Merge pull request 'fourier-debian: Path A — ffmpeg into /opt/fourier prefix (no more KDE cascade)' (#36) from noether/fourier-private-prefix into main

Reviewed-on: #36

debian/daedalus-v4l2/build-deb.sh

@@ -17,7 +17,7 @@ set -euo pipefail
 # a pixel-correct decoded frame back in ffmpeg.
 UPSTREAM_COMMIT=f55b2cdab8a8c0bc04e8c1bb1d0b6ca85e7d96d2
 PKGVER=0.1.0+r16+gf55b2cd
-PKGREL=1
+PKGREL=2  # pkgrel=2 — Depends on ffmpeg-v4l2-request-fourier (Path A SONAME .so.62)
 
 HERE=$(dirname "$(readlink -f "$0")")
 
@@ -81,7 +81,7 @@ Version: ${PKGVER}-${PKGREL}
 Section: video
 Priority: optional
 Architecture: arm64
-Depends: ffmpeg (>= 7.1), libdrm2
+Depends: ffmpeg-v4l2-request-fourier (>= 2:8.1+rfourier), libdrm2
 Recommends: daedalus-v4l2-dkms
 Maintainer: Markus Fritsche <mfritsche@reauktion.de>
 Homepage: https://git.reauktion.de/reauktion/daedalus-v4l2

debian/ffmpeg-v4l2-request-fourier/build-deb.sh

@@ -8,14 +8,18 @@
 # mpv-fourier (and the kdirect bit-exact reference test rig) work
 # end-to-end without a stock-Debian FFmpeg fallback.
 #
-# Conflicts: ffmpeg, libav* — this is a drop-in replacement.  Pi 5 /
-# CM5 (BCM2712) hosts using daedalus_v4l2 + libva-v4l2-request-fourier
-# DON'T strictly need this package (stock Debian ffmpeg + libva path
-# is sufficient for the VAAPI route), but the kdirect bit-exact
-# reference + firefox-fourier / mpv-fourier consumers do.
+# **Private prefix /opt/fourier** (Path A per fourier-debian
+# architecture discussion 2026-05-19).  Stock Debian trixie ships
+# FFmpeg 7.1.x = libavcodec.so.61; this package ships FFmpeg 8.1 =
+# libavcodec.so.62 — different SOVERSION, NOT a drop-in for trixie's
+# KDE/VLC/etc.  Living in /opt/fourier/lib keeps the stock system
+# intact; only fourier-aware consumers (firefox-fourier, mpv-fourier,
+# daedalus-v4l2) RPATH into /opt/fourier/lib.  Postinst drops an
+# ld.so.conf.d entry so dlopen-based consumers (firefox at runtime)
+# find the libs by SONAME without LD_LIBRARY_PATH wrappers.
 #
 # Big build: 25-40 min on a runner.  Output is a single .deb that
-# bundles ffmpeg/ffprobe + libavcodec.so.61 + libavformat.so.61 etc.
+# bundles ffmpeg/ffprobe + libavcodec.so.62 + libavformat.so.62 etc.
 # all together — no split per-library subpackages.  Easier to consume,
 # trades off finer-grained downgrades.
 #
@@ -29,7 +33,7 @@ FFMPEG_VERSION=8.1
 # epoch 2 matches Debian's stock ffmpeg (currently 7:7.1.x in trixie);
 # +rfourier suffix to avoid colliding with upstream/Debian rebuilds.
 PKGVER=2:${FFMPEG_VERSION}+rfourier+gb57fbbe
-PKGREL=1
+PKGREL=2  # pkgrel=2 — Path A move to /opt/fourier prefix (2026-05-19)
 
 HERE=$(dirname "$(readlink -f "$0")")
 
@@ -60,10 +64,15 @@ patch -Np1 -i "$HERE/0002-nv15-to-p010-unpack.patch"
 # JACK, GSM, Speex) — not needed on the Fourier fleet, keeps the .deb
 # smaller and the dependency graph tighter.
 ./configure \
-    --prefix=/usr \
-    --libdir=/usr/lib/aarch64-linux-gnu \
-    --shlibdir=/usr/lib/aarch64-linux-gnu \
-    --incdir=/usr/include/aarch64-linux-gnu \
+    --prefix=/opt/fourier \
+    --bindir=/opt/fourier/bin \
+    --libdir=/opt/fourier/lib \
+    --shlibdir=/opt/fourier/lib \
+    --incdir=/opt/fourier/include \
+    --datadir=/opt/fourier/share/ffmpeg \
+    --mandir=/opt/fourier/share/man \
+    --extra-ldexeflags='-Wl,-rpath,/opt/fourier/lib' \
+    --extra-ldsoflags='-Wl,-rpath,/opt/fourier/lib' \
     --disable-debug \
     --disable-static \
     --disable-doc \
@@ -104,7 +113,23 @@ make tools/qt-faststart
 # Stage
 ROOT="$work/pkgroot"
 make DESTDIR="$ROOT" install
-install -Dm755 tools/qt-faststart "$ROOT/usr/bin/qt-faststart"
+install -Dm755 tools/qt-faststart "$ROOT/opt/fourier/bin/qt-faststart"
+
+# ld.so.conf.d entry so dlopen-based consumers (firefox-fourier at
+# runtime) find /opt/fourier/lib/libavcodec.so.62 by SONAME without an
+# LD_LIBRARY_PATH wrapper.  No risk of contaminating stock binaries:
+# stock KDE/VLC link against libavcodec.so.61 (different SONAME), so
+# the loader never sees our .so.62 as a match for their .so.61.
+install -Dm644 /dev/stdin "$ROOT/etc/ld.so.conf.d/fourier.conf" <<EOF
+# fourier campaign: FFmpeg 8.1 fork + libVA fork in private prefix.
+/opt/fourier/lib
+EOF
+
+# Optional /usr/bin shims so users can call ffmpeg-fourier without
+# remembering the /opt path.  No conflict with stock /usr/bin/ffmpeg.
+install -d "$ROOT/usr/bin"
+ln -sf /opt/fourier/bin/ffmpeg   "$ROOT/usr/bin/ffmpeg-fourier"
+ln -sf /opt/fourier/bin/ffprobe  "$ROOT/usr/bin/ffprobe-fourier"
 
 # Doc
 mkdir -p "$ROOT/usr/share/doc/ffmpeg-v4l2-request-fourier" "$ROOT/DEBIAN"
@@ -143,19 +168,9 @@ Depends: libc6,
          libv4l-0,
          libva2,
          libva-drm2
-Conflicts: ffmpeg, libavcodec61, libavformat61, libavutil59,
-           libswresample5, libswscale8, libavdevice61, libavfilter10,
-           libpostproc58
-Replaces: ffmpeg, libavcodec61, libavformat61, libavutil59,
-          libswresample5, libswscale8, libavdevice61, libavfilter10,
-          libpostproc58
-Provides: ffmpeg (= ${PKGVER}-${PKGREL}),
-          libavcodec.so.61,
-          libavformat.so.61,
-          libavutil.so.59
 Maintainer: Markus Fritsche <mfritsche@reauktion.de>
 Homepage: https://github.com/Kwiboo/FFmpeg
-Description: FFmpeg with V4L2 Request API hwaccel (Kwiboo fork)
+Description: FFmpeg with V4L2 Request API hwaccel (Kwiboo fork, /opt/fourier prefix)
  FFmpeg ${FFMPEG_VERSION} patched with the V4L2 Request API stateless
  video decoder hwaccel — Kwiboo's long-running rebase of Jernej
  Škrabec's v4l2-request patchset onto FFmpeg release tags.
@@ -167,11 +182,40 @@ Description: FFmpeg with V4L2 Request API hwaccel (Kwiboo fork)
  backing FFmpeg, and as the kdirect bit-exact reference in libva-v4l2-
  request-fourier validation.
  .
+ INSTALLED TO /opt/fourier (NOT /usr): this is FFmpeg 8.1 (libav*.so.62)
+ sitting alongside Debian trixie's stock FFmpeg 7.1 (libav*.so.61) —
+ different SONAMEs, no symbol clash.  Consumer binaries RPATH into
+ /opt/fourier/lib; ld.so.conf.d/fourier.conf adds the path to ld.so
+ cache for dlopen-by-SONAME (firefox).  /usr/bin/ffmpeg-fourier and
+ /usr/bin/ffprobe-fourier are convenience symlinks to /opt/fourier/bin.
+ Stock 'ffmpeg' command unaffected.
+ .
  Drops X11/AMF/CUDA/Bluray/JACK/Vulkan/SDL2/Theora/XVid/Speex/JPEG-XL
  per Fourier fleet policy (Wayland + ARM + video-decode focus).
  No 'ffplay' binary; mpv-fourier covers interactive playback.
 EOF
 
+# ldconfig must be re-run after install so /opt/fourier/lib is in the cache.
+cat > "$ROOT/DEBIAN/postinst" <<'PEOF'
+#!/bin/sh
+set -e
+if [ "$1" = "configure" ]; then
+    ldconfig
+fi
+#DEBHELPER#
+PEOF
+chmod 755 "$ROOT/DEBIAN/postinst"
+
+cat > "$ROOT/DEBIAN/postrm" <<'PEOF'
+#!/bin/sh
+set -e
+if [ "$1" = "remove" ] || [ "$1" = "purge" ]; then
+    ldconfig
+fi
+#DEBHELPER#
+PEOF
+chmod 755 "$ROOT/DEBIAN/postrm"
+
 DEB_OUT="ffmpeg-v4l2-request-fourier_${PKGVER//:/%3a}-${PKGREL}_arm64.deb"
 dpkg-deb --root-owner-group --build "$ROOT" "$HERE/$DEB_OUT"
 echo "built: $HERE/$DEB_OUT"