Software Mixer

Sofware Mixer

What should the software mixer do and how should it be implemented?

implementation

• xform
  • can be inserted as an effect
  • API is already there
• special xform
  • like the ringbuffer, inserted by the server
  • probably good to support software volume fallback, but maybe not using current volume API
• internal
  • can do more funky stuff than xforms
  • can silently replace hardware volume using current volume API

format support

• signed/unsigned 8-, 16-, and 32-bit
• float/double

input range

• 0-100%
  • fits in well with hardware volume range
  • imits us to maximum and minimum range of the hardware
• 0->100%
  • overlaps with hardware volume range
  • allows increasing volume of faint songs or normalization
• -<100%->100%
  • overlaps with hardware volume range
  • allows phase inversion
  • allows increasing volume of faint songs or normalization

channel support

• multiple channels should be supported separately

usage

• always-on - user can just drop this in the chain and have software volume support all the time
  • controlled using xforms API, or
  • controlled using (new) softvol API
• fallback - used only when there is no hardware volume support
  • controlled using xforms API, or
  • controlled using volume API