arch/daedalus-v4l2: new package — userspace daemon + tools

PKGBUILD pinning daedalus-v4l2 @ f04d700 (Phase 8.13 close).

Installs:
- /usr/bin/daedalus_v4l2_daemon — the FFmpeg-backed decode daemon
- /usr/libexec/daedalus-v4l2/{test_chardev_pingpong,test_m2m_decode,
  test_m2m_stream} — verification harnesses
- /usr/include/daedalus_v4l2_proto.h — shared kernel↔daemon wire
  protocol (for third-party chardev clients)
- /usr/share/doc/daedalus-v4l2/ — README + Phase 8.x closure docs

Runtime deps: ffmpeg (libavformat/libavcodec/libavutil dlopen'd
at runtime per Option γ — daemon binary is link-clean from
FFmpeg), libdrm.

optdepends:
- daedalus-v4l2-dkms: companion kernel module
- libva-v4l2-request-fourier: VAAPI consumer routing through us

Sibling Debian package: debian/daedalus-v4l2/

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

arch/daedalus-v4l2/PKGBUILD

@@ -0,0 +1,105 @@
+# Maintainer: Markus Fritsche <fritsche.markus@gmail.com>
+#
+# daedalus-v4l2 — userspace daemon + V4L2 m2m test tools.
+#
+# Pair to daedalus-v4l2-dkms (kernel module).  Together they expose
+# /dev/videoNN + /dev/mediaNN as a V4L2 stateless decoder shim on Pi 5 /
+# CM5, decoding VP9 / AV1 / H.264 via dlopen'd FFmpeg in a single-
+# threaded daemon and shipping decoded NV12 / P010 back through dmabuf.
+# Consumed end-to-end by libva-v4l2-request-fourier (>= 1.0.0.r376) so
+# `ffmpeg -hwaccel vaapi` against vp9_small.ivf produces byte-exact NV12.
+#
+# Project: https://git.reauktion.de/reauktion/daedalus-v4l2
+# Sibling kernel package: daedalus-v4l2-dkms
+# Sibling consumer: libva-v4l2-request-fourier
+
+pkgname=daedalus-v4l2
+_upstreampkg=daedalus-v4l2
+
+# Pin the daedalus-v4l2 tip.  f04d700 = "Phase 8.13: byte-exact end-to-
+# end via libva (consumer target hit)" — first commit where the full
+# ffmpeg -hwaccel vaapi → libva → /dev/video0 → daemon path lands a
+# pixel-correct decoded frame back in ffmpeg.  Promote to a later pin
+# only after a future phase closes cleanly.
+_commit=f04d7000f858fe51d867aba14a529d3aef4fbd54
+
+# 0.1.0 (pre-1.0) + commit count + short sha.  Bump the .Y on each
+# Phase 8.x close.  pkgver() recomputes at build time.
+pkgver=0.1.0.r15.f04d700
+pkgrel=1
+pkgdesc="Userspace daemon for the daedalus-v4l2 V4L2 stateless decoder shim (VP9/AV1/H.264 on Pi 5 / CM5)"
+arch=('aarch64')
+url="https://git.reauktion.de/reauktion/daedalus-v4l2"
+license=('BSD-2-Clause' 'GPL-2.0-or-later')
+# Daemon dlopens libavformat.so.61 / libavcodec.so.61 / libavutil.so.59
+# at runtime (Option γ — see daemon/src/ffmpeg_loader.h).  ffmpeg
+# provides those; we don't link them.
+depends=('ffmpeg' 'libdrm')
+# Headers from libav*-dev needed at compile time for type-safe function
+# pointer signatures; pkg-config locates them.
+makedepends=('cmake' 'ninja' 'pkgconf' 'git' 'ffmpeg')
+optdepends=('daedalus-v4l2-dkms: kernel module providing /dev/video0 + /dev/daedalus-v4l2'
+            'libva-v4l2-request-fourier: VA-API consumer routing through this daemon')
+
+source=("git+https://git.reauktion.de/reauktion/daedalus-v4l2.git#commit=${_commit}")
+sha256sums=('SKIP')
+
+pkgver() {
+    cd "${srcdir}/${_upstreampkg}"
+    printf '0.1.0.r%s.%s' \
+        "$(git rev-list --count HEAD)" \
+        "$(git rev-parse --short=7 HEAD)"
+}
+
+build() {
+    cd "${srcdir}/${_upstreampkg}/daemon"
+    cmake -B build -G Ninja \
+        -DCMAKE_BUILD_TYPE=Release \
+        -DCMAKE_INSTALL_PREFIX=/usr
+    cmake --build build
+
+    cd "${srcdir}/${_upstreampkg}/tools"
+    make
+}
+
+package() {
+    cd "${srcdir}/${_upstreampkg}"
+
+    # Daemon binary
+    install -Dm755 daemon/build/daedalus_v4l2_daemon \
+        "${pkgdir}/usr/bin/daedalus_v4l2_daemon"
+
+    # Test tools (under /usr/libexec to keep them out of the default PATH
+    # — they're for verification, not daily use).
+    install -Dm755 tools/test_chardev_pingpong \
+        "${pkgdir}/usr/libexec/daedalus-v4l2/test_chardev_pingpong"
+    install -Dm755 tools/test_m2m_decode \
+        "${pkgdir}/usr/libexec/daedalus-v4l2/test_m2m_decode"
+    install -Dm755 tools/test_m2m_stream \
+        "${pkgdir}/usr/libexec/daedalus-v4l2/test_m2m_stream"
+
+    # Shared wire-protocol header (kernel ↔ daemon); useful for
+    # third-party clients of the chardev.
+    install -Dm644 include/daedalus_v4l2_proto.h \
+        "${pkgdir}/usr/include/daedalus_v4l2_proto.h"
+
+    # Documentation
+    install -Dm644 README.md \
+        "${pkgdir}/usr/share/doc/${pkgname}/README.md"
+    for d in docs/*.md; do
+        install -Dm644 "$d" "${pkgdir}/usr/share/doc/${pkgname}/$(basename "$d")"
+    done
+
+    # Licenses: BSD-2-Clause for daemon/tools, GPL for the kernel proto
+    # header; the SPDX headers in src/ are the canonical declaration but
+    # ship a short note here for package-manager-driven license queries.
+    install -dm755 "${pkgdir}/usr/share/licenses/${pkgname}"
+    cat > "${pkgdir}/usr/share/licenses/${pkgname}/LICENSE" <<'EOF'
+daedalus-v4l2 userspace components are BSD-2-Clause licensed.
+The shared kernel↔daemon wire protocol header
+(/usr/include/daedalus_v4l2_proto.h) is GPL-2.0-or-later WITH
+Linux-syscall-note for kernel-side compatibility.  See SPDX
+headers on individual source files for the canonical
+per-file declaration.
+EOF
+}