Wade, You should validate the format when the SetDataFormat dispatch is invoked, and return STATUS_NO_MATCH if it does not correspond to the currently available settings. Also note that unless pOldFormat (the second parameter) is set, then SetDataFormat only validates the format, but does not actually set the format for the pin. Whenever the format is actually set (either by SetDataFormat with pOldFormat, or when the pin is created) you must also update the allocator framing. I don't think that you should ever need to KsEdit the KSPIN_DESCRIPTOR_EX to remove formats that are not currently supported, but it shouldn't hurt either. Harry -----Original Message----- From: wade [mailto:wdawson61@xxxxxxxxx] Sent: Thursday, July 10, 2003 12:25 PM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] AVStream - Dynamically constraining to a specific DataRange based on HW. Hi: I have a capture-only, pin-centric AVStreams capture driver. I need to force clients of the driver to accept a specific bit-depth and sample rate as dictated by the bitsream connect to my hardware. Does anyone know the best way to do this? I am attempting to KsEdit the KSPIN_DESCRIPTOR_EX datarange on the fly to reflect ONLY the curent sample rate and bit depth, but don't know if this is the right procedure. I have also tried supplying an IntersectHandler function through the IntersectHandler member of the pin's KSPIN_DESCRIPTOR_EX structure. I was hoping I could just return a WAVEFORMATPCMEX structure which refelcts my current hardware reported sample rate and bit depth. Unfortunately, my IntersectHandler function is never getting called. Do I have to return STATUS_NO_MATCH from the pin's SetDataFormat() dispatch at least once to force a format negotiation or something? I'm curently returning STATUS_SUCESS form this dispatch. Thanks for any help. _____ Do you Yahoo!? SBC <http://pa.yahoo.com/*http:/rd.yahoo.com/evt=1207/*http:/promo.yahoo.com/sbc /> Yahoo! DSL - Now only $29.95 per month!