I'm looking for an efficient way to use the GPU on the Wandboard for image and general data processing. Currently I'm using OpenGL and C++ with Qt5.6 on the 5.0.2 Android image.
Uploading data to the GPU via glTexDirectVIV is fast enough for my needs, but reading back isn't. For readback, I'm using PBOs as described here. However, the glReadPixels call with a PBO attached takes around 290ms for a 32-bit VGA GL_RGBA image. Is there any faster way to get rendered data back into CPU memory?