Given this thread is basically coming alive again, I have found that I can load data into a buffer by using the (void *) cast to remove the const qualifier as mentioned in a previous thread here: Fake GV Camera - Setting next frame
But it is basically impossible to make a callback in any other way without breaking the const return of arv_buffer_get_data as the private structure for ArvBufferPrivate does not have its header available inarv.h. This means that the callback is a challenge to create, to a large degree. I’m not sure how this would even work in Python, unless swig is already handling this special case.
Even so, I can’t get the data to actually copy over using memcpy, so I wonder if there is more going on here. I can’t get data to copy in if using get_image_data or get_data, and without the ability to modify the buffer outside of aravis, or even the data structures available, I don’t see the point of having the callback, really.