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ALSA or Advanced Linux Sound Architecture is a project, which seeks to provide audio and MIDI functionality to the Linux operating system. ALSA has the following significant features.


  • Effcient support for all soundcards from consumer to professional multichannel audio devices
  • Fully modularized sound drivers
  • SMP and thread-safe design
  • alsa-lib in order to simplify the high level API
  • Support for the older OSS API.


There are many advantages ALSA has over the older (but perhaps not the newer) OSS API:

  • multi-thread safe design
  • transparent use of plugin architecture to handle format,rate,channel cnt and many other conversions
  • support for non-interleaved interfaces
  • user-space software mixing (dmix)
  • user-space "loopback/snoop" capabilities
  • merging multiple cards into a single virtual device
  • hiding non-ALSA-drivers behind a consistent user-space API (e.g. IEEE1394 drivers, or JACK)
  • consistent and generic control API for managing hardware controls
  • Flexible mixer architecture to handle modern audio interfaces fully (rather than reducing them to a simplistic device)
  • consistent support for multiple instances of the same card
  • linked operations of multiple cards

Development API


ALSA Library API

ALSA Documentation

External links

  • ALSA wiki a large wiki pertaining to major ALSA related topics.