Efficient MPEG-4 to H.264/AVC Transcoding with Spatial Downscaling

  • Nguyen, Toan Dinh (Department of Electronics and Computer Engineering, Chonnam National University) ;
  • Lee, Guee-Sang (Department of Electronics and Computer Engineering, Chonnam National University) ;
  • Chang, June-Young (IT Convergence & Components Laboratory, ETRI) ;
  • Cho, Han-Jin (IT Convergence & Components Laboratory, ETRI)
  • Received : 2007.05.03
  • Published : 2007.12.31

Abstract

Efficient downscaling in a transcoder is important when the output should be converted to a lower resolution video. In this letter, we suggest an efficient algorithm for transcoding from MPEG-4 SP (with simple profile) to H.264/AVC with spatial downscaling. First, target image blocks are classified into monotonous, complex, and very complex regions for fast mode decision. Second, adaptive search ranges are applied to these image classes for fast motion estimation in an H.264/AVC encoder with predicted motion vectors. Simulation results show that our transcoder considerably reduces transcoding time while video quality is kept almost optimal.

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