libcamera supports several environment variables that can override
configuration options. This requires components that use such overrides
to call the special envOption() and envListOption() functions, spreading
knowledge of the overrides through the code base. This will hinder
future enhancements to the global configuration, such as implementing
per-camera options that will override pipeline handler-level options. To
prepare for that, move handling of the environment variables to the
GlobalConfiguration class.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Isaac Scott <isaac.scott@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
The GlobalConfiguration::Option type was introduced to decouple the
configuration option storage from its users, and make changes to the
underlying implementation easier. While the type could indeed be changed
to map to a different class, the API would need to remain the same. The
Option type therefore brings little value. Drop it.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Isaac Scott <isaac.scott@ideasonboard.com>
global_configuration.h uses std::initializer_list, include the
corresponding header. Add a comment in global_configuration.cpp to close
an anonymous namespace, as mandated by the coding style.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Isaac Scott <isaac.scott@ideasonboard.com>
Member functions should be implemented in the .cpp file in the same
order as in the class definition, within each access group. Move them to
the right location. While at it, move load() before loadFile() in the
class definition to match execution order, making the code easier to
read.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Isaac Scott <isaac.scott@ideasonboard.com>
The YamlObject class is now a generic data container to model trees of
values. Rename it to ValueNode and expand the class documentation.
While at it, drop the unneeded libcamera:: namespace prefix when using
the ValueNode class.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
The YamlObject class was designed to represent data parsed from YAML
files. It is outgrowing the initial needs. Move it to a separate file to
prepare for a rename.
Most files that include yaml_parser.h only need access to a YamlObject.
Switch them to yaml_object.h. pipeline_base.cpp was including
yaml_parser.h indirectly through pipeline_base.h, include it directly
now.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Isaac Scott <isaac.scott@ideasonboard.com>
Let's add some helpers to make accessing simple configuration values
simpler. The helpers are used in the followup patches.
GlobalConfiguration::option ensures that no value is returned rather
than a value of YamlObject::empty.
Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Currently, libcamera can be configured in runtime using several
environment variables. With introducing more and more variables, this
mechanism reaches its limits. It would be simpler and more flexible if
it was possible to configure libcamera in a single file.
For example, there was a request to define pipeline precedence in
runtime. We want to compile in multiple pipelines, in order to have
them accessible within single packages in distributions. And then being
able to select among the pipelines manually as needed based on the
particular hardware or operating system environment. Having the
configuration file then allows easy switching between hardware, GPU or
CPU IPAs. The configuration file can also be used to enable or disable
experimental features and avoid the need to track local patches changing
configuration options hard-wired in the code when working on new
features.
This patch introduces basic support for configuration files.
GlobalConfiguration class reads and stores the configuration. Its
instance can be used by other libcamera objects to access the
configuration. A GlobalConfiguration instance is supposed to be stored
in a well-defined place, e.g. a CameraManager instance. It is possible
to have multiple GlobalConfiguration instances, which may or may not
make sense.
libcamera configuration can be specified using a system-wide
configuration file or a user configuration file. The user configuration
file takes precedence if present. There is currently no way to merge
multiple configuration files, the one found is used as the only
configuration file. If no configuration file is present, nothing
changes to the current libcamera behavior (except for some log
messages related to configuration file lookup).
The configuration file is a YAML file. We already have a mechanism for
handling YAML configuration files in libcamera and the given
infrastructure can be reused for the purpose. However, the
configuration type is abstracted to make contingent future change of the
underlying class easier while retaining (most of) the original API.
The configuration is versioned. This has currently no particular
meaning but is likely to have its purpose in future, especially once
configuration validation is introduced.
The configuration YAML file looks as follows:
---
version: 1
configuration:
WHATEVER CONFIGURATION NEEDED
This patch introduces just the basic idea. Actually using the
configuration in the corresponding places (everything what is currently
configurable via environment variables should be configurable in the
file configuration) and other enhancements are implemented in the
followup patches.
Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Laurent Pinchart
Milan Zamazal