Sampling only the Y plane of an NV12 EGLImage?

It is really neat that samplerExternalOES can read from an NV12 EGLImage and return RGB like magic. But, is there a way to sample only the Y plane? I’m in a bandwidth-constrained situation and I need the exact Y values. I’d rather not read and convert YUV->RGB just to approximately reconstruct Y.

I’m working on a Xavier, btw.