Windows Arm64 native support: FFmpeg/libavif builders (hardware-verified on windows-11-arm)

.github/workflows/build_ffmpeg.yaml

@@ -14,6 +14,8 @@ on:
   pull_request:
     paths:
       - packaging/build_ffmpeg.sh
+      - packaging/build_ffmpeg_arm64.bat
+      - packaging/build_ffmpeg.bat
       - .github/workflows/build_ffmpeg.yaml # self reference
   schedule:
     - cron: '0 0 * * 0'  # on sunday
@@ -119,3 +121,41 @@ jobs:
         artifact_dir="${RUNNER_ARTIFACT_DIR}/$(date +%Y-%m-%d)/windows_$(uname -m)"
         mkdir -p "${artifact_dir}"
         mv ffmpeg.tar.gz "${artifact_dir}/${FFMPEG_VERSION}.tar.gz"
+
+  # Native Windows ARM64 counterpart of LGPL-Windows. Runs on GitHub's
+  # standard `windows-11-arm` hosted runner (GA for public repos since
+  # 2025-08-07) instead of pytorch/test-infra's windows_job.yml wrapper,
+  # since that reusable workflow targets test-infra's own x86_64 runner
+  # fleet. This job only produces a build artifact; per this workflow's
+  # header comment, uploading it to the S3 bucket consumed by
+  # BUILD_AGAINST_ALL_FFMPEG_FROM_S3 is a separate, manual, maintainer-only
+  # step that must be done once to unblock windows_wheel.yaml's arm64 build.
+  LGPL-Windows-arm64:
+    strategy:
+      fail-fast: false
+      matrix:
+        ffmpeg-version: ["4.4.4", "5.1.4", "6.1.1", "7.0.1", "8.0", "9.0"]
+    runs-on: windows-11-arm
+    defaults:
+      run:
+        shell: bash -l -eo pipefail {0}
+    steps:
+      - name: Check out repo
+        uses: actions/checkout@v6
+
+      - name: Build FFmpeg (LGPL, decode/encode symbols only) and package artifact
+        run: |
+          export FFMPEG_VERSION="${{ matrix.ffmpeg-version }}"
+          export FFMPEG_ROOT="${PWD}/ffmpeg"
+
+          packaging/build_ffmpeg_arm64.bat
+
+          tar -cf ffmpeg.tar.gz ffmpeg/include ffmpeg/bin
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: ffmpeg-lgpl-windows_arm64-${{ matrix.ffmpeg-version }}
+          path: ffmpeg.tar.gz
+          if-no-files-found: error
+          retention-days: 14

.github/workflows/build_libavif.yaml

@@ -14,6 +14,7 @@ on:
     paths:
       - packaging/build_libavif.sh
       - packaging/build_libavif.bat
+      - packaging/build_libavif_arm64.bat
       - .github/workflows/build_libavif.yaml
   schedule:
     - cron: '0 0 * * 0'  # on sunday
@@ -121,3 +122,39 @@ jobs:
         artifact_dir="${RUNNER_ARTIFACT_DIR}/$(date +%Y-%m-%d)/windows_$(uname -m)"
         mkdir -p "${artifact_dir}"
         mv libavif.tar.gz "${artifact_dir}/${LIBAVIF_VERSION}.tar.gz"
+
+  # Native Windows ARM64 counterpart of libavif-Windows. See the equivalent
+  # LGPL-Windows-arm64 job in build_ffmpeg.yaml for why this uses GitHub's
+  # standard `windows-11-arm` hosted runner directly instead of
+  # pytorch/test-infra's windows_job.yml. Same manual-S3-upload caveat
+  # applies here too.
+  libavif-Windows-arm64:
+    strategy:
+      fail-fast: false
+      matrix:
+        libavif-version: ["1.4.2"]
+    runs-on: windows-11-arm
+    defaults:
+      run:
+        shell: bash -l -eo pipefail {0}
+    steps:
+      - name: Check out repo
+        uses: actions/checkout@v6
+
+      - name: Build libavif (decode-only) and package artifact
+        run: |
+          export LIBAVIF_VERSION="${{ matrix.libavif-version }}"
+          export LIBAVIF_ROOT="${PWD}/libavif"
+
+          packaging/build_libavif_arm64.bat
+
+          # Include lib (import lib) and bin (DLL) so the consumer has both.
+          tar -cf libavif.tar.gz libavif/include libavif/lib libavif/bin libavif/licenses
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: libavif-windows_arm64-${{ matrix.libavif-version }}
+          path: libavif.tar.gz
+          if-no-files-found: error
+          retention-days: 14

.github/workflows/windows_arm64_wheel.yaml

@@ -0,0 +1,136 @@
+name: Windows ARM64 Wheel
+
+on:
+  workflow_dispatch:
+  pull_request:
+    paths:
+      - .github/workflows/windows_arm64_wheel.yaml
+      - packaging/build_ffmpeg.sh
+      - packaging/build_ffmpeg_arm64.bat
+      - packaging/build_libavif.sh
+      - packaging/build_libavif_arm64.bat
+      - packaging/vc_env_helper_arm64.bat
+      - packaging/install_build_dependencies.sh
+      - packaging/pre_build_script.sh
+      - packaging/post_build_script.sh
+      - packaging/install_pytorch.sh
+      - packaging/install_torchcodec_wheel.sh
+      - packaging/install_test_dependencies.sh
+      - packaging/remove_src.sh
+      - packaging/assert_ffmpeg_version.py
+      - test/smoke_test.py
+      - pyproject.toml
+      - CMakeLists.txt
+      - src/torchcodec/_core/**
+  push:
+    branches:
+      - winarm64-hackathon
+    paths:
+      - .github/workflows/windows_arm64_wheel.yaml
+      - packaging/build_ffmpeg.sh
+      - packaging/build_ffmpeg_arm64.bat
+      - packaging/build_libavif.sh
+      - packaging/build_libavif_arm64.bat
+      - packaging/vc_env_helper_arm64.bat
+      - packaging/install_build_dependencies.sh
+      - packaging/pre_build_script.sh
+      - packaging/post_build_script.sh
+      - packaging/install_pytorch.sh
+      - packaging/install_torchcodec_wheel.sh
+      - packaging/install_test_dependencies.sh
+      - packaging/remove_src.sh
+      - packaging/assert_ffmpeg_version.py
+      - test/smoke_test.py
+      - pyproject.toml
+      - CMakeLists.txt
+      - src/torchcodec/_core/**
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref_name }}-${{ github.ref_type == 'branch' && github.sha }}-${{ github.event_name == 'workflow_dispatch' }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  build-and-test:
+    runs-on: windows-11-arm
+    defaults:
+      run:
+        shell: bash -l -eo pipefail {0}
+    env:
+      FFMPEG_VERSION: "9.0"
+      LIBAVIF_VERSION: "1.4.2"
+      TORCHCODEC_BUILD_HEIC: "0"
+      FAIL_WITHOUT_IMAGE_CODECS: "1"
+      FAIL_WITHOUT_HEIC: "0"
+    steps:
+      - name: Check out repo
+        uses: actions/checkout@v6
+
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Update pip
+        run: python -m pip install --upgrade pip
+
+      - name: Install PyTorch
+        run: bash packaging/install_pytorch.sh cpu "torch torchvision"
+
+      - name: Install build dependencies
+        run: |
+          python -m pip install pybind11 "scikit-build-core>=0.10" ninja
+
+      - name: Build FFmpeg
+        run: |
+          export FFMPEG_ROOT="${PWD}/ffmpeg"
+          packaging/build_ffmpeg_arm64.bat
+
+      - name: Build libavif
+        run: |
+          export LIBAVIF_ROOT="${PWD}/libavif"
+          packaging/build_libavif_arm64.bat
+
+      - name: Build wheel
+        shell: cmd
+        run: |
+          call packaging\vc_env_helper_arm64.bat ^
+            set BUILD_AGAINST_ALL_FFMPEG_FROM_S3= ^&^& ^
+            set BUILD_AGAINST_ALL_FFMPEG_FROM_LOCAL=1 ^&^& ^
+            set FFMPEG_ROOT=%CD%\ffmpeg ^&^& ^
+            set LIBAVIF_ROOT=%CD%\libavif ^&^& ^
+            set TORCHCODEC_BUILD_HEIC=0 ^&^& ^
+            python -m build --wheel -vvv --no-isolation
+
+      - name: Repair and inspect wheel
+        run: |
+          bash packaging/post_build_script.sh
+          ls -R
+          ls -R dist || true
+          ls -R wheelhouse || true
+
+      - name: Upload wheel artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: torchcodec-windows-arm64-py311
+          path: |
+            dist/*.whl
+            wheelhouse/*.whl
+          if-no-files-found: error
+          retention-days: 14
+
+      - name: Remove src/ folder
+        run: bash packaging/remove_src.sh
+
+      - name: Install torchcodec from the wheel
+        run: bash packaging/install_torchcodec_wheel.sh
+
+      - name: Install test dependencies
+        run: bash packaging/install_test_dependencies.sh false
+
+      - name: Run ARM64 smoke test
+        run: |
+          python packaging/assert_ffmpeg_version.py 9
+          FAIL_WITHOUT_IMAGE_CODECS=1 FAIL_WITHOUT_HEIC=0 pytest --override-ini="addopts=-v" test/smoke_test.py --tb=short