Windows Native audio engine APIs

XAudio2

  • high-level audio engine built on top of WASAPI.

Features

  • Multi-voice mixing

  • Submix graph

  • DSP chains per voice or submix

  • Sample-rate conversion

  • Channel mapping

  • 3D audio (X3DAudio)

  • HRTF (Windows Sonic)

  • Real-time effects

  • Sample-accurate timing

  • Streaming buffers

  • Low-latency control

  • Custom DSP effects (COM-based)

  • Voice sends

  • Audio routing graph

  • Async buffer submission

  • Hardware acceleration (historically)

  • Tight WASAPI integration

Cons

  • No Cross-platform support

  • No Built-in decoding (same as OpenAL)

  • No modern API ergonomics (COM, verbose)

  • No active evolution (API is stable, not evolving fast)

WASAPI (Windows Audio Session API)

  • Modern Windows audio API (Vista+).

  • Direct interface to Windows audio engine.

  • Two modes:

    • Shared mode (through system mixer)

    • Exclusive mode (low latency, bypass mixer)

  • Event-driven or polling.

  • Sample-accurate timing possible.

  • Closest to “metal” on Windows.

DirectSound

  • DirectX-era audio API (DirectX 3–9).

  • Windows Vista+ → emulated on top of WASAPI.

  • Typical use today

    • Legacy games

    • Compatibility layers

WinMM (Windows Multimedia API)

  • Old Windows audio API (1990s).