I've been working on libglvideo, that supports HAPQ on Windows and Mac (at least). I'm preparing to release the first version in the next week, but you could start playing with it now. It requires CMake, and doesn't have an explicit Cinder block (yet), but it's easy enough to integrate:
using namespace glvideo;
Movie::ref mMovie = nullptr;
mMovie = Movie::create( Context::create( 4 ), path );
auto frame = mMovie->getCurrentFrame();
gl::Texture2dRef tex = nullptr;
if ( frame ) tex = gl::Texture2d::create( frame->getTextureTarget(), frame->getTextureId(), mMovie->getWidth(), mMovie->getHeight(), true /* doNotDispose */ );
I haven't tested it with Alpha channels yet, but that should be pretty straightforward.