Laurent Pinchart
e8dc74317a
libcamera uses pixel format FourCC and modifier values from DRM. This requires inclusion of drm_fourcc.h, creating a dependency on a header that is packaged differently between distributions, and causing possible issues with third-party applications. Define constants for the supported pixel formats in the new formats.h public API header, in order to remove the dependency on drm_fourcc.h. The header is generated by a Python script from a list of supported formats. The numerical values for the FourCC and modifier are extracted from drm_fourcc.h by the script, ensuring that numerical values are not inadvertently modified and preserving the direct interoperability. The pixel formats constants can't be generated solely from drm_fourcc.h, as that header defines FourCC values and modifier values, but doesn't list the valid combinations. The supported formats are thus stored in a YAML file, which contains the FourCC and optional modifier for each supported format. We may later extend the YAML file to include formats documentation, and possibly formats metadata to populate the pixelFormatInfo map (in formats.cpp) automatically. Now that two formats.h header are present (one in include/libcamera/ and one in include/libcamera/internal/), we need to explicitly qualify the Doxygen \file directive with a path. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
.. SPDX-License-Identifier: CC-BY-SA-4.0
.. section-begin-libcamera
===========
libcamera
===========
**A complex camera support library for Linux, Android, and ChromeOS**
Cameras are complex devices that need heavy hardware image processing
operations. Control of the processing is based on advanced algorithms that must
run on a programmable processor. This has traditionally been implemented in a
dedicated MCU in the camera, but in embedded devices algorithms have been moved
to the main CPU to save cost. Blurring the boundary between camera devices and
Linux often left the user with no other option than a vendor-specific
closed-source solution.
To address this problem the Linux media community has very recently started
collaboration with the industry to develop a camera stack that will be
open-source-friendly while still protecting vendor core IP. libcamera was born
out of that collaboration and will offer modern camera support to Linux-based
systems, including traditional Linux distributions, ChromeOS and Android.
.. section-end-libcamera
.. section-begin-getting-started
Getting Started
---------------
To fetch the sources, build and install:
::
git clone git://linuxtv.org/libcamera.git
cd libcamera
meson 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}
for libcamera: [required]
meson (>= 0.47) ninja-build python3-yaml
If your distribution doesn't provide a recent enough version of meson,
you can install or upgrade it using pip3.
.. code::
pip3 install --user meson
pip3 install --user --upgrade meson
for device hotplug enumeration: [optional]
pkg-config libudev-dev
for documentation: [optional]
python3-sphinx doxygen
for gstreamer: [optional]
libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev
for IPA module signing: [required]
libgnutls28-dev openssl
for qcam: [optional]
qtbase5-dev libqt5core5a libqt5gui5 libqt5widgets5
Using GStreamer plugin
~~~~~~~~~~~~~~~~~~~~~~
To use GStreamer plugin from source tree, set the following environment so that
GStreamer can find it.
export GST_PLUGIN_PATH=$(pwd)/build/src/gstreamer
The debugging tool `gst-launch-1.0` can be used to construct and pipeline and test
it. The following pipeline will stream from the camera named "Camera 1" onto the
default video display element on your system.
.. code::
gst-launch-1.0 libcamerasrc camera-name="Camera 1" ! videoconvert ! autovideosink
.. section-end-getting-started