Changing the returned data from the buffer so that it can be modified and read without copying
Submitted by Daniel Klamt
The map function of the buffer element has returned a copy of the c buffer as an bytes object as MapInfo.data. This is bad when you want to edit the video buffer in an gst-python element because teh bytes element always copies the Data.
Therefor i changed the Buffer functions map and unmap and the class MapInfo to return the data as an memory-view on the c buffer
The MapInfo class has the same attributes as before and should be compatible