ls_mixer

A lightweight C sound mixing library that I've written for myself to use instead of SDL_Mixer.

The key differences to SDL_Mixer are:

• No distinction between music and sounds, everything is just audio, whether it be long or short
• No external library dependencies other than SDL2
• The playback speed per channel can be contolled like on a turntable
• An arbitrary number of Ogg/Vorbis files can be decoded on the fly, no sound data is kept in decoded form in memory
• One arbitrary second order IIR filter available for each channel, with convenience functions for low/high-pass and band pass/stop filters
• One master second order IIR filter available for the mixed signal
• Can only play back Ogg/Vorbis or WAVE files
• The maximum number of audio channels is set during compile time via pre-processor definition in ls_mixer.h

With this library you can:

• Play sounds with adjustable
  • Gain
  • Panning
  • Pitch
  • IIR-filter coefficients
• Seamlessly loop / pause / resume audio
• Apply IIR filters to your audio channels
• Create callback functions for when a channel stopped
• Automatically fade channels in or out

This project reuses code from:

• cmixer.c (https://github.com/rxi/cmixer)
• stb_vorbis.c (https://github.com/nothings/stb)
• liir.c (https://exstrom.com/journal/sigproc/dsigproc.html)

Documentation

See ls_mixer.h for a documented list of functions and demo.c for a demonstration of most features. Use CMake to compile the demo program (only tested on GNU/Linux so far...)

Usage

Add the *.c and *.h files to your project and include ls_mixer.h in your code. No need to link to anything else except SDL2.