Runtime configuration — libcamera v0.7.2 documentation

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# 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
        mode: # cpu/gpu
        threads: # integer >= 1, number of render threads to use, default 2

## 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
        mode: gpu
        threads: 2

## List of environment 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`

LIBCAMERA_SOFTISP_MODE, software_isp.mode

  Select if the software ISP should use GPU or CPU image processsing, one of `cpu` or `gpu`. When set to `gpu` and EGL is not available the software ISP will automatically fall back to the CPU.

  Example value: `gpu`

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`

software_isp.threads

  Number of render threads the software ISP uses when using the CPU. This must be between 1 and 8 and the default is 2.

  Example value: `2`

## 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.