Enum AlphError 

pub enum AlphError {
    EmptyPayload,
    DimensionsOverflow {
        width: u32,
        height: u32,
    },
    RawLengthMismatch {
        expected: usize,
        actual: usize,
    },
    UnsupportedCompression(u8),
    Vp8l(DecodeError),
}

Errors raised by the §2.7.1.2 ALPH info-byte parser and the decode_alpha bitstream decoder.

Variants

EmptyPayload

The ALPH payload is empty — at minimum one info byte is required per §2.7.1.2 Figure 10, even if the alpha bitstream itself is zero-length (which §2.7.1.2 does not forbid).

DimensionsOverflow

width * height overflowed usize (or u32), so the plane cannot be addressed on this platform.

Fields

width: u32

The implicit width passed by the caller.

height: u32

The implicit height passed by the caller.

RawLengthMismatch

Compression method 0 (raw) but the alpha bitstream length does not equal width * height (§2.7.1.2: “a byte sequence of length = width * height”).

Fields

expected: usize

The expected width * height byte count.

actual: usize

The actual number of bytes available in the bitstream.

UnsupportedCompression(u8)

Compression method C was 2 or 3 — undefined by §2.7.1.2.

Vp8l(DecodeError)

The compression-method-1 §3 VP8L image-stream failed to decode.

Trait Implementations

impl Clone for AlphError

fn clone(&self) -> AlphError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for AlphError

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

Formats the value using the given formatter.

impl Display for AlphError

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

Formats the value using the given formatter.

impl Eq for AlphError

impl Error for AlphError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

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

Provides type-based access to context intended for error reports.

impl From<AlphError> for Error

fn from(e: AlphError) -> Self

Converts to this type from the input type.

impl From<DecodeError> for AlphError

fn from(e: DecodeError) -> Self

Converts to this type from the input type.

impl PartialEq for AlphError

fn eq(&self, other: &AlphError) -> 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 AlphError