public Buffer buffer_straw_get_buffer (Element bin, Pad pad)
Get one buffer from
Implemented via buffer probes. This function will block until the pipeline passes a buffer over
pad, so for robust behavior in
unit tests, you need to use check's timeout to fail out in the case that a buffer never arrives.
You must have previously called
the pipeline previously started via buffer_straw_start_pipeline
the pad previously passed to buffer_straw_start_pipeline
the captured Buffer.