GL_MESA_ycbcr_texture
http://oss.sgi.com/projects/ogl-sample/registry/MESA/ycbcr_texture.txt
	GL_UNSIGNED_SHORT_8_8_MESA 0x85BA
	GL_UNSIGNED_SHORT_8_8_REV_MESA 0x85BB
	GL_YCBCR_MESA 0x8757