Methods and apparatuses for display stream compression pixel format extension using subpixel packing are disclosed. In one aspect, the method involves packing pixel values arranged in an O-channel format for encoding by an M-channel codec. The method may further involve receiving a set of input pixel values, each input pixel value including O input subpixel values arranged in the O-channel format. The method may involve rearranging each of the input subpixel values into a set of output pixel values, each set of output pixel values comprising M output subpixel values arranged in an M-channel format, O having a greater value than M, wherein at least a portion of the rearranged M output subpixels maintain their relative spatial positioning from prior to being rearranged from the O input subpixel values. The method may also involve providing the output pixel values to the M-channel codec.