@ -29,10 +29,12 @@ Checkboxes may be marked complete only when the implementation and the verificat
## Delivery dashboard
## Delivery dashboard
Last reconciled with the source tree on 2026-08-30 against production checkpoint `a0d1b5af56acb3a3a9aebb29c916d1b36cd49367`. Committed checkpoints include the AV1 transform architecture, OBU framing, tile partitioning, mode information, segmentation, delta quantization, transform-size selection, coefficient decoding, inverse quantization, inverse transforms, complete intra prediction, intra-block copy, official extreme-displacement intra-block-copy conformance, the 12-profile reconstruction matrix, corrected twelve-bit inverse-transform SIMD arithmetic, layered-item properties, layered reference/header/CDF/motion-field state, inter-frame intra blocks, SIMD-first translational prediction, complete single-reference inter reconstruction, compound reference trees and modes, paired reference-MV derivation, reference-dependent bounded sequence decoding, allocation-free SIMD-first equal averaging, selected inter-intra prediction, selectable compound blending, OBMC, scaled-reference reconstruction, local warped prediction, non-translational global prediction, official motion-vector conformance, official spatial- and temporal-layer default-operating-point conformance, official active-film-grain and monochrome sequence conformance, selected spatial-layer presentation, and progressive color and auxiliary-alpha conformance. This dashboard is the authoritative delivery order. The detailed phase checklists below provide subsystem evidence; they do not override the current-stage marker or permit work to skip ahead.
Last reconciled with the source tree on 2026-08-30 against production checkpoint `35e65e9546dd78847d4de7cae082e26229b3a744`. Committed checkpoints include the AV1 transform architecture, OBU framing, tile partitioning, mode information, segmentation, delta quantization, transform-size selection, coefficient decoding, inverse quantization, inverse transforms, complete intra prediction, intra-block copy, official extreme-displacement intra-block-copy conformance, the 12-profile reconstruction matrix, corrected twelve-bit inverse-transform SIMD arithmetic, layered-item properties, layered reference/header/CDF/motion-field state, inter-frame intra blocks, SIMD-first translational prediction, complete single-reference inter reconstruction, compound reference trees and modes, paired reference-MV derivation, reference-dependent bounded sequence decoding, allocation-free SIMD-first equal averaging, selected inter-intra prediction, selectable compound blending, OBMC, scaled-reference reconstruction, local warped prediction, non-translational global prediction, official motion-vector conformance, official spatial- and temporal-layer default-operating-point conformance, official active-film-grain and monochrome sequence conformance, selected spatial-layer presentation, progressive color and auxiliary-alpha conformance, and pinned-HM HEVC CABAC verification. This dashboard is the authoritative delivery order. The detailed phase checklists below provide subsystem evidence; they do not override the current-stage marker or permit work to skip ahead.
Commit `a0d1b5af56acb3a3a9aebb29c916d1b36cd49367` restores the established JPEG color-converter operator architecture throughout the HEIF implementation. `Av1ForwardTransformer` owns its nested one-dimensional contract and all twelve concrete forward transform operators; `Av1Inverse2dTransformer` owns the corresponding inverse contract and operators; and `Av1InverseTransformer` owns the byte and high-bit-depth reconstruction-output operators. Each contract lives in the owner's `.Operator.cs`, while every semantic transform with a shared traversal has its own `<Owner>.<Semantic>Operator.cs` partial-family file and implements concrete scalar and SIMD overload bodies without a forwarding semantic core. The same owner-and-partial-file rule now covers HEVC inverse transforms and intra prediction, AV1 and HEVC deblocking, AV1 CDEF, and HEVC transform-skip reconstruction. Vector-width and sample-storage adapters that are not semantic dispatch operators are named `Operations`; no operator type is named after a hardware width, no static contract uses CRTP, no source file groups multiple concrete semantic operator structs, and no semantic operator remains top-level. Roslynk reports zero compiler errors, both Release source targets build with zero warnings and errors, and 736 focused `net10.0` transform, loop-filter, prediction, reconstruction, transfer-function, and film-grain cases pass without failures or skips through the existing `FeatureTestRunner` coverage. All 56 new C# paths resolve to the existing `csharp` diff driver without an attributes change, and `git diff --check` is clean.
Commit `a0d1b5af56acb3a3a9aebb29c916d1b36cd49367` restores the established JPEG color-converter operator architecture throughout the HEIF implementation. `Av1ForwardTransformer` owns its nested one-dimensional contract and all twelve concrete forward transform operators; `Av1Inverse2dTransformer` owns the corresponding inverse contract and operators; and `Av1InverseTransformer` owns the byte and high-bit-depth reconstruction-output operators. Each contract lives in the owner's `.Operator.cs`, while every semantic transform with a shared traversal has its own `<Owner>.<Semantic>Operator.cs` partial-family file and implements concrete scalar and SIMD overload bodies without a forwarding semantic core. The same owner-and-partial-file rule now covers HEVC inverse transforms and intra prediction, AV1 and HEVC deblocking, AV1 CDEF, and HEVC transform-skip reconstruction. Vector-width and sample-storage adapters that are not semantic dispatch operators are named `Operations`; no operator type is named after a hardware width, no static contract uses CRTP, no source file groups multiple concrete semantic operator structs, and no semantic operator remains top-level. Roslynk reports zero compiler errors, both Release source targets build with zero warnings and errors, and 736 focused `net10.0` transform, loop-filter, prediction, reconstruction, transfer-function, and film-grain cases pass without failures or skips through the existing `FeatureTestRunner` coverage. All 56 new C# paths resolve to the existing `csharp` diff driver without an attributes change, and `git diff --check` is clean.
Commit `35e65e9546dd78847d4de7cae082e26229b3a744` closes the Phase 4 HEVC CABAC checkpoint without a production correction. Exact comparison with HM commit `9c1f298659ab0cee9dc13d23d0304221575410b9` confirms the context-initialization equation, all 178 retained intra-picture initialization values, both 128-entry probability-state transition tables, the 64-by-4 least-probable-symbol range table, the 32-entry normalization table, arithmetic decision and refill paths, ordinary and aligned bypass paths, termination, alignment validation, and PCM restart. Focused tests cover QP 0, 22, and 51 initialization, every reachable packed context state, both arithmetic outcomes, bypass, termination, invalid alignment, and PCM suspension/restart. A fresh Release run passes all 26 CABAC and production complete-slice cases without failures or skips: ten official Sony GENERAL Range Extensions first pictures match their exact native planes and published digests, five real HEIC item payloads match HM output exactly, and both constructor-failure and constrained-allocation ownership cases remain balanced. Roslynk reports zero compiler errors, scoped StyleCop and whitespace verification are clean, and `git diff --check` is clean.
Commit `1c58d855f70b024170ced9eb0a7005f0f9c955ad` records the complete official motion-vector conformance checkpoint. The official IVF has SHA-1 `F064290D7FCD3B3DE19020E8AEC6C43C88D3A505`, matching the pinned libaom test-data manifest, and SHA-256 `222A9050059B254DAB17CFB802FF829C778E3F93AF18961A622C8268576C1395`; its pinned-libaom Y4M has SHA-256 `D97AC78C81782CF1507549368047769DC677DBE205706458D1EE9C807DE6EC78`. Both source targets build with zero warnings and errors, the `net10.0` test-project analyzer build completes with zero errors and 1,014 pre-existing repository warnings, Roslynk reports zero compiler errors, 3,985 focused `net10.0` cases pass without failures or skips, and `git diff --check` is clean.
Commit `1c58d855f70b024170ced9eb0a7005f0f9c955ad` records the complete official motion-vector conformance checkpoint. The official IVF has SHA-1 `F064290D7FCD3B3DE19020E8AEC6C43C88D3A505`, matching the pinned libaom test-data manifest, and SHA-256 `222A9050059B254DAB17CFB802FF829C778E3F93AF18961A622C8268576C1395`; its pinned-libaom Y4M has SHA-256 `D97AC78C81782CF1507549368047769DC677DBE205706458D1EE9C807DE6EC78`. Both source targets build with zero warnings and errors, the `net10.0` test-project analyzer build completes with zero errors and 1,014 pre-existing repository warnings, Roslynk reports zero compiler errors, 3,985 focused `net10.0` cases pass without failures or skips, and `git diff --check` is clean.
Commit `019ac5648b4380a6ff4865072c96fde29ce09fad` records the complete selected-spatial-layer presentation checkpoint. An essential `lsel` selecting the genuine 40x40 base layer of the committed 40x40-to-80x80 progressive AVIF returns that exact pinned-libaom native reconstruction, then scales its YUV444 planes to the 80x80 `ispe` extent before color conversion and matches pinned libavif's RGBA output exactly. Retained reconstructed planes remain at coded dimensions; presentation planes use group-safe allocator-owned rows and are returned exactly once under a 1,024-byte constrained allocator. Portable `Vector128` and scalar two-times filters match pinned libyuv edge, quarter-sample, and rounding results at 8 and 12 bits through `FeatureTestRunner`. Both source targets build with zero warnings and errors, the `net10.0` test-project analyzer build completes with zero errors and 1,014 pre-existing repository warnings, Roslynk reports zero compiler errors, 156 focused reconstruction and color cases pass without failures or skips, and `git diff --check` is clean.
Commit `019ac5648b4380a6ff4865072c96fde29ce09fad` records the complete selected-spatial-layer presentation checkpoint. An essential `lsel` selecting the genuine 40x40 base layer of the committed 40x40-to-80x80 progressive AVIF returns that exact pinned-libaom native reconstruction, then scales its YUV444 planes to the 80x80 `ispe` extent before color conversion and matches pinned libavif's RGBA output exactly. Retained reconstructed planes remain at coded dimensions; presentation planes use group-safe allocator-owned rows and are returned exactly once under a 1,024-byte constrained allocator. Portable `Vector128` and scalar two-times filters match pinned libyuv edge, quarter-sample, and rounding results at 8 and 12 bits through `FeatureTestRunner`. Both source targets build with zero warnings and errors, the `net10.0` test-project analyzer build completes with zero errors and 1,014 pre-existing repository warnings, Roslynk reports zero compiler errors, 156 focused reconstruction and color cases pass without failures or skips, and `git diff --check` is clean.
@ -71,15 +73,15 @@ Status meanings:
- **Not started:** supporting primitives may exist, but the production format path is absent.
- **Not started:** supporting primitives may exist, but the production format path is absent.
- **Current:** the only work item that should be advanced before taking the next queued item.
- **Current:** the only work item that should be advanced before taking the next queued item.
Current development stage: **Stage 4 — complete HEVC still-image decoding.** The AV1 still-image exit gate is complete across the exact 12-profile matrix, layered reference-dependent items, every connected normative reconstruction tool, official quantizer and size boundaries, constrained allocation, and pinned native and presentation output. The bounded HEVC item-local syntax and allocator-backed decoder lifecycle are implemented and verified through official native-plane, real HEIC payload, constrained-allocation, constructor-failure, and public presentation cases. The next dependency is complete CABAC arithmetic and context-transition verification. Neither AV1 nor HEVC production encoding is implemented.
Current development stage: **Stage 4 — complete HEVC still-image decoding.** The AV1 still-image exit gate is complete across the exact 12-profile matrix, layered reference-dependent items, every connected normative reconstruction tool, official quantizer and size boundaries, constrained allocation, and pinned native and presentation output. The bounded HEVC item-local syntax, allocator-backed decoder lifecycle, and CABAC arithmetic and context state are implemented and verified through pinned-HM tables, official native-plane output, real HEIC payloads, constrained allocation, constructor failure, and public presentation cases. The next dependency is complete coding-tree, coding-unit, prediction-unit, and transform-unit traversal across every permitted size and partition mode. Neither AV1 nor HEVC production encoding is implemented.
Immediate checkpoint: **current — verify Phase 4 HEVC CABAC arithmetic and every required context transition.** Reconcile the existing syntax reader and context tables with the pinned HM implementation, close any valid still-image gaps, and retain focused bit-exact and complete-slice evidence before advancing to traversal.
Immediate checkpoint: **current — complete Phase 4 HEVC coding-tree traversal.** Reconcile coding-tree, coding-unit, prediction-unit, and transform-unit traversal with the pinned HM implementation across every permitted size and partition mode, close any valid still-image gaps, and retain focused syntax and complete-slice evidence before advancing to prediction.
| Order | Delivery stage | State | Delivered state | Gate that remains open |
| Order | Delivery stage | State | Delivered state | Gate that remains open |
| --- | --- | --- | --- | --- |
| --- | --- | --- | --- | --- |
| 1 | Baseline, provenance, documentation, and public contract | In progress | Pinned codec references, a bounded image-only scope, encoder options, typed bit depth, decoder-option propagation, and extensive HEIF documentation exist. | Complete the all-file documentation audit, record a fresh Release baseline, finish distinct public HEIC/AVIF save boundaries, and close API review. |
| 1 | Baseline, provenance, documentation, and public contract | In progress | Pinned codec references, a bounded image-only scope, encoder options, typed bit depth, decoder-option propagation, and extensive HEIF documentation exist. | Complete the all-file documentation audit, record a fresh Release baseline, finish distinct public HEIC/AVIF save boundaries, and close API review. |
| 2 | Bounded HEIF item and image-sequence container | In progress | Still-item parsing, grids, auxiliary alpha, metadata properties, bounded image-sequence tracks, Identify, and all-sync AV1 sequence presentation are connected. | Complete adversarial boundary coverage, remaining item/property behavior, reference-dependent sequence reconstruction, and the bounded sequence writer. |
| 2 | Bounded HEIF item and image-sequence container | In progress | Still-item parsing, grids, auxiliary alpha, metadata properties, bounded image-sequence tracks, Identify, and all-sync AV1 sequence presentation are connected. | Complete adversarial boundary coverage, remaining item/property behavior, reference-dependent sequence reconstruction, and the bounded sequence writer. |
| 3 | Still-image AV1 and HEVC decoding | **Current** | AV1 still-image decoding has passed its complete exact native/presentation profile, layered-item, normative-tool, official-sequence, constrained-allocation, and SIMD-fallback exit gate. HEVC item-local syntax and reconstruction pass exact HM/libheif fixtures across the recorded 8/10/12-bit and chroma cases. | Complete HEVC lifecycle verification, then the remaining normative-tool, profile, and Range Extensions matrix in dependency order. |
| 3 | Still-image AV1 and HEVC decoding | **Current** | AV1 still-image decoding has passed its complete exact native/presentation profile, layered-item, normative-tool, official-sequence, constrained-allocation, and SIMD-fallback exit gate. HEVC item-local syntax, lifecycle, CABAC, and reconstruction pass exact HM/libheif fixtures across the recorded 8/10/12-bit and chroma cases. | Complete coding-tree traversal, then the remaining normative-tool, profile, and Range Extensions matrix in dependency order. |
| 4 | Complete decoded presentation and animation | In progress | Shared SIMD-first AV1/HEVC color conversion, ICC application, grids, transforms, direct planar alpha composition, frame metadata, repetition, and independently decodable AV1 sequence samples exist. | Close the full color/ICC cross-product, HEVC sequence decoding, AV1/HEVC reference-dependent samples, frame-local metadata/alpha behavior, and independent animated decode vectors. |
| 4 | Complete decoded presentation and animation | In progress | Shared SIMD-first AV1/HEVC color conversion, ICC application, grids, transforms, direct planar alpha composition, frame metadata, repetition, and independently decodable AV1 sequence samples exist. | Close the full color/ICC cross-product, HEVC sequence decoding, AV1/HEVC reference-dependent samples, frame-local metadata/alpha behavior, and independent animated decode vectors. |
| 5 | AV1/AVIF encoding | Not started | RGB-to-planar conversion, forward transforms, OBU writer foundations, options, and container-writing infrastructure exist. | `HeifEncoderCore` still rejects AV1. Implement a real independently decodable lossy/lossless AV1 payload and the complete AVIF item/metadata matrix. |
| 5 | AV1/AVIF encoding | Not started | RGB-to-planar conversion, forward transforms, OBU writer foundations, options, and container-writing infrastructure exist. | `HeifEncoderCore` still rejects AV1. Implement a real independently decodable lossy/lossless AV1 payload and the complete AVIF item/metadata matrix. |
| 6 | HEVC/HEIC encoding | Not started | Shared input color conversion, options, and HEIF writer infrastructure exist. | `HeifEncoderCore` still rejects HEVC. Implement a real independently decodable lossy/lossless HEVC payload and the complete HEIC item/metadata matrix. |
| 6 | HEVC/HEIC encoding | Not started | Shared input color conversion, options, and HEIF writer infrastructure exist. | `HeifEncoderCore` still rejects HEVC. Implement a real independently decodable lossy/lossless HEVC payload and the complete HEIC item/metadata matrix. |
@ -136,7 +138,8 @@ Immediate checkpoint: **current — verify Phase 4 HEVC CABAC arithmetic and eve
- [x] Add the missing official ten-bit sequence evidence from libaom's pinned test-data manifest. All ten active-film-grain YUV420 frames and all ten monochrome frames match the pinned generic libaom native Y4M samples exactly under normal and scalar `FeatureTestRunner` dispatch, and both complete sequences pass through a 2 KiB constrained tracked allocator with balanced exactly-once returns. The three new focused cases and all 20 official-sequence regression cases pass without failures or skips, the scoped Release test-project analyzer build completes with zero errors and 1,011 repository warnings, Roslynk reports zero compiler errors, and `git diff --check` is clean. The existing production decoder required no correction. Commit `deefeba2340932909aa3e27516d965a294cf6faa` records the checkpoint.
- [x] Add the missing official ten-bit sequence evidence from libaom's pinned test-data manifest. All ten active-film-grain YUV420 frames and all ten monochrome frames match the pinned generic libaom native Y4M samples exactly under normal and scalar `FeatureTestRunner` dispatch, and both complete sequences pass through a 2 KiB constrained tracked allocator with balanced exactly-once returns. The three new focused cases and all 20 official-sequence regression cases pass without failures or skips, the scoped Release test-project analyzer build completes with zero errors and 1,011 repository warnings, Roslynk reports zero compiler errors, and `git diff --check` is clean. The existing production decoder required no correction. Commit `deefeba2340932909aa3e27516d965a294cf6faa` records the checkpoint.
- [x] Add official minimum- and maximum-quantizer dependent-frame evidence for the eight- and ten-bit libaom matrices. The four retained streams and pinned generic-libaom Y4M references pass exact native comparison under normal and scalar `FeatureTestRunner` dispatch, and the combined sequences pass through a 2,560-byte row-aligned constrained tracked allocator with balanced exactly-once returns. All three new focused cases and all 23 official-sequence regression cases pass without failures or skips, the scoped Release test-project analyzer build completes with zero errors and 1,011 repository warnings, Roslynk reports zero compiler errors, and `git diff --check` is clean. The existing production decoder required no correction. Commit `68cbe2fb9483215db36977a06a2dcac04e2d90bc` records the checkpoint.
- [x] Add official minimum- and maximum-quantizer dependent-frame evidence for the eight- and ten-bit libaom matrices. The four retained streams and pinned generic-libaom Y4M references pass exact native comparison under normal and scalar `FeatureTestRunner` dispatch, and the combined sequences pass through a 2,560-byte row-aligned constrained tracked allocator with balanced exactly-once returns. All three new focused cases and all 23 official-sequence regression cases pass without failures or skips, the scoped Release test-project analyzer build completes with zero errors and 1,011 repository warnings, Roslynk reports zero compiler errors, and `git diff --check` is clean. The existing production decoder required no correction. Commit `68cbe2fb9483215db36977a06a2dcac04e2d90bc` records the checkpoint.
- [x] Add exact official frame-size evidence at all four corners of libaom's 196-to-226-pixel matrix. Both frames from each retained stream match the pinned generic-libaom native Y4M samples under normal and scalar `FeatureTestRunner` dispatch, and all four sequences pass through a 1 KiB constrained tracked allocator with balanced exactly-once returns. Both new focused cases and all 25 official-sequence regression cases pass without failures or skips, the scoped Release test-project analyzer build completes with zero errors and 1,011 repository warnings, Roslynk reports zero compiler errors, and `git diff --check` is clean. The existing production decoder required no correction. Commit `ccdcddc92e3f7c45eb0a964569a9c8d2756c0526` records the checkpoint.
- [x] Add exact official frame-size evidence at all four corners of libaom's 196-to-226-pixel matrix. Both frames from each retained stream match the pinned generic-libaom native Y4M samples under normal and scalar `FeatureTestRunner` dispatch, and all four sequences pass through a 1 KiB constrained tracked allocator with balanced exactly-once returns. Both new focused cases and all 25 official-sequence regression cases pass without failures or skips, the scoped Release test-project analyzer build completes with zero errors and 1,011 repository warnings, Roslynk reports zero compiler errors, and `git diff --check` is clean. The existing production decoder required no correction. Commit `ccdcddc92e3f7c45eb0a964569a9c8d2756c0526` records the checkpoint.
- [ ] **Current:** verify HEVC CABAC arithmetic and every required context transition, then complete the remaining HEVC still-image dependencies and Range Extensions matrix in Phase 4 order.
- [x] Verify HEVC CABAC arithmetic and every required context transition against pinned HM tables and complete production slices.
- [ ] **Current:** complete coding-tree, coding-unit, prediction-unit, and transform-unit traversal across every permitted size and partition mode, then continue the remaining HEVC still-image dependencies in Phase 4 order.
- [ ] Close shared decoded presentation, ICC, alpha, grid, transform, metadata, and animated AV1/HEVC decode gates.
- [ ] Close shared decoded presentation, ICC, alpha, grid, transform, metadata, and animated AV1/HEVC decode gates.
- [ ] Implement and independently verify real AV1/AVIF still encoding.
- [ ] Implement and independently verify real AV1/AVIF still encoding.
- [ ] Implement and independently verify real HEVC/HEIC still encoding.
- [ ] Implement and independently verify real HEVC/HEIC still encoding.
@ -674,8 +677,8 @@ Implement and verify in dependency order:
- [x] HEIF item-local length-delimited NAL units, `hvcC`, VPS, SPS, PPS, and the parameter-set and slice-header syntax needed to decode the one independently coded picture carried by a supported still-image item. The production path remains item-local and exposes no Annex B byte-stream API or access-unit/timeline abstraction. Ten official Sony GENERAL Range Extensions first pictures, five real HEIC item payloads, and five public HEIC presentation cases pass exactly in Release: 20 cases with no failures or skips.
- [x] HEIF item-local length-delimited NAL units, `hvcC`, VPS, SPS, PPS, and the parameter-set and slice-header syntax needed to decode the one independently coded picture carried by a supported still-image item. The production path remains item-local and exposes no Annex B byte-stream API or access-unit/timeline abstraction. Ten official Sony GENERAL Range Extensions first pictures, five real HEIC item payloads, and five public HEIC presentation cases pass exactly in Release: 20 cases with no failures or skips.
- [x] One bounded decoder lifecycle owns only the parameter sets, current-picture state, slice/tile entropy state, and reconstructed planes required by that image item. Every allocator-backed child constructor and the owning picture decoder now unwind unpublished rents in reverse order. Focused tests exercise every constructor allocation-failure position and a complete real HEIC reconstruction through 2 KiB allocator groups with balanced exactly-once returns; all 22 official native-plane, real-item, ownership, constrained-allocation, and public presentation cases pass without failures or skips. Both Release source targets build with zero warnings and errors, the scoped Release test-project analyzer build completes with zero errors and 1,011 repository warnings, Roslynk reports zero compiler errors, and `git diff --check` is clean. Commit `b6ba2dbf2f90c7b0a5d9da4e9f45d045bbce1a65` records the syntax reconciliation and lifecycle correction.
- [x] One bounded decoder lifecycle owns only the parameter sets, current-picture state, slice/tile entropy state, and reconstructed planes required by that image item. Every allocator-backed child constructor and the owning picture decoder now unwind unpublished rents in reverse order. Focused tests exercise every constructor allocation-failure position and a complete real HEIC reconstruction through 2 KiB allocator groups with balanced exactly-once returns; all 22 official native-plane, real-item, ownership, constrained-allocation, and public presentation cases pass without failures or skips. Both Release source targets build with zero warnings and errors, the scoped Release test-project analyzer build completes with zero errors and 1,011 repository warnings, Roslynk reports zero compiler errors, and `git diff --check` is clean. Commit `b6ba2dbf2f90c7b0a5d9da4e9f45d045bbce1a65` records the syntax reconciliation and lifecycle correction.
- [] CABAC arithmetic decoding and every required context transition.
- [x] CABAC arithmetic decoding and every required context transition. Commit `35e65e9546dd78847d4de7cae082e26229b3a744` records exact pinned-HM table and algorithm comparison, 9 focused arithmetic/context cases, 17 complete production-slice and allocator-lifecycle cases, zero Roslynk compiler errors, clean scoped StyleCop and whitespace verification, and clean `git diff --check`.
- [ ] Coding-tree, coding-unit, prediction-unit, and transform-unit traversal across all permitted sizes and partition modes.
- [ ] **Current:** coding-tree, coding-unit, prediction-unit, and transform-unit traversal across all permitted sizes and partition modes.
- [ ] Intra prediction for every luma and chroma mode, including strong intra smoothing and constrained prediction rules.
- [ ] Intra prediction for every luma and chroma mode, including strong intra smoothing and constrained prediction rules.
- [x] Implement and verify the allocation-free SIMD-first predictor primitive for all 35 modes, 4/8/16/32 blocks, and 8/10/12-bit samples.
- [x] Implement and verify the allocation-free SIMD-first predictor primitive for all 35 modes, 4/8/16/32 blocks, and 8/10/12-bit samples.
- [x] Implement reconstructed-plane reference collection, substitution, asymmetric chroma-unit handling, and reference-filter selection from caller-owned availability and scratch spans.
- [x] Implement reconstructed-plane reference collection, substitution, asymmetric chroma-unit handling, and reference-filter selection from caller-owned availability and scratch spans.