Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) Summary: [Nested Classes](https://developer.android.com/reference/android/media/audiofx/Visualizer#nestedclasses) \| [Constants](https://developer.android.com/reference/android/media/audiofx/Visualizer#constants) \| [Ctors](https://developer.android.com/reference/android/media/audiofx/Visualizer#pubctors) \| [Methods](https://developer.android.com/reference/android/media/audiofx/Visualizer#pubmethods) \| [Protected Methods](https://developer.android.com/reference/android/media/audiofx/Visualizer#promethods) \| [Inherited Methods](https://developer.android.com/reference/android/media/audiofx/Visualizer#inhmethods) # Visualizer *** ** * ** *** [Kotlin](https://developer.android.com/reference/kotlin/android/media/audiofx/Visualizer "View this page in Kotlin") \|Java ` public class Visualizer ` ` extends https://developer.android.com/reference/java/lang/Object ` ` ` |---|---| | [java.lang.Object](https://developer.android.com/reference/java/lang/Object) || | ↳ | android.media.audiofx.Visualizer |
*** ** * ** *** The Visualizer class enables application to retrieve part of the currently playing audio for visualization purpose. It is not an audio recording interface and only returns partial and low quality audio content. However, to protect privacy of certain audio data (e.g voice mail) the use of the visualizer requires the permission android.permission.RECORD_AUDIO. The audio session ID passed to the constructor indicates which audio content should be visualized: - If the session is 0, the audio output mix is visualized - If the session is not 0, the audio from a particular `https://developer.android.com/reference/android/media/MediaPlayer` or `https://developer.android.com/reference/android/media/AudioTrack` using this audio session is visualized Two types of representation of audio content can be captured: - Waveform data: consecutive 8-bit (unsigned) mono samples by using the `https://developer.android.com/reference/android/media/audiofx/Visualizer#getWaveForm(byte[])` method - Frequency data: 8-bit magnitude FFT by using the `https://developer.android.com/reference/android/media/audiofx/Visualizer#getFft(byte[])` method The length of the capture can be retrieved or specified by calling respectively `https://developer.android.com/reference/android/media/audiofx/Visualizer#getCaptureSize()` and `https://developer.android.com/reference/android/media/audiofx/Visualizer#setCaptureSize(int)` methods. The capture size must be a power of 2 in the range returned by `https://developer.android.com/reference/android/media/audiofx/Visualizer#getCaptureSizeRange()`. In addition to the polling capture mode described above with `https://developer.android.com/reference/android/media/audiofx/Visualizer#getWaveForm(byte[])` and `https://developer.android.com/reference/android/media/audiofx/Visualizer#getFft(byte[])` methods, a callback mode is also available by installing a listener by use of the `https://developer.android.com/reference/android/media/audiofx/Visualizer#setDataCaptureListener(android.media.audiofx.Visualizer.OnDataCaptureListener,%20int,%20boolean,%20boolean)` method. The rate at which the listener capture method is called as well as the type of data returned is specified. Before capturing data, the Visualizer must be enabled by calling the `https://developer.android.com/reference/android/media/audiofx/Visualizer#setEnabled(boolean)` method. When data capture is not needed any more, the Visualizer should be disabled. It is good practice to call the `https://developer.android.com/reference/android/media/audiofx/Visualizer#release()` method when the Visualizer is not used anymore to free up native resources associated to the Visualizer instance. Creating a Visualizer on the output mix (audio session 0) requires permission `https://developer.android.com/reference/android/Manifest.permission#MODIFY_AUDIO_SETTINGS` The Visualizer class can also be used to perform measurements on the audio being played back. The measurements to perform are defined by setting a mask of the requested measurement modes with `https://developer.android.com/reference/android/media/audiofx/Visualizer#setMeasurementMode(int)`. Supported values are `https://developer.android.com/reference/android/media/audiofx/Visualizer#MEASUREMENT_MODE_NONE` to cancel any measurement, and `https://developer.android.com/reference/android/media/audiofx/Visualizer#MEASUREMENT_MODE_PEAK_RMS` for peak and RMS monitoring. Measurements can be retrieved through `https://developer.android.com/reference/android/media/audiofx/Visualizer#getMeasurementPeakRms(android.media.audiofx.Visualizer.MeasurementPeakRms)`. ## Summary | ### Nested classes || |---|---| | ` class` | `https://developer.android.com/reference/android/media/audiofx/Visualizer.MeasurementPeakRms` A class to store peak and RMS values. | | ` interface` | `https://developer.android.com/reference/android/media/audiofx/Visualizer.OnDataCaptureListener` The OnDataCaptureListener interface defines methods called by the Visualizer to periodically update the audio visualization capture. | | ### Constants || |---|---| | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#ALREADY_EXISTS` Internal operation status. | | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR` Unspecified error. | | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_BAD_VALUE` Operation failed due to bad parameter value. | | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_DEAD_OBJECT` Operation failed due to dead remote object. | | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_INVALID_OPERATION` Operation failed because it was requested in wrong state. | | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_NO_INIT` Operation failed due to bad object initialization. | | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_NO_MEMORY` Operation failed due to lack of memory. | | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#MEASUREMENT_MODE_NONE` Defines a measurement mode in which no measurements are performed. | | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#MEASUREMENT_MODE_PEAK_RMS` Defines a measurement mode which computes the peak and RMS value in mB below the "full scale", where 0mB is normally the maximum sample value (but see the note below). | | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#SCALING_MODE_AS_PLAYED` Defines a capture mode where the playback volume will affect (scale) the range of the captured data. | | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#SCALING_MODE_NORMALIZED` Defines a capture mode where amplification is applied based on the content of the captured data. | | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#STATE_ENABLED` State of a Visualizer object that is active. | | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#STATE_INITIALIZED` State of a Visualizer object that is ready to be used. | | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#STATE_UNINITIALIZED` State of a Visualizer object that was not successfully initialized upon creation | | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#SUCCESS` Successful operation. | | ### Public constructors || |---|---| | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#Visualizer(int)(int audioSession) ` Class constructor. | | ### Public methods || |---|---| | ` int` | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#getCaptureSize()() ` Returns current capture size. | | ` static int[]` | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#getCaptureSizeRange()() ` Returns the capture size range. | | ` boolean` | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#getEnabled()() ` Get current activation state of the visualizer. | | ` int` | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#getFft(byte[])(byte[] fft) ` Returns a frequency capture of currently playing audio content. | | ` static int` | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#getMaxCaptureRate()() ` Returns the maximum capture rate for the callback capture method. | | ` int` | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#getMeasurementMode()() ` Returns the current measurement modes performed by this audio effect | | ` int` | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#getMeasurementPeakRms(android.media.audiofx.Visualizer.MeasurementPeakRms)(https://developer.android.com/reference/android/media/audiofx/Visualizer.MeasurementPeakRms measurement) ` Retrieves the latest peak and RMS measurement. | | ` int` | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#getSamplingRate()() ` Returns the sampling rate of the captured audio. | | ` int` | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#getScalingMode()() ` Returns the current scaling mode on the captured visualization data. | | ` int` | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#getWaveForm(byte[])(byte[] waveform) ` Returns a waveform capture of currently playing audio content. | | ` void` | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#release()() ` Releases the native Visualizer resources. | | ` int` | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#setCaptureSize(int)(int size) ` Sets the capture size, i.e. | | ` int` | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#setDataCaptureListener(android.media.audiofx.Visualizer.OnDataCaptureListener,%20int,%20boolean,%20boolean)(https://developer.android.com/reference/android/media/audiofx/Visualizer.OnDataCaptureListener listener, int rate, boolean waveform, boolean fft) ` Registers an OnDataCaptureListener interface and specifies the rate at which the capture should be updated as well as the type of capture requested. | | ` int` | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#setEnabled(boolean)(boolean enabled) ` Enable or disable the visualization engine. | | ` int` | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#setMeasurementMode(int)(int mode) ` Sets the combination of measurement modes to be performed by this audio effect. | | ` int` | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#setScalingMode(int)(int mode) ` Set the type of scaling applied on the captured visualization data. | | ### Protected methods || |---|---| | ` void` | ` https://developer.android.com/reference/android/media/audiofx/Visualizer#finalize()() ` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. | | ### Inherited methods | |---|---| | From class ` https://developer.android.com/reference/java/lang/Object ` |---|---| | ` https://developer.android.com/reference/java/lang/Object` | ` https://developer.android.com/reference/java/lang/Object#clone()() ` Creates and returns a copy of this object. | | ` boolean` | ` https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object)(https://developer.android.com/reference/java/lang/Object obj) ` Indicates whether some other object is "equal to" this one. | | ` void` | ` https://developer.android.com/reference/java/lang/Object#finalize()() ` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. | | ` final https://developer.android.com/reference/java/lang/Class` | ` https://developer.android.com/reference/java/lang/Object#getClass()() ` Returns the runtime class of this `Object`. | | ` int` | ` https://developer.android.com/reference/java/lang/Object#hashCode()() ` Returns a hash code value for the object. | | ` final void` | ` https://developer.android.com/reference/java/lang/Object#notify()() ` Wakes up a single thread that is waiting on this object's monitor. | | ` final void` | ` https://developer.android.com/reference/java/lang/Object#notifyAll()() ` Wakes up all threads that are waiting on this object's monitor. | | ` https://developer.android.com/reference/java/lang/String` | ` https://developer.android.com/reference/java/lang/Object#toString()() ` Returns a string representation of the object. | | ` final void` | ` https://developer.android.com/reference/java/lang/Object#wait(long,%20int)(long timeoutMillis, int nanos) ` Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*, or until a certain amount of real time has elapsed. | | ` final void` | ` https://developer.android.com/reference/java/lang/Object#wait(long)(long timeoutMillis) ` Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*, or until a certain amount of real time has elapsed. | | ` final void` | ` https://developer.android.com/reference/java/lang/Object#wait()() ` Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*. | || ## Constants ### ALREADY_EXISTS Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int ALREADY_EXISTS ``` Internal operation status. Not returned by any method.
Constant Value: -2 (0xfffffffe) ### ERROR Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int ERROR ``` Unspecified error.
Constant Value: -1 (0xffffffff) ### ERROR_BAD_VALUE Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int ERROR_BAD_VALUE ``` Operation failed due to bad parameter value.
Constant Value: -4 (0xfffffffc) ### ERROR_DEAD_OBJECT Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int ERROR_DEAD_OBJECT ``` Operation failed due to dead remote object.
Constant Value: -7 (0xfffffff9) ### ERROR_INVALID_OPERATION Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int ERROR_INVALID_OPERATION ``` Operation failed because it was requested in wrong state.
Constant Value: -5 (0xfffffffb) ### ERROR_NO_INIT Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int ERROR_NO_INIT ``` Operation failed due to bad object initialization.
Constant Value: -3 (0xfffffffd) ### ERROR_NO_MEMORY Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int ERROR_NO_MEMORY ``` Operation failed due to lack of memory.
Constant Value: -6 (0xfffffffa) ### MEASUREMENT_MODE_NONE Added in [API level 19](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int MEASUREMENT_MODE_NONE ``` Defines a measurement mode in which no measurements are performed.
Constant Value: 0 (0x00000000) ### MEASUREMENT_MODE_PEAK_RMS Added in [API level 19](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int MEASUREMENT_MODE_PEAK_RMS ``` Defines a measurement mode which computes the peak and RMS value in mB below the "full scale", where 0mB is normally the maximum sample value (but see the note below). Minimum value depends on the resolution of audio samples used by the audio framework. The value of -9600mB is the minimum value for 16-bit audio systems and -14400mB or below for "high resolution" systems. Values for peak and RMS can be retrieved with `https://developer.android.com/reference/android/media/audiofx/Visualizer#getMeasurementPeakRms(android.media.audiofx.Visualizer.MeasurementPeakRms)`. **Note:** when Visualizer effect is attached to the global session (with session ID 0), it is possible to observe RMS peaks higher than 0 dBFS, for example in the case when there are multiple audio sources playing simultaneously. In this case `https://developer.android.com/reference/android/media/audiofx/Visualizer#getMeasurementPeakRms(android.media.audiofx.Visualizer.MeasurementPeakRms)` method can return a positive value.
Constant Value: 1 (0x00000001) ### SCALING_MODE_AS_PLAYED Added in [API level 16](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int SCALING_MODE_AS_PLAYED ``` Defines a capture mode where the playback volume will affect (scale) the range of the captured data. A low playback volume will lead to low sample and fft values, and vice-versa.
Constant Value: 1 (0x00000001) ### SCALING_MODE_NORMALIZED Added in [API level 16](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int SCALING_MODE_NORMALIZED ``` Defines a capture mode where amplification is applied based on the content of the captured data. This is the default Visualizer mode, and is suitable for music visualization.
Constant Value: 0 (0x00000000) ### STATE_ENABLED Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int STATE_ENABLED ``` State of a Visualizer object that is active.
Constant Value: 2 (0x00000002) ### STATE_INITIALIZED Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int STATE_INITIALIZED ``` State of a Visualizer object that is ready to be used.
Constant Value: 1 (0x00000001) ### STATE_UNINITIALIZED Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int STATE_UNINITIALIZED ``` State of a Visualizer object that was not successfully initialized upon creation
Constant Value: 0 (0x00000000) ### SUCCESS Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static final int SUCCESS ``` Successful operation.
Constant Value: 0 (0x00000000) ## Public constructors ### Visualizer Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public Visualizer (int audioSession) ``` Class constructor.
| Parameters || |---|---| | `audioSession` | `int`: system wide unique audio session identifier. If audioSession is not 0, the visualizer will be attached to the MediaPlayer or AudioTrack in the same audio session. Otherwise, the Visualizer will apply to the output mix.
| | Throws || |---|---| | | java.lang.RuntimeException | | | java.lang.UnsupportedOperationException | | `https://developer.android.com/reference/java/lang/RuntimeException` | | | `https://developer.android.com/reference/java/lang/UnsupportedOperationException` | | ## Public methods ### getCaptureSize Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public int getCaptureSize () ``` Returns current capture size.
| Returns || |---|---| | `int` | the capture size in bytes.
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/IllegalStateException` | | ### getCaptureSizeRange Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static int[] getCaptureSizeRange () ``` Returns the capture size range.
| Returns || |---|---| | `int[]` | the mininum capture size is returned in first array element and the maximum in second array element.
| ### getEnabled Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public boolean getEnabled () ``` Get current activation state of the visualizer.
| Returns || |---|---| | `boolean` | true if the visualizer is active, false otherwise
| ### getFft Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public int getFft (byte[] fft) ``` Returns a frequency capture of currently playing audio content. This method must be called when the Visualizer is enabled. The capture is an 8-bit magnitude FFT, the frequency range covered being 0 (DC) to half of the sampling rate returned by `https://developer.android.com/reference/android/media/audiofx/Visualizer#getSamplingRate()`. The capture returns the real and imaginary parts of a number of frequency points equal to half of the capture size plus one. Note: only the real part is returned for the first point (DC) and the last point (sampling frequency / 2). The layout in the returned byte array is as follows: - n is the capture size returned by getCaptureSize() - Rfk, Ifk are respectively the real and imaginary parts of the kth frequency component - If Fs is the sampling frequency retuned by getSamplingRate() the kth frequency is: k \* Fs / n |---|---|---|---|---|---|---|---|---|---| | Index
| 0
| 1
| 2
| 3
| 4
| 5
| ...
| n - 2
| n - 1
| | Data
| Rf0
| Rf(n/2)
| Rf1
| If1
| Rf2
| If2
| ...
| Rf(n/2-1)
| If(n/2-1)
| In order to obtain magnitude and phase values the following code can be used: ```transact-sql int n = fft.size(); float[] magnitudes = new float[n / 2 + 1]; float[] phases = new float[n / 2 + 1]; magnitudes[0] = (float)Math.abs(fft[0]); // DC magnitudes[n / 2] = (float)Math.abs(fft[1]); // Nyquist phases[0] = phases[n / 2] = 0; for (int k = 1; k < n / 2; k++) { int i = k * 2; magnitudes[k] = (float)Math.hypot(fft[i], fft[i + 1]); phases[k] = (float)Math.atan2(fft[i + 1], fft[i]); } ```

| Parameters || |---|---| | `fft` | `byte`: array of bytes where the FFT should be returned
| | Returns || |---|---| | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#SUCCESS` in case of success, `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_NO_MEMORY`, `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_INVALID_OPERATION` or `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_DEAD_OBJECT` in case of failure.
| | Throws || |---|---| | | java.lang.IllegalStateException | | `https://developer.android.com/reference/java/lang/IllegalStateException` | | ### getMaxCaptureRate Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public static int getMaxCaptureRate () ``` Returns the maximum capture rate for the callback capture method. This is the maximum value for the rate parameter of the `https://developer.android.com/reference/android/media/audiofx/Visualizer#setDataCaptureListener(android.media.audiofx.Visualizer.OnDataCaptureListener,%20int,%20boolean,%20boolean)` method.
| Returns || |---|---| | `int` | the maximum capture rate expressed in milliHertz
| ### getMeasurementMode Added in [API level 19](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public int getMeasurementMode () ``` Returns the current measurement modes performed by this audio effect
| Returns || |---|---| | `int` | the mask of the measurements, `https://developer.android.com/reference/android/media/audiofx/Visualizer#MEASUREMENT_MODE_NONE` (when no measurements are performed) or `https://developer.android.com/reference/android/media/audiofx/Visualizer#MEASUREMENT_MODE_PEAK_RMS`.
| | Throws || |---|---| | | java.lang.IllegalStateException | | `https://developer.android.com/reference/java/lang/IllegalStateException` | | ### getMeasurementPeakRms Added in [API level 19](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public int getMeasurementPeakRms (Visualizer.MeasurementPeakRms measurement) ``` Retrieves the latest peak and RMS measurement. Sets the peak and RMS fields of the supplied `https://developer.android.com/reference/android/media/audiofx/Visualizer.MeasurementPeakRms` to the latest measured values.
| Parameters || |---|---| | `measurement` | `Visualizer.MeasurementPeakRms`: a non-null `https://developer.android.com/reference/android/media/audiofx/Visualizer.MeasurementPeakRms` instance to store the measurement values.
| | Returns || |---|---| | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#SUCCESS` in case of success, `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_BAD_VALUE`, `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_NO_MEMORY`, `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_INVALID_OPERATION` or `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_DEAD_OBJECT` in case of failure.
| ### getSamplingRate Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public int getSamplingRate () ``` Returns the sampling rate of the captured audio.
| Returns || |---|---| | `int` | the sampling rate in milliHertz.
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/IllegalStateException` | | ### getScalingMode Added in [API level 16](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public int getScalingMode () ``` Returns the current scaling mode on the captured visualization data.
| Returns || |---|---| | `int` | the scaling mode, see `https://developer.android.com/reference/android/media/audiofx/Visualizer#SCALING_MODE_NORMALIZED` and `https://developer.android.com/reference/android/media/audiofx/Visualizer#SCALING_MODE_AS_PLAYED`.
| | Throws || |---|---| | | java.lang.IllegalStateException | | `https://developer.android.com/reference/java/lang/IllegalStateException` | | ### getWaveForm Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public int getWaveForm (byte[] waveform) ``` Returns a waveform capture of currently playing audio content. The capture consists in a number of consecutive 8-bit (unsigned) mono PCM samples equal to the capture size returned by `https://developer.android.com/reference/android/media/audiofx/Visualizer#getCaptureSize()`. This method must be called when the Visualizer is enabled.
| Parameters || |---|---| | `waveform` | `byte`: array of bytes where the waveform should be returned, array length must be at least equals to the capture size returned by `https://developer.android.com/reference/android/media/audiofx/Visualizer#getCaptureSize()`.
| | Returns || |---|---| | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#SUCCESS` in case of success, `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_NO_MEMORY`, `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_INVALID_OPERATION` or `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_DEAD_OBJECT` in case of failure.
| | Throws || |---|---| | | java.lang.IllegalArgumentException | | | java.lang.IllegalStateException | | `https://developer.android.com/reference/java/lang/IllegalStateException` | | ### release Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public void release () ``` Releases the native Visualizer resources. It is a good practice to release the visualization engine when not in use.
### setCaptureSize Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public int setCaptureSize (int size) ``` Sets the capture size, i.e. the number of bytes returned by `https://developer.android.com/reference/android/media/audiofx/Visualizer#getWaveForm(byte[])` and `https://developer.android.com/reference/android/media/audiofx/Visualizer#getFft(byte[])` methods. The capture size must be a power of 2 in the range returned by `https://developer.android.com/reference/android/media/audiofx/Visualizer#getCaptureSizeRange()`. This method must not be called when the Visualizer is enabled.
| Parameters || |---|---| | `size` | `int`: requested capture size
| | Returns || |---|---| | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#SUCCESS` in case of success, `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_INVALID_OPERATION` if Visualizer effect enginer not enabled.
| | Throws || |---|---| | `https://developer.android.com/reference/java/lang/IllegalArgumentException` | if the size parameter is invalid (out of supported range). | | `https://developer.android.com/reference/java/lang/IllegalStateException` | if the effect is not in proper state. | ### setDataCaptureListener Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public int setDataCaptureListener (Visualizer.OnDataCaptureListener listener, int rate, boolean waveform, boolean fft) ``` Registers an OnDataCaptureListener interface and specifies the rate at which the capture should be updated as well as the type of capture requested. Call this method with a null listener to stop receiving the capture updates.
| Parameters || |---|---| | `listener` | `Visualizer.OnDataCaptureListener`: OnDataCaptureListener registered. This value may be `null`.
| | `rate` | `int`: rate in milliHertz at which the capture should be updated
| | `waveform` | `boolean`: true if a waveform capture is requested: the onWaveFormDataCapture() method will be called on the OnDataCaptureListener interface.
| | `fft` | `boolean`: true if a frequency capture is requested: the onFftDataCapture() method will be called on the OnDataCaptureListener interface.
| | Returns || |---|---| | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#SUCCESS` in case of success, `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_NO_INIT` or `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_BAD_VALUE` in case of failure.
| ### setEnabled Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public int setEnabled (boolean enabled) ``` Enable or disable the visualization engine.
| Parameters || |---|---| | `enabled` | `boolean`: requested enable state
| | Returns || |---|---| | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#SUCCESS` in case of success, `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_INVALID_OPERATION` or `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_DEAD_OBJECT` in case of failure.
| | Throws || |---|---| | | java.lang.IllegalStateException | | `https://developer.android.com/reference/java/lang/IllegalStateException` | | ### setMeasurementMode Added in [API level 19](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public int setMeasurementMode (int mode) ``` Sets the combination of measurement modes to be performed by this audio effect.
| Parameters || |---|---| | `mode` | `int`: a mask of the measurements to perform. The valid values are `https://developer.android.com/reference/android/media/audiofx/Visualizer#MEASUREMENT_MODE_NONE` (to cancel any measurement) or `https://developer.android.com/reference/android/media/audiofx/Visualizer#MEASUREMENT_MODE_PEAK_RMS`.
| | Returns || |---|---| | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#SUCCESS` in case of success, `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_BAD_VALUE` in case of failure.
| | Throws || |---|---| | | java.lang.IllegalStateException | | `https://developer.android.com/reference/java/lang/IllegalStateException` | | ### setScalingMode Added in [API level 16](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` public int setScalingMode (int mode) ``` Set the type of scaling applied on the captured visualization data.
| Parameters || |---|---| | `mode` | `int`: see `https://developer.android.com/reference/android/media/audiofx/Visualizer#SCALING_MODE_NORMALIZED` and `https://developer.android.com/reference/android/media/audiofx/Visualizer#SCALING_MODE_AS_PLAYED`
| | Returns || |---|---| | `int` | `https://developer.android.com/reference/android/media/audiofx/Visualizer#SUCCESS` in case of success, `https://developer.android.com/reference/android/media/audiofx/Visualizer#ERROR_BAD_VALUE` in case of failure.
| | Throws || |---|---| | | java.lang.IllegalStateException | | `https://developer.android.com/reference/java/lang/IllegalStateException` | | ## Protected methods ### finalize Added in [API level 9](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) ``` protected void finalize () ``` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. A subclass overrides the `finalize` method to dispose of system resources or to perform other cleanup. The general contract of `finalize` is that it is invoked if and when the Java virtual machine has determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, except as a result of an action taken by the finalization of some other object or class which is ready to be finalized. The `finalize` method may take any action, including making this object available again to other threads; the usual purpose of `finalize`, however, is to perform cleanup actions before the object is irrevocably discarded. For example, the finalize method for an object that represents an input/output connection might perform explicit I/O transactions to break the connection before the object is permanently discarded. The `finalize` method of class `Object` performs no special action; it simply returns normally. Subclasses of `Object` may override this definition. The Java programming language does not guarantee which thread will invoke the `finalize` method for any given object. It is guaranteed, however, that the thread that invokes finalize will not be holding any user-visible synchronization locks when finalize is invoked. If an uncaught exception is thrown by the finalize method, the exception is ignored and finalization of that object terminates. After the `finalize` method has been invoked for an object, no further action is taken until the Java virtual machine has again determined that there is no longer any means by which this object can be accessed by any thread that has not yet died, including possible actions by other objects or classes which are ready to be finalized, at which point the object may be discarded. The `finalize` method is never invoked more than once by a Java virtual machine for any given object. Any exception thrown by the `finalize` method causes the finalization of this object to be halted, but is otherwise ignored.