Launch a gst pipeline in background for test cases with multiple
gst pipelines collaborating with each other.
Example usage:
gstTestBackground "background pipeline description" TCNAME 0 0 5
// launching the pipeline with 5s timeout for launching-timeout
// Note that the timeout only waits for the pipeline initialization.
// The pipeline shouldn't have indefinite prerolling wait.
// If this pipeline waits for inputs after the launch, make it
// async=false (at sink) so that it may skip prerolling
gstTest "foreground pipeline description, collaborating with above" ...
wait $pid
// the global variable "pid" is the PID of the background pipeline.
// alternatively
kill $pid // the background pipeline is no more needed.
Signed-off-by: MyungJoo Ham <email address hidden>
