Working on SoftISP
5801dedd2a
The V4L2 compatibility layer uses devnum to match video device nodes to libcamera Cameras. Some pipeline handlers don't report a devnum for their camera, which prevents the V4L2 compatibility layer from matching video device nodes to these cameras. To fix this, we first allow the camera manager to map multiple devnums to a camera. Next, we walk the media device and entity list and tell the camera manager to map every one of these devnums that is a video capture node to the camera. Since we decided that all video capture nodes that belong to a camera can be opened via the V4L2 compatibility layer to map to that camera, it would cause confusion for users if some pipeline handlers decided that only specific device nodes would map to the camera. To prevent this confusion, remove the ability for pipeline handlers to declare their own devnum-to-camera mapping. The only pipeline handler that declares the devnum mapping is the UVC pipeline handler, so remove the devnum there. We considered walking the media entity list and taking the devnum from just the one with the default flag set, but we found that some drivers (eg. vimc) don't set this flag for any entity. Instead, we take all the video capture nodes (entities with the sink pad flag set). Signed-off-by: Paul Elder <paul.elder@ideasonboard.com> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> |
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| Documentation | ||
| include | ||
| LICENSES | ||
| package/gentoo/media-libs/libcamera | ||
| src | ||
| test | ||
| utils | ||
| .clang-format | ||
| .gitignore | ||
| meson.build | ||
| meson_options.txt | ||
| README.rst | ||
.. 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