Channel Upmixing and Downmixing

Synthizer has built-in understanding of mono (1 channel) and stereo (2 channels) audio formats. It will mix other formats to these as necessary. Specifically, we:

• If converting from mono to any other format, broadcast the mono channel to all of those in the other format.
• If going to mono, sum and normalize the channels in the other format.
• Otherwise, either drop extra channels or fill extra channels with silence.

Synthizer will be extended to support surround sound in future, which will give it a proper understanding of 4, 6, and 8 channels. Since Synthizer is aimed at non-experimental home media applications, we assume that the channel count is sufficient to know what the format is going to be. For example, there is no real alternative to 5.1 audio in the home environment if the audio has 6 channels. If you need more complex multichannel handling, you can pre-convert your audio to something Synthizer understands. Otherwise, other libraries may be a better option.