@ -29,7 +29,7 @@ Checkboxes may be marked complete only when the implementation and the verificat
## Delivery dashboard
## Delivery dashboard
Last reconciled with the source tree on 2026-08-28 against production checkpoint `096fb9af8` and the uncommitted single-reference inter-decoding work identified below. Committed checkpoints include the AV1 transform architecture, OBU framing, intra-block copy, 12-profile reconstruction matrix, layered-item properties, layered reference/header state, inter-frame intra blocks, SIMD-first translational prediction, and normalized self-guided-filter dispatch. The progressive fixture audit found that the initial `.bit` file appended a physically adjacent auxiliary-alpha extent instead of the color item's second `iloc` extent. The corrected 55-plus-17-byte logical color payload decodes as two frames with exact pinned libaom output, and the three production-path progressive tests now pass for native planes, final libavif presentation, constrained allocation, and decoder-result ownership. The complete focused Release matrix, documentation review, and final diff checks remain open. 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 2026-08-29 against production checkpoint `8b9aa4b2cfe59ff0f8c348d9bb06678a5ff12f2a` and the verified equal-average compound work described below. Committed checkpoints include the AV1 transform architecture, OBU framing, intra-block copy, 12-profile reconstruction matrix, layered-item properties, layered reference/header/CDF/motion-field state, inter-frame intra blocks, SIMD-first translational prediction, and complete single-reference inter reconstruction. The current checkpoint adds compound reference trees and modes, paired reference-MV derivation, reference-dependent bounded sequence decoding, and allocation-free SIMD-first equal averaging. A pinned libavif/libaom 19-frame YUV444 sequence passes exact final native-plane and RGBA presentation comparison, production `DecodeBlock()` coverage, constrained allocation, and exactly-once allocator-return tracking. Both source target builds pass with zero warnings and errors; the test-project analyzer build passes with zero errors and only pre-existing repository warnings; 119 direct focused cases and three `FeatureTestRunner` cases pass with zero failures or skips; and `git diff --check` is clean. 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.
Status meanings:
Status meanings:
@ -39,15 +39,15 @@ 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 3 — complete AV1 still-image decoding.** The committed decoder retains reference/header/CDF/motion-field state, derives frame-level skip-mode references, consumes temporal segment prediction, and decodes intra-coded blocks inside inter frames. The uncommitted working tree adds single-reference selection, spatial and temporal reference-MV derivation, NEAREST/NEAR/NEW/GLOBAL mode parsing, DRL, interpolation-filter syntax, motion-mode eligibility, and simple translational reconstruction before residual traversal. The exact dependent-frame oracle, constrained-allocation path, and decoder-result motion-field ownership test pass in Release; the complete focused Release matrix and final source/documentation review remain open. Compound prediction, inter-intra, OBMC, warped motion, scaled references, and non-translational global prediction remain explicitly unsupported. Neither AV1 nor HEVC production encoding is implemented.
Current development stage: **Stage 3 — complete AV1 still-image decoding.** The decoder retains reference/header/CDF/motion-field state, derives frame-level skip-mode references, consumes temporal segment prediction, decodes intra-coded blocks inside inter frames, reconstructs single-reference NEAREST/NEAR/NEW/GLOBAL translational blocks, and now reconstructs two retained predictors with equal-weight compound averaging before residual traversal. Exact dependent-frame and 19-frame compound-sequence native/presentation comparisons, constrained allocation, and ownership evidence pass. Selectable distance-weighted and masked compound blending, inter-intra prediction, OBMC, warped motion, scaled references, and non-translational global prediction remain explicitly unsupported. Neither AV1 nor HEVC production encoding is implemented.
Immediate checkpoint: **finish the source audit, independently verify, document, and commit the existing single-reference AV1 inter-block slice before implementing another codec feature.** Pinned libaom source confirms that interpolation syntax is omitted for an identity `GLOBALMV` block of sufficient size and that the spatial single-reference extension loops stop at two candidates; the current predicates match those two call paths. The corrected logical color payload and two-frame YUV444-alpha reference now prove the exact final native planes and libavif presentation through the complete production decoder, including constrained frame-plane allocation and decoder-result motion-field ownership. The complete focused Release verification and final source/documentation review remain required. This work remains inside the existing image-item and bounded image-sequence surfaces and must not expand into a general ISO BMFF/video model.
Immediate checkpoint: **implement and independently verify selected inter-intra prediction and selectable compound blending before advancing to OBMC.** Preserve the committed translational predictor and equal-average rounding contracts, consume each selection tree in normative order, keep mask and predictor workspaces allocator-owned and allocation-free per block, and prove each production branch with independently encoded bounded AVIF content and exact native-plane comparison. This work remains inside the existing image-item and bounded image-sequence surfaces and must not expand into a general ISO BMFF/video model.
| 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** | HEVC reconstruction reaches exact HM/libheif fixtures across the recorded 8/10/12-bit and chroma cases. Committed AV1 work includes bounded OBU framing, reconstruction, filters, grain, color, transforms, intra-block copy, an exact independent 12-profile bit-depth/chroma matrix through every dispatch tier, retained layered reference/header/CDF state, temporal segment prediction, inter-frame intra blocks, and SIMD-first translational prediction. The working tree contains an unverified simple single-reference inter path. | Close the simple single-reference checkpoint with exact dependent-frame evidence; implement compound, inter-intra, OBMC, scaled-reference, warped, and non-translational global prediction; remove every other valid AV1 still-image unsupported branch with independent vectors; then complete the remaining HEVC profile and Range Extensions matrix. |
| 3 | Still-image AV1 and HEVC decoding | **Current** | HEVC reconstruction reaches exact HM/libheif fixtures across the recorded 8/10/12-bit and chroma cases. AV1 work includes bounded OBU framing, reconstruction, filters, grain, color, transforms, intra-block copy, an exact independent 12-profile bit-depth/chroma matrix through every dispatch tier, retained layered reference/header/CDF/motion-field state, temporal segment prediction, inter-frame intra blocks, SIMD-first translational prediction, exact single-reference inter reconstruction, and exact equal-average compound reconstruction through a reference-dependent bounded sequence. | Implement inter-intra and selectable compound blending, then OBMC, scaled-reference, warped, and non-translational global prediction; remove every other valid AV1 still-image unsupported branch with independent vectors; then complete the remaining HEVC profile and Range Extensions matrix. |
| 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. |
- [x] Use counted frame/reference ownership for allocator-owned retained and temporal motion fields, with allocation tracking for initialization, retained-slot aliases, failure unwinding, presentation ownership, decoder-result ownership, and exactly-once final disposal.
- [x] Use counted frame/reference ownership for allocator-owned retained and temporal motion fields, with allocation tracking for initialization, retained-slot aliases, failure unwinding, presentation ownership, decoder-result ownership, and exactly-once final disposal.
- [x] Request the existing contiguous ImageSharp allocation contract for every padded AV1 frame plane. Constrained-allocator coverage verifies complete-plane block reconstruction without copying or per-block allocation.
- [x] Request the existing contiguous ImageSharp allocation contract for every padded AV1 frame plane. Constrained-allocator coverage verifies complete-plane block reconstruction without copying or per-block allocation.
- [x] Complete source review of the new motion-mode and single-reference tests.
- [x] Complete source review of the new motion-mode and single-reference tests.
- [x] Pass the exact current tree's Release verification: `net10.0` and `net11.0` source builds and the `net10.0` test-project analyzer build complete with zero warnings and errors; 293 focused `net10.0` entropy, candidate, motion, interpolation, lifecycle, reconstruction, ownership, and `FeatureTestRunner` cases pass with zero failures or skips; and `git diff --check` is clean.
- [x] Pass the exact single-reference checkpoint's Release verification: `net10.0` and `net11.0` source builds complete with zero warnings and errors; the `net10.0` test-project analyzer build completes with zero errors and pre-existing repository warnings; 293 focused `net10.0` entropy, candidate, motion, interpolation, lifecycle, reconstruction, ownership, and `FeatureTestRunner` cases pass with zero failures or skips; and `git diff --check` is clean.
- [x] Correct the progressive dependent-frame extraction and compare the final frame's first three native planes with pinned libaom output and its final RGBA presentation with pinned libavif exactly. The unmodified AVIF has the recorded SHA-256 and stores the primary color item's 55-byte base extent at offset 511 and 17-byte dependent extent at offset 583. The corrected logical `.bit` payload decodes as two YUV444 frames with pinned libaom `03087864cf4bea6abb0d28f95cf7843511413d8f`; the retained two-frame YUV444-alpha reference and final PNG come from pinned libavif linked to that build. The production test selects the second native frame, requires inter-coded blocks, and passes exact native and presentation comparisons through `FeatureTestRunner`.
- [x] Correct the progressive dependent-frame extraction and compare the final frame's first three native planes with pinned libaom output and its final RGBA presentation with pinned libavif exactly. The unmodified AVIF has the recorded SHA-256 and stores the primary color item's 55-byte base extent at offset 511 and 17-byte dependent extent at offset 583. The corrected logical `.bit` payload decodes as two YUV444 frames with pinned libaom `03087864cf4bea6abb0d28f95cf7843511413d8f`; the retained two-frame YUV444-alpha reference and final PNG come from pinned libavif linked to that build. The production test selects the second native frame, requires inter-coded blocks, and passes exact native and presentation comparisons through `FeatureTestRunner`.
- [ ] Decode compound and inter-intra modes, masked blending, OBMC, scaled references, and warped and non-translational global-motion prediction without changing the single-reference predictor contract or rounding model.
- [x] Decode all compound reference-pair trees and inter modes, retain paired spatial/temporal reference-MV candidates through DRL selection, and reconstruct two translational predictors with allocation-free equal-weight averaging across 8/10/12-bit samples without changing the single-reference predictor contract or rounding model.
- [ ] Verify every connected mode and filter with independently encoded dependent-layer AV1 image-item fixtures and exact native-plane comparisons.
- [x] Verify the equal-average production branch with the pinned 19-frame libavif YUV444 sequence. The final native Y, U, and V planes match pinned libaom exactly, final RGBA presentation matches pinned libavif exactly, production `DecodeBlock()` is covered at 8/10/12 bit, constrained plane allocation passes, and allocator tracking returns every retained and temporal motion-field buffer exactly once.
- [ ] Decode selected inter-intra prediction and selectable distance-weighted, wedge, and difference-weighted compound blending.
- [ ] Verify every remaining connected mode and filter with independently encoded bounded AV1 content and exact native-plane comparisons.
- [ ] Return the explicitly selected spatial layer or the final displayed layer, keeping reference reconstruction separate from display-only film grain.
- [ ] Return the explicitly selected spatial layer or the final displayed layer, keeping reference reconstruction separate from display-only film grain.
- [ ] Verify color and auxiliary-alpha output exactly against both pinned libavif progressive fixtures under normal SIMD dispatch and all required `FeatureTestRunner` fallbacks.
- [ ] Verify color and auxiliary-alpha output exactly against both pinned libavif progressive fixtures under normal SIMD dispatch and all required `FeatureTestRunner` fallbacks.
- [ ] Correct the audited 12-bit inverse ADST4, Identity4, and Identity16 SIMD arithmetic by widening only the libaom-widened multiply/accumulate operations, with exact conformant-range vectors and `FeatureTestRunner` coverage.
- [ ] Correct the audited 12-bit inverse ADST4, Identity4, and Identity16 SIMD arithmetic by widening only the libaom-widened multiply/accumulate operations, with exact conformant-range vectors and `FeatureTestRunner` coverage.
@ -349,7 +352,7 @@ This table is intentionally incomplete. Add a row before each additional AV1 or
## Current implementation assessment
## Current implementation assessment
This assessment was reconciled with the source tree on 2026-08-27, including production checkpoint `096fb9af8` and the explicitly identified uncommitted work. Unless a result is stated explicitly, each item is a source-inspection finding rather than a verified interoperability claim.
This assessment was reconciled with the source tree on 2026-08-29, including production checkpoint `8b9aa4b2cfe59ff0f8c348d9bb06678a5ff12f2a` and the verified equal-average compound checkpoint. Unless a result is stated explicitly, each item is a source-inspection finding rather than a verified interoperability claim.
### Public integration
### Public integration
@ -386,10 +389,11 @@ This assessment was reconciled with the source tree on 2026-08-27, including pro
### AV1 decoder
### AV1 decoder
- The bounded `Av1Decoder` session parses all tile state before allocating and reconstructing each coded image layer. After successful completion it retains the ungrained reference planes, frame header, frame information, and published entropy snapshot in the refreshed slots, while presentation-only ownership remains separate. A new accepted sequence header resets both parser and retained-owner state. This is dependency reconstruction within one bounded image item; `show_existing_frame` playback remains rejected and no animation/video reference model is exposed.
- The bounded `Av1Decoder` session parses all tile state before allocating and reconstructing each coded image layer or sequence sample. After successful completion it retains the ungrained reference planes, frame header, frame information, and published entropy snapshot in the refreshed slots, while presentation-only ownership remains separate. A new accepted sequence header resets both parser and retained-owner state. Bounded image-sequence decoding accepts `show_existing_frame`, including its key-frame reference reset and separate film-grain presentation ownership, without exposing a general animation/video reference model.
- Committed inter-frame support reaches the intra-coded-block branch and provides SIMD-first translational prediction. The uncommitted working tree additionally parses single-reference selection, builds the fixed-capacity spatial and temporal reference-MV stack, decodes NEAREST/NEAR/NEW/GLOBAL and DRL syntax, decodes or infers interpolation filters, checks inter-intra and motion-mode eligibility, and invokes simple translational prediction before residual reconstruction. The exact corrected dependent-frame fixture now passes native-plane and final-presentation comparisons through the production decoder, but the slice is not delivered until the complete focused Release matrix, final review, and checkpoint commit pass.
- Committed inter-frame support parses single-reference selection, builds the fixed-capacity spatial and temporal reference-MV stack, decodes NEAREST/NEAR/NEW/GLOBAL and DRL syntax, decodes or infers interpolation filters, checks inter-intra and motion-mode eligibility, and invokes simple translational prediction before residual reconstruction. Commit `8b9aa4b2cfe59ff0f8c348d9bb06678a5ff12f2a` records exact corrected dependent-frame native-plane and final-presentation comparisons plus the complete focused Release matrix and ownership/allocation evidence.
- The verified equal-average compound checkpoint owns every compound reference-selection and inter-mode distribution through the retained CDF lifecycle, derives primary and secondary candidate vectors as inseparable pairs, reconstructs both retained references through the existing translational predictor, and combines them through one SIMD-first byte/ushort averaging operator with scalar parity. The pinned 19-frame libavif sequence exercises the complete production block branch and matches pinned libaom native planes and pinned libavif presentation exactly after decoding all preceding reference samples.
- Source inspection against pinned libaom `03087864cf4bea6abb0d28f95cf7843511413d8f` resolves two disputed audit claims in favor of the current predicates. The interpolation call path uses `is_nontrans_global_motion()`, which returns false only for `TRANSLATION`, so an identity `GLOBALMV` block omits filter symbols. The single-reference spatial extension loops use `MAX_MV_REF_CANDIDATES`, which is two, while the full reference-MV stack capacity is eight. These loops are spatial extension, not temporal extension.
- Source inspection against pinned libaom `03087864cf4bea6abb0d28f95cf7843511413d8f` resolves two disputed audit claims in favor of the current predicates. The interpolation call path uses `is_nontrans_global_motion()`, which returns false only for `TRANSLATION`, so an identity `GLOBALMV` block omits filter symbols. The single-reference spatial extension loops use `MAX_MV_REF_CANDIDATES`, which is two, while the full reference-MV stack capacity is eight. These loops are spatial extension, not temporal extension.
- The remaining single-reference audit issues are concrete and open. The working tree now requests contiguous allocation for all padded AV1 frame planes and adds constrained-allocator coverage, but that contract has not passed the complete focused matrix. Motion fields use allocator-owned storage and counted leases, with new allocation tracking for aliases, success ownership, failure unwinding, and exactly-once disposal; those tests are also unverified. The supplied progressive fixture cannot reach the production inter branch: ImageSharp and exact pinned libaom both reject the enhancement frame's nonzero byte-alignment padding, while the supplied one-frame Y4M's first three planes exactly match the separately decoded base layer.
- Every padded AV1 frame plane requests ImageSharp's contiguous allocation contract, and constrained-allocator reconstruction passes without copying. Motion fields use allocator-owned storage and counted leases; allocation tracking passes for initialization, retained aliases, failure unwinding, presentation ownership, decoder-result ownership, and exactly-once disposal. The corrected logical progressive color payload reaches the production inter branch and its final native planes match pinned libaom exactly.
- Transform coefficient entropy derivation and updates now address the above contexts relative to the tile column and the left contexts relative to the current superblock row, preserve luma coordinates independently of chroma subsampling, and test every packed context entry for the libaom any-nonzero rule. Extended vertical partition updates advance the mode-information column rather than the row. The existing multi-superblock 4:4:4 AVIF fixture now completes tile parsing; independent coefficient-context vectors across tile boundaries, chroma layouts, bit depths, and edge-clipped transforms remain required.
- Transform coefficient entropy derivation and updates now address the above contexts relative to the tile column and the left contexts relative to the current superblock row, preserve luma coordinates independently of chroma subsampling, and test every packed context entry for the libaom any-nonzero rule. Extended vertical partition updates advance the mode-information column rather than the row. The existing multi-superblock 4:4:4 AVIF fixture now completes tile parsing; independent coefficient-context vectors across tile boundaries, chroma layouts, bit depths, and edge-clipped transforms remain required.
- The reconstruction pipeline now records plane-relative transform geometry, preserves tile-local delta-Q and delta-LF predictors, derives segmentation and reference-adjusted filter levels, and runs the exact AV1 4-, 6-, 8-, and 14-tap deblocking kernels in normative vertical-then-horizontal order. Deblocking uses the same closed edge-operator architecture as the HEVC filter, with operators specialized by sample storage and orientation, `Vector128<int>` lanes representing the four rows or columns along an edge, and an allocation-free scalar fallback for disabled intrinsics. Exact native-plane comparison with pinned scalar libaom output now verifies active deblocking and complete reconstruction for real 8-bit 4:2:0, 10-bit 4:4:4, and 12-bit 4:4:4 content; genuine AVIF containers separately verify presentation and public bit-depth metadata. The pipeline then applies CDEF through one semantic filter architecture: paired AVX2 and single-block `Vector128` direction analysis, closed primary/secondary strength operators, packed 4x4/4x8/8x4/8x8 constrained filtering, byte/16-bit output operators, and an exact allocation-free scalar fallback. Decoder orchestration now owns the immutable plane snapshots and clean direction/variance maps through ImageSharp's memory allocator, widens 8-bit source rows with the same AVX2/128-bit/scalar tiers as libaom, lists each unit's non-skipped blocks in fixed inline storage, analyzes listed blocks in pairs, and writes filtered bytes or 16-bit samples directly to the frame planes. Independently encoded active-CDEF 8-bit 4:2:0 and 10/12-bit 4:4:4 streams match every visible native sample produced by pinned scalar libaom with restoration disabled. Independently encoded AVIF containers at the same three bit depths also match pinned scalar-libavif presentation exactly under normal, 256-bit, 128-bit, and scalar color-conversion dispatch. Active super-resolution derives the Appendix A bounded coded width and applies the exact 64-phase, 8-tap horizontal filter with aligned reconstruction-edge input, 8/10/12-bit clipping, and the existing cross-platform `Vector128_.MultiplyAddAdjacent` helper. Independently encoded active-super-resolution AV1 streams at 8, 10, and 12 bits match every visible native sample produced by pinned scalar libaom under normal and forced-scalar dispatch. Independently packaged AVIF containers at the same bit depths retain matching libavif profile, dimensions, chroma, and CICP properties, require active super-resolution in their actual AV1 item, and match pinned scalar-libavif presentation exactly under normal, 256-bit, 128-bit, and scalar color-conversion dispatch. Loop restoration follows super-resolution, preserves the required pre-CDEF deblocked context at internal stripes, and applies decoded Wiener or self-guided units from immutable plane snapshots. Independently encoded active-restoration streams at 8, 10, and 12 bits now match every native sample from pinned scalar libaom across AVX2, 128-bit, and scalar dispatch, with the fixture matrix proving both Wiener and self-guided unit selection. The matching AVIF containers also match pinned scalar-libavif presentation exactly, and an independent direct-window definition verifies all sixteen self-guided parameter sets at each supported bit depth across vector and scalar dispatch. Combined 8-bit 4:2:0, 10-bit 4:2:2, and 12-bit 4:4:4 streams additionally verify restoration-unit boundaries after super-resolution, including clipped chroma transform traversal at a coded-frame edge.
- The reconstruction pipeline now records plane-relative transform geometry, preserves tile-local delta-Q and delta-LF predictors, derives segmentation and reference-adjusted filter levels, and runs the exact AV1 4-, 6-, 8-, and 14-tap deblocking kernels in normative vertical-then-horizontal order. Deblocking uses the same closed edge-operator architecture as the HEVC filter, with operators specialized by sample storage and orientation, `Vector128<int>` lanes representing the four rows or columns along an edge, and an allocation-free scalar fallback for disabled intrinsics. Exact native-plane comparison with pinned scalar libaom output now verifies active deblocking and complete reconstruction for real 8-bit 4:2:0, 10-bit 4:4:4, and 12-bit 4:4:4 content; genuine AVIF containers separately verify presentation and public bit-depth metadata. The pipeline then applies CDEF through one semantic filter architecture: paired AVX2 and single-block `Vector128` direction analysis, closed primary/secondary strength operators, packed 4x4/4x8/8x4/8x8 constrained filtering, byte/16-bit output operators, and an exact allocation-free scalar fallback. Decoder orchestration now owns the immutable plane snapshots and clean direction/variance maps through ImageSharp's memory allocator, widens 8-bit source rows with the same AVX2/128-bit/scalar tiers as libaom, lists each unit's non-skipped blocks in fixed inline storage, analyzes listed blocks in pairs, and writes filtered bytes or 16-bit samples directly to the frame planes. Independently encoded active-CDEF 8-bit 4:2:0 and 10/12-bit 4:4:4 streams match every visible native sample produced by pinned scalar libaom with restoration disabled. Independently encoded AVIF containers at the same three bit depths also match pinned scalar-libavif presentation exactly under normal, 256-bit, 128-bit, and scalar color-conversion dispatch. Active super-resolution derives the Appendix A bounded coded width and applies the exact 64-phase, 8-tap horizontal filter with aligned reconstruction-edge input, 8/10/12-bit clipping, and the existing cross-platform `Vector128_.MultiplyAddAdjacent` helper. Independently encoded active-super-resolution AV1 streams at 8, 10, and 12 bits match every visible native sample produced by pinned scalar libaom under normal and forced-scalar dispatch. Independently packaged AVIF containers at the same bit depths retain matching libavif profile, dimensions, chroma, and CICP properties, require active super-resolution in their actual AV1 item, and match pinned scalar-libavif presentation exactly under normal, 256-bit, 128-bit, and scalar color-conversion dispatch. Loop restoration follows super-resolution, preserves the required pre-CDEF deblocked context at internal stripes, and applies decoded Wiener or self-guided units from immutable plane snapshots. Independently encoded active-restoration streams at 8, 10, and 12 bits now match every native sample from pinned scalar libaom across AVX2, 128-bit, and scalar dispatch, with the fixture matrix proving both Wiener and self-guided unit selection. The matching AVIF containers also match pinned scalar-libavif presentation exactly, and an independent direct-window definition verifies all sixteen self-guided parameter sets at each supported bit depth across vector and scalar dispatch. Combined 8-bit 4:2:0, 10-bit 4:2:2, and 12-bit 4:4:4 streams additionally verify restoration-unit boundaries after super-resolution, including clipped chroma transform traversal at a coded-frame edge.
- The visible still-image path applies the complete self-contained film-grain parameter set after all in-loop filters. Independently encoded pinned-libaom vectors match every native sample at 8, 10, and 12 bits across monochrome, 4:2:0, 4:2:2, and 4:4:4 layouts, full and restricted ranges, identity-matrix signaling, overlap, and odd 33x11 frame extension. `FeatureTestRunner` verifies normal, AVX-disabled, and fully scalar dispatch. A full-HD-equivalent 4:2:0 benchmark reports zero allocation: 8-bit AVX2 is 2.335 ms versus 5.806 ms scalar, while 12-bit AVX2 is 3.195 ms, cross-platform 128-bit is 7.382 ms, and scalar is 8.614 ms on the measured Ryzen platform. The slower 8-bit 128-bit lookup construction is deliberately not dispatched.
- The visible still-image path applies the complete self-contained film-grain parameter set after all in-loop filters. Independently encoded pinned-libaom vectors match every native sample at 8, 10, and 12 bits across monochrome, 4:2:0, 4:2:2, and 4:4:4 layouts, full and restricted ranges, identity-matrix signaling, overlap, and odd 33x11 frame extension. `FeatureTestRunner` verifies normal, AVX-disabled, and fully scalar dispatch. A full-HD-equivalent 4:2:0 benchmark reports zero allocation: 8-bit AVX2 is 2.335 ms versus 5.806 ms scalar, while 12-bit AVX2 is 3.195 ms, cross-platform 128-bit is 7.382 ms, and scalar is 8.614 ms on the measured Ryzen platform. The slower 8-bit 128-bit lookup construction is deliberately not dispatched.
@ -418,7 +422,7 @@ This assessment was reconciled with the source tree on 2026-08-27, including pro
### Tests
### Tests
- HEVC coverage includes exact native-plane comparison with HM output, exact complete-image comparison with pinned libheif/libde265 references, and the 10 official Sony GENERAL Range Extensions first-picture fixtures across 8/10/12-bit monochrome, 4:2:0, 4:2:2, and 4:4:4 reconstruction. The remaining exposed profiles and individual Range Extensions tools still need exact independent vectors.
- HEVC coverage includes exact native-plane comparison with HM output, exact complete-image comparison with pinned libheif/libde265 references, and the 10 official Sony GENERAL Range Extensions first-picture fixtures across 8/10/12-bit monochrome, 4:2:0, 4:2:2, and 4:4:4 reconstruction. The remaining exposed profiles and individual Range Extensions tools still need exact independent vectors.
- AV1 has focused bitstream, prediction, entropy, reconstruction, filter, film-grain, color, and transform coverage, plus real libavif inputs. A real two-layer libavif-derived OBU stream verifies the bounded frame lifecycle, retained-slot occupancy, resolved inter references, and `frame_size_with_refs` dimensions through a fake tile lifecycle. A real palette stream truncated inside its tile entropy payload verifies libaom-equivalent overflow/trailing-bit rejection and decoder-session recovery. The last broad committed Release checkpoint passed all 2,422 selected entropy, ownership, reference, predictor, intra-block-copy, and transform cases. Commit `096fb9af8` separately passes the self-guided filter test under four `FeatureTestRunner` configurations. The 191-case `net10.0` result and zero-error `net10.0`/`net11.0` builds apply only to the pre-fixture tree. The exact current tree builds the focused `net10.0` test project, but its dependent-frame test fails before reconstruction; no current-tree claim inherits the older evidence. No test currently decodes a real dependent inter frame and compares its reconstructed pixels with libaom. Valid still-image syntax paths still contain explicit unsupported branches, so the independent AV1 decode matrix is not complete.
- AV1 has focused bitstream, prediction, entropy, reconstruction, filter, film-grain, color, and transform coverage, plus real libavif inputs. A real two-layer libavif-derived OBU stream verifies the bounded frame lifecycle, retained-slot occupancy, resolved inter references, and `frame_size_with_refs` dimensions through a fake tile lifecycle. The corrected progressive color item then verifies its production single-reference inter branch against exact pinned-libaom native planes and pinned-libavif presentation. The pinned 19-frame YUV444 sequence separately reaches production equal-average compound reconstruction after every preceding reference sample and matches its final native and presented references exactly. A real palette stream truncated inside its tile entropy payload verifies libaom-equivalent overflow/trailing-bit rejection and decoder-session recovery. The current compound checkpoint passes 119 direct focused cases plus three `FeatureTestRunner` cases, zero-warning `net10.0` and `net11.0` source builds, a zero-error test-project analyzer build with pre-existing repository warnings, allocator lifetime validation, and `git diff --check`. Valid still-image syntax paths still contain explicit unsupported branches, so the independent AV1 decode matrix is not complete.
- The AV1 transform matrix verifies scalar, `Vector128`, `Vector256`, and `Vector512` forward representations plus the production inverse tiers across every valid size/type combination and supported bit depth. All 511 focused forward and inverse cases pass in Release; `FeatureTestRunner` isolates hardware tiers, every two-dimensional configuration exercises production dispatch, and the complete-block benchmark records zero managed allocation.
- The AV1 transform matrix verifies scalar, `Vector128`, `Vector256`, and `Vector512` forward representations plus the production inverse tiers across every valid size/type combination and supported bit depth. All 511 focused forward and inverse cases pass in Release; `FeatureTestRunner` isolates hardware tiers, every two-dimensional configuration exercises production dispatch, and the complete-block benchmark records zero managed allocation.
- Independent libavif fixtures cover primary, grid, auxiliary-alpha, ICC, metadata-skipping, and all-sync image-sequence presentation. Reference-dependent AV1 and HEVC sequence reconstruction and independent HEVC ICC sequence coverage remain open.
- Independent libavif fixtures cover primary, grid, auxiliary-alpha, ICC, metadata-skipping, and all-sync image-sequence presentation. Reference-dependent AV1 and HEVC sequence reconstruction and independent HEVC ICC sequence coverage remain open.
- Focused decoder-option tests cover strict, ancillary-only, image-data, and metadata-skipping behavior for still items and sequence samples. Complete adversarial dimension, allocation, malformed-container, and resource-limit coverage remains open.
- Focused decoder-option tests cover strict, ancillary-only, image-data, and metadata-skipping behavior for still items and sequence samples. Complete adversarial dimension, allocation, malformed-container, and resource-limit coverage remains open.
@ -561,10 +565,13 @@ Implement and verify in dependency order:
- [x] Store frame-sized retained and temporal motion fields in ImageSharp allocator-owned memory with deterministic counted disposal. Allocation tracking verifies aliases, success ownership, failure unwinding, presentation and decoder-result ownership, and exactly-once final disposal.
- [x] Store frame-sized retained and temporal motion fields in ImageSharp allocator-owned memory with deterministic counted disposal. Allocation tracking verifies aliases, success ownership, failure unwinding, presentation and decoder-result ownership, and exactly-once final disposal.
- [x] Request the established contiguous allocation contract for every padded frame plane and verify complete-plane reconstruction with a constrained ImageSharp allocator without copying.
- [x] Request the established contiguous allocation contract for every padded frame plane and verify complete-plane reconstruction with a constrained ImageSharp allocator without copying.
- [x] Complete source review of the new motion-mode and single-reference tests.
- [x] Complete source review of the new motion-mode and single-reference tests.
- [x] Pass the exact current tree's Release verification. The `net10.0` and `net11.0` source builds and the `net10.0` test-project analyzer build complete with zero warnings and errors. All 293 focused `net10.0` syntax, CDF lifecycle, candidate, vector, interpolation, lifecycle, reconstruction, ownership, and `FeatureTestRunner` cases pass with zero failures or skips, including exact dependent-frame native-plane and presentation comparisons, constrained allocation, and motion-field lifetime coverage. `git diff --check` is clean.
- [x] Pass the exact single-reference checkpoint's Release verification. The `net10.0` and `net11.0` source builds complete with zero warnings and errors, while the `net10.0` test-project analyzer build completes with zero errors and pre-existing repository warnings. All 293 focused `net10.0` syntax, CDF lifecycle, candidate, vector, interpolation, lifecycle, reconstruction, ownership, and `FeatureTestRunner` cases pass with zero failures or skips, including exact dependent-frame native-plane and presentation comparisons, constrained allocation, and motion-field lifetime coverage. `git diff --check` is clean.
- [x] Correct the logical progressive color payload and compare the final dependent frame's native planes and libavif presentation exactly. Pinned libaom decodes both layers from the primary item's two `iloc` extents, and pinned libavif produces the retained two-frame YUV444-alpha reference and final PNG. The exact production-path comparisons pass through `FeatureTestRunner`.
- [x] Correct the logical progressive color payload and compare the final dependent frame's native planes and libavif presentation exactly. Pinned libaom decodes both layers from the primary item's two `iloc` extents, and pinned libavif produces the retained two-frame YUV444-alpha reference and final PNG. The exact production-path comparisons pass through `FeatureTestRunner`.
- [ ] Decode and reconstruct compound prediction, selected inter-intra prediction, masked blending, OBMC, scaled references, warped motion, and non-translational global motion through reconstructed reference planes.
- [x] Decode all compound reference trees and inter modes, derive and retain paired reference-MV candidates, reconstruct both unscaled translational references, and combine them with equal-weight averaging through `Vector512`, `Vector256`, `Vector128`, and scalar paths without per-block allocation.
- [ ] Verify every connected inter mode and filter with independently encoded dependent-layer AV1 image-item fixtures and exact native-plane comparisons.
- [x] Verify equal-average compound reconstruction with the pinned 19-frame libavif sequence, exact pinned-libaom final native planes, exact pinned-libavif final presentation, direct 8/10/12-bit production-block tests, constrained allocation, and exactly-once motion-field disposal. Both Release source targets pass with zero warnings and errors; the test-project analyzer build passes with zero errors and pre-existing repository warnings; 119 direct focused cases and three `FeatureTestRunner` cases pass without failures or skips; and `git diff --check` is clean.
- [ ] Decode and reconstruct selected inter-intra prediction and selectable distance-weighted, wedge, and difference-weighted compound blending through reconstructed reference planes.
- [ ] Decode and reconstruct OBMC, scaled references, warped motion, and non-translational global motion through reconstructed reference planes.
- [ ] Verify every remaining connected inter mode and filter with independently encoded bounded AV1 content and exact native-plane comparisons.
- [ ] Lossless and high-bit-depth reconstruction with correct clipping and intermediate precision.
- [ ] Lossless and high-bit-depth reconstruction with correct clipping and intermediate precision.
- [x] Route lossless 4x4 blocks through allocation-free reversible inverse Walsh-Hadamard reconstruction for 8/10/12-bit samples, including the DC-only specialization, `Vector128` production traversal, scalar fallback, exact clipping, and `FeatureTestRunner` parity.
- [x] Route lossless 4x4 blocks through allocation-free reversible inverse Walsh-Hadamard reconstruction for 8/10/12-bit samples, including the DC-only specialization, `Vector128` production traversal, scalar fallback, exact clipping, and `FeatureTestRunner` parity.
- [x] Verify lossless syntax, inverse quantization, prediction, and presented reconstruction with independently encoded 8/10/12-bit AVIF fixtures. The tests require coded residuals with palette and intra-block copy disabled, compare every native YUV sample with the pinned generic libaom-backed decoder, and compare every presented RGBA byte with pinned generic libavif exactly under normal hardware dispatch and the scalar fallback.
- [x] Verify lossless syntax, inverse quantization, prediction, and presented reconstruction with independently encoded 8/10/12-bit AVIF fixtures. The tests require coded residuals with palette and intra-block copy disabled, compare every native YUV sample with the pinned generic libaom-backed decoder, and compare every presented RGBA byte with pinned generic libavif exactly under normal hardware dispatch and the scalar fallback.
@ -800,8 +807,9 @@ No valid HEVC or AV1 color, compression, or bit-depth row may remain `unsupporte
The dashboard and immediate execution queue define the remaining critical path. In phase terms, work proceeds as follows:
The dashboard and immediate execution queue define the remaining critical path. In phase terms, work proceeds as follows:
- [x] Finish the Phase 8 checkpoint for the implemented AV1 `Vector512` transforms, including Release, feature-isolation, and benchmark evidence.
- [x] Finish the Phase 8 checkpoint for the implemented AV1 `Vector512` transforms, including Release, feature-isolation, and benchmark evidence.
- [x] Finish the complete focused Release matrix, final source/documentation review, and checkpoint implementation for the simple single-reference inter slice. The corrected real dependent-frame AVIF passes exact pinned-libaom native-plane and pinned-libavif presentation comparisons, and all 293 focused cases pass with zero failures or skips.
- [x] Finish the complete focused Release matrix, final source/documentation review, and checkpoint implementation for the simple single-reference inter slice. Commit `8b9aa4b2cfe59ff0f8c348d9bb06678a5ff12f2a` records the corrected real dependent-frame AVIF, exact pinned-libaom native-plane and pinned-libavif presentation comparisons, and 293 focused cases passing with zero failures or skips.
- [ ] Complete the remaining Phase 3 inter modes in dependency order: compound reference selection and averaging, inter-intra and masked blending, OBMC, scaled references, warped motion, and non-translational global prediction. Each mode requires an independent fixture before the next begins.
- [x] Implement compound reference selection and equal averaging with paired reference-MV derivation, allocation-free SIMD/scalar parity, and exact independent native/presentation evidence through a reference-dependent bounded AVIF sequence.
- [ ] **Current:** implement selected inter-intra prediction and selectable distance-weighted, wedge, and difference-weighted compound blending, then continue the remaining Phase 3 inter modes in dependency order: OBMC, scaled references, warped motion, and non-translational global prediction. Each mode requires independent exact evidence before the next begins.
- [ ] Remove every other unsupported valid AV1 still-image syntax path, correct the audited 12-bit inverse-transform arithmetic, and prove the complete AVIF decode matrix with independent inputs and scalar/SIMD parity.
- [ ] Remove every other unsupported valid AV1 still-image syntax path, correct the audited 12-bit inverse-transform arithmetic, and prove the complete AVIF decode matrix with independent inputs and scalar/SIMD parity.
- [ ] Close Phase 4 by completing the remaining HEVC profile and Range Extensions matrix with exact native-plane and presented-image evidence.
- [ ] Close Phase 4 by completing the remaining HEVC profile and Range Extensions matrix with exact native-plane and presented-image evidence.
- [ ] Close Phase 5 and the decode portion of the bounded sequence ledger: color, ICC, alpha, grids, presentation transforms, reference-dependent samples, and complete animated AVIF/HEIC decode.
- [ ] Close Phase 5 and the decode portion of the bounded sequence ledger: color, ICC, alpha, grids, presentation transforms, reference-dependent samples, and complete animated AVIF/HEIC decode.
| `*-film-grain-*` | Full and restricted range, monochrome, identity matrix, 8/10/12-bit synthesis, overlap, and odd frame dimensions |
| `*-film-grain-*` | Full and restricted range, monochrome, identity matrix, 8/10/12-bit synthesis, overlap, and odd frame dimensions |
| `libavif-progressive-draw-points-8b` | A real two-layer color item whose final frame uses single-reference inter reconstruction, plus its progressive auxiliary alpha item |
| `libavif-progressive-draw-points-8b` | A real two-layer color item whose final frame uses single-reference inter reconstruction, plus its progressive auxiliary alpha item |
| `libavif-webp-logo-average-compound` | A 19-frame YUV444 image sequence whose retained references reach equal-weight compound inter reconstruction |
The corresponding tests also assert the syntax required by each family before comparing output. This prevents an inactive tool or an incorrectly substituted stream from passing solely because its final pixels happen to match.
The corresponding tests also assert the syntax required by each family before comparing output. This prevents an inactive tool or an incorrectly substituted stream from passing solely because its final pixels happen to match.
@ -51,6 +52,23 @@ The primary color item's `a1lx` property divides its logical 72-byte AV1 payload
Exact pinned libaom decodes the corrected logical payload into two 33x11 YUV444 frames. Both frames' 1,089 color samples match the corresponding first three planes of the pinned libavif YUV444-alpha outputs exactly. The retained Y4M contains both progressive YUV444-alpha frames, and the PNG contains pinned libavif's final RGBA presentation. The production-path test selects the second native frame, requires inter-coded blocks in the final ImageSharp frame, and compares both native color and final presentation without a tolerance.
Exact pinned libaom decodes the corrected logical payload into two 33x11 YUV444 frames. Both frames' 1,089 color samples match the corresponding first three planes of the pinned libavif YUV444-alpha outputs exactly. The retained Y4M contains both progressive YUV444-alpha frames, and the PNG contains pinned libavif's final RGBA presentation. The production-path test selects the second native frame, requires inter-coded blocks in the final ImageSharp frame, and compares both native color and final presentation without a tolerance.
## Equal-average compound fixture
The `libavif-webp-logo-average-compound.avif` fixture was encoded from the pinned libavif tree's `tests/data/webp_logo_animated.y4m` source. The source SHA-256 is `0872208D9C19B68B10A1647FA6849CFC4E2B21A19561ACD672E0629C70EFACA2`. It was generated with:
```text
./avifenc -j 1 -c aom -s 4 -q 80 -a enable-dist-wtd-comp=0 -a enable-masked-comp=0 -a enable-interintra-comp=0 -a enable-obmc=0 -a enable-warped-motion=0 -a enable-global-motion=0 tests/data/webp_logo_animated.y4m libavif-webp-logo-average-compound.avif
```
Pinned scalar libavif generated the retained references with:
The AVIF SHA-256 is `7919049D367EEDB7C965E170309D6759660DDBFD4BB1AEF9496F9D66E314846A`. The retained frame-18 Y4M SHA-256 is `41FF2408DEB473D5483F3398882DF7F7AB6C7D376561C19798881595EB0C5C0C`, and the frame-18 PNG SHA-256 is `BCFABC1E1C7E17D8ECB40569849A04FFAC6CA1FCDF613F217B33816CA47337AC`. The test decodes every preceding hidden and shown sample to establish the same retained-reference state before comparing all native Y, U, and V samples and the final RGBA presentation.
## Updating fixtures
## Updating fixtures
Do not create conformance references with ImageSharp. Generate both the native-plane and presentation references with an independent decoder, record the exact upstream revisions and source license, and preserve exact comparisons. A new tool-specific fixture should demonstrate that the relevant syntax is active and should be no larger than required to cover that behavior.
Do not create conformance references with ImageSharp. Generate both the native-plane and presentation references with an independent decoder, record the exact upstream revisions and source license, and preserve exact comparisons. A new tool-specific fixture should demonstrate that the relevant syntax is active and should be no larger than required to cover that behavior.
James Jackson-South
5 days ago
