ohm recon 2026-04-24: hantro-only, no rkvdec2; kernel 6.19.10-danctnix1

Step 1 (live recon) on ohm. Findings folded into README under new
"Recon 2026-04-24" subsection, replacing the pre-recon "Open question"
paragraph and the now-stale "Current blocker: ohm offline" note.

- Kernel 6.19.10-danctnix1-1-pinetab2 (README had 6.15 — stale by 4 minors).
- Only Hantro VPU decoder bound (rockchip,rk3568-vpu @ fdea0400); exposes
  stateless H.264 (S264), MPEG-2 (MG2S), VP8 (VP8F). No HEVC/VP9.
- No rkvdec2 DT node, no rkvdec2 driver, /lib/firmware/rockchip/ has only
  dptx.bin. HEVC/VP9 HW decode unavailable on this image.
- Stock ffmpeg 8.1 has v4l2m2m only (no v4l2request hwaccel) — cannot drive
  the stateless decoder; need ffmpeg-v4l2-request-git. GStreamer 1.28.2
  v4l2codecs already exposes v4l2sl{h264,mpeg2,vp8}dec.
- Unrelated noise: bes2600 Wi-Fi OOT driver WARNs every ~30 s.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.md

@@ -113,9 +113,30 @@ mpv --hwdec=drm --vo=dmabuf-wayland input.mp4
 2023 coverage: **MPEG-2, VP8, H.264**. 1080p60 H.264 hit ~80% of one CPU core
 — decode was on the hardware; the CPU was in the compositor path.
 
-**Open question**: does the current linux-pinetab2 6.15-danctnix2 carry
-out-of-tree rkvdec2 patches for HEVC/VP9, and if so, does the 2023 recipe
-still work verbatim? Next live recon on ohm answers this.
+### Recon 2026-04-24 (ohm)
+
+- Running kernel: `6.19.10-danctnix1-1-pinetab2`.
+- Decoder: `hantro-vpu` on `/dev/video1` (DT `rockchip,rk3568-vpu` at
+  `fdea0400`); encoder on `/dev/video2`.
+- Exposed stateless formats: `S264` (H.264), `MG2S` (MPEG-2), `VP8F` (VP8)
+  → `NV12`. No HEVC, no VP9.
+- No rkvdec2 DT node, no rkvdec2 driver, no decoder firmware blob
+  (`/lib/firmware/rockchip/` only carries `dptx.bin`). HEVC/VP9 hardware
+  decode is **not available on this image** — needs a kernel rebuild with
+  out-of-tree rkvdec2 patches + firmware. Tree-side confirmation (does the
+  danctnix PKGBUILD even attempt to carry rkvdec2?) still pending.
+- Userspace: `ffmpeg 8.1` (stock, v4l2m2m only — **no v4l2request hwaccel**,
+  does not drive the stateless decoder), `gstreamer 1.28.2` with
+  `v4l2codecs` exposing `v4l2sl{h264,mpeg2,vp8}dec`, `mpv 0.41.0`,
+  `libva 2.23.0`. No `ffmpeg-v4l2-request-git`, no `libva-v4l2-request`,
+  no `kodi`.
+- Noise: `bes2600` Wi-Fi OOT driver spams `WARN` every ~30 s. Unrelated to
+  decode; ignore for this umbrella.
+
+So: 2023 recipe works verbatim for H.264 / MPEG-2 / VP8 once
+`ffmpeg-v4l2-request-git` is installed. GStreamer `v4l2slh264dec` is the
+shortest path to a first decode proof. HEVC/VP9 park until the kernel side
+picks up rkvdec2 patches.
 
 ### Plan (tasks #18–24 in the noether task list)
 
@@ -132,9 +153,10 @@ still work verbatim? Next live recon on ohm answers this.
 6. **Kodi + mpv validation** — 1080p HEVC at <30% of one core target
 7. **Document** — freeze the final recipe in this README
 
-**Current blocker**: ohm offline. Last known VPN state — only `nc` connected;
-LAN gives "No route to host" for `ohm.fritz.box` (192.168.88.168). Ask
-Markus to wake / reach out when ready.
+**Status 2026-04-24**: ohm reachable; step 1 (live recon) complete; step 3
+effectively done for H.264 / MPEG-2 / VP8 (driver bound, node exposed).
+Open threads: step 2 (SW baseline numbers) and step 5 (ffmpeg-v4l2-request
+build + install).
 
 ### Acceptance criterion