The audio amplifier mixer device supports extensions to the basic and required command sets. A device context of the audio amplifier mixer is a channel, either stereo or monaural, so most commands apply to channel levels. The exception is commands that apply to the final (output) mix, such as master volume.
Note that volume commands can be sent directly to player devices. These devices forward the volume command to the connected audio amplifier mixer channel device context when the output of the player is to an amplifier mixer. Other shaping functions, such as bass and treble, must be sent to the amplifier mixer.
The ampmix device is a conduit of information and relies on another device to provide the flow of information. Therefore, commands for the transport of information (such as play, seek, or stop), are sent to the attached device. Commands for transforming the information (such as treble or bass) are sent directly to the ampmix device. If the application needs to talk directly to the ampmix device, the value of the stream connector can be queried using the CONNECTION command, which returns a device context connection. An alias can be established for the connected device. Ampmix commands can then be sent directly to the ampmix device.
The ampmix device supports the device-type specific command, MIXNOTIFY, and extensions to the following basic and required commands: