1.3.12. Debugging

Configuring GStreamer

Use the gstreamerDebugLevel() function to set the GStreamer debug level. Note that the debug level is the GStreamer library debug level type GstDebugLevel, not the Proximie SDK logging severity level.

You may also set the target of the GStreamer debug output using gstreamerLogTarget(). You may choose either GStreamerLogger::PXLOGGER to log to the Proximie SDK logging system, or GStreamerLogger::CONSOLE for standard output. The default is to output to standard output.

// Set the GStreamer debug level
config.gstreamerDebugLevel(GST_LEVEL_DEBUG);

// Set the GStreamer log target
config.gstreamerLogTarget(PxMedia::Configuration::GStreamerLogger::PXLOGGER);

PxMedia diagnostics folder

Certain diagnostic functions can write files to a folder for further analysis (e.g. GStreamer pipeline graphs - see below).

You may set the target folder for these files using PxMedia::Configuration::diagnosticsFolder. If no folder has been set, the configuration will default to a standard system temp folder, which typically differs depending on operating system and environment.

Pipeline output

The SDK will output pipeline details to the logging system, using the PxLogger::LogSeverity severity level as INFO. By default this logging level is enabled, so you should see pipeline details in the log output unless you have altered the logging level.

Pipeline graphs

Feed objects that have a pipeline running can generate a graph of the underlying GStreamer pipeline for debugging and diagnostics.

Internally, this uses the GStreamer GStreamer debugging function as described in gst_debug_bin_to_dot_data.

The graph data is in the standard DOT graph description format. The application can either obtain the graph data as a text string using getPipelineGraph() or request it be written to a file directly using writePipelineGraphToFile(). When using file output, you provide a file name which may be absolute or relative to the PxMedia::Configuration diagnostics folder as mentioned above.

feed->onFeedStarted([](auto& feed) {
    std::cout << "Feed " << feed->streamId() << " started playing" << std::endl;

    auto path = feed->writePipelineGraphToFile("feed-" + feed->label() + ".dot");
    std::cout << "Wrote pipeline graph file to " << path.value() << std::endl;
});

You may customise the detail level of the graph output using the function variants getPipelineGraphWithDetails() and writePipelineGraphWithDetailsToFile(), both of which take the GStreamer detail constants as outline in GstDebugGraphDetails.`

There are various tools that read DOT files, e.g. to convert to a PNG:

dot -Tpng feed-graph.dot -o feed-graph.png