Basic functionality

2-Apr-1999

   This is, so far, just my initiative. Please, comment on it.

   The basic sound processing unit is the mixer. On the right, you will find a diagram of what a mixer is. Basically, a mixer gathers sound data from one or more channels, processes that sound data according to a series of parameters and generates an output sound stream.

   Channels are the points where the sound data enters the mixer. They can accept one or more of several types of sounds: wave sound buffers, wave sound streams, wave sound generators, MIDI sound buffers, MIDI sound streams, MIDI sound generators, MOD files, etc... Normally, channels will only accept one type of sound, but this is not always necessarily true.

   Output is the result from the mixer's operations. It is always a sound stream. Usually, it will be a wave stream, but it can also be a MIDI stream.

   Mixer parameters are application-selectable values that affect the way the mixer operates. Some values are channel-specific (e.g. channel volume, channel tempo). Others are global, and affect all the channels or a group of them (e.g. master volume, MIDI sound bank).

   The mixer concept is very general. All sound processing can be explained in terms of a mixer. We should define types of mixers for internal organization and such, and the whole OpenAL should be designed as a huge, all-encompassing mixer. We should begin defining sound inputs, channel parametrs, mixer parameters, output formats, etc...