0219dc71b3
While closed-source IPA modules will always be sandboxed, open-source IPA modules may be run in the main libcamera process or be sandboxed, depending on platform configuration. These two models exhibit very different timings, which require extensive testing with both configurations. When run into the main libcamera process, IPA modules are executed in the pipeline handler thread (which is currently a global CameraManager thread). Time-consuming operations in the IPA may thus slow down the pipeline handler and compromise real-time behaviour. At least some pipeline handlers will thus likely spawn a thread to isolate the IPA, leading to code duplication in pipeline handlers. Solve both issues by always proxying IPA modules. For open-source IPA modules that run in the libcamera process, a new IPAProxyThread class is added to run the IPA in a separate thread. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> [Niklas: Move thread start/stop of thread into start()/stop()] Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
.. 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 qcam: [optional]
qtbase5-dev libqt5core5a libqt5gui5 libqt5widgets5
for documentation: [optional]
python3-sphinx doxygen
for gstreamer: [optional]
libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev
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