gstreamer/validate/docs/qa-usage.txt

Using gst-qa is quite simple, there are 2 ways to test your pipeline/element.

== Creating a Runner
This method requires writing a specific application (or modifying yours) to
add a GstQaRunner to it. Create a GstQaRunner with gst_qa_runner_new
(GstPipeline *) and pass the pipeline you want to monitor to it.

Then call gst_qa_runner_setup to start up the qa system for your pipeline.
After that just use the GstPipeline as usual and the gst-qa system will
collect the reports. You can access them after your pipeline has stopped.

== Using LD_PRELOAD and an existing application
If you want to test an already existing application without modifying it. Just
use:

LD_PRELOAD=path/to/libgstqa.so yourapp ...

gst-qa will try to replace GstPipeline creating functions and already
configure runners for you, reports will be printed to stdout when they
are found.