PJMEDIA Audio Device API is a cross-platform audio API appropriate for use with VoIP applications and other types of audio streaming applications.
PJMEDIA-Audiodev supports the following platforms/devices:
Older devices that are no longer supported:
Symbian audio streaming/multimedia framework (MMF) implementation
Nokia Audio Proxy Server (APS) implementation
Core features supported by PJMEDIA Audio Device API:
The new API has been designed to be extensible, it will support new API’s as well as new features that may be introduced in the future without breaking compatibility with applications that use this API as well as compatibility with existing device implementations.
At the heart of the API is device capabilities management, where all possible audio capabilities of audio devices should be able to be handled in a generic manner. With this framework, new capabilities that may be discovered in the future can be handled in manner without breaking existing applications.
The device capabilities framework enables applications to use and control audio features built-in in the device, such as:
audio routing (e.g. to earpiece or loudspeaker),
voice activity detector,
Some audio devices such as Nokia/Symbian Audio Proxy Server (APS) and Nokia VoIP Audio Services (VAS) support built-in hardware audio codecs (e.g. G.729, iLBC, and AMR), and application can use the sound device in encoded mode to make use of these hardware codecs.
The new API supports multiple audio backends (called factories or drivers in the code) to be active simultaneously, and audio backends may be added or removed during run-time.
Using the Audio Device API
Follow the instructions below to enable the device. TBD.
ALSA support is detected and enabled automatically by the
configure script. Check the
configure output for ALSA detection:
checking for alsa/version.h... yes Checking sound device backend... alsa
If ALSA is not detected, make sure ALSA development package is installed (e.g. on Debian
Once ALSA is built, you should see ALSA device detection results on pjsua log level 5 like this:
$ pjsip-apps/bin/pjsua-x86_64-unknown-linux-gnu --log-level 5 .. 07:46:25.081 alsa_dev.c ..ALSA driver found 32 devices 07:46:25.081 alsa_dev.c ..ALSA initialized ..
From Oboe GitHub page: “Oboe is a C++ library which makes it easy to build high-performance audio apps on Android”. PJMEDIA support Oboe audio capture and playback device.
Integration instructions: see https://github.com/pjsip/pjproject/pull/2707
bdIMAD by BdSound
bdIMAD (BdSound IMproved Audio Device) is bdSound advanced audio device for PJSIP, supporting advanced speech processing features such as Full Duplex Acoustic Echo Cancellation, Noise Reduction, Automatic Level Control, Loudness Manager, Adaptive Comfort Noise)
This driver supports Windows, Mac OS X, Linux, Embedded Linux, Windows Embedded, iOS, and Android. Please see http://www.bdsound.com/support/category/bdimad/ for most up to to date information and instructions on how to use it.
CoreAudio (Mac OS X and iPhone)
WMME (Windows and Windows Mobile devices)
WMME is Windows Multimedia API that is available in every Windows operating systems. PJMEDIA has native support for WMME audio device.
To enable WMME suport, add this to your
#define PJMEDIA_AUDIO_DEV_HAS_WMME 1
And rebuild the Visual Studio project.
WASAPI (Windows Audio Session API)
No longer supported devices:
PortAudio (PA) is a open source portable audio device abstraction by http://portaudio.com/. It supports Windows, Macintosh OS X, and Unix (OSS/ALSA). Since PJMEDIA already supports native many audio devices in platforms that PA supports, we no longer actively maintain PortAudio support.
Follow these guides below to enable PA support in PJMEDIA:
Download and build PortAudio for your platform
For Mac OS/Linux/Unix, run
--with-external-paoption. This should pick up PortAudio headers and libs in standard locations. If PA is not in standard locations, you need to set
$ ./configure --with-external-pa $ make
Make sure PA headers and libs are in standard location. If not, modify
pjmedia-audiodevVisual Studio project and set header and library directories as appropriate.
Add this to your
#define PJMEDIA_AUDIO_DEV_HAS_PORTAUDIO 1
Rebuild the workspace