[wdmaudiodev] Re: silly question about pin property and filter property

  • From: "Yong Liu" <ly.didiom@xxxxxxxxx>
  • To: wdmaudiodev <wdmaudiodev@xxxxxxxxxxxxx>
  • Date: Wed, 28 Feb 2007 13:40:37 -0800

Thanks for all your responses. As I checked DDK, I got copyto and copyfrom
is used for data operation with DMA. Since this is a virtual driver, no real
DMA is created, and only some buffers are allocated to m_pvDmaBuffer during
the creation of newstream, so what I thought is there is no need to use
copyto and copyfrom, therefore, I only use RtlCopyMemory to copy audio data
to m_pvDmaBuffer. I am new to audio driver, I do not know what the driver or
system do with those buffer (m_pvDmaBuffer), and how driver or system send
data in the buffer to the pin. I know in AVstream driver, pin is defined
clearly with buffer called frame to save data, but for portcls, I totally do
not understand how data flow. Thank you very much for your help.

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