FA-52855 / Raster memory layout / Member archive

Packed 422 Macropixels: Second luma lane is confused with U or reversed · case 05

The returned physical layout descriptor disagrees with the declared buffer mapping at luma_lane.

Member previewVariant 5 · 3 implementations · 6 checks per implementation

Case contract

A stipulated 4:2:2 image stores each pair as [Y0,U,Y1,V], with two bytes per component. Odd final pairs still reserve both luma slots. Three-byte row prefixes precede complete macropixels. Return the named intermediate layout descriptor and final address fields; all quantities are integer byte offsets unless explicitly stated.

Why this case matters

Offline raster resource, upload, readback, and storage-layout regression model.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
layout fixture 2	`{"address": 146, "allocation_end": 399, "component_lane": 1, "luma_lane": 1, "pair_id": 0, "pair_origin": 144, "pairs": 5, "row_origin": 144, "row_pitch": 43, "valid_luma_slots": 2}`	`{"address": 146, "allocation_end": 399, "component_lane": 1, "luma_lane": 2, "pair_id": 0, "pair_origin": 144, "pairs": 5, "row_origin": 144, "row_pitch": 43, "valid_luma_slots": 2}`	Failed

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This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

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