IDCT output range before clipping in MPEG video coding

摘要

The precision of the IDCT output before clipping in an MPEG hardware decoder should be sufficient to cover the maximum output range of the IDCT transform. This paper has theoretically proved that the IDCT output range is [−1805, 1805], and in order to avoid IDCT overflow, at least 11 bit or maximal 12 bit should be used to represent the IDCT output of MPEG video coding with TM5 (Test Model 5, Draft version 2) quantizer before its clipping.