An approach for enabling DCT/IDCT energy reduction scalability in MPEG-2 video codecs

It would be desirable, in terms of energy conservation, to use a low complexity approximate algorithm to do all DCT and IDCT computation in an MPEG-2 video codec. However, there is a significant quality penalty associated with this approach that may not always be acceptable. A practical algorithmic method is studied for achieving scalable energy reduction during DCT and IDCT computation in MPEG-2 video codecs at the expense of reasonable amounts of quality. For example, by applying exact and approximate DCT/IDCT algorithms appropriately, the energy consumption of DCT and IDCT execution in two video codecs communicating with one another can be reduced by 8% for quality reduction of 0.4 dB average PSNR, 14% for 0.8 dB; reduction, or 22% for 1.4 dB reduction.