Verify official AV1 two-temporal-layer sequence

HEIF_IMPLEMENTATION_PLAN.md

@@ -29,7 +29,7 @@ Checkboxes may be marked complete only when the implementation and the verificat
 
 ## Delivery dashboard
 
-Last reconciled with the source tree on 2026-08-29 against production checkpoint `ea2fa484716944b86fadac5eac3eef23874ac25b`. Committed checkpoints include the AV1 transform architecture, OBU framing, 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, 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 2026-08-29 against production checkpoint `27ebcd54dc732aff8c665ee1ab61e72ed9621b42`. Committed checkpoints include the AV1 transform architecture, OBU framing, 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 two-spatial-layer default-operating-point 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.
 
 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.
 
@@ -43,6 +43,8 @@ Commit `5ba048be3667064f219ee230be7c8976927ea200` records the complete, verified
 
 Commit `ea2fa484716944b86fadac5eac3eef23874ac25b` records the complete official extreme-displacement intra-block-copy checkpoint. The two-frame 1920x1080 YUV420 IVF has SHA-1 `C7F336958E7AF6162C20DDC84D67C7DFA9826910`, exactly matching the pinned libaom manifest, and SHA-256 `0252716FE7A7C7F1EBB1EB23920A6737F45C10DFBA942304BD339AE42B5C576C`; its pinned-libaom Y4M has SHA-256 `8CF7851E112172C62799F8BFDF895505742A3CA77E339C12E547AD2C47AF41B3`. The source corrects the spatial scan's four-mode-info-unit step threshold from 16-sample blocks to libaom's 64-sample boundary, clamps the ranked displacement stack before reference selection, and treats intra-block-copy neighbors as inter for transform-size context. Exact production native-plane comparison covers both complete official frames under normal and scalar `FeatureTestRunner` dispatch, while the existing independent 8/10/12-bit native-plane and presentation matrix remains clean. Both Release source targets build with zero warnings and errors, Roslynk reports zero compiler errors, 170 focused intra-block-copy, frame-buffer, reference-MV, inter-mode, and transform-size tests pass without failures or skips, and `git diff --check` is clean.
 
+Commit `27ebcd54dc732aff8c665ee1ab61e72ed9621b42` records the official two-spatial-layer L2T1 default-operating-point checkpoint. The manifest-matching 159,037-byte IVF and pinned-libaom Y4M prove all eight 1280x720 YUV420 frames exactly under normal and scalar dispatch; constrained tracked allocation verifies balanced exactly-once returns. The existing decoder required no production correction. Both Release source targets build with zero warnings and errors, the scoped test-project analyzer build completes with zero errors and 1,011 repository warnings, Roslynk reports zero compiler errors, all five focused compact-sequence cases pass without failures or skips, and `git diff --check` is clean.
+
 Status meanings:
 
 - **Complete:** the implementation and its phase exit evidence are recorded.
@@ -53,7 +55,7 @@ Status meanings:
 
 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, and reconstructs translational single-reference, compound, inter-intra, OBMC, scaled-reference, local warped, and non-translational global prediction before residual traversal. Commit `1c58d855f70b024170ced9eb0a7005f0f9c955ad` adds exact official four-frame coverage through all ordinary inter modes, all three motion modes, every regular/smooth/sharp dual-filter pair, sub-8x8 chroma prediction, and no-round compound intermediates. Commit `019ac5648b4380a6ff4865072c96fde29ce09fad` adds exact selected-layer native reconstruction and scaled presentation. Neither AV1 nor HEVC production encoding is implemented.
 
-Immediate checkpoint: **verification complete; commit pending — official two-spatial-layer AV1 default-operating-point decoding.** The exact pinned-manifest IVF and pinned-libaom eight-frame 1280x720 YUV420 reference pass full-frame native-plane comparison under normal/scalar `FeatureTestRunner` dispatch and constrained tracked allocation with exactly-once returns. The existing decoder required no production correction for this stream. Both Release source targets build with zero warnings and errors, the scoped test-project analyzer build completes with zero errors and 1,011 repository warnings, Roslynk reports zero compiler errors, all five focused compact-sequence cases pass without failures or skips, and `git diff --check` is clean. Only the checkpoint commit remains open.
+Immediate checkpoint: **verification complete; commit pending — official one-spatial-layer, two-temporal-layer L1T2 AV1 sequence.** All eight 640x360 YUV420 frames match pinned libaom exactly under normal/scalar dispatch, and constrained tracked allocation returns every allocation exactly once. The existing decoder required no production correction. The scoped test-project analyzer build completes with zero errors and 1,011 repository warnings, Roslynk reports zero compiler errors, both focused cases pass without failures or skips, and `git diff --check` is clean. Only the checkpoint commit remains open.
 
 | Order | Delivery stage | State | Delivered state | Gate that remains open |
 | --- | --- | --- | --- | --- |
@@ -604,6 +606,7 @@ Implement and verify in dependency order:
   - [x] Verify every connected inter mode and filter with exact independent content. Complete official coverage masks prove all ordinary inter modes, all motion modes, and every switchable regular/smooth/sharp filter pair, while the committed bounded AVIF fixtures independently prove every compound, inter-intra, OBMC, scaled, local-warp, and global-warp reconstruction branch.
   - [x] Return an explicitly selected lower spatial layer at the item's presentation extent without rescaling retained references. The essential-`lsel` derivative selects the exact pinned-libaom 40x40 YUV444 base, scales native planes to 80x80 before color conversion, and matches pinned-libavif output. The allocator-owned presentation buffer uses group-safe rows, portable `Vector128` two-times filtering with scalar fallback, exact 8/12-bit libyuv-shaped vectors, constrained-allocation lifetime tracking, and leaves committed final-layer and display-only film-grain results unchanged.
   - [x] Decode the official two-spatial-layer L2T1 sequence at its default operating point. The 159,037-byte IVF has manifest-matching SHA-1 `E14825F50FF845B8A6932C64CB254007A0B5E3A1` and SHA-256 `D65824E8E7C19BC958DB810D728B2132B513B5A93CB5F99CA3D7995E19A226E1`; its pinned-libaom Y4M has SHA-256 `7A427631ECBF144F435AA4612F1201415FB1A9BCF9A67BA010AEF830B0C3AB81`. All eight 1280x720 YUV420 frames match exactly under normal and scalar dispatch, and an 8 KiB constrained tracked allocator verifies balanced exactly-once returns. The existing decoder required no production correction. Both Release source targets build with zero warnings and errors, the scoped test-project analyzer build completes with zero errors and 1,011 repository warnings, Roslynk reports zero compiler errors, and all five focused compact-sequence cases pass without failures or skips.
+  - [x] Decode the official one-spatial-layer, two-temporal-layer L1T2 sequence at its default operating point. The 48,883-byte IVF has manifest-matching SHA-1 `E94687EB0E90179B3800B6D5E11EB7E9BFB34EEC` and SHA-256 `EADE696AB60415D476E1D2A489EC2CCCD24D5EAAADFA4559C6488B7932274C5E`; its pinned-libaom Y4M has SHA-256 `4012DE2D4AFD095E7BB68EAE18B50B0674781BB4971CECABC0E5471E63373ED3`. All eight 640x360 YUV420 frames match exactly under normal/scalar dispatch, and an 8 KiB constrained tracked allocator verifies balanced exactly-once returns. The existing decoder required no production correction. The scoped test-project analyzer build completes with zero errors and 1,011 repository warnings, Roslynk reports zero compiler errors, and both focused cases pass without failures or skips.
 - [ ] 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] 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.

tests/ImageSharp.Tests/Formats/Heif/Av1/Av1ReconstructionConformanceTests.cs

@@ -201,6 +201,21 @@ public class Av1ReconstructionConformanceTests
     /// </summary>
     private const int OfficialTwoSpatialLayerFixtureFrameCount = 8;
 
+    /// <summary>
+    /// The displayed width of the official libaom two-temporal-layer sequence.
+    /// </summary>
+    private const int OfficialTwoTemporalLayerFixtureWidth = 640;
+
+    /// <summary>
+    /// The displayed height of the official libaom two-temporal-layer sequence.
+    /// </summary>
+    private const int OfficialTwoTemporalLayerFixtureHeight = 360;
+
+    /// <summary>
+    /// The number of default-operating-point frames in the official libaom two-temporal-layer sequence.
+    /// </summary>
+    private const int OfficialTwoTemporalLayerFixtureFrameCount = 8;
+
     /// <summary>
     /// The coverage bit representing tile-local adaptive CDF updates.
     /// </summary>
@@ -1284,6 +1299,56 @@ public class Av1ReconstructionConformanceTests
             OfficialTwoSpatialLayerFixtureWidth,
             OfficialTwoSpatialLayerFixtureHeight);
 
+    /// <summary>
+    /// Verifies the default operating point of an official two-temporal-layer sequence against exact pinned-libaom
+    /// native output under normal and scalar dispatch.
+    /// </summary>
+    [Fact]
+    public void DecodeOfficialTwoTemporalLayerSequenceMatchesPinnedLibaomReference()
+        => FeatureTestRunner.RunWithHwIntrinsicsFeature(
+            ValidateOfficialTwoTemporalLayerFixture,
+            ReconstructionConfigurations);
+
+    /// <summary>
+    /// Verifies the official two-temporal-layer sequence through constrained tracked allocation.
+    /// </summary>
+    [Fact]
+    [ValidateDisposedMemoryAllocations]
+    public void DecodeOfficialTwoTemporalLayerSequenceWithConstrainedAllocator()
+    {
+        TestMemoryAllocator allocator = new() { BufferCapacityInBytes = 8_192 };
+        allocator.EnableNonThreadSafeLogging();
+        Configuration configuration = Configuration.Default.Clone();
+        configuration.MemoryAllocator = allocator;
+
+        ValidateOfficialCompactSequence(
+            configuration,
+            TestImages.Heif.Av1OfficialTwoTemporalLayerSequence,
+            TestImages.Heif.Av1OfficialTwoTemporalLayerSequenceNativeReference,
+            OfficialTwoTemporalLayerFixtureFrameCount,
+            OfficialTwoTemporalLayerFixtureWidth,
+            OfficialTwoTemporalLayerFixtureHeight);
+
+        Assert.Equal(allocator.AllocationLog.Count, allocator.ReturnLog.Count);
+        Assert.All(
+            allocator.AllocationLog,
+            allocation => Assert.Single(
+                allocator.ReturnLog,
+                returned => returned.AllocationId == allocation.AllocationId));
+    }
+
+    /// <summary>
+    /// Decodes the default operating point of the official two-temporal-layer sequence.
+    /// </summary>
+    private static void ValidateOfficialTwoTemporalLayerFixture()
+        => ValidateOfficialCompactSequence(
+            Configuration.Default,
+            TestImages.Heif.Av1OfficialTwoTemporalLayerSequence,
+            TestImages.Heif.Av1OfficialTwoTemporalLayerSequenceNativeReference,
+            OfficialTwoTemporalLayerFixtureFrameCount,
+            OfficialTwoTemporalLayerFixtureWidth,
+            OfficialTwoTemporalLayerFixtureHeight);
+
     /// <summary>
     /// Decodes one compact official IVF sequence, compares every native sample, and returns its active frame-state
     /// coverage mask.

tests/ImageSharp.Tests/TestImages.cs

@@ -1400,6 +1400,8 @@ public static class TestImages
         public const string Av1OfficialIntraBlockCopySequenceNativeReference = "Heif/Av1/Conformance/libaom-av1-1-b8-16-intra_only-intrabc-extreme-dv-libaom.y4m";
         public const string Av1OfficialTwoSpatialLayerSequence = "Heif/Av1/Conformance/libaom-av1-1-b8-22-svc-L2T1.ivf";
         public const string Av1OfficialTwoSpatialLayerSequenceNativeReference = "Heif/Av1/Conformance/libaom-av1-1-b8-22-svc-L2T1-libaom.y4m";
+        public const string Av1OfficialTwoTemporalLayerSequence = "Heif/Av1/Conformance/libaom-av1-1-b8-22-svc-L1T2.ivf";
+        public const string Av1OfficialTwoTemporalLayerSequenceNativeReference = "Heif/Av1/Conformance/libaom-av1-1-b8-22-svc-L1T2-libaom.y4m";
         public const string Av1Cdef8BitPayload = "Heif/Av1/Conformance/libaom-cdef-kodim23-8b.bit";
         public const string Av1Cdef8BitReference = "Heif/Av1/Conformance/libaom-cdef-kodim23-8b-libaom.yuv";
         public const string Av1Cdef8BitAvif = "Heif/Av1/Conformance/libavif-cdef-kodim23-8b.avif";

tests/Images/Input/Heif/Av1/Conformance/libaom-av1-1-b8-22-svc-L1T2-libaom.y4m

@@ -0,0 +1,3 @@
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+oid sha256:4012de2d4afd095e7bb68eae18b50b0674781bb4971cecabc0e5471e63373ed3
+size 2764886

tests/Images/Input/Heif/Av1/Conformance/libaom-av1-1-b8-22-svc-L1T2.ivf

@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:eade696ab60415d476e1d2a489ec2cccd24d5eaaadfa4559c6488b7932274c5e
+size 48883