Casanova/Collabora v7.0 HEVC series forgot to register
V4L2_CID_STATELESS_HEVC_SLICE_PARAMS in vdpu38x_hevc_ctrl_descs[].
The legacy rkvdec_hevc_ctrl_descs[] (RK3399 path) has it; the new
vdpu381/vdpu383 path doesn't. Every per-frame S_EXT_CTRLS fails
with EINVAL ("cannot find control id 0xa40a92").
Surfaced via dev_debug=0x3f on /sys/class/video4linux/videoN —
prepare_ext_ctrls's "cannot find" dprintk is gated behind
V4L2_DEV_DEBUG_CTRL (bit 0x20), invisible by default.
1-line patch (5 lines with formatting) mirrors the legacy entry:
SLICE_PARAMS as DYNAMIC_ARRAY, dims={600} (HEVC level >6 max).
Verified on ampere: no EINVAL, no dmesg errors, ffmpeg exit 0,
3-frame NV12 output structurally valid. But output bytes are all
Y=16/Cb=Cr=128 (solid black) — separate downstream bitstream-
feeding bug, deferred to iter5.
Iter5 starts with LIBVA_V4L2_DUMP_OUTPUT to confirm whether the
OUTPUT bitstream is reaching the kernel correctly.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Markus Fritsche