PortAudio - portable audio I/O library

This is a fork of PortAudio that adds Pa_RefreshDevice functionality (see commit 1f01a3ddc05df7ee3bb3cad5ef960d335aff018b), which allows runtime detection of audio device changes without restarting your application.

PortAudio is a portable audio I/O library designed for cross-platform support of audio. It uses either a callback mechanism to request audio processing, or blocking read/write calls to buffer data between the native audio subsystem and the client. Audio can be processed in various formats, including 32 bit floating point, and will be converted to the native format internally.

Documentation:

• Documentation is available at http://www.portaudio.com/docs/
• Or at /doc/html/index.html after running Doxygen.
• Also see src/common/portaudio.h for the API spec.
• And see the examples/ and test/ directories for many examples of usage. (We suggest examples/paex_saw.c for an example.)

For information on compiling programs with PortAudio, please see the tutorial at:

http://portaudio.com/docs/v19-doxydocs/tutorial_start.html

We have an active mailing list for user and developer discussions. Please feel free to join. See http://www.portaudio.com for details.

Important Files and Folders:

include/portaudio.h     = header file for PortAudio API. Specifies API.	
src/common/             = platform independent code, host independent 
                          code for all implementations.
src/os                  = os specific (but host api neutral) code
src/hostapi             = implementations for different host apis

Host API Implementations:

src/hostapi/alsa        = Advanced Linux Sound Architecture (ALSA)
src/hostapi/asihpi      = AudioScience HPI
src/hostapi/asio        = ASIO for Windows and Macintosh
src/hostapi/coreaudio   = Macintosh Core Audio for OS X
src/hostapi/dsound      = Windows Direct Sound
src/hostapi/jack        = JACK Audio Connection Kit
src/hostapi/oss         = Unix Open Sound System (OSS)
src/hostapi/wasapi      = Windows Vista WASAPI
src/hostapi/wdmks       = Windows WDM Kernel Streaming
src/hostapi/wmme        = Windows MultiMedia Extensions (MME)

Test Programs:

test/pa_fuzz.c         = guitar fuzz box
test/pa_devs.c         = print a list of available devices
test/pa_minlat.c       = determine minimum latency for your machine
test/paqa_devs.c       = self test that opens all devices
test/paqa_errs.c       = test error detection and reporting
test/patest_clip.c     = hear a sine wave clipped and unclipped
test/patest_dither.c   = hear effects of dithering (extremely subtle)
test/patest_pink.c     = fun with pink noise
test/patest_record.c   = record and playback some audio
test/patest_maxsines.c = how many sine waves can we play? Tests Pa_GetCPULoad().
test/patest_sine.c     = output a sine wave in a simple PA app
test/patest_sync.c     = test synchronization of audio and video
test/patest_wire.c     = pass input to output, wire simulator

Using with Node.js

This fork can be used with the nodeaudio Node.js bindings, which provide native audio I/O capabilities to JavaScript/TypeScript applications.

Building PortAudio

Build portaudio:

./configure and make

At the time of writing (MacOS 12.1) I initially received build errors (-WError) about unused variables, so I had to remove -WError flag from the build rules.

Anytime the build configuration changes, make sure to run (see PortAudio docs):

autoreconf -if

Use find command in usr/local/lib to see install state:

find /usr/local/lib -name "libport*" -maxdepth 1

The default build of PortAudio sets an absolute install path (usr/local/lib) which causes issues if you want to package the .dylib in a project. To fix this, use install_name_tool to rename the binary using a relative @loader_path:

install_name_tool -id "@loader_path/libportaudio.dylib" libportaudio.dylib

Ideally, this would be set in the build config settings of PortAudio, but I haven't figured out how to do that yet.

Using with nodeaudio

The nodeaudio bindings wrap this PortAudio fork to expose audio I/O capabilities to Node.js applications. Clone and build the nodeaudio project to get started:

git clone https://andrewgundersen.net/repos/nodeaudio
cd nodeaudio
node-gyp rebuild

This will link against the PortAudio library you've built, allowing you to use audio functionality from JavaScript.

TODO: Sign on build Of course, any binary (e.g. libportaudio.dylib) must be signed before distribution.