wrapper: build libk4arecord_v2.so — the library the recorder actually dlopens

The recorder does not load the stock libk4a/libk4arecord. It dlopens a single
custom libk4arecord_v2.so: the wrapper's MKV-writing sources linked to a
pure-data shim (k4a_shim.cpp) instead of libk4a, so recording has no OrbbecSDK
dependency. That target is FTF's own (wrapper/recordv2/), absent from the stock
wrapper the Orin carried — so ship it and inject+build it, the same pattern as
the recorder in the SDK examples tree. Idempotent; only added when missing.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

scripts/build_k4a_wrapper.sh

@@ -1,24 +1,29 @@
 #!/usr/bin/env bash
-# Makes sure the Orbbec K4A wrapper is built for THIS platform, and prints where
-# it is as K4A_WRAPPER_DIR=... for build_sdk.sh (the recorder example needs its
-# headers) and for the recorder's runtime rpath (its libk4a.so/libk4arecord.so).
+# Makes sure the Orbbec K4A wrapper is built for THIS platform, INCLUDING FTF's
+# libk4arecord_v2.so, and prints K4A_WRAPPER_DIR=... for build_sdk.sh (the recorder
+# example needs the headers) and for the recorder's runtime rpath.
 #
-# This is the libk4a provider — Orbbec's own, NOT Microsoft's Azure Kinect SDK.
-# It bundles its own OrbbecSDK internally, so it builds standalone. The recorder
-# dlopens the libk4a it produces (RTLD_DEEPBIND) rather than link-time linking it,
-# which is why only its build/lib path matters at runtime, not link time.
+# This is the libk4a provider — Orbbec's own, NOT Microsoft's Azure Kinect SDK. It
+# bundles its own OrbbecSDK, so it builds standalone.
 #
-# Reuses an existing build (leaving a working node untouched) or clones + builds.
+# The recorder does not dlopen the stock libk4a/libk4arecord. It dlopens a single
+# custom library, libk4arecord_v2.so: the wrapper's own MKV-writing sources linked
+# to a pure-data shim (k4a_shim.cpp) instead of libk4a — K4A-compatible recording
+# with no OrbbecSDK dependency. That target is FTF's (wrapper/recordv2/ in this
+# repo), not part of the stock wrapper, so it is injected and built here.
+#
+# Reuses an existing build; only adds the v2 target if it is missing.
 set -euo pipefail
 
 here=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+repo=$(cd "$here/.." && pwd)
 eval "$("$here/detect_platform.sh")"
 
 REPO_URL="${OB_K4A_REPO:-https://github.com/orbbec/OrbbecSDK-K4A-Wrapper}"
-# The tag the Nano runs. A caller can override to one known to build on a newer
-# JetPack.
 REF="${OB_K4A_REF:-v1.10.4}"
 
+# A usable wrapper base: headers and the stock libk4a. The v2 target is ensured
+# separately, so a wrapper built before this repo existed still qualifies.
 find_wrapper() {
     local d="$1"
     [[ -f "$d/include/k4a/k4a.h" ]] || return 1
@@ -26,42 +31,68 @@ find_wrapper() {
     echo "$d"
 }
 
+# Injects FTF's recordv2 sources and builds libk4arecord_v2.so if it is not there.
+# Idempotent: the add_subdirectory line and the copy are guarded.
+ensure_recordv2() {
+    local d="$1"
+    [[ -f "$d/build/lib/libk4arecord_v2.so" ]] && return 0
+
+    echo ">> libk4arecord_v2.so absent — injection de recordv2 et compilation…" >&2
+    local dst="$d/src/orbbec/recordv2"
+    mkdir -p "$dst"
+    cp "$repo/wrapper/recordv2/CMakeLists.txt" "$dst/"
+    cp "$repo/wrapper/recordv2/k4a_shim.cpp"   "$dst/"
+
+    local ob_cmake="$d/src/orbbec/CMakeLists.txt"
+    if [[ -f "$ob_cmake" ]] && ! grep -q "add_subdirectory(recordv2)" "$ob_cmake"; then
+        echo "add_subdirectory(recordv2)" >> "$ob_cmake"
+    fi
+
+    ( cd "$d/build"
+      cmake .. -DCMAKE_BUILD_TYPE=Release >&2
+      make -j"$(nproc)" k4arecord_v2 >&2 )
+
+    [[ -f "$d/build/lib/libk4arecord_v2.so" ]]
+}
+
+# 1 & 2: reuse a wrapper base, then make sure the v2 target is present.
 for candidate in "${K4A_WRAPPER_DIR:-}" \
                  "$HOME/OrbbecSDK-K4A-Wrapper" \
                  "$HOME/Downloads/OrbbecSDK-K4A-Wrapper"; do
     [[ -z "$candidate" ]] && continue
     if find_wrapper "$candidate" >/dev/null 2>&1; then
-        echo ">> Wrapper K4A deja bati, reutilise: $candidate" >&2
-        echo "K4A_WRAPPER_DIR=$candidate"
-        exit 0
+        echo ">> Wrapper K4A trouve: $candidate" >&2
+        if ensure_recordv2 "$candidate"; then
+            echo "K4A_WRAPPER_DIR=$candidate"
+            exit 0
+        fi
+        echo "!! libk4arecord_v2.so n'a pas pu etre bati dans $candidate" >&2
+        exit 1
     fi
 done
 
+# 3: clone + build the wrapper base, then the v2 target.
 dir="${K4A_WRAPPER_DIR:-$HOME/OrbbecSDK-K4A-Wrapper}"
 echo ">> Wrapper K4A absent — clone et compilation (JetPack ${JETPACK}, ${SOC})" >&2
 echo ">> ${REPO_URL} @ ${REF} -> ${dir}" >&2
 
 if [[ ! -d "$dir/.git" ]]; then
-    # --recursive: the wrapper carries its OrbbecSDK and depth engine as submodules.
     git clone --recursive --depth 1 --branch "$REF" "$REPO_URL" "$dir" >&2
 fi
 
 mkdir -p "$dir/build"
-(
-    cd "$dir/build"
-    cmake .. -DCMAKE_BUILD_TYPE=Release >&2
-    make -j"$(nproc)" k4a k4arecord >&2
-)
+( cd "$dir/build"
+  cmake .. -DCMAKE_BUILD_TYPE=Release >&2
+  make -j"$(nproc)" k4a k4arecord >&2 )
 
-if ! find_wrapper "$dir" >/dev/null 2>&1; then
+if ! find_wrapper "$dir" >/dev/null 2>&1 || ! ensure_recordv2 "$dir"; then
     cat >&2 <<EOF
 
-!! La compilation du wrapper K4A ne s'est pas terminee comme attendu
-!! (libk4a.so absent de $dir/build/lib).
+!! La compilation du wrapper K4A (ou de libk4arecord_v2.so) a echoue dans $dir.
 !! Bâtis-le une fois a la main, puis relance install.sh avec :
 !!     K4A_WRAPPER_DIR=$dir ./install.sh
 EOF
     exit 1
 fi
-echo ">> Wrapper K4A bati: $dir" >&2
+echo ">> Wrapper K4A + libk4arecord_v2.so batis: $dir" >&2
 echo "K4A_WRAPPER_DIR=$dir"