Add ability to build cuda wheels

.github/workflows/linux_cuda_wheel.yaml

@@ -0,0 +1,144 @@
+name: Build and test Linux CUDA wheels
+
+on:
+  pull_request:
+  push:
+    branches:
+      - nightly
+      - main
+      - release/*
+    tags:
+        - v[0-9]+.[0-9]+.[0-9]+-rc[0-9]+
+  workflow_dispatch:
+
+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:
+  id-token: write
+  contents: write
+
+defaults:
+  run:
+    shell: bash -l -eo pipefail {0}
+
+jobs:
+  generate-matrix:
+    uses: pytorch/test-infra/.github/workflows/generate_binary_build_matrix.yml@main
+    with:
+      package-type: wheel
+      os: linux
+      test-infra-repository: pytorch/test-infra
+      test-infra-ref: main
+      with-cpu: disable
+      with-xpu: disable
+      with-rocm: disable
+      with-cuda: enable
+      build-python-only: "disable"
+  build:
+    needs: generate-matrix
+    strategy:
+      fail-fast: false
+    name: Build and Upload wheel
+    uses: pytorch/test-infra/.github/workflows/build_wheels_linux.yml@main
+    with:
+      repository: pytorch/torchcodec
+      ref: ""
+      test-infra-repository: pytorch/test-infra
+      test-infra-ref: main
+      build-matrix: ${{ needs.generate-matrix.outputs.matrix }}
+      post-script: packaging/post_build_script.sh
+      smoke-test-script: packaging/fake_smoke_test.py
+      package-name: torchcodec
+      trigger-event: ${{ github.event_name }}
+      build-platform: "python-build-package"
+      build-command: "BUILD_AGAINST_ALL_FFMPEG_FROM_S3=1 ENABLE_CUDA=1 python -m build --wheel -vvv --no-isolation"
+
+  install-and-test:
+    runs-on: linux.4xlarge.nvidia.gpu
+    strategy:
+      fail-fast: false
+      matrix:
+          # 3.9 corresponds to the minimum python version for which we build
+          # the wheel unless the label cliflow/binaries/all is present in the
+          # PR.
+          # For the actual release we should add that label and change this to
+          # include more python versions.
+        python-version: ['3.9']
+        cuda-version: ['11.8', '12.1', '12.4']
+        ffmpeg-version-for-tests: ['5', '6', '7']
+    container:
+      image: "pytorch/manylinux-builder:cuda${{ matrix.cuda-version }}"
+      options: "--gpus all -e NVIDIA_DRIVER_CAPABILITIES=video,compute,utility"
+    if: ${{ always() }}
+    needs: build
+    steps:
+      - name: Setup env vars
+        run: |
+          cuda_version_without_periods=$(echo "${{ matrix.cuda-version }}" | sed 's/\.//g')
+          echo cuda_version_without_periods=${cuda_version_without_periods} >> $GITHUB_ENV
+      - uses: actions/download-artifact@v3
+        with:
+          name: pytorch_torchcodec__3.9_cu${{ env.cuda_version_without_periods }}_x86_64
+          path: pytorch/torchcodec/dist/
+      - name: Setup miniconda using test-infra
+        uses: ahmadsharif1/test-infra/.github/actions/setup-miniconda@14bc3c29f88d13b0237ab4ddf00aa409e45ade40
+        with:
+          python-version: ${{ matrix.python-version }}
+          default-packages: "conda-forge::ffmpeg=${{ matrix.ffmpeg-version-for-tests }}"
+      - name: Check env
+        run: |
+          ${CONDA_RUN} env
+          ${CONDA_RUN} conda info
+          ${CONDA_RUN} nvidia-smi
+      - name: Update pip
+        run: ${CONDA_RUN} python -m pip install --upgrade pip
+      - name: Install PyTorch
+        run: |
+          ${CONDA_RUN} python -m pip install --pre torch --index-url https://download.pytorch.org/whl/nightly/cu${{ env.cuda_version_without_periods }}
+          ${CONDA_RUN} python -c 'import torch; print(f"{torch.__version__}"); print(f"{torch.__file__}"); print(f"{torch.cuda.is_available()=}")'
+      - name: Install torchcodec from the wheel
+        run: |
+          wheel_path=`find pytorch/torchcodec/dist -type f -name "*.whl"`
+          echo Installing $wheel_path
+          ${CONDA_RUN} python -m pip install $wheel_path -vvv
+
+      - name: Check out repo
+        uses: actions/checkout@v3
+
+      - name: Install cuda runtime dependencies
+        run: |
+          # For some reason nvidia::libnpp=12.4 doesn't install but nvidia/label/cuda-12.4.0::libnpp does.
+          # So we use the latter convention for libnpp.
+          ${CONDA_RUN} conda install --yes nvidia/label/cuda-${{ matrix.cuda-version }}.0::libnpp nvidia::cuda-nvrtc=${{ matrix.cuda-version }} nvidia::cuda-toolkit=${{ matrix.cuda-version }} nvidia::cuda-cudart=${{ matrix.cuda-version }} nvidia::cuda-driver-dev=${{ matrix.cuda-version }}
+      - name: Install test dependencies
+        run: |
+          ${CONDA_RUN} python -m pip install --pre torchvision --index-url https://download.pytorch.org/whl/nightly/cpu
+          # Ideally we would find a way to get those dependencies from pyproject.toml
+          ${CONDA_RUN} python -m pip install numpy pytest pillow
+
+      - name: Delete the src/ folder just for fun
+        run: |
+          # The only reason we checked-out the repo is to get access to the
+          # tests. We don't care about the rest. Out of precaution, we delete
+          # the src/ folder to be extra sure that we're running the code from
+          # the installed wheel rather than from the source.
+          # This is just to be extra cautious and very overkill because a)
+          # there's no way the `torchcodec` package from src/ can be found from
+          # the PythonPath: the main point of `src/` is precisely to protect
+          # against that and b) if we ever were to execute code from
+          # `src/torchcodec`, it would fail loudly because the built .so files
+          # aren't present there.
+          rm -r src/
+          ls
+      - name: Smoke test
+        run: |
+          ${CONDA_RUN} python test/decoders/manual_smoke_test.py
+      - name: Run Python tests
+        run: |
+          # We skip test_get_ffmpeg_version because it may not have a micro version.
+          ${CONDA_RUN} FAIL_WITHOUT_CUDA=1 pytest test -k "not test_get_ffmpeg_version" -vvv
+      - name: Run Python benchmark
+        run: |
+          ${CONDA_RUN} time python benchmarks/decoders/gpu_benchmark.py --devices=cuda:0,cpu --resize_devices=none

packaging/post_build_script.sh

@@ -6,7 +6,14 @@ wheel_path=$(pwd)/$(find dist -type f -name "*.whl")
 echo "Wheel content:"
 unzip -l $wheel_path
 
-for ffmpeg_major_version in 4 5 6 7; do
+ffmpeg_versions=(4 5 6 7)
+
+# TODO: Make ffmpeg4 work with nvcc.
+if [ "$ENABLE_CUDA" -eq 1 ]; then
+    ffmpeg_versions=(5 6 7)
+fi
+
+for ffmpeg_major_version in ${ffmepg_versions[@]}; do
     assert_in_wheel $wheel_path torchcodec/libtorchcodec${ffmpeg_major_version}.so
 done
 assert_not_in_wheel $wheel_path libtorchcodec.so

src/torchcodec/decoders/_core/CMakeLists.txt

@@ -37,7 +37,7 @@ function(make_torchcodec_library library_name ffmpeg_target)
     set(NEEDED_LIBRARIES ${ffmpeg_target} ${TORCH_LIBRARIES}
         ${Python3_LIBRARIES})
     if(ENABLE_CUDA)
-        list(APPEND NEEDED_LIBRARIES ${CUDA_CUDA_LIBRARY}
+        list(APPEND NEEDED_LIBRARIES
             ${CUDA_nppi_LIBRARY} ${CUDA_nppicc_LIBRARY} )
     endif()
     target_link_libraries(
@@ -76,10 +76,15 @@ if(DEFINED ENV{BUILD_AGAINST_ALL_FFMPEG_FROM_S3})
         ${CMAKE_CURRENT_SOURCE_DIR}/fetch_and_expose_non_gpl_ffmpeg_libs.cmake
     )
 
-    make_torchcodec_library(libtorchcodec4 ffmpeg4)
-    make_torchcodec_library(libtorchcodec5 ffmpeg5)
-    make_torchcodec_library(libtorchcodec6 ffmpeg6)
-    make_torchcodec_library(libtorchcodec7 ffmpeg7)
+
+    if(NOT ENABLE_CUDA)
+	    # TODO: Enable more ffmpeg versions for cuda.
+	    make_torchcodec_library(libtorchcodec4 ffmpeg4)
+	endif()
+	make_torchcodec_library(libtorchcodec7 ffmpeg7)
+	make_torchcodec_library(libtorchcodec6 ffmpeg6)
+	make_torchcodec_library(libtorchcodec5 ffmpeg5)
+
 else()
     message(
         STATUS

test/utils.py

@@ -15,6 +15,8 @@
 # Decorator for skipping CUDA tests when CUDA isn't available
 def needs_cuda(test_item):
     if not torch.cuda.is_available():
+        if os.environ.get("FAIL_WITHOUT_CUDA") == "1":
+            raise RuntimeError("CUDA is required for this test")
         return pytest.mark.skip(reason="CUDA not available")(test_item)
     return test_item