Early Detection of All-Zero Coefficients in H.263

Alice Yu, Ruby Lee, Michael Flynn

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


We characterize H.263 bitstreams to determine the distribution of inter-macroblocks whose quantized DCT coefficients are completely zero. Based on this analysis, we propose a new H.263-compatible algorithm that predicts blocks with all-zero quantized DCT coefficients, which eliminates the DCT and quantization computation for those blocks. Simulation results show that, relative to the base H.263 encoder, our early-detection mechanism can reduce the computational requirements of the DCT/Quantizer by as much as 81% while simultaneously reducing the bit rate, with virtually no visible change in video fidelity. We analyze the performance of this enhancement using different types of motion searches.

Original languageEnglish (US)
Pages (from-to)X33-162
Issue number143
StatePublished - 1997

All Science Journal Classification (ASJC) codes

  • Software
  • Hardware and Architecture

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