MyNamesEMurray · MyNamesEMurray · Aug 5, 2026 · Aug 5, 2026
diff --git a/.github/actions/static-ffmpeg/action.yml b/.github/actions/static-ffmpeg/action.yml
@@ -0,0 +1,136 @@
+name: Static FFmpeg (decode-only)
+description: >-
+  Builds a minimal static FFmpeg — H.264/HEVC decode plus the platform's
+  GPU decode API, nothing else — into ffmpeg-static/ at the workspace
+  root, cached between runs. Plugin binaries link this instead of the
+  FFmpeg inside OBS: FFmpeg's library names change with its major
+  version (avcodec-61.dll, libavcodec.so.60, ...), so a plugin linked
+  against OBS's copy stops loading the moment an OBS update ships a
+  newer FFmpeg (issues #65, #91, #93). With the decoder built in, one
+  plugin release keeps working across OBS updates.
+
+inputs:
+  version:
+    description: FFmpeg release to build
+    required: false
+    default: "7.1"
+
+runs:
+  using: composite
+  steps:
+    # hashFiles of this action: editing any configure flag or build step
+    # invalidates the cache automatically — no manual key bump to forget.
+    - name: Cache static FFmpeg
+      id: cache
+      uses: actions/cache@v6
+      with:
+        path: ffmpeg-static
+        key: ffmpeg-static-${{ runner.os }}-${{ inputs.version }}-${{ hashFiles('.github/actions/static-ffmpeg/**') }}
+
+    # Unconditional (not gated on the cache): libva-dev is needed again
+    # later when the plugin links the cached static libavutil, whose
+    # VAAPI hwcontext references libva symbols.
+    - name: Install Linux build dependencies
+      if: runner.os == 'Linux'
+      shell: bash
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y nasm libva-dev libdrm-dev
+
+    # H.264/HEVC decode + VAAPI, nothing else; the only FFmpeg-related
+    # runtime needs left are libva/libva-drm, whose soname has been
+    # stable since 2017 and which every VAAPI-capable system ships.
+    - name: Build (Linux)
+      if: runner.os == 'Linux' && steps.cache.outputs.cache-hit != 'true'
+      shell: bash
+      env:
+        FFMPEG_VERSION: ${{ inputs.version }}
+      run: |
+        curl -LO "https://ffmpeg.org/releases/ffmpeg-${FFMPEG_VERSION}.tar.xz"
+        tar xf "ffmpeg-${FFMPEG_VERSION}.tar.xz"
+        cd "ffmpeg-${FFMPEG_VERSION}"
+        ./configure --prefix="$GITHUB_WORKSPACE/ffmpeg-static" \
+          --disable-everything --disable-programs --disable-doc \
+          --disable-avformat --disable-avfilter --disable-swscale \
+          --disable-swresample --disable-avdevice --disable-network \
+          --disable-debug --disable-autodetect \
+          --enable-decoder=h264,hevc --enable-parser=h264,hevc \
+          --enable-vaapi --enable-hwaccel=h264_vaapi,hevc_vaapi \
+          --enable-pic --disable-shared --enable-static \
+          || { tail -n 50 ffbuild/config.log; exit 1; }
+        make -j"$(nproc)"
+        make install
+
+    # Same shape with VideoToolbox, built once per slice and merged with
+    # lipo to match the universal plugin. The linking side of this lives
+    # in CMakeLists.txt: the plugin links the CoreMedia/VideoToolbox
+    # frameworks the static hwaccel resolves against.
+    - name: Build (macOS, universal)
+      if: runner.os == 'macOS' && steps.cache.outputs.cache-hit != 'true'
+      shell: bash
+      env:
+        FFMPEG_VERSION: ${{ inputs.version }}
+      run: |
+        brew install nasm
+        curl -LO "https://ffmpeg.org/releases/ffmpeg-${FFMPEG_VERSION}.tar.xz"
+        tar xf "ffmpeg-${FFMPEG_VERSION}.tar.xz"
+        # --enable-cross-compile on the native slice too: it only turns
+        # off configure-time runtime probing, and keeps both invocations
+        # identical.
+        for arch in arm64 x86_64; do
+          mkdir -p "ffmpeg-build-$arch"
+          (cd "ffmpeg-build-$arch" && \
+           "../ffmpeg-${FFMPEG_VERSION}/configure" \
+             --prefix="$GITHUB_WORKSPACE/ffmpeg-arch-$arch" \
+             --enable-cross-compile --target-os=darwin \
+             --arch="$arch" --cc="clang -arch $arch" \
+             --extra-cflags="-mmacosx-version-min=13.0" \
+             --extra-ldflags="-mmacosx-version-min=13.0" \
+             --disable-everything --disable-programs --disable-doc \
+             --disable-avformat --disable-avfilter --disable-swscale \
+             --disable-swresample --disable-avdevice --disable-network \
+             --disable-debug --disable-autodetect \
+             --enable-decoder=h264,hevc --enable-parser=h264,hevc \
+             --enable-videotoolbox \
+             --enable-hwaccel=h264_videotoolbox,hevc_videotoolbox \
+             --enable-pic --disable-shared --enable-static \
+             || { tail -n 50 ffbuild/config.log; exit 1; } && \
+           make -j"$(sysctl -n hw.ncpu)" && make install)
+        done
+        # One header set is enough: avconfig.h is identical for both
+        # slices (same endianness and word size). No pkgconfig dir on
+        # purpose — the per-arch .pc files carry the wrong prefix, and
+        # the workflows pass explicit library paths instead.
+        mkdir -p ffmpeg-static/lib
+        cp -R ffmpeg-arch-arm64/include ffmpeg-static/include
+        for lib in libavcodec libavutil; do
+          lipo -create "ffmpeg-arch-arm64/lib/$lib.a" \
+            "ffmpeg-arch-x86_64/lib/$lib.a" \
+            -output "ffmpeg-static/lib/$lib.a"
+        done
+
+    # FFmpeg's build system is a shell script, but the compiler must be
+    # MSVC (cl.exe) so the archives link into the plugin's Visual Studio
+    # build: import the vcvars64 environment into this process, then run
+    # the build under the runner's stock MSYS2 with that environment
+    # inherited (build-windows.sh).
+    - name: Build (Windows)
+      if: runner.os == 'Windows' && steps.cache.outputs.cache-hit != 'true'
+      shell: pwsh
+      env:
+        FFMPEG_VERSION: ${{ inputs.version }}
+      run: |
+        $vswhere = "${env:ProgramFiles(x86)}\Microsoft Visual Studio\Installer\vswhere.exe"
+        $vs = & $vswhere -latest -products * `
+          -requires Microsoft.VisualStudio.Component.VC.Tools.x86.x64 `
+          -property installationPath
+        cmd /s /c "`"$vs\VC\Auxiliary\Build\vcvars64.bat`" > nul 2>&1 && set" |
+          ForEach-Object {
+            $name, $value = $_ -split '=', 2
+            if ($name -and $value) { Set-Item -Path "env:$name" -Value $value }
+          }
+        $env:MSYS2_PATH_TYPE = "inherit"
+        $env:CHERE_INVOKING = "1"
+        $script = "${env:GITHUB_ACTION_PATH}\build-windows.sh" -replace '\\', '/'
+        C:\msys64\usr\bin\bash -l $script
+        if ($LASTEXITCODE -ne 0) { throw "static FFmpeg build failed" }
diff --git a/.github/actions/static-ffmpeg/build-windows.sh b/.github/actions/static-ffmpeg/build-windows.sh
@@ -0,0 +1,58 @@
+#!/usr/bin/env bash
+# Runs under the runner's stock MSYS2 with the MSVC (vcvars64)
+# environment inherited — see action.yml. Produces static
+# avcodec.lib/avutil.lib in $GITHUB_WORKSPACE/ffmpeg-static.
+set -euxo pipefail
+
+# MSYS2's coreutils /usr/bin/link shadows MSVC's link.exe, and FFmpeg's
+# configure --toolchain=msvc needs the latter.
+rm -f /usr/bin/link.exe
+
+pacman -Sy --noconfirm --needed make nasm diffutils xz
+
+curl -LO "https://ffmpeg.org/releases/ffmpeg-${FFMPEG_VERSION}.tar.xz"
+tar xf "ffmpeg-${FFMPEG_VERSION}.tar.xz"
+cd "ffmpeg-${FFMPEG_VERSION}"
+
+prefix="$(cygpath -u "$GITHUB_WORKSPACE")/ffmpeg-static"
+
+# Same minimal decode-only shape as the Linux/macOS builds, with the
+# Windows GPU decode APIs (D3D11VA + the DXVA2 fallback) in place of
+# VAAPI. The *_d3d11va2 hwaccels are the AV_HWDEVICE_TYPE_D3D11VA +
+# hw_device_ctx path the decoder actually uses; the *_d3d11va ones are
+# the legacy API, enabled alongside for completeness. -MD matches the
+# /MD CRT of the plugin's Release build. The linking side lives in
+# CMakeLists.txt: bcrypt/ole32/user32 resolve the static libavutil's
+# RNG and DXVA2 device setup.
+./configure --prefix="$prefix" --toolchain=msvc \
+	--extra-cflags="-MD" \
+	--disable-everything --disable-programs --disable-doc \
+	--disable-avformat --disable-avfilter --disable-swscale \
+	--disable-swresample --disable-avdevice --disable-network \
+	--disable-debug --disable-autodetect \
+	--enable-decoder=h264,hevc --enable-parser=h264,hevc \
+	--enable-d3d11va --enable-dxva2 \
+	--enable-hwaccel=h264_d3d11va,h264_d3d11va2,h264_dxva2 \
+	--enable-hwaccel=hevc_d3d11va,hevc_d3d11va2,hevc_dxva2 \
+	--disable-shared --enable-static \
+	|| { tail -n 50 ffbuild/config.log; exit 1; }
+
+make -j"$(nproc)"
+make install
+
+# The archive names configure emits have varied (libavcodec.a vs
+# avcodec.lib); pin one canonical name the workflows can rely on, and
+# fail loudly if neither shows up.
+cd "$prefix/lib"
+for lib in avcodec avutil; do
+	if [ ! -f "$lib.lib" ]; then
+		for cand in "lib$lib.a" "$lib.a" "lib$lib.lib"; do
+			if [ -f "$cand" ]; then
+				mv "$cand" "$lib.lib"
+				break
+			fi
+		done
+	fi
+	[ -f "$lib.lib" ]
+done
+ls -l
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
@@ -51,8 +51,10 @@ jobs:
           git fetch --depth=1 origin "$BASE"
           CHANGED=$(git diff --name-only "$BASE" HEAD)
           # A workflow edit rebuilds everything: it may change any job.
+          # .github/actions/ is in the plugin set: the static-ffmpeg
+          # composite action feeds the plugin builds.
           if echo "$CHANGED" | \
-             grep -qE '^(obs-plugin/|installer/|\.github/workflows/build\.yml)'; then
+             grep -qE '^(obs-plugin/|installer/|\.github/workflows/build\.yml|\.github/actions/)'; then
             echo "plugin=true" >> "$GITHUB_OUTPUT"
           else
             echo "plugin=false" >> "$GITHUB_OUTPUT"
@@ -130,9 +132,12 @@ jobs:
     if: needs.changes.outputs.plugin == 'true'
     runs-on: windows-2022
     env:
-      # Keep in sync with the OBS release users run: the plugin links the
-      # FFmpeg DLLs from this deps bundle, and OBS must ship the same ones.
-      # OBS 32.1.2 pins obs-deps 2025-08-23 (see its CMakePresets.json).
+      # Pins the libobs the plugin compiles/links against, and the Qt6
+      # bundle for the status-bar/dock UI. FFmpeg deliberately does NOT
+      # come from this bundle: the plugin links its own static
+      # decode-only FFmpeg (.github/actions/static-ffmpeg), so an OBS
+      # update swapping its bundled FFmpeg DLLs can't break plugin
+      # loading (issues #91, #93).
       OBS_REF: "32.1.2"
       DEPS_TAG: "2025-08-23"
     steps:
@@ -148,7 +153,7 @@ jobs:
           ref: ${{ env.OBS_REF }}
           path: obs-studio
 
-      - name: Download OBS prebuilt dependencies (FFmpeg, Qt6)
+      - name: Download OBS prebuilt dependencies (for libobs; Qt6)
         run: |
           curl -L -o deps.zip "https://github.com/obsproject/obs-deps/releases/download/${{ env.DEPS_TAG }}/windows-deps-${{ env.DEPS_TAG }}-x64.zip"
           7z x deps.zip -oobs-deps
@@ -159,6 +164,9 @@ jobs:
           curl -L -o deps-qt6.zip "https://github.com/obsproject/obs-deps/releases/download/${{ env.DEPS_TAG }}/windows-deps-qt6-${{ env.DEPS_TAG }}-x64.zip"
           7z x -y deps-qt6.zip -oobs-deps
 
+      - name: Build static FFmpeg (H.264/HEVC decode only)
+        uses: ./.github/actions/static-ffmpeg
+
       - name: Cache libobs build
         id: cache-libobs
         uses: actions/cache@v6
@@ -177,18 +185,43 @@ jobs:
             -DENABLE_AJA=OFF
           cmake --build obs-build --target libobs --config Release
 
+      # DISABLE_FIND_PACKAGE_PkgConfig: if a pkg-config on the runner
+      # ever resolved FFmpeg from the obs-deps bundle, the DLL would
+      # silently regress to importing OBS's avcodec-NN.dll; force the
+      # explicit static paths instead. The guard below backstops it.
       - name: Build plugin
         run: |
           cmake -S obs-plugin -B plugin-build -G "Visual Studio 17 2022" -A x64 `
             -DCMAKE_PREFIX_PATH="${{ github.workspace }}\obs-deps" `
             -DLIBOBS_INCLUDE_DIR="${{ github.workspace }}\obs-studio\libobs;${{ github.workspace }}\obs-build\config;${{ github.workspace }}\obs-studio\deps\w32-pthreads" `
             -DLIBOBS_LIBRARY="${{ github.workspace }}\obs-build\libobs\Release\obs.lib;${{ github.workspace }}\obs-build\deps\w32-pthreads\Release\w32-pthreads.lib" `
             -DOBS_FRONTEND_API_HINT="${{ github.workspace }}\obs-studio\frontend\api;${{ github.workspace }}\obs-studio\UI\obs-frontend-api" `
-            -DFFMPEG_INCLUDE_DIR="${{ github.workspace }}\obs-deps\include" `
-            -DAVCODEC_LIBRARY="${{ github.workspace }}\obs-deps\lib\avcodec.lib" `
-            -DAVUTIL_LIBRARY="${{ github.workspace }}\obs-deps\lib\avutil.lib"
+            -DCMAKE_DISABLE_FIND_PACKAGE_PkgConfig=ON `
+            -DFFMPEG_INCLUDE_DIR="${{ github.workspace }}\ffmpeg-static\include" `
+            -DAVCODEC_LIBRARY="${{ github.workspace }}\ffmpeg-static\lib\avcodec.lib" `
+            -DAVUTIL_LIBRARY="${{ github.workspace }}\ffmpeg-static\lib\avutil.lib"
           cmake --build plugin-build --config Release
 
+      # A lenslink.dll that imports avcodec-NN.dll/avutil-NN.dll only
+      # loads while OBS ships that exact FFmpeg major — the next OBS
+      # update breaks it with LoadLibrary error 126 (issues #91, #93).
+      # The obs.dll check keeps the negative check honest: an empty or
+      # misread dependents dump would otherwise pass it vacuously.
+      - name: Verify FFmpeg linked statically
+        run: |
+          $vswhere = "${env:ProgramFiles(x86)}\Microsoft Visual Studio\Installer\vswhere.exe"
+          $dumpbin = & $vswhere -latest -products * `
+            -find "VC\Tools\MSVC\**\bin\Hostx64\x64\dumpbin.exe" |
+            Select-Object -First 1
+          $deps = & $dumpbin /dependents plugin-build\Release\lenslink.dll | Out-String
+          Write-Host $deps
+          if ($deps -match "avcodec|avutil") {
+            throw "lenslink.dll imports OBS's FFmpeg DLLs (breaks on OBS updates)"
+          }
+          if ($deps -notmatch "obs\.dll") {
+            throw "obs.dll import missing - dependents dump looks wrong"
+          }
+
       - name: Package (drop into C:\Program Files\obs-studio)
         run: |
           New-Item -ItemType Directory -Force -Path stage\obs-plugins\64bit | Out-Null
@@ -219,9 +252,13 @@ jobs:
     if: needs.changes.outputs.plugin == 'true'
     runs-on: macos-15
     env:
-      # Keep in sync with the OBS release users run (same pins as the
-      # Windows job): the plugin links the FFmpeg dylibs from this deps
-      # bundle, and OBS must ship the same ones.
+      # Pins the libobs the plugin compiles/links against, and the Qt6
+      # bundle for the status-bar/dock UI (same pins as the Windows
+      # job). FFmpeg deliberately does NOT come from this bundle: the
+      # plugin links its own static decode-only FFmpeg
+      # (.github/actions/static-ffmpeg), so an OBS update swapping its
+      # bundled FFmpeg dylibs can't break plugin loading (issues #91,
+      # #93 hit exactly that on Windows).
       OBS_REF: "32.1.2"
       DEPS_TAG: "2025-08-23"
     steps:
@@ -237,7 +274,7 @@ jobs:
           ref: ${{ env.OBS_REF }}
           path: obs-studio
 
-      - name: Download OBS prebuilt dependencies (FFmpeg, Qt6)
+      - name: Download OBS prebuilt dependencies (for libobs; Qt6)
         run: |
           curl -L -o deps.tar.xz "https://github.com/obsproject/obs-deps/releases/download/${{ env.DEPS_TAG }}/macos-deps-${{ env.DEPS_TAG }}-universal.tar.xz"
           mkdir obs-deps
@@ -246,6 +283,9 @@ jobs:
           curl -L -o deps-qt6.tar.xz "https://github.com/obsproject/obs-deps/releases/download/${{ env.DEPS_TAG }}/macos-deps-qt6-${{ env.DEPS_TAG }}-universal.tar.xz"
           tar -xJf deps-qt6.tar.xz -C obs-deps
 
+      - name: Build static FFmpeg (H.264/HEVC decode only)
+        uses: ./.github/actions/static-ffmpeg
+
       # "macos" in the key: cache keys are not runner-scoped, and the
       # Windows job already uses libobs-<ref>-<tag> for its MSVC build.
       - name: Cache libobs build
@@ -274,6 +314,10 @@ jobs:
             -DENABLE_BROWSER=OFF -DENABLE_SCRIPTING=OFF
           cmake --build obs-build --target libobs --config Release
 
+      # DISABLE_FIND_PACKAGE_PkgConfig: the runner ships a pkg-config,
+      # and CMake feeds it CMAKE_PREFIX_PATH (obs-deps) — without this
+      # the build could silently resolve OBS's shared FFmpeg instead of
+      # the static one. The guard below backstops it.
       - name: Build plugin
         run: |
           cmake -S obs-plugin -B plugin-build \
@@ -285,11 +329,26 @@ jobs:
             -DOBS_FRONTEND_API_HINT="$PWD/obs-studio/frontend/api;$PWD/obs-studio/UI/obs-frontend-api" \
             -DLIBOBS_INCLUDE_DIR="$PWD/obs-studio/libobs;$PWD/obs-build/config" \
             -DLIBOBS_LIBRARY="$PWD/obs-build/libobs/Release/libobs.framework" \
-            -DFFMPEG_INCLUDE_DIR="$PWD/obs-deps/include" \
-            -DAVCODEC_LIBRARY="$PWD/obs-deps/lib/libavcodec.dylib" \
-            -DAVUTIL_LIBRARY="$PWD/obs-deps/lib/libavutil.dylib"
+            -DCMAKE_DISABLE_FIND_PACKAGE_PkgConfig=ON \
+            -DFFMPEG_INCLUDE_DIR="$PWD/ffmpeg-static/include" \
+            -DAVCODEC_LIBRARY="$PWD/ffmpeg-static/lib/libavcodec.a" \
+            -DAVUTIL_LIBRARY="$PWD/ffmpeg-static/lib/libavutil.a"
           cmake --build plugin-build
 
+      # A lenslink.so referencing libavcodec.NN.dylib only loads while
+      # OBS ships that exact FFmpeg major — the next OBS update breaks
+      # it (the macOS twin of Windows issues #91, #93). The libobs check
+      # keeps the negative check honest. Plain `if grep`, not `! grep`:
+      # a `!` line that isn't last is non-fatal under bash -e.
+      - name: Verify FFmpeg linked statically
+        run: |
+          otool -L plugin-build/lenslink.so | tee deps.log
+          if grep -E "libav(codec|util)" deps.log; then
+            echo "::error::lenslink.so links OBS's shared FFmpeg dylibs"
+            exit 1
+          fi
+          grep -q "libobs" deps.log
+
       # Assemble the .plugin bundle on PRs too, so a broken Info.plist or
       # layout change can't reach a release build. Takes seconds.
       - name: Package (drop into ~/Library/Application Support/obs-studio/plugins)