# Getting Started

To fetch the sources, build and install:

    git clone https://git.libcamera.org/libcamera/libcamera.git
    cd libcamera
    meson setup build
    ninja -C build install

## Dependencies

The following Debian/Ubuntu packages are required for building libcamera. Other distributions may have differing package names:

A C++ toolchain: [required]

  Either {g++, clang}

Meson Build system: [required]

  meson (>= 0.60) ninja-build pkg-config

for the libcamera core: [required]

  libyaml-dev python3-yaml python3-ply python3-jinja2

for IPA module signing: [recommended]

  Either libgnutls28-dev or libssl-dev, openssl

  Without IPA module signing, all IPA modules will be isolated in a separate process. This adds an unnecessary extra overhead at runtime.

for improved debugging: [optional]

  libdw-dev libunwind-dev

  libdw and libunwind provide backtraces to help debugging assertion failures. Their functions overlap, libdw provides the most detailed information, and libunwind is not needed if both libdw and the glibc backtrace() function are available.

for device hotplug enumeration: [optional]

  libudev-dev

for documentation: [optional]

  python3-sphinx doxygen graphviz texlive-latex-extra

for gstreamer: [optional]

  libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev

for Python bindings: [optional]

  libpython3-dev pybind11-dev

for cam: [optional]

  libevent-dev is required to support cam, however the following optional dependencies bring more functionality to the cam test tool:

  - libdrm-dev: Enables the KMS sink

  - libjpeg-dev: Enables MJPEG on the SDL sink

  - libsdl2-dev: Enables the SDL sink

for qcam: [optional]

  libtiff-dev qtbase5-dev qttools5-dev-tools

for tracing with lttng: [optional]

  liblttng-ust-dev python3-jinja2 lttng-tools

for android: [optional]

  libexif-dev libjpeg-dev

for lc-compliance: [optional]

  libevent-dev libgtest-dev

for abi-compat.sh: [optional]

  abi-compliance-checker

## Basic testing with cam utility

The `cam` utility can be used for basic testing. You can list the cameras detected on the system with `cam -l`, and capture ten frames from the first camera and save them to disk with `cam -c 1 --capture=10 --file`. See `cam -h` for more information about the `cam` tool.

In case of problems, a detailed debug log can be obtained from libcamera by setting the `LIBCAMERA_LOG_LEVELS` environment variable:

    :~$ LIBCAMERA_LOG_LEVELS=*:DEBUG cam -l

## Using GStreamer plugin

To use GStreamer plugin from source tree, set the following environment so that GStreamer can find it. This isn’t necessary when libcamera is installed.

    export GST_PLUGIN_PATH=$(pwd)/build/src/gstreamer

The debugging tool `gst-launch-1.0` can be used to construct a pipeline and test it. The following pipeline will stream from the camera named “Camera 1” onto the OpenGL accelerated display element on your system.

    gst-launch-1.0 libcamerasrc camera-name="Camera 1" ! glimagesink

To show the first camera found you can omit the camera-name property, or you can list the cameras and their capabilities using:

    gst-device-monitor-1.0 Video

This will also show the supported stream sizes which can be manually selected if desired with a pipeline such as:

    gst-launch-1.0 libcamerasrc ! 'video/x-raw,width=1280,height=720' ! \
          glimagesink

The libcamerasrc element has two log categories, named libcamera-provider (for the video device provider) and libcamerasrc (for the operation of the camera). All corresponding debug messages can be enabled by setting the `GST_DEBUG` environment variable to `libcamera*:7`.

Presently, to prevent element negotiation failures it is required to specify the colorimetry and framerate as part of your pipeline construction. For instance, to capture and encode as a JPEG stream and receive on another device the following example could be used as a starting point:

    gst-launch-1.0 libcamerasrc ! \
         video/x-raw,colorimetry=bt709,format=NV12,width=1280,height=720,framerate=30/1 ! \
         jpegenc ! multipartmux ! \
         tcpserversink host=0.0.0.0 port=5000

Which can be received on another device over the network with:

    gst-launch-1.0 tcpclientsrc host=$DEVICE_IP port=5000 ! \
         multipartdemux ! jpegdec ! autovideosink