav1d’s output on a corrupt stream.

Strict

Reject what the AV1 reference decoder (libaom) rejects. Default.

On top of Lenient:

• dav1d’s strict_std_compliance checks — OBU trailing bits after sequence and frame headers, the padding after each tile’s symbol decoder (AV1 §8.2.4), the OBU forbidden bit, zero timing_info fields, an intra_only frame refreshing every reference slot, show_existing_frame of a non-showable frame, identity matrix coefficients with subsampled chroma, and — under frame threading — an error in a reference frame failing the frames that depend on it instead of concealing;
• the AV1 §6.10.8 requirement that a decoded segment_id lies in 0..=LastActiveSegId (libaom: “Corrupted segment_ids”). dav1d resets an out-of-range id to 0 and keeps parsing a symbol stream that has already desynchronised, so every block after it is garbage.

A rejected frame surfaces as Error::InvalidData.

Trait Implementations

impl Clone for Strictness

fn clone(&self) -> Strictness

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Strictness

impl Debug for Strictness

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

Formats the value using the given formatter.

impl Default for Strictness

fn default() -> Strictness

Returns the “default value” for a type.

impl Eq for Strictness

impl Hash for Strictness

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

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 Ord for Strictness

fn cmp(&self, other: &Strictness) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl PartialEq for Strictness

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for Strictness

fn partial_cmp(&self, other: &Strictness) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralPartialEq for Strictness