The Vulkan Video 10-bit path was the least-exercised code on this branch:
nothing had ever created a Main10 video session, so the profile query, the
`G10X6…3PACK16` picture allocation, the scratch→plane copy, the hand-packed
AV1 sequence header and the colour signalling were all first-run-on-glass.
Three `#[ignore]`d smokes now drive them, and they were run.
`.116` (Bazzite f43, AMD 780M, RADV / Mesa 26.0.4), all three green:
* `vulkan_smoke_10bit` — HEVC Main10 through the compute CSC;
* `vulkan_smoke_10bit_av1` — AV1 at 10 bits;
* `vulkan_smoke_rgb_10bit` — HDR with NO host CSC, the EFC converting BT.2020
off the packed 10-bit source. It did **not** soft-skip, which answers the one
capability in this whole feature I had only ever read in a registry: RADV's
VCN EFC really does advertise `MODEL_YCBCR_2020` and accept a 10-bit
packed-RGB encode source.
Every stream decodes 0-error and reports `yuv420p10le` + `bt2020nc` /
`smpte2084` / `bt2020`. The AV1 one parsing at all is the load-bearing result
there: `high_bitdepth` precedes the CICP bytes in `color_config()`, so a wrong
bit would have thrown every later field out of phase rather than merely
mislabelling the depth.
Round-trip on solid frames, fed (160,160,800) as 10-bit codes:
compute CSC -> (159, 158, 796)
EFC -> (159, 158, 796)
AV1 -> (158, 159, 794)
Under 0.5%, all of it limited-range quantisation and lossy encode. The compute
and EFC results being IDENTICAL is the strongest check available: two
independent BT.2020 NCL implementations — my shader and AMD's fixed-function
block — agreeing to within rounding.
The smokes deliberately assert structure (submits encode, AU count, the depth
the encoder settled on), not colour: a shader writing the 10 bits into the
wrong end of the word still produces a decodable stream. Colour is the dump +
ffmpeg round-trip above, which is what actually caught nothing this time.
Also corrects a comment: I claimed a wrong store factor was a "~1.6% luminance
error". It is not. The `<< 6` PLACEMENT is the load-bearing part (dropping it
is 64x too dark); `1/1023` vs `64/65535` is ~0.1% and harmless.
enricobuehler
576bf7e294