GstValidate Environment Variables

The runtime behaviour of GstValidate applications can be influenced by a number of environment variables.

GST_VALIDATE.

This environment variable can be set to a list of debug options, which cause GstValidate to print out different types of test result information and consider differently the level of the reported issues.

  • fatal-criticals: Causes GstValidate to consider only critical issues as import enough to consider the test failed (default behaviour)
  • fatal-warnings: Causes GstValidate to consider warning, and critical issues as import enough to consider the test failed
  • fatal-issues: Causes GstValidate to consider issue, warning, and critical issues as import enough to consider the test failed
  • print-issues: Causes GstValidate to print issue, warning and critical issues in the final reports (default behaviour)
  • print-warnings: Causes GstValidate to only print warning and critical issues in the final reports
  • print-criticals: Causes GstValidate to only print critical issues in the final reports

GST_VALIDATE_FILE.

Set this variable to a colon-separated list of paths to redirect all GstValidate messages to this file. If left unset, debug messages will be outputed into the standard error.

You can use the special names stdout and stderr to use those output.

GST_VALIDATE_SCENARIOS_PATH.

Set this variable to a colon-separated list of paths. GstValidate will scan these paths for GstValidate scenario files. By default GstValidate will look for scenarios in the user data directory as specified in the XDG standard: .local/share/gstreamer-GST_API_VERSION/validate/scenarios and the system wide user data directory: /usr/lib/gstreamer-GST_API_VERSION/validate/scenarios

GST_VALIDATE_CONFIG.

Set this variable to a colon-separated list of paths to GstValidate config files or directly as a string in the GstCaps serialization format. The config file has a format similar to the scenario file. The name of the configuration corresponds to the name of the plugin the configuration applies to.

The special name "core" is used to configure GstValidate core functionalities (monitors, scenarios, etc...).

If you want to make sure to set a property on a element of a type (for example to disable QoS on all sinks) you can do:

core, action=set-property, target-element-klass=Sink

If you want the GstPipeline to get dumped when an issue of a certain level (and higher) happens, you can do:

core, action=dot-pipeline, report-level=issue

Note that you will still need to set GST_DEBUG_DUMP_DOT_DIR.

For more examples you can look at the ssim GstValidate plugin documentation to see how to configure that plugin.

You can also check that a src pad is pushing buffers at a minimum frequency. For example to check if v4l2src is producing at least 60 frames per second you can do:

    core,min-buffer-frequency=60,target-element-factory-name=v4l2src

This config accepts the following fields:

  • min-buffer-frequency: the expected minimum rate, in buffers per second, at which buffers are pushed on the pad

  • target-element-{factory-name,name,klass}: the factory-name, object name or class of the element to check

  • name: (optional) only check the frequency if the src pad has this name

  • buffer-frequency-start: (optional) if defined, validate will ignore the frequency of the pad during the time specified in this field, in ns. This can be useful when testing live pipelines where configuring and setting up elements can take some time slowing down the first buffers until the pipeline reaches its cruising speed. GST_VALIDATE_OVERRIDE.

Set this variable to a colon-separated list of dynamically linkable files that GstValidate will scan looking for overrides. By default GstValidate will look for scenarios in the user data directory as specified in the XDG standard: .local/share/gstreamer-GST_API_VERSION/validate/scenarios and the system wide user data directory: /usr/lib/gstreamer-GST_API_VERSION/validate/scenarios

GST_VALIDATE_SCENARIO_WAIT_MULITPLIER.

A decimal number to set as a multiplier for the wait actions. For example if you set GST_VALIDATE_SCENARIO_WAIT_MULITPLIER=0.5, for a wait action that has a duration of 2.0 the waiting time will only be of 1.0 second. If set to 0, wait action will be ignored.

GST_VALIDATE_REPORTING_DETAILS.

The reporting level can be set through the GST_VALIDATE_REPORTING_DETAILS environment variable, as a comma-separated list of (optional) object categories / names and levels. Omit the object category / name to set the global level.

Examples:

GST_VALIDATE_REPORTING_DETAILS=synthetic,h264parse:all
GST_VALIDATE_REPORTING_DETAILS=none,h264parse::sink_0:synthetic

Levels being:

  • none: No debugging level specified or desired. Used to deactivate debugging output.
  • synthetic: Summary of the issues found, with no details.
  • subchain: If set as the default level, similar issues can be reported multiple times for different subchains. If set as the level for a particular object (my_object:subchain), validate will report the issues where the object is the first to report an issue for a subchain.
  • monitor: If set as the default level, all the distinct issues for all the monitors will be reported. If set as the level for a particular object, all the distinct issues for this object will be reported. Note that if the same issue happens twice on the same object, up until this level that issue is only reported once.
  • all: All the issues will be reported, even those that repeat themselves inside the same object. This can be very verbose if set globally.

Setting the reporting level allows to control the way issues are reported when calling gst_validate_runner_printf().

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