Debugging

• Elements should never use their standard output for debugging (using functions such as printf () or g_print ()). Instead, elements should use the logging functions provided by GStreamer, named GST_DEBUG (), GST_LOG (), GST_INFO (), GST_WARNING () and GST_ERROR (). The various logging levels can be turned on and off at runtime and can thus be used for solving issues as they turn up. Instead of GST_LOG () (as an example), you can also use GST_LOG_OBJECT () to print the object that you're logging output for.

• Ideally, elements should use their own debugging category. Most elements use the following code to do that:

  GST_DEBUG_CATEGORY_STATIC (myelement_debug); #define GST_CAT_DEFAULT myelement_debug [..] static void gst_myelement_class_init (GstMyelementClass *klass) { [..] GST_DEBUG_CATEGORY_INIT (myelement_debug, "myelement", 0, "My own element"); }

  At runtime, you can turn on debugging using the commandline option --gst-debug=myelement:5.