#ciXtract ciXtract is a CinderBlock for LibXtract, a real-time audio feature extraction library developed by Jamie Bullock.

##Notes

Requires Cinder >= 0.8.6

This CinderBlock includes the Xcode and VS2012 examples and the CinderBlock template.
There are several issues related to LibXtract, some of the features are either inaccurate or not working yet.
On Windows seems there is a problem witht the last bin in the Fft, I'll update the block as soon as these issues are fixed in LibXtract

##Get the code LibXtract is included as headers + precompiled static library for OSX and Windows.

cd CINDER_PATH/blocks

git clone git://github.com/q-depot/ciXtract.git

##How to use it

// include the headers
#include "cinder/audio/Context.h"
#include "cinder/audio/MonitorNode.h"

#include "ciXtract.h"
#include "ciXtractUtilities.h"

ciXtractRef                     mXtract;			// declare a ciXtract object
vector<ciXtractFeatureRef>      mFeatures;			// declare a vector to save a reference of the features

audio::InputDeviceNodeRef       mInputDeviceNode;	// this is what you need to get the PCM buffer using the Cinder audio api
audio::MonitorNodeRef           mMonitorNode;
audio::Buffer                   mPcmBuffer;

void TestApp::setup()
{
	// Initialise the audio input
    auto ctx = audio::Context::master();

    vector<audio::DeviceRef> devices = audio::Device::getInputDevices();
    console() << "List audio devices:" << endl;
    for( size_t k=0; k < devices.size(); k++ )
        console() << devices[k]->getName() << endl;

    // find and initialise a device by name
     audio::DeviceRef dev;

     dev = audio::Device::findDeviceByName( "Soundflower (2ch)" );                              // on OSX i use Soundflower to hijack the system audio
     
     if ( !dev )                                                                                
         dev = audio::Device::findDeviceByName( "CABLE Output (VB-Audio Virtual Cable)" );      // on Windows there is similar tool called VB Cable
    
     if ( !dev )                                                                                // initialise default input device
        mInputDeviceNode = ctx->createInputDeviceNode();
     else
         mInputDeviceNode = ctx->createInputDeviceNode( dev );

    // initialise MonitorNode to get the PCM data
    auto monitorFormat = audio::MonitorNode::Format().windowSize( CIXTRACT_PCM_SIZE );
    mMonitorNode = ctx->makeNode( new audio::MonitorNode( monitorFormat ) );

    // pipe the input device into the MonitorNode
    mInputDeviceNode >> mMonitorNode;

    // InputDeviceNode (and all InputNode subclasses) need to be enabled()'s to process audio. So does the Context:
    mInputDeviceNode->enable();
    ctx->enable();


    // Initialise ciXtract
    mXtract     = ciXtract::create();
    mFeatures   = mXtract->getFeatures();

    // List all available features, this prints out the enumerator that can be used to get the feature
    mXtract->listFeatures();

    // Features are disabled by default, call enableFeature( feature_enum ) or enableAllFeatures()
    mXtract->enableAllFeatures();
}

void TestApp::update()
{
	mPcmBuffer = mMonitorNode->getBuffer();
    
    float pcmGain = 2.0f;

    if ( !mPcmBuffer.isEmpty() )								// ensure the PCM buffer exists
        mXtract->update( mPcmBuffer.getData(), pcmGain );		// update ciXtract, optionally you can pass the gain for the PCM signal
}

void TestApp::draw()
{
	// draw the PCM and a feature using the ciXtractUtilities

    ciXtractUtilities::drawPcm( Rectf( 0.0f, 0.0f, getWindowWidth(), 60.0f ), &mPcmBuffer );	// draw the PCM buffer

	ciXtractFeatureRef feature = mXtract->getFeature( XTRACT_SPECTRUM );						// get a feature
	ciXtractUtilities::drawData( feature, Rectf( 15, 15, 200, 90 ), mFont );					// draw the feature, you must pass a TextureFontRef
																								// optionally you can specify plot/bg/label colors
}

##About LibXtract

LibXtract is a simple, portable, lightweight library of audio feature extraction functions. The purpose of the library is to provide a relatively exhaustive set of feature extraction primatives that are designed to be 'cascaded' to create a extraction hierarchies.

LibXtract on github

LIBXTRACT: A LIGHTWEIGHT LIBRARY FOR AUDIO FEATURE EXTRACTION

LibXtract documentation

#Disclaimer THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.