Hello John, I am guessing the problem you are seeing is due to the placement of the SUM node in your topology. When the topology parser in wdmaud sees this node it assumes there is some sort of branching going on and looks downstream for master controls. Thus if your Volume and mute controls are upstream fro this node they would not be considered the master. What is the exact topology you are describing? Thanks, DJ Sisolak Microsoft Corp. This posting is provided "AS IS" with no warranties, and confers no rights. ________________________________ From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of John D. Farmer Sent: Friday, August 20, 2004 9:47 AM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] AVStream Mixer Problems Greetings, I'm creating a AVStream audio device that registers itself as a audio playback device. When I select the device as my default playback device, I can hear the sound and everything is fine and good. But now I am working on implementing the audio mixer for the device (e.g. Volume, Mute, Microphone Volume, ect). When I open up the Sounds and Audio Devices control panel, 'Device volume' section is grayed out as well as the buttons in the 'Speaker settings' section on the Volume tab. When I go to the Audio tab I can access the Volume and Advanced buttons for both my Sound playback and Sound recording. If I choose the Volume button for Sound playback, I see my Wave, CD Audio, and SW Synth mixers, but I seem to lack the Master Volume mixer. If I go to the properties in Sndvol32 for my device I see "Playback" and "Recording" radio buttons. Under playback I see the same mixers as I saw previously, and under Recording I see no volume controls. I assume once I implement the Master Volume mixer that the controls on the 'Device volume' and 'Speaker settings' sections will be enabled. So how do I implement the Master Volume mixer? I've created a simple wave topology that implements Volume, Mute, SUM, ADC and DAC nodes for my speaker and microphone pins. When I look in KS Studio I see my driver under the KSCATEGORY_AUDIO Filter Factories as a Audio device (or a \wave device). I looked at other soundcards on different systems and they also seem to have a Mixer node (or a \topology device). I assume that these soundcard drivers are portcls drivers. When I instantiate both of these filters they automatically connect (I've seen this behavior before in the MSVAD sample and understand the theory of how these filters work together). So is there a way to create a Topology Filter and a Wave Filter for my device, or does AVStream do it a different way. I see that portcls drivers uses PcRegisterSubDevice to register these filters but I have been unable to find the AVStream equivalent. Any help would be greatly appreciated. Regards, John Farmer