RFC 3551 RTP A/V Profile July 2003 4.five.one DVI4 DVI4 takes advantage of an adaptive delta pulse code modulation (ADPCM) encoding plan which was specified by the Interactive Multimedia Association (IMA) as the "IMA ADPCM wave kind". Even so, the encoding defined here as DVI4 differs in 3 respects through the IMA specification: o The RTP DVI4 head