CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

What this repository is

DALI_deps provides the build scripts and source snapshots (as git submodules) for all third-party C/C++ dependencies required for a bare-metal NVIDIA DALI build. It has no DALI source code itself.

Dependencies managed here are outlined in README.rst

Cloning

Use shallow submodule clones to avoid fetching full upstream histories:

git clone https://github.com/NVIDIA/DALI_deps
git submodule init
git submodule update --depth 1 --recursive

Building all dependencies

export HOST_INSTALL_PREFIX=$HOME/prefix
export PATH=$HOME/prefix/bin:$PATH
export LD_LIBRARY_PATH=$HOME/prefix/lib:$LD_LIBRARY_PATH
export CPATH=$HOME/prefix/include:$CPATH
bash -ex build_scripts/build_deps.sh

Do not run as sudo — use a user-writable prefix instead.

Key env vars for build_deps.sh:

• HOST_INSTALL_PREFIX / INSTALL_PREFIX — installation prefix (default /usr/local)
• CC_COMP / CXX_COMP — compiler selection (default gcc/g++)
• CMAKE_TARGET_ARCH — target architecture (default: host arch)
• WITH_FFMPEG — set to 0 to skip FFmpeg (default 1)
• CLEANUP=1 — runs git clean -fdx on all submodules before building

Building a single dependency

Each dependency has its own script in build_scripts/:

bash -ex build_scripts/build_opencv.sh
bash -ex build_scripts/build_ffmpeg.sh
# etc.

Dependency-specific build notes

Notes here cover build decisions that aren't obvious from the script alone. Most dependencies don't need an entry; add one when a build script relies on a non-obvious workaround or constraint future changes need to preserve.

Google Cloud Storage

build_google-cloud-cpp.sh passes -DGOOGLE_CLOUD_CPP_ENABLE=storage, so only the GCS client is built out of the ~200 libraries in the SDK. google-cloud-cpp always adds monitoring, trace, opentelemetry and universe_domain on top of that, which is why gRPC and opentelemetry-cpp are dependencies even though the GCS client itself talks REST.

Abseil is not a submodule - build_protobuf.sh fetches and installs it as part of protobuf, and build_grpc.sh reuses that copy (along with protobuf, zlib and OpenSSL) via gRPC_*_PROVIDER=package so that no second, differently versioned copy is installed over it. The googleapis protobuf definitions are downloaded by google-cloud-cpp while configuring; GOOGLE_CLOUD_CPP_OVERRIDE_GOOGLEAPIS_URL points that at a local copy.

Patches

The patches/ directory contains patches applied on top of upstream sources during the build scripts (e.g. CVE fixes for libsndfile, FFmpeg fixes, lmdb Makefile patch). Patches are applied by the individual build_scripts/*.sh scripts — do not apply them manually.