I have a USB Avstream audio driver that works perfectly 16bit (nBlockAlign=4) mode and also in 24bit (nBLobkalign=6) mode (eventually), but has an issue when the 24bit format is first selected in Sound->Line Out Properties->Adavnced->Default Format and the “Test” button is clicked. In the 24bit failure mode, audio will not play from Media Player or the “Test” button in the Default format selection dialog. If a 16 bit is selected and “Tested” then, a 24 bit format can be selected and "Tested
and Media Player will successfully stream 24bit (nBlockAlign=6) stereo audio.
When audio is played from Media Player in with the driver in 24bit mode, the driver transitions from STOP->ACQUIRE->PAUSE->ACQUIRE -> STOP, but never to RUN. When the driver’s WAVEFORMATEX specifies 16bit audio (nBlockAlign=4) the sequence is STOP->ACQUIRE->PAUSE->RUN…->PAUSE… -> STOP.
The IntersetHandler() , SetDataFormat() and Pin creation are all successful in both cases, but the PIN never transition to RUN in the initial 24bit case. Is there a way to trace why the AudioEngine never transitions the pin to RUN when the format is initially set to 24bit?