Hi Ken, you should probably be using WaveCyc instead of WavePCI. It should simplify > your driver significantly. > Yes, WaveCyclic is the easiest approach but audio quality is not really good in waveCyclic miniport driver, As we have little control over our data handling. So according to MSDN there is similar but efficient way i.e. WavePCI that's why I am trying it. Hi Tim, > If there is no real hardware involved, where are > you going to copy the data to, and for what purpose? Who is consuming > and producing the data? Once you answer that, you'll know the answer to > the question. > The data is going to come in driver through Renderer Stream, and at the same time capture stream of same driver is opened which is requesting it. As in WaveCyclic simply data copy is done to and from DmaChannel, which I implemented through IDmaChannel. But in WavePCI we have to create DmaChannel through NewMasterDmaChannel () call. WavePCI is having approach of mapping of data. My problem is that how in WavePCI capture stream will get these mappings of renderer stream. I tried with shared mapping table between both the streams, but that didn't worked. Thanks.