Audacity PortAudio v19

From Audacity Wiki
Revision as of 06:27, 21 March 2008 by Galeandrews (talk | contribs) (amended date of latest update)
Jump to: navigation, search
This page reflects the status of support in Audacity Beta for the current v19  version of the PortAudio Audio I/O library. The status of PortAudio v19 in the Audacity stable 1.2.x line is very simple, being completely unmaintained and unsupported.

In Audacity Beta, v19 is the default PortAudio version for all platforms. At the time of writing the current Audacity Beta release (1.3.4) uses a snapshot of the PortAudio development code from 1st July 2007. Our PortAudio snapshot for CVS is now updated to 18 March 2008 (SVN r1373). Amongst the improvements recent updates bring are ones to make more symbols visible in libraries for platform-specific functions, and stability improvements in OS X.

 
Related article(s):

Windows

PortAudio appears to be stable and relatively well behaved on Windows. Support is primarily for MME (Multi Media Extensions) drivers, although DirectSound devices are also supported. ASIO is not supported as discussed on the ASIO_Audio_Interface page.

Mac OS X

CoreAudio  support only, no ASIO as discussed on ASIO_Audio_Interface. Recent changes to PortAudio v19 appear to be causing regressions here, and it works much less well that v18 does with many USB audio devices. On the other hand, it's reported to work better with Firewire audio devices (which are quite popular on Mac it seems). A shortage of Mac developers on Audacity has meant slow progress in testing and development. The update of CVS to the PortAudio snapshot from 09 Dec 07 made provision in the build system for OS X 10.5 (Leopard). The update on 14 Jan 08 improved general stability.

Linux

ALSA  is supported and works fine on development systems, although some distributions repeatedly report problems that don't show up anywhere else.

  • JACK  is not tested and known to have multiple issues - see the JACK section of our Linux Issues page for more detail. Help, especially patches to fix this issue would be much appreciated. The previous update of CVS to the PortAudio snapshot from 09 Dec 07 cured one problem with Jackd starting automatically.
  • OSS output is problematical, due to OSS emulation relying on overloading certain function calls and diverting them to ALSA if they relate to sound devices. Unfortunately Portaudio v19 for OSS uses a call which the OSS emulation doesn't "catch" and so thinks there are no OSS devices. A patch to fix this has been submitted to the Portaudio developers for review.