IImageWrapper memory allocation

I am constantly streaming JPeg textures to my low powered android phone.
To get the raw pixels I call:
IImageWrapperPtr->SetCompressed(…)
and
IImageWrapperPtr->GetRaw(…)
quite alot.

I want to make sure I am not allocating a new uncompressed buffer for every image that I am downloading.
So I wanted to ask how the memory allocation for this works, is a new buffer allocated every time I decode an image in the wrapper?
Or does the uncompress algorithm reuse a preallocated buffer?
(the jpegs are all the same resolution)