Runtime configuration#

The libcamera behaviour can be tuned through a configuration file or environment variables. This document lists all the configuration options and describes their usage.

General rules#

The configuration file is looked up in the following locations, in this order:

$XDG_CONFIG_HOME/libcamera/configuration.yaml
LIBCAMERA_SYSCONF_DIR/configuration.yaml
LIBCAMERA_DATA_DIR/libcamera/configuration.yaml

The first configuration file found wins, configuration files in other locations are ignored.

Settings in environment variables take precedence over settings in configuration files. This allows overriding behaviour temporarily without the need to modify configuration files.

Configuration options#

Here is an overview of the available configuration options, in the YAML file structure:

configuration:
  ipa:
    force_isolation: # true/false
    config_paths:
      - ... # full path to a directory
    module_paths:
      - ... # full path to a directory
  pipelines_match_list:
    - ... # pipeline name
  pipelines:
    simple:
      supported_devices:
        - driver: # driver name, e.g. `mxc-isi`
          software_isp: # true/false
  software_isp:
    copy_input_buffer: # true/false
    measure:
      skip: # non-negative integer, frames to skip initially
      number: # non-negative integer, frames to measure

Configuration file example#

---
version: 1
configuration:
  ipa:
    config_paths:
      - /home/user/.libcamera/share/ipa
      - /opt/libcamera/vendor/share/ipa
    module_paths:
      - /home/user/.libcamera/lib
      - /opt/libcamera/vendor/lib
    proxy_paths:
      - /home/user/.libcamera/proxy/worker
      - /opt/libcamera/vendor/proxy/worker
    force_isolation: true
  pipelines_match_list:
    - rkisp1
    - simple
  pipelines:
    simple:
      supported_devices:
        - driver: mxc-isi
          software_isp: true
  software_isp:
    copy_input_buffer: false
    measure:
      skip: 50
      number: 30

List of variables and configuration options#

LIBCAMERA_LOG_FILE

The custom destination for log output.

Example value: /home/{user}/camera_log.log

LIBCAMERA_LOG_LEVELS

Configure the verbosity of log messages for different categories (more).

Example value: *:DEBUG

LIBCAMERA_LOG_COLOR

Control the coloring of log messages (more).

LIBCAMERA_IPA_CONFIG_PATH, ipa.config_paths

Define custom search locations for IPA configurations (more).

Example value: ${HOME}/.libcamera/share/ipa:/opt/libcamera/vendor/share/ipa

LIBCAMERA_IPA_FORCE_ISOLATION, ipa.force_isolation

When set to a non-empty string, force process isolation of all IPA modules.

Example value: 1

LIBCAMERA_IPA_MODULE_PATH, ipa.module_paths

Define custom search locations for IPA modules (more).

Example value: ${HOME}/.libcamera/lib:/opt/libcamera/vendor/lib

LIBCAMERA_IPA_PROXY_PATH, ipa.proxy_paths

Define custom full path for a proxy worker for a given executable name.

Example value: ${HOME}/.libcamera/proxy/worker:/opt/libcamera/vendor/proxy/worker

LIBCAMERA_PIPELINES_MATCH_LIST, pipelines_match_list

Define an ordered list of pipeline names to be used to match the media devices in the system. The pipeline handler names used to populate the variable are the ones passed to the REGISTER_PIPELINE_HANDLER() macro in the source code.

Example value: rkisp1,simple

LIBCAMERA_RPI_CONFIG_FILE

Define a custom configuration file to use in the Raspberry Pi pipeline handler.

Example value: /usr/local/share/libcamera/pipeline/rpi/vc4/minimal_mem.yaml

LIBCAMERA_<NAME>_TUNING_FILE

Define a custom IPA tuning file to use with the pipeline handler NAME.

Example value: /usr/local/share/libcamera/ipa/rpi/vc4/custom_sensor.json

pipelines.simple.supported_devices.driver, pipelines.simple.supported_devices.software_isp

Override whether software ISP is enabled for the given driver.

Example driver value: mxc-isi

Example software_isp value: true

software_isp.copy_input_buffer

Define whether input buffers should be copied into standard (cached) memory in software ISP. This is done by default to prevent very slow processing on platforms with non-cached buffers. It can be set to false on platforms with cached buffers to avoid an unnecessary overhead.

Example value: false

software_isp.measure.skip, software_isp.measure.number

Define per-frame time measurement parameters in software ISP. skip defines how many initial frames are skipped before starting the measurement; number defines how many frames then participate in the measurement.

Set software_isp.measure.number to 0 to disable the measurement.

Example skip value: 50

Example number value: 30

Further details#

Notes about debugging#

The environment variables LIBCAMERA_LOG_FILE, LIBCAMERA_LOG_LEVELS and LIBCAMERA_LOG_COLOR are used to modify the default configuration of the libcamera logger.

By default, libcamera logs all messages to the standard error (std::cerr). The LIBCAMERA_LOG_COLOR environment variable can be used to control whether the messages will be colored or not. The possible values are: auto, yes, and no. The default value is auto, which enables coloring if the standard error is connected to a TTY.

The default log destination can also be directed to a file by setting the LIBCAMERA_LOG_FILE environment variable to the log file name. This also disables coloring.

Log levels are controlled through the LIBCAMERA_LOG_LEVELS variable, which accepts a comma-separated list of ‘category:level’ pairs.

The level part is mandatory and can either be specified by name or by numerical index associated with each level.

The optional category is a string matching the categories defined by each file in the source base using the logging infrastructure. It can include a wildcard (‘*’) character at the end to match multiple categories.

For more information refer to the API documentation.

Examples:

Enable full debug output to a separate file, for every category within a local environment:

:~$ LIBCAMERA_LOG_FILE='/tmp/example_log.log' \
    LIBCAMERA_LOG_LEVELS=0 \
    cam --list

Enable full debug output for the categories Camera and V4L2 within a global environment:

:~$ export LIBCAMERA_LOG_LEVELS='Camera:DEBUG,V4L2:DEBUG'
:~$ cam --list

Log levels#

This is the list of available log levels, notice that all levels below the chosen one are printed, while those above are discarded.

DEBUG (0)
INFO (1)
WARN (2)
ERROR (3)
FATAL (4)

Example: If you choose WARN (2), you will be able to see WARN (2), ERROR (3) and FATAL (4) but not DEBUG (0) and INFO (1).

Log categories#

Every category represents a specific area of the libcamera codebase, the names can be located within the source code, for example: src/libcamera/camera_manager.cpp

LOG_DEFINE_CATEGORY(Camera)

There are two available macros used to assign a category name to a part of the libcamera codebase:

LOG_DEFINE_CATEGORY: This macro is required, in order to use the LOGC macro for a particular category. It can only be used once for each category. If you want to create log messages within multiple compilation units for the same category utilize the LOG_DECLARE_CATEGORY macro, in every file except the definition file.
LOG_DECLARE_CATEGORY: Used for sharing an already defined category between multiple separate compilation units.

Both macros have to be used within the libcamera namespace of the C++ source code.

IPA configuration#

IPA modules use their own configuration files to store parameters. The format and contents of the configuration files is specific to the IPA module. They usually contain tuning parameters for the algorithms, in JSON format.

The LIBCAMERA_IPA_CONFIG_PATH variable can be used to specify custom storage locations to search for those configuration files.

Examples

IPA module#

In order to locate the correct IPA module for your hardware, libcamera gathers existing IPA modules from multiple locations. The default locations for this operation are the installed system path (for example on Debian: /usr/local/x86_64-pc-linux-gnu/libcamera) and the build directory. With the LIBCAMERA_IPA_MODULE_PATH, you can specify a non-default location to search for IPA modules.

Runtime configuration

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