Data processing overhead in GhostPads

[Michael Tretter]

Hi,

The documentation of GstGhostPad contains the following note:

	Note that GhostPads add overhead to the data processing of a pipeline.

I see that a GhostPad adds 4 additional function calls to the processing
pipeline to call the gst_pad_push() function on the internal pad after
gst_pad_push() has been called on the GhostPad. The functions add a few
checks, but basically just pass the pointer to the buffer to the internal pad.
While this is some overhead, I would think that this overhead is pretty low
compared to the remaining pipeline.

Therefore, I wonder why the documentation explicitly states that a GhostPad
adds overhead and if I am missing something important. Unfortunately, the git
history was not helpful to find the reason for the note.

Michael