a timeout in nanoseconds, or GST_CLOCK_TIME_NONE to wait forever
message types to take into account, GST_MESSAGE_ANY for any type
a #GstMessage matching the filter in @types, or %NULL if no matching message was found on the bus until the timeout expired. The message is taken from the bus and needs to be unreffed with gst_message_unref() after usage.
MT safe.
Get a message from the bus whose type matches the message type mask @types, waiting up to the specified timeout (and discarding any messages that do not match the mask provided).
If @timeout is 0, this function behaves like gst_bus_pop_filtered(). If @timeout is #GST_CLOCK_TIME_NONE, this function will block forever until a matching message was posted on the bus.