Split-radix DET algorithms and the computation of DCT and DST

Split-radix direct algorithms for four types of discrete exponent transforms (DETs) are introduced. The DCT and DST may be directly computed using the split-radix DET algorithms. It is shown that the direct computations of DCT and DST have simple structure and in-place implementation. Their output is in bit-reserved order, rather than Hadamard order or other complex order. The direct computations can be implemented using the software or hardware of split-radix DFT algorithms.<>