Video compression complexity reduction with adaptive down-sampling

Encoding video sequences is a computation- demanding task in high-performance codecs. Optimizing this stage may result in a substantial encoding speed-up. In this paper, we propose a faster approach to encode sequences with the H.264/AVC codec, using mixed-resolution. By having some of the frames down-sampled, the overall computation is reduced, without greatly affecting the rate-distortion performance, which remains evaluated using the sequence´s original resolution. In addition to this approach, a method which regards only the most frequent prediction modes of a frame is incorporated, so that the combined complexity reduction can be significant with negligible performance losses.