avdivan · Nov 15, 2026 · Nov 15, 2026 · Nov 15, 2026 · Nov 15, 2026 · Nov 15, 2026
diff --git a/.github/workflows/build_wheels_macos.yml b/.github/workflows/build_wheels_macos.yml
@@ -15,8 +15,57 @@ on:
   workflow_dispatch:
 
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+env:
+  BREW_CACHE_VERSION: v1
+
 jobs:
+  FFmpeg:
+    # Builds LGPL FFmpeg and its dependencies that have no Homebrew bottles,
+    # and caches the bottles for the Build jobs.
+    # If it runs out of time, the cache is saved anyway: re-run the job to continue.
+    # The cache key has the runner image in it: update it along with runs-on.
+    # Outdated bottles are dropped by version. Bump BREW_CACHE_VERSION if the bottles change otherwise,
+    # e.g. the ffmpeg formula conversion rules in travis_config.sh.
+    runs-on: ${{ matrix.platform == 'arm64' && 'macos-15' || 'macos-15-intel' }}
+    timeout-minutes: 360
+    strategy:
+      fail-fast: false
+      matrix:
+        platform: [x86_64, arm64]
+    env:
+      BREW_LOCAL_BOTTLE_DIR: ${{ github.workspace }}/../local_bottle_metadata
+      BREW_TIME_LIMIT: 19200 # 320 min
+      BREW_TIME_HARD_LIMIT: 20400 # 340 min
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v7
+      with:
+        submodules: false
+    - name: Restore Homebrew bottles
+      uses: actions/cache/restore@v5
+      with:
+        path: ${{ env.BREW_LOCAL_BOTTLE_DIR }}
+        key: brew-bottles-${{ env.BREW_CACHE_VERSION }}-macos15-${{ matrix.platform }}-${{ github.run_id }}-${{ github.run_attempt }}
+        restore-keys: brew-bottles-${{ env.BREW_CACHE_VERSION }}-macos15-${{ matrix.platform }}-
+    - name: Build FFmpeg
+      id: ffmpeg
+      run: |
+        export IS_OSX=1
+        source travis_config.sh
+        install_ffmpeg_lgpl
+    - name: Save Homebrew bottles
+      if: ${{ always() && steps.ffmpeg.outcome != 'skipped' }}
+      uses: actions/cache/save@v5
+      with:
+        path: ${{ env.BREW_LOCAL_BOTTLE_DIR }}
+        key: brew-bottles-${{ env.BREW_CACHE_VERSION }}-macos15-${{ matrix.platform }}-${{ github.run_id }}-${{ github.run_attempt }}
+
   Build:
+    needs: [FFmpeg]
     runs-on: ${{ matrix.platform == 'arm64' && 'macos-15' || 'macos-15-intel' }}
     strategy:
       fail-fast: false
@@ -44,6 +93,7 @@ jobs:
       ENABLE_HEADLESS: ${{ matrix.without_gui }}
       ENABLE_CONTRIB: ${{ matrix.with_contrib }}
       PIP_INDEX_URL: https://pypi.tuna.tsinghua.edu.cn/simple
+      BREW_LOCAL_BOTTLE_DIR: ${{ github.workspace }}/../local_bottle_metadata
     steps:
     - uses: actions/setup-python@v7
       with:
@@ -61,12 +111,25 @@ jobs:
       with:
         submodules: false
         fetch-depth: 0
+    - name: Restore Homebrew bottles
+      uses: actions/cache/restore@v5
+      with:
+        path: ${{ env.BREW_LOCAL_BOTTLE_DIR }}
+        key: brew-bottles-${{ env.BREW_CACHE_VERSION }}-macos15-${{ matrix.platform }}-${{ github.run_id }}-${{ github.run_attempt }}
+        restore-keys: brew-bottles-${{ env.BREW_CACHE_VERSION }}-macos15-${{ matrix.platform }}-
+        fail-on-cache-miss: true
+    - name: Install FFmpeg
+      run: |
+        export IS_OSX=1
+        source travis_config.sh
+        install_ffmpeg_lgpl
     - name: Build a package
       run: |
         git submodule update --init multibuild
         echo $ENABLE_CONTRIB > contrib.enabled
         echo $ENABLE_HEADLESS > headless.enabled
-        export MACOSX_DEPLOYMENT_TARGET=14.0
+        # Homebrew bottles are built for macOS 15
+        export MACOSX_DEPLOYMENT_TARGET=15.0
         python --version
         python -m pip install delocate toml && python -c 'import toml; c = toml.load("pyproject.toml"); print("\n".join(c["build-system"]["requires"]))' | python -m pip install -r /dev/stdin
         python setup.py bdist_wheel --py-limited-api=cp37 --dist-dir=wheelhouse -v

diff --git a/travis_config.sh b/travis_config.sh
@@ -48,53 +48,91 @@ if [ -n "$IS_OSX" ]; then
 
     source travis_osx_brew_cache.sh
 
+    # Projected build times in minutes on a GitHub-hosted runner
     BREW_SLOW_BUILIDING_PACKAGES=$(printf '%s\n' \
         "cmake 15" \
-        "ffmpeg 10" \
+        "opencv/local/ffmpeg-lgpl 15" \
+        "openssl@3 15" \
+        "python@3.15 25" \
     )
 
+    FFMPEG_LGPL_FORMULA="opencv/local/ffmpeg-lgpl"
+
     function generate_ffmpeg_formula {
-        local FF="ffmpeg"
-        local LFF="ffmpeg"
-        local FF_FORMULA; FF_FORMULA=$(brew formula "${FF}")
-        local LFF_FORMULA; LFF_FORMULA="$(dirname "$FF_FORMULA")/${LFF}.rb"
-
-        local REGENERATE
-        if [ -f "$LFF_FORMULA" ]; then
-            local UPSTREAM_VERSION VERSION
-            _brew_parse_package_info "$FF" " " UPSTREAM_VERSION _ _
-            _brew_parse_package_info "$LFF" " " VERSION _ _   || REGENERATE=1
-            #`rebuild` clause is ignored on `brew bottle` and deleted
-            # from newly-generated formula on `brew bottle --merge` for some reason
-            # so can't compare rebuild numbers
-            if [ "$UPSTREAM_VERSION" != "$VERSION" ]; then
-                REGENERATE=1
-            fi
-        else
-            REGENERATE=1
+        # Make an LGPL build of FFmpeg out of the upstream formula:
+        #  no GPL parts, the same set of external libraries as in Linux builds.
+        local TAP="${FFMPEG_LGPL_FORMULA%/*}"
+        local TAP_DIR; TAP_DIR="$(brew --repository "$TAP")"
+        [ -d "$TAP_DIR" ] || brew tap-new --no-git "$TAP"
+        mkdir -p "$TAP_DIR/Formula"
+        # Homebrew refuses to load formulae from third-party taps otherwise
+        brew trust "$TAP"
+
+        local FF_FORMULA; FF_FORMULA=$(mktemp)
+        # Formulae from the JSON API have no source on disk, so `brew cat` doesn't work for them.
+        # Fetch the source for the homebrew-core revision the API data is from.
+        local FF_SOURCE_URL FF_SOURCE_SHA256
+        read -r FF_SOURCE_URL FF_SOURCE_SHA256 < <(brew info --json=v2 ffmpeg | python3 -c 'if True:
+            import sys, json; data=json.load(sys.stdin)["formulae"][0]
+            print("https://raw.githubusercontent.com/Homebrew/homebrew-core/%s/%s" % (data["tap_git_head"], data["ruby_source_path"]),
+                  data["ruby_source_checksum"]["sha256"])
+            ')
+        curl -fsSL --retry 3 -o "$FF_FORMULA" "$FF_SOURCE_URL"
+        if [ "$(shasum -a 256 "$FF_FORMULA" | cut -d' ' -f1)" != "$FF_SOURCE_SHA256" ]; then
+            echo "Checksum mismatch for $FF_SOURCE_URL" >&2
+            return 1
         fi
-        if [ -n "$REGENERATE" ]; then
-            echo "Regenerating custom ffmpeg formula"
-            # Bottle block syntax: https://docs.brew.sh/Bottles#bottle-dsl-domain-specific-language
-            perl -wpe 'BEGIN {our ($found_blank, $bottle_block);}
-                if (/(^class )(Ffmpeg)(\s.*)/) {$_=$1."Opencv".$3."\n"; next;}
-                if (!$found_blank && /^$/) {$_.="conflicts_with \"ffmpeg\"\n\n"; $found_blank=1; next;}
-                if (!$bottle_block && /^\s*bottle do$/) { $bottle_block=1; next; }
-                if ($bottle_block) { if (/^\s*end\s*$/) { $bottle_block=0} elsif (/^\s*sha256\s/) {$_=""} next; }
-if (/^\s*depends_on "(x264|x265|xvid|frei0r|rubberband|libvidstab)"$/) {$_=""; next;}
-                if (/^\s*--enable-(gpl|libx264|libx265|libxvid|frei0r|librubberband|libvidstab)$/) {$_=""; next;}
-                ' <"$FF_FORMULA" >"$LFF_FORMULA"
-            diff -u "$FF_FORMULA" "$LFF_FORMULA" || test $? -le 1
-
-            (   cd "$(dirname "$LFF_FORMULA")"
-                # This is the official way to add a formula
-                # https://docs.brew.sh/Formula-Cookbook#commit
-                git add "$(basename "$LFF_FORMULA")"
-                git commit -m "add/update custom ffmpeg ${VERSION}"
-            )
+        local LFF_FORMULA; LFF_FORMULA="$TAP_DIR/Formula/${FFMPEG_LGPL_FORMULA##*/}.rb"
+
+        echo "Generating custom ffmpeg formula"
+        # Bottle block syntax: https://docs.brew.sh/Bottles#bottle-dsl-domain-specific-language
+        perl -wpe 'BEGIN {our $bottle_block;}
+            if (/^class Ffmpeg < Formula$/) {$_="class FfmpegLgpl < Formula\n"; next;}
+            if (/^(\s*)license\s/) {$_=$1."license \"LGPL-2.1-or-later\"\n".$1."keg_only \"it conflicts with the GPL-licensed ffmpeg formula\"\n"; next;}
+            if (!$bottle_block && /^\s*bottle do$/) { $bottle_block=1; $_=""; next; }
+            if ($bottle_block) { $bottle_block=0 if /^\s*end\s*$/; $_=""; next; }
+            if (/^\s*depends_on "(lame|libvmaf|opus|sdl2-compat|svt-av1|x264|x265|xz)"(\s*#.*)?$/) {$_=""; next;}
+            if (/^\s*--enable-(gpl|version3|libsvtav1|libopus|libx264|libx265|libmp3lame|libvmaf)$/) {$_=""; next;}
+            s/--enable-ffplay$/--disable-ffplay/;
+            ' <"$FF_FORMULA" >"$LFF_FORMULA"
+        diff -u "$FF_FORMULA" "$LFF_FORMULA" || test $? -le 1
+        rm -f "$FF_FORMULA"
+
+        if grep -qE -e '--enable-(gpl|nonfree|version3)$' -e 'depends_on "x26[45]"' "$LFF_FORMULA"; then
+            echo "The generated ffmpeg formula still has GPL parts. Update the conversion rules!" >&2
+            return 1
         fi
     }
 
+    function install_ffmpeg_lgpl {
+        # Install LGPL FFmpeg and its dependencies, building and caching what has no bottles
+
+        # Runner images may have an outdated Homebrew,
+        #  e.g. 7.0.12 can't install bottles from files
+        brew update
+        brew --version
+
+        generate_ffmpeg_formula
+        brew_add_local_bottles
+        brew_install_and_cache_within_time_limit "$FFMPEG_LGPL_FORMULA" || return $?
+        # OpenCV finds FFmpeg with pkg-config
+        brew_install_and_cache_within_time_limit pkgconf || return $?
+
+        local FF_PREFIX; FF_PREFIX="$(brew --prefix "$FFMPEG_LGPL_FORMULA")"
+        local FF_LICENSE; FF_LICENSE="$("$FF_PREFIX/bin/ffmpeg" -hide_banner -L)"
+        # The license text is wrapped, the phrase can be split between lines
+        if ! tr -s '\n ' '  ' <<<"$FF_LICENSE" | grep -qF "GNU Lesser General Public License"; then
+            echo "$FF_LICENSE"
+            echo "The built FFmpeg is not LGPL!" >&2
+            return 1
+        fi
+
+        # The formula is keg-only, so OpenCV has to be pointed to it
+        local PC_PATH; PC_PATH="$FF_PREFIX/lib/pkgconfig:$(brew --prefix openssl@3)/lib/pkgconfig"
+        export PKG_CONFIG_PATH="$PC_PATH${PKG_CONFIG_PATH:+:$PKG_CONFIG_PATH}"
+        if [ -n "$GITHUB_ENV" ]; then echo "PKG_CONFIG_PATH=$PKG_CONFIG_PATH" >>"$GITHUB_ENV"; fi
+    }
+
 fi
 
 function pre_build {
@@ -116,11 +154,7 @@ function pre_build {
     echo 'Installing FFmpeg'
 
     brew update
-    generate_ffmpeg_formula
-    brew_add_local_bottles
-    brew install --build-bottle ffmpeg
-    # It needs when we use not the latest ffmpeg formula
-    brew link ffmpeg
+    install_ffmpeg_lgpl || return $?
 
     if [ -n "$CACHE_STAGE" ]; then
         brew_go_bootstrap_mode 0