Foobar2000:Components/WASAPI output support (foo out wasapi): Difference between revisions

From Hydrogenaudio Knowledgebase
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(Updated for 3.0.)
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* Guarantees muting of any other sounds played through the soundcard - with ASIO and KS, muting occurred with some soundcards but not with all of them; it was a side effect rather than a feature.
* Guarantees muting of any other sounds played through the soundcard - with ASIO and KS, muting occurred with some soundcards but not with all of them; it was a side effect rather than a feature.


== Limitations of this component ==
== WASAPI plug-in version 3.0: two output modes: push and event-driven ==
* Volume control is delayed.
As for the latest version of the component, two different output modes are available - push and event-driven; certain soundcards - especially USB devices - are known to cooperate better with the event-driven mode while certain other soundcards do not support the event-driven mode at all.
* Windows Vista Service Pack 1 or newer is strongly recommended; WASAPI exclusive mode is unusable on significant percentage of pre-SP1 machines because of bugs in Windows Vista.
 
* With certain soundcards you might need to fiddle with output buffer length in [[Foobar2000:Preferences:Output|output preferences]] before getting acceptable results - with certain buffer lengths, playback may fail to start entirely or get stuck after a few seconds. USB audio devices typically require low buffer lengths to operate properly. [[Foobar2000:Components 0.9/Kernel Streaming Output (foo out ks)|Kernel Streaming]] is known to work better with such devices.
== WASAPI plug-in version 3.0: sandbox ==
Unfortunately, WASAPI is affected by various bugs in both Windows mixer and soundcard drivers. To keep these from crashing foobar2000, all WASAPI access is now sandboxed in a separate process for better stability.


== Links ==
== Links ==
* [[Bypassing Windows Mixer]]
* [[Bypassing Windows Mixer]]
* [http://www.foobar2000.org/components/view/foo_out_wasapi Official Website]
* [http://www.foobar2000.org/components/view/foo_out_wasapi Official Website]

Revision as of 09:23, 2 September 2012

Foobar2000_Logo.png

Windows Audio Session API output support

Description

The foobar2000 Windows Audio Session API (WASAPI) output support component allows you to play your music using WASAPI exclusive mode.

WASAPI is a new audio output method introduced in Windows Vista; among other things, it provides an exclusive mode that allows applications to take full control over soundcard's resources (muting any sounds played by other applications) and play unaltered bitstream without passing it through the Windows mixer.

Differences between WASAPI and ASIO / Kernel Streaming from foobar2000 user's perspective

  • Requires Windows Vista or Windows 7 - not available on Windows XP or older.
  • Works with more soundcards - contrary to e.g. ASIO, it doesn't require any special support from soundcard's manufacturer, other than providing a Windows Vista compatible driver.
  • Guarantees muting of any other sounds played through the soundcard - with ASIO and KS, muting occurred with some soundcards but not with all of them; it was a side effect rather than a feature.

WASAPI plug-in version 3.0: two output modes: push and event-driven

As for the latest version of the component, two different output modes are available - push and event-driven; certain soundcards - especially USB devices - are known to cooperate better with the event-driven mode while certain other soundcards do not support the event-driven mode at all.

WASAPI plug-in version 3.0: sandbox

Unfortunately, WASAPI is affected by various bugs in both Windows mixer and soundcard drivers. To keep these from crashing foobar2000, all WASAPI access is now sandboxed in a separate process for better stability.

Links