The OpenAL mixer library aims to provide a multi-platform API built on top of OpenAL to get/set volume values (including support for capture devices), list input/output lines, and select the input line and mute output lines. This library is aimed to those OpenAL users who really need to have control over the system's mixer, and not just over the output gain provided by pure OpenAL implementations. You can control the volume of capture devices (like microphone) and of rendering devices (like speakers, headphones, etc.). You can select the recording device amongst those available on your sound card (selecting which device should be enabled for the input "mixer"), and you can mute/unmute playout lines. It was based on the PortMixer project made for PortAudio, but it extends its functions and works for one-way audio channel only too.