1. An apparatus for encoding input signals, the input signals being in a signal domain, comprising: (a) difference means for generating a difference signal between a current input signal and a current reference signal; (b) first transform means for applying a first transform to the difference signal to generate a transformed signal in a transform domain; (c) quantization means for quantizing the transformed signal to generate a quantized signal; (d) encoding means for further encoding the quantized signal to generate an encoded signal; (e) transmitting means for transmitting the encoded signal; (f) dequantization means for dequantizing the quantized signal generated by the quantization means to generate a dequantized signal; (g) second transform means for applying a second transform to the dequantized signal to generate a reference difference signal in the signal domain; and (h) addition means for generating a next reference signal in accordance with the reference difference signal and the current reference signal, wherein: the first transform means comprises a transform circuit configured to implement the first transform; the second transform means comprises the transform circuit configured to implement the second transform; the input signal comprises a video signal corresponding to a video frame; the difference means comprises a frame difference circuit; the addition means comprises a frame addition circuit; the dequantization means begins to dequantize the quantized signal corresponding to the current input signal before the quantization means completes the quantization of the transformed signal corresponding to the current input signal; and the transform circuit begins to apply the second transform to the dequantized signal corresponding to the current input signal before the transform circuit completes the application of the first transform to the difference signal corresponding to the current input signal.