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jAudio 1.0 Online Help

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Choosing Features for Extraction

Selecting Features for Analysis

Features are selected by left clicking on the checkbox immediately to their right in the feature selection toolbox. Note that all features can be saved independently. All dependencies are tracked internally so that the system tracks what dependencies are needed and silently calculates them without requiring them to be specifically selected by the user.


Sorting Features in the Feature Table

The table of features can be sorted by number of features, whether selected, or by feature name. To sort by a given field, left-click its header. To reset the table back to its original order, double-click on one of the feature table's header.


Editing Features

Every feature in the features table is editable. By double clicking on a feature, a window is displayed. This window contains both all editable properties of the given feature along with that features description. Each entry is validated on save with errors reported at that time. If the window is canceled, all changes are discarded.


Globally Editing all Feature Windows

When changing the sample rate, it is often desirable to keep the same length of time for averaging windows such as mean and standard deviation. The "Global Window Change" menu option allows changing all such windows at once. The default window length is 100 windows. The dialog box will only accept positive integer window lengths.


Adding Features

jAudio can insert additional features not in its base set using the features.xml file in the base directory. Each entry has its own XML descriptor describing it. For instance:

	<feature>
		<class>jAudioFeatureExtractor.AudioFeatures.SpectralCentroid</class>
		<on/>
	</feature>

The class must be the fully qualified class name. The <On> tag specifies that the feature is on by default. It can be omitted. All other data is included in the FeatureDefinition in the feature and does not need to be specified again.

Plugin Folder

The plugin folder is defined at the start of the features.xml file. All classes inside are automatically loaded into jAudio on startup exactly as javac would compile a java file there. i.e. jAudioFeatureExtgractor.DataModel would need to be placed in $plugin$/jAudioFeatureExtractor/DataModel.class where $plugin$ is the folder specified in the plugin XML entry. The plugin folder must be a fully qualified URL (HTTP locations permitted) of the syntax:

        <pluginFolder>file://Users/mcennis/jAudio/plugin</pluginFolder>