j2k_types/
decode_payload.rs

1// SPDX-License-Identifier: MIT OR Apache-2.0
2
3//! Borrowed-input byte descriptors shared by prepared decode plans.
4
5/// Byte range inside a complete encoded J2K, JP2, or JPH input.
6#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
7pub struct J2kCodestreamRange {
8    /// Zero-based offset from the beginning of the encoded input.
9    pub offset: usize,
10    /// Number of bytes in the range.
11    pub length: usize,
12}
13
14impl J2kCodestreamRange {
15    /// End offset, or `None` when the range overflows `usize`.
16    #[must_use]
17    pub const fn end(self) -> Option<usize> {
18        self.offset.checked_add(self.length)
19    }
20}
21
22/// One retained cleanup/refinement record for an HTJ2K code block.
23///
24/// The first record for a code block contains its cleanup range and may
25/// contain the first refinement fragment. When refinement bytes are split
26/// across packets, immediately following continuation records have an empty
27/// cleanup range and a non-empty refinement range. Consumers use the code
28/// block's declared refinement length to determine where the next block starts.
29#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
30pub struct HtCodeBlockPayloadRanges {
31    /// Cleanup-pass payload range.
32    pub cleanup: J2kCodestreamRange,
33    /// SigProp/MagRef payload fragment, when refinement is present.
34    pub refinement: Option<J2kCodestreamRange>,
35}
36
37/// Ordered encoded-input fragment span for one classic JPEG 2000 code block.
38#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
39pub struct J2kClassicCodeBlockPayload {
40    /// Index of the first fragment in the owning plan's range array.
41    pub first_range: usize,
42    /// Number of ordered fragments contributing to this code block.
43    pub range_count: usize,
44    /// Total bytes after concatenating every fragment.
45    pub combined_length: usize,
46}
47
48impl J2kClassicCodeBlockPayload {
49    /// Exclusive fragment index, or `None` when the descriptor overflows.
50    #[must_use]
51    pub const fn end_range(self) -> Option<usize> {
52        self.first_range.checked_add(self.range_count)
53    }
54}
j2k_types/decode_payload.rs

j2k_types/
decode_payload.rs
