mberz / playrec

A Matlab and Octave utility (MEX file) that provides simple yet versatile access to soundcards using PortAudio

Playrec is a Matlab and Octave utility (MEX file) that provides simple yet versatile access to soundcards using PortAudio, a free, open-source audio I/O library. It can be used on different platforms (Windows, Macintosh, Unix) and access the soundcard via different host API including ASIO, WMME and DirectSound under Windows.

Playrec's main features include:

Non-blocking soundcard access.

All samples are buffered so Matlab can continue with other processing whilst output and recording occur.

Continuous play and record with no glitches.

All new output samples are automatically appended to any remaining samples. This makes it possible for the audio data to be generated as required, the only limit being the processing power of the computer. Recording in multiple sections without missed samples can also easily be achieved.

Minimal configuration.

A list of all available devices can be easily obtained. Configuration then just requires the sample rate and the unique id of the device(s) to be used for output and/or recording. There is no need to specify how much buffering is required as this is all handled dynamically.

No imposed sample count restrictions.

There is no limit imposed to restrict the minimum or maximum number of samples that can be passed to the utility at any one time, the only restrictions are those due to limitations in available memory or processing power.

Multi-channel soundcard support.

The utility was specifically designed to simplify working with soundcards with any number of channels: output samples only need to be provided for those channels which are not zero, and samples will only be recorded on channels specified. This reduces memory usage and makes accessing arbitrary channels on the device very simple. Additionally because this information is provided with the samples, different sets of channels can be used without the need for reconfiguration.

Multiple platform and host API support.

By using PortAudio to access the soundcard, Playrec should function on all platforms and with all host APIs that PortAudio supports.

Download and compilation with cmake

cmake based build will install playrec.mex to the top level of playrec source directory. It can be moved from there to desired location.

Clone the playrec repository from github

% git clone [e-mail]:hbe72/playrec.git

####Compilation with system's installation of portaudio

#####Ubuntu:

% sudo apt-get install cmake 
% sudo apt-get install portaudio19-dev
% export MATLAB_ROOT=/opt/MATLAB/R2015b

#####Mac: Install homebrew install homebrew (see. brew.sh)

% brew install cmake
% brew install portaudio
% export MATLAB_ROOT=/Applications/MATLAB_R2015b.app 

#####Compile:

% cd playrec 
% mkdir build; cd build 
% cmake .. 
% make 
% make install 

Compilation from scratch from portaudio sources:

Ubuntu, Mac & MinGW

% mkdir portaudio; cd portaudio
% ../playrec/compile_portaudio.sh [installation directory]

See further instructions from the end of compile_portaudio.sh for setting the environment variables

% export PKG_CONFIG_PATH=<absolute path to portaudio installation directory>/lib/pkgconfig:$PKG_CONFIG_PATH
% export MATLAB_ROOT=/Applications/MATLAB_R2015b.app  
% cd ../playrec 
% mkdir build; cd build 
% cmake .. 
% make 
% make install 

Windows with Visual Studio

Suggested directory structure for FindPortaudio.cmake

--- portaudio --- portaudio
 |              |
 |              -- ASIOSDK2.3
 |              |
 |              -- build
 |              -- lib
 |              -- bin
 |              -- include
 -- playrec

Thus download and uncompress portaudio and asiosdk accordingly from http://www.portaudio.com/archives/pa_snapshot.tgz and http://www.steinberg.net/sdk_downloads/asiosdk2.3.zip

Open "VS x64 Cross Tools Command Prompt" and browse to portaudio subdirectory

Build portaudio

> mkdir build
> cd build
> cmake -G "NMake Makefiles" -DCMAKE_INSTALL_PREFIX=<portaudio_install_dir> -DCMAKE_BUILD_TYPE=Release ../portaudio
> nmake /f Makefile
> nmake /f Makefile install

Thus installation is done to lib, bin and include subdirectories of portaudio_install_dir. portaudio_install_dir has to be absolute path to the portaudio subdirectory beside playrec subdirectory for FindPortaudio.cmake to find it.

Build playrec

Have MATLAB_ROOT environment variable point to Matlab installation directory

> cd ../../playrec
> mkdir build
> cd build
> cmake -G "NMake Makefiles" -DCMAKE_BUILD_TYPE=Release ..
> nmake /f Makefile
> nmake /f Makefile install

Test the installation

On Matlab command prompt at playrec directory:

>> playrec('about')

Clone playrec-examples from

% git clone [e-mail]:PlayrecForMatlab/playrec-examples.git

Add playrec to Matlab path and execute test_playrec.m from playrec-examples directory

>> test_playrec