FA-52250 / Raster memory layout / Member archive

Semiplanar Padded Components: UV-pair count drops odd edge or treats every luma texel as a pair · case 05

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

Member previewVariant 5 · 3 implementations · 6 checks per implementation

Case contract

A stipulated semiplanar image stores two-byte luma samples and UV pairs of two-byte components. Luma rows have a four-byte guard; chroma rows have an eight-byte guard, and a six-byte separator precedes chroma. 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 1	`{"allocation_end": 75, "chroma_base": 67, "chroma_pairs": 0, "chroma_pitch": 8, "chroma_rows": 1, "component_offset": 0, "luma_address": 55, "luma_pitch": 6, "pair_offset": 0, "sample_address": 67}`	`{"allocation_end": 79, "chroma_base": 67, "chroma_pairs": 1, "chroma_pitch": 12, "chroma_rows": 1, "component_offset": 0, "luma_address": 55, "luma_pitch": 6, "pair_offset": 0, "sample_address": 67}`	Failed

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

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