File	Doc	Category	Size	Date	Package
Equalizer.java	API Doc	Android 5.1 API	21617	Thu Mar 12 22:22:30 GMT 2015	android.media.audiofx

Equalizer

• java.lang.Object
  • android.media.audiofx.AudioEffect

Fields Summary
private static final String	TAG
public static final int	PARAM_NUM_BANDS Number of bands. Parameter ID for OnParameterChangeListener
public static final int	PARAM_LEVEL_RANGE Band level range. Parameter ID for OnParameterChangeListener
public static final int	PARAM_BAND_LEVEL Band level. Parameter ID for OnParameterChangeListener
public static final int	PARAM_CENTER_FREQ Band center frequency. Parameter ID for OnParameterChangeListener
public static final int	PARAM_BAND_FREQ_RANGE Band frequency range. Parameter ID for {@link android.media.audiofx.Equalizer.OnParameterChangeListener}
public static final int	PARAM_GET_BAND Band for a given frequency. Parameter ID for OnParameterChangeListener
public static final int	PARAM_CURRENT_PRESET Current preset. Parameter ID for OnParameterChangeListener
public static final int	PARAM_GET_NUM_OF_PRESETS Request number of presets. Parameter ID for OnParameterChangeListener
public static final int	PARAM_GET_PRESET_NAME Request preset name. Parameter ID for OnParameterChangeListener
private static final int	PARAM_PROPERTIES
public static final int	PARAM_STRING_SIZE_MAX Maximum size for preset name
private short	mNumBands Number of bands implemented by Equalizer engine
private int	mNumPresets Number of presets implemented by Equalizer engine
private String[]	mPresetNames Names of presets implemented by Equalizer engine
private OnParameterChangeListener	mParamListener Registered listener for parameter changes.
private BaseParameterListener	mBaseParamListener Listener used internally to to receive raw parameter change event from AudioEffect super class
private final Object	mParamListenerLock Lock for access to mParamListener

Constructors Summary

public Equalizer(int priority, int audioSession) Class constructor. param priority the priority level requested by the application for controlling the Equalizer engine. As the same engine can be shared by several applications, this parameter indicates how much the requesting application needs control of effect parameters. The normal priority is 0, above normal is a positive number, below normal a negative number. param audioSession system wide unique audio session identifier. The Equalizer will be attached to the MediaPlayer or AudioTrack in the same audio session. throws java.lang.IllegalStateException throws java.lang.IllegalArgumentException throws java.lang.UnsupportedOperationException throws java.lang.RuntimeException super(EFFECT_TYPE_EQUALIZER, EFFECT_TYPE_NULL, priority, audioSession); if (audioSession == 0) { Log.w(TAG, "WARNING: attaching an Equalizer to global output mix is deprecated!"); } getNumberOfBands(); mNumPresets = (int)getNumberOfPresets(); if (mNumPresets != 0) { mPresetNames = new String[mNumPresets]; byte[] value = new byte[PARAM_STRING_SIZE_MAX]; int[] param = new int[2]; param[0] = PARAM_GET_PRESET_NAME; for (int i = 0; i < mNumPresets; i++) { param[1] = i; checkStatus(getParameter(param, value)); int length = 0; while (value[length] != 0) length++; try { mPresetNames[i] = new String(value, 0, length, "ISO-8859-1"); } catch (java.io.UnsupportedEncodingException e) { Log.e(TAG, "preset name decode error"); } } }

Methods Summary
public short	getBand(int frequency) Gets the band that has the most effect on the given frequency. param frequency frequency in milliHertz which is to be equalized via the returned band. return the frequency band that has most effect on the given frequency. throws IllegalStateException throws IllegalArgumentException throws UnsupportedOperationException int[] param = new int[2]; short[] result = new short[1]; param[0] = PARAM_GET_BAND; param[1] = frequency; checkStatus(getParameter(param, result)); return result[0];
public int[]	getBandFreqRange(short band) Gets the frequency range of the given frequency band. param band frequency band whose frequency range is requested. The numbering of the bands starts from 0 and ends at (number of bands - 1). return the frequency range in millHertz in an array of integers. The first element is the lower limit of the range, the second element the upper limit. throws IllegalStateException throws IllegalArgumentException throws UnsupportedOperationException int[] param = new int[2]; int[] result = new int[2]; param[0] = PARAM_BAND_FREQ_RANGE; param[1] = (int)band; checkStatus(getParameter(param, result)); return result;
public short	getBandLevel(short band) Gets the gain set for the given equalizer band. param band frequency band whose gain is requested. The numbering of the bands starts from 0 and ends at (number of bands - 1). return the gain in millibels of the given band. throws IllegalStateException throws IllegalArgumentException throws UnsupportedOperationException int[] param = new int[2]; short[] result = new short[1]; param[0] = PARAM_BAND_LEVEL; param[1] = (int)band; checkStatus(getParameter(param, result)); return result[0];
public short[]	getBandLevelRange() Gets the level range for use by {@link #setBandLevel(short,short)}. The level is expressed in milliBel. return the band level range in an array of short integers. The first element is the lower limit of the range, the second element the upper limit. throws IllegalStateException throws IllegalArgumentException throws UnsupportedOperationException short[] result = new short[2]; checkStatus(getParameter(PARAM_LEVEL_RANGE, result)); return result;
public int	getCenterFreq(short band) Gets the center frequency of the given band. param band frequency band whose center frequency is requested. The numbering of the bands starts from 0 and ends at (number of bands - 1). return the center frequency in milliHertz throws IllegalStateException throws IllegalArgumentException throws UnsupportedOperationException int[] param = new int[2]; int[] result = new int[1]; param[0] = PARAM_CENTER_FREQ; param[1] = (int)band; checkStatus(getParameter(param, result)); return result[0];
public short	getCurrentPreset() Gets current preset. return the preset that is set at the moment. throws IllegalStateException throws IllegalArgumentException throws UnsupportedOperationException short[] result = new short[1]; checkStatus(getParameter(PARAM_CURRENT_PRESET, result)); return result[0];
public short	getNumberOfBands() Gets the number of frequency bands supported by the Equalizer engine. return the number of bands throws IllegalStateException throws IllegalArgumentException throws UnsupportedOperationException if (mNumBands != 0) { return mNumBands; } int[] param = new int[1]; param[0] = PARAM_NUM_BANDS; short[] result = new short[1]; checkStatus(getParameter(param, result)); mNumBands = result[0]; return mNumBands;
public short	getNumberOfPresets() Gets the total number of presets the equalizer supports. The presets will have indices [0, number of presets-1]. return the number of presets the equalizer supports. throws IllegalStateException throws IllegalArgumentException throws UnsupportedOperationException short[] result = new short[1]; checkStatus(getParameter(PARAM_GET_NUM_OF_PRESETS, result)); return result[0];
public java.lang.String	getPresetName(short preset) Gets the preset name based on the index. param preset index of the preset. The valid range is [0, number of presets-1]. return a string containing the name of the given preset. throws IllegalStateException throws IllegalArgumentException throws UnsupportedOperationException if (preset >= 0 && preset < mNumPresets) { return mPresetNames[preset]; } else { return ""; }
public android.media.audiofx.Equalizer$Settings	getProperties() Gets the equalizer properties. This method is useful when a snapshot of current equalizer settings must be saved by the application. return an Equalizer.Settings object containing all current parameters values throws IllegalStateException throws IllegalArgumentException throws UnsupportedOperationException byte[] param = new byte[4 + mNumBands * 2]; checkStatus(getParameter(PARAM_PROPERTIES, param)); Settings settings = new Settings(); settings.curPreset = byteArrayToShort(param, 0); settings.numBands = byteArrayToShort(param, 2); settings.bandLevels = new short[mNumBands]; for (int i = 0; i < mNumBands; i++) { settings.bandLevels[i] = byteArrayToShort(param, 4 + 2*i); } return settings;
public void	setBandLevel(short band, short level) Sets the given equalizer band to the given gain value. param band frequency band that will have the new gain. The numbering of the bands starts from 0 and ends at (number of bands - 1). param level new gain in millibels that will be set to the given band. getBandLevelRange() will define the maximum and minimum values. throws IllegalStateException throws IllegalArgumentException throws UnsupportedOperationException see #getNumberOfBands() int[] param = new int[2]; short[] value = new short[1]; param[0] = PARAM_BAND_LEVEL; param[1] = (int)band; value[0] = level; checkStatus(setParameter(param, value));
public void	setParameterListener(android.media.audiofx.Equalizer$OnParameterChangeListener listener) Registers an OnParameterChangeListener interface. param listener OnParameterChangeListener interface registered synchronized (mParamListenerLock) { if (mParamListener == null) { mParamListener = listener; mBaseParamListener = new BaseParameterListener(); super.setParameterListener(mBaseParamListener); } }
public void	setProperties(android.media.audiofx.Equalizer$Settings settings) Sets the equalizer properties. This method is useful when equalizer settings have to be applied from a previous backup. param settings an Equalizer.Settings object containing the properties to apply throws IllegalStateException throws IllegalArgumentException throws UnsupportedOperationException if (settings.numBands != settings.bandLevels.length || settings.numBands != mNumBands) { throw new IllegalArgumentException("settings invalid band count: " +settings.numBands); } byte[] param = concatArrays(shortToByteArray(settings.curPreset), shortToByteArray(mNumBands)); for (int i = 0; i < mNumBands; i++) { param = concatArrays(param, shortToByteArray(settings.bandLevels[i])); } checkStatus(setParameter(PARAM_PROPERTIES, param));
public void	usePreset(short preset) Sets the equalizer according to the given preset. param preset new preset that will be taken into use. The valid range is [0, number of presets-1]. throws IllegalStateException throws IllegalArgumentException throws UnsupportedOperationException see #getNumberOfPresets() checkStatus(setParameter(PARAM_CURRENT_PRESET, preset));