https://openjdk.java.net/ 
/*
 * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package javax.sound.sampled;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;


AudioFormat is the class that specifies a particular arrangement of data in a sound stream. By examining the information stored in the audio format, you can discover how to interpret the bits in the binary sound data. 

Every data line has an audio format associated with its data stream. The
audio format of a source (playback) data line indicates what kind of data the
data line expects to receive for output. For a target (capture) data line,
the audio format specifies the kind of the data that can be read from the
line.

 Sound files also have audio formats, of course. The AudioFileFormat class encapsulates an AudioFormat in addition to other, file-specific information. Similarly, an AudioInputStream has an AudioFormat. 
 The AudioFormat class accommodates a number of common sound-file encoding techniques, including pulse-code modulation (PCM), mu-law encoding, and a-law encoding. These encoding techniques are predefined, but service providers can create new encoding types. The encoding that a specific format uses is named by its encoding field. 

In addition to the encoding, the audio format includes other properties that
further specify the exact arrangement of the data. These include the number
of channels, sample rate, sample size, byte order, frame rate, and frame
size. Sounds may have different numbers of audio channels: one for mono, two
for stereo. The sample rate measures how many "snapshots" (samples) of the
sound pressure are taken per second, per channel. (If the sound is stereo
rather than mono, two samples are actually measured at each instant of time:
one for the left channel, and another for the right channel; however, the
sample rate still measures the number per channel, so the rate is the same
regardless of the number of channels. This is the standard use of the term.)
The sample size indicates how many bits are used to store each snapshot; 8
and 16 are typical values. For 16-bit samples (or any other sample size
larger than a byte), byte order is important; the bytes in each sample are
arranged in either the "little-endian" or "big-endian" style. For encodings
like PCM, a frame consists of the set of samples for all channels at a given
point in time, and so the size of a frame (in bytes) is always equal to the
size of a sample (in bytes) times the number of channels. However, with some
other sorts of encodings a frame can contain a bundle of compressed data for
a whole series of samples, as well as additional, non-sample data. For such
encodings, the sample rate and sample size refer to the data after it is
decoded into PCM, and so they are completely different from the frame rate
and frame size.

 An AudioFormat object can include a set of properties. A property is a pair of key and value: the key is of type String, the associated property value is an arbitrary object. Properties specify additional format specifications, like the bit rate for compressed formats. Properties are mainly used as a means to transport additional information of the audio format to and from the service providers. Therefore, properties are ignored in the matches(AudioFormat) method. However, methods which rely on the installed service providers, like 
isConversionSupported may consider properties, depending on the respective service provider implementation. 

The following table lists some common properties which service providers
should use, if applicable:


Audio Format Properties

  

    Property key
    Value type
    Description



  

    "bitrate"
    Integer average bit rate in bits per second
  

    "vbr"
    Boolean true, if the file is encoded in variable bit rate (VBR) 

    "quality"
    Integer encoding/conversion quality, 1..100






Vendors of service providers (plugins) are encouraged to seek information
about other already established properties in third party plugins, and follow
the same conventions.

Author:Kara Kytle, Florian Bomers
See Also:
Since:1.3
/**
 * {@code AudioFormat} is the class that specifies a particular arrangement of
 * data in a sound stream. By examining the information stored in the audio
 * format, you can discover how to interpret the bits in the binary sound data.
 * <p>
 * Every data line has an audio format associated with its data stream. The
 * audio format of a source (playback) data line indicates what kind of data the
 * data line expects to receive for output. For a target (capture) data line,
 * the audio format specifies the kind of the data that can be read from the
 * line.
 * <p>
 * Sound files also have audio formats, of course. The {@link AudioFileFormat}
 * class encapsulates an {@code AudioFormat} in addition to other, file-specific
 * information. Similarly, an {@link AudioInputStream} has an
 * {@code AudioFormat}.
 * <p>
 * The {@code AudioFormat} class accommodates a number of common sound-file
 * encoding techniques, including pulse-code modulation (PCM), mu-law encoding,
 * and a-law encoding. These encoding techniques are predefined, but service
 * providers can create new encoding types. The encoding that a specific format
 * uses is named by its {@code encoding} field.
 * <p>
 * In addition to the encoding, the audio format includes other properties that
 * further specify the exact arrangement of the data. These include the number
 * of channels, sample rate, sample size, byte order, frame rate, and frame
 * size. Sounds may have different numbers of audio channels: one for mono, two
 * for stereo. The sample rate measures how many "snapshots" (samples) of the
 * sound pressure are taken per second, per channel. (If the sound is stereo
 * rather than mono, two samples are actually measured at each instant of time:
 * one for the left channel, and another for the right channel; however, the
 * sample rate still measures the number per channel, so the rate is the same
 * regardless of the number of channels. This is the standard use of the term.)
 * The sample size indicates how many bits are used to store each snapshot; 8
 * and 16 are typical values. For 16-bit samples (or any other sample size
 * larger than a byte), byte order is important; the bytes in each sample are
 * arranged in either the "little-endian" or "big-endian" style. For encodings
 * like PCM, a frame consists of the set of samples for all channels at a given
 * point in time, and so the size of a frame (in bytes) is always equal to the
 * size of a sample (in bytes) times the number of channels. However, with some
 * other sorts of encodings a frame can contain a bundle of compressed data for
 * a whole series of samples, as well as additional, non-sample data. For such
 * encodings, the sample rate and sample size refer to the data after it is
 * decoded into PCM, and so they are completely different from the frame rate
 * and frame size.
 * <p>
 * An {@code AudioFormat} object can include a set of properties. A property is
 * a pair of key and value: the key is of type {@code String}, the associated
 * property value is an arbitrary object. Properties specify additional format
 * specifications, like the bit rate for compressed formats. Properties are
 * mainly used as a means to transport additional information of the audio
 * format to and from the service providers. Therefore, properties are ignored
 * in the {@link #matches(AudioFormat)} method. However, methods which rely on
 * the installed service providers, like
 * {@link AudioSystem#isConversionSupported (AudioFormat, AudioFormat)
 * isConversionSupported} may consider properties, depending on the respective
 * service provider implementation.
 * <p>
 * The following table lists some common properties which service providers
 * should use, if applicable:
 *
 * <table class="striped">
 * <caption>Audio Format Properties</caption>
 * <thead>
 *   <tr>
 *     <th scope="col">Property key
 *     <th scope="col">Value type
 *     <th scope="col">Description
 * </thead>
 * <tbody>
 *   <tr>
 *     <th scope="row">"bitrate"
 *     <td>{@link java.lang.Integer Integer}
 *     <td>average bit rate in bits per second
 *   <tr>
 *     <th scope="row">"vbr"
 *     <td>{@link java.lang.Boolean Boolean}
 *     <td>{@code true}, if the file is encoded in variable bit rate (VBR)
 *   <tr>
 *     <th scope="row">"quality"
 *     <td>{@link java.lang.Integer Integer}
 *     <td>encoding/conversion quality, 1..100
 * </tbody>
 * </table>
 * <p>
 * Vendors of service providers (plugins) are encouraged to seek information
 * about other already established properties in third party plugins, and follow
 * the same conventions.
 *
 * @author Kara Kytle
 * @author Florian Bomers
 * @see DataLine#getFormat
 * @see AudioInputStream#getFormat
 * @see AudioFileFormat
 * @see javax.sound.sampled.spi.FormatConversionProvider
 * @since 1.3
 */
public class AudioFormat {

    
The audio encoding technique used by this format.

/**
     * The audio encoding technique used by this format.
     */
    protected Encoding encoding;

    
The number of samples played or recorded per second, for sounds that have
this format.

/**
     * The number of samples played or recorded per second, for sounds that have
     * this format.
     */
    protected float sampleRate;

    
The number of bits in each sample of a sound that has this format.

/**
     * The number of bits in each sample of a sound that has this format.
     */
    protected int sampleSizeInBits;

    
The number of audio channels in this format (1 for mono, 2 for stereo).

/**
     * The number of audio channels in this format (1 for mono, 2 for stereo).
     */
    protected int channels;

    
The number of bytes in each frame of a sound that has this format.

/**
     * The number of bytes in each frame of a sound that has this format.
     */
    protected int frameSize;

    
The number of frames played or recorded per second, for sounds that have
this format.

/**
     * The number of frames played or recorded per second, for sounds that have
     * this format.
     */
    protected float frameRate;

    
Indicates whether the audio data is stored in big-endian or little-endian
order.

/**
     * Indicates whether the audio data is stored in big-endian or little-endian
     * order.
     */
    protected boolean bigEndian;

    
The set of properties.

/**
     * The set of properties.
     */
    private HashMap<String, Object> properties;

    
Constructs an AudioFormat with the given parameters. The encoding specifies the convention used to represent the data. The other parameters are further explained in the class description. 
Params:
  • encoding – the audio encoding technique
  • sampleRate – the number of samples per second
  • sampleSizeInBits – the number of bits in each sample
  • channels – the number of channels (1 for mono, 2 for stereo, and so
        on)
  • frameSize – the number of bytes in each frame
  • frameRate – the number of frames per second
  • bigEndian – indicates whether the data for a single sample is stored in big-endian byte order (false means little-endian)
/**
     * Constructs an {@code AudioFormat} with the given parameters. The encoding
     * specifies the convention used to represent the data. The other parameters
     * are further explained in the {@link AudioFormat class description}.
     *
     * @param  encoding the audio encoding technique
     * @param  sampleRate the number of samples per second
     * @param  sampleSizeInBits the number of bits in each sample
     * @param  channels the number of channels (1 for mono, 2 for stereo, and so
     *         on)
     * @param  frameSize the number of bytes in each frame
     * @param  frameRate the number of frames per second
     * @param  bigEndian indicates whether the data for a single sample is
     *         stored in big-endian byte order ({@code false} means
     *         little-endian)
     */
    public AudioFormat(Encoding encoding, float sampleRate, int sampleSizeInBits,
                       int channels, int frameSize, float frameRate, boolean bigEndian) {

        this.encoding = encoding;
        this.sampleRate = sampleRate;
        this.sampleSizeInBits = sampleSizeInBits;
        this.channels = channels;
        this.frameSize = frameSize;
        this.frameRate = frameRate;
        this.bigEndian = bigEndian;
        this.properties = null;
    }

    
Constructs an AudioFormat with the given parameters. The encoding specifies the convention used to represent the data. The other parameters are further explained in the class description. 
Params:
  • encoding – the audio encoding technique
  • sampleRate – the number of samples per second
  • sampleSizeInBits – the number of bits in each sample
  • channels – the number of channels (1 for mono, 2 for stereo, and so
        on)
  • frameSize – the number of bytes in each frame
  • frameRate – the number of frames per second
  • bigEndian – indicates whether the data for a single sample is stored in big-endian byte order (false means little-endian)
  • properties – a Map<String, Object> object containing format properties
Since:1.5
/**
     * Constructs an {@code AudioFormat} with the given parameters. The encoding
     * specifies the convention used to represent the data. The other parameters
     * are further explained in the {@link AudioFormat class description}.
     *
     * @param  encoding the audio encoding technique
     * @param  sampleRate the number of samples per second
     * @param  sampleSizeInBits the number of bits in each sample
     * @param  channels the number of channels (1 for mono, 2 for stereo, and so
     *         on)
     * @param  frameSize the number of bytes in each frame
     * @param  frameRate the number of frames per second
     * @param  bigEndian indicates whether the data for a single sample is
     *         stored in big-endian byte order ({@code false} means
     *         little-endian)
     * @param  properties a {@code Map<String, Object>} object containing format
     *         properties
     * @since 1.5
     */
    public AudioFormat(Encoding encoding, float sampleRate,
                       int sampleSizeInBits, int channels,
                       int frameSize, float frameRate,
                       boolean bigEndian, Map<String, Object> properties) {
        this(encoding, sampleRate, sampleSizeInBits, channels,
             frameSize, frameRate, bigEndian);
        this.properties = new HashMap<>(properties);
    }

    
Constructs an AudioFormat with a linear PCM encoding and the given parameters. The frame size is set to the number of bytes required to contain one sample from each channel, and the frame rate is set to the sample rate. 
Params:
  • sampleRate – the number of samples per second
  • sampleSizeInBits – the number of bits in each sample
  • channels – the number of channels (1 for mono, 2 for stereo, and so
        on)
  • signed – indicates whether the data is signed or unsigned
  • bigEndian – indicates whether the data for a single sample is stored in big-endian byte order (false means little-endian)
/**
     * Constructs an {@code AudioFormat} with a linear PCM encoding and the
     * given parameters. The frame size is set to the number of bytes required
     * to contain one sample from each channel, and the frame rate is set to the
     * sample rate.
     *
     * @param  sampleRate the number of samples per second
     * @param  sampleSizeInBits the number of bits in each sample
     * @param  channels the number of channels (1 for mono, 2 for stereo, and so
     *         on)
     * @param  signed indicates whether the data is signed or unsigned
     * @param  bigEndian indicates whether the data for a single sample is
     *         stored in big-endian byte order ({@code false} means
     *         little-endian)
     */
    public AudioFormat(float sampleRate, int sampleSizeInBits,
                       int channels, boolean signed, boolean bigEndian) {

        this((signed == true ? Encoding.PCM_SIGNED : Encoding.PCM_UNSIGNED),
             sampleRate,
             sampleSizeInBits,
             channels,
             (channels == AudioSystem.NOT_SPECIFIED || sampleSizeInBits == AudioSystem.NOT_SPECIFIED)?
             AudioSystem.NOT_SPECIFIED:
             ((sampleSizeInBits + 7) / 8) * channels,
             sampleRate,
             bigEndian);
    }

    
Obtains the type of encoding for sounds in this format.

See Also:
Returns:the encoding type
/**
     * Obtains the type of encoding for sounds in this format.
     *
     * @return the encoding type
     * @see Encoding#PCM_SIGNED
     * @see Encoding#PCM_UNSIGNED
     * @see Encoding#ULAW
     * @see Encoding#ALAW
     */
    public Encoding getEncoding() {
        return encoding;
    }

    
Obtains the sample rate. For compressed formats, the return value is the sample rate of the uncompressed audio data. When this AudioFormat is used for queries (e.g. 
AudioSystem.isConversionSupported) or capabilities (e.g. DataLine.Info.getFormats), a sample rate of AudioSystem.NOT_SPECIFIED means that any sample rate is acceptable. AudioSystem.NOT_SPECIFIED is also returned when the sample rate is not defined for this audio format. 
See Also:
Returns:the number of samples per second, or AudioSystem.NOT_SPECIFIED
/**
     * Obtains the sample rate. For compressed formats, the return value is the
     * sample rate of the uncompressed audio data. When this {@code AudioFormat}
     * is used for queries (e.g.
     * {@link AudioSystem#isConversionSupported(AudioFormat, AudioFormat)
     * AudioSystem.isConversionSupported}) or capabilities (e.g.
     * {@link DataLine.Info#getFormats DataLine.Info.getFormats}), a sample rate
     * of {@code AudioSystem.NOT_SPECIFIED} means that any sample rate is
     * acceptable. {@code AudioSystem.NOT_SPECIFIED} is also returned when the
     * sample rate is not defined for this audio format.
     *
     * @return the number of samples per second, or
     *         {@code AudioSystem.NOT_SPECIFIED}
     * @see #getFrameRate()
     * @see AudioSystem#NOT_SPECIFIED
     */
    public float getSampleRate() {
        return sampleRate;
    }

    
Obtains the size of a sample. For compressed formats, the return value is the sample size of the uncompressed audio data. When this AudioFormat is used for queries (e.g. 
AudioSystem.isConversionSupported) or capabilities (e.g. DataLine.Info.getFormats), a sample size of AudioSystem.NOT_SPECIFIED means that any sample size is acceptable. AudioSystem.NOT_SPECIFIED is also returned when the sample size is not defined for this audio format. 
See Also:
Returns:the number of bits in each sample, or AudioSystem.NOT_SPECIFIED
/**
     * Obtains the size of a sample. For compressed formats, the return value is
     * the sample size of the uncompressed audio data. When this
     * {@code AudioFormat} is used for queries (e.g.
     * {@link AudioSystem#isConversionSupported(AudioFormat,AudioFormat)
     * AudioSystem.isConversionSupported}) or capabilities (e.g.
     * {@link DataLine.Info#getFormats DataLine.Info.getFormats}), a sample size
     * of {@code AudioSystem.NOT_SPECIFIED} means that any sample size is
     * acceptable. {@code AudioSystem.NOT_SPECIFIED} is also returned when the
     * sample size is not defined for this audio format.
     *
     * @return the number of bits in each sample, or
     *         {@code AudioSystem.NOT_SPECIFIED}
     * @see #getFrameSize()
     * @see AudioSystem#NOT_SPECIFIED
     */
    public int getSampleSizeInBits() {
        return sampleSizeInBits;
    }

    
Obtains the number of channels. When this AudioFormat is used for queries (e.g. AudioSystem.isConversionSupported) or capabilities (e.g. DataLine.Info.getFormats), a return value of AudioSystem.NOT_SPECIFIED means that any (positive) number of channels is acceptable. 
See Also:
Returns:The number of channels (1 for mono, 2 for stereo, etc.), or AudioSystem.NOT_SPECIFIED
/**
     * Obtains the number of channels. When this {@code AudioFormat} is used for
     * queries (e.g. {@link AudioSystem#isConversionSupported(AudioFormat,
     * AudioFormat) AudioSystem.isConversionSupported}) or capabilities (e.g.
     * {@link DataLine.Info#getFormats DataLine.Info.getFormats}), a return
     * value of {@code AudioSystem.NOT_SPECIFIED} means that any (positive)
     * number of channels is acceptable.
     *
     * @return The number of channels (1 for mono, 2 for stereo, etc.), or
     *         {@code AudioSystem.NOT_SPECIFIED}
     * @see AudioSystem#NOT_SPECIFIED
     */
    public int getChannels() {
        return channels;
    }

    
Obtains the frame size in bytes. When this AudioFormat is used for queries (e.g. AudioSystem.isConversionSupported) or capabilities (e.g. DataLine.Info.getFormats), a frame size of AudioSystem.NOT_SPECIFIED means that any frame size is acceptable. AudioSystem.NOT_SPECIFIED is also returned when the frame size is not defined for this audio format. 
See Also:
Returns:the number of bytes per frame, or AudioSystem.NOT_SPECIFIED
/**
     * Obtains the frame size in bytes. When this {@code AudioFormat} is used
     * for queries (e.g. {@link AudioSystem#isConversionSupported(AudioFormat,
     * AudioFormat) AudioSystem.isConversionSupported}) or capabilities (e.g.
     * {@link DataLine.Info#getFormats DataLine.Info.getFormats}), a frame size
     * of {@code AudioSystem.NOT_SPECIFIED} means that any frame size is
     * acceptable. {@code AudioSystem.NOT_SPECIFIED} is also returned when the
     * frame size is not defined for this audio format.
     *
     * @return the number of bytes per frame, or
     *         {@code AudioSystem.NOT_SPECIFIED}
     * @see #getSampleSizeInBits()
     * @see AudioSystem#NOT_SPECIFIED
     */
    public int getFrameSize() {
        return frameSize;
    }

    
Obtains the frame rate in frames per second. When this AudioFormat is used for queries (e.g. 
AudioSystem.isConversionSupported) or capabilities (e.g. DataLine.Info.getFormats), a frame rate of AudioSystem.NOT_SPECIFIED means that any frame rate is acceptable. AudioSystem.NOT_SPECIFIED is also returned when the frame rate is not defined for this audio format. 
See Also:
Returns:the number of frames per second, or AudioSystem.NOT_SPECIFIED
/**
     * Obtains the frame rate in frames per second. When this
     * {@code AudioFormat} is used for queries (e.g.
     * {@link AudioSystem#isConversionSupported(AudioFormat,AudioFormat)
     * AudioSystem.isConversionSupported}) or capabilities (e.g.
     * {@link DataLine.Info#getFormats DataLine.Info.getFormats}), a frame rate
     * of {@code AudioSystem.NOT_SPECIFIED} means that any frame rate is
     * acceptable. {@code AudioSystem.NOT_SPECIFIED} is also returned when the
     * frame rate is not defined for this audio format.
     *
     * @return the number of frames per second, or
     *         {@code AudioSystem.NOT_SPECIFIED}
     * @see #getSampleRate()
     * @see AudioSystem#NOT_SPECIFIED
     */
    public float getFrameRate() {
        return frameRate;
    }

    
Indicates whether the audio data is stored in big-endian or little-endian
byte order. If the sample size is not more than one byte, the return
value is irrelevant.

Returns:true if the data is stored in big-endian byte order, false if little-endian
/**
     * Indicates whether the audio data is stored in big-endian or little-endian
     * byte order. If the sample size is not more than one byte, the return
     * value is irrelevant.
     *
     * @return {@code true} if the data is stored in big-endian byte order,
     *         {@code false} if little-endian
     */
    public boolean isBigEndian() {
        return bigEndian;
    }

    
Obtain an unmodifiable map of properties. The concept of properties is further explained in the class description. 
See Also:
Returns:a Map<String, Object> object containing all properties. If no properties are recognized, an empty map is returned.
Since:1.5
/**
     * Obtain an unmodifiable map of properties. The concept of properties is
     * further explained in the {@link AudioFileFormat class description}.
     *
     * @return a {@code Map<String, Object>} object containing all properties.
     *         If no properties are recognized, an empty map is returned.
     * @see #getProperty(String)
     * @since 1.5
     */
    @SuppressWarnings("unchecked") // Cast of result of clone.
    public Map<String,Object> properties() {
        Map<String,Object> ret;
        if (properties == null) {
            ret = new HashMap<>(0);
        } else {
            ret = (Map<String,Object>) (properties.clone());
        }
        return Collections.unmodifiableMap(ret);
    }

    
Obtain the property value specified by the key. The concept of properties is further explained in the class description. 
 If the specified property is not defined for a particular file format, this method returns null. 
Params:
  • key – the key of the desired property
See Also:
Returns:the value of the property with the specified key, or null if the property does not exist
Since:1.5
/**
     * Obtain the property value specified by the key. The concept of properties
     * is further explained in the {@link AudioFileFormat class description}.
     * <p>
     * If the specified property is not defined for a particular file format,
     * this method returns {@code null}.
     *
     * @param  key the key of the desired property
     * @return the value of the property with the specified key, or {@code null}
     *         if the property does not exist
     * @see #properties()
     * @since 1.5
     */
    public Object getProperty(String key) {
        if (properties == null) {
            return null;
        }
        return properties.get(key);
    }

    
Indicates whether this format matches the one specified. To match, two formats must have the same encoding, and consistent values of the number of channels, sample rate, sample size, frame rate, and frame size. The values of the property are consistent if they are equal or the specified format has the property value AudioSystem.NOT_SPECIFIED. The byte order (big-endian or little-endian) must be the same if the sample size is greater than one byte. 
Params:
  • format – format to test for match
Returns:true if this format matches the one specified, false otherwise
/**
     * Indicates whether this format matches the one specified. To match, two
     * formats must have the same encoding, and consistent values of the number
     * of channels, sample rate, sample size, frame rate, and frame size. The
     * values of the property are consistent if they are equal or the specified
     * format has the property value {@code AudioSystem.NOT_SPECIFIED}. The byte
     * order (big-endian or little-endian) must be the same if the sample size
     * is greater than one byte.
     *
     * @param  format format to test for match
     * @return {@code true} if this format matches the one specified,
     *         {@code false} otherwise
     */
    public boolean matches(AudioFormat format) {
        if (format.getEncoding().equals(getEncoding())
                && (format.getChannels() == AudioSystem.NOT_SPECIFIED
                    || format.getChannels() == getChannels())
                && (format.getSampleRate() == (float)AudioSystem.NOT_SPECIFIED
                    || format.getSampleRate() == getSampleRate())
                && (format.getSampleSizeInBits() == AudioSystem.NOT_SPECIFIED
                    || format.getSampleSizeInBits() == getSampleSizeInBits())
                && (format.getFrameRate() == (float)AudioSystem.NOT_SPECIFIED
                    || format.getFrameRate() == getFrameRate())
                && (format.getFrameSize() == AudioSystem.NOT_SPECIFIED
                    || format.getFrameSize() == getFrameSize())
                && (getSampleSizeInBits() <= 8
                    || format.isBigEndian() == isBigEndian())) {
            return true;
        }
        return false;
    }

    
Returns a string that describes the format, such as: "PCM SIGNED 22050 Hz
16 bit mono big-endian". The contents of the string may vary between
implementations of Java Sound.

Returns:a string that describes the format parameters
/**
     * Returns a string that describes the format, such as: "PCM SIGNED 22050 Hz
     * 16 bit mono big-endian". The contents of the string may vary between
     * implementations of Java Sound.
     *
     * @return a string that describes the format parameters
     */
    @Override
    public String toString() {
        String sEncoding = "";
        if (getEncoding() != null) {
            sEncoding = getEncoding().toString() + " ";
        }

        String sSampleRate;
        if (getSampleRate() == (float) AudioSystem.NOT_SPECIFIED) {
            sSampleRate = "unknown sample rate, ";
        } else {
            sSampleRate = "" + getSampleRate() + " Hz, ";
        }

        String sSampleSizeInBits;
        if (getSampleSizeInBits() == (float) AudioSystem.NOT_SPECIFIED) {
            sSampleSizeInBits = "unknown bits per sample, ";
        } else {
            sSampleSizeInBits = "" + getSampleSizeInBits() + " bit, ";
        }

        String sChannels;
        if (getChannels() == 1) {
            sChannels = "mono, ";
        } else
            if (getChannels() == 2) {
                sChannels = "stereo, ";
            } else {
                if (getChannels() == AudioSystem.NOT_SPECIFIED) {
                    sChannels = " unknown number of channels, ";
                } else {
                    sChannels = ""+getChannels()+" channels, ";
                }
            }

        String sFrameSize;
        if (getFrameSize() == (float) AudioSystem.NOT_SPECIFIED) {
            sFrameSize = "unknown frame size, ";
        } else {
            sFrameSize = "" + getFrameSize()+ " bytes/frame, ";
        }

        String sFrameRate = "";
        if (Math.abs(getSampleRate() - getFrameRate()) > 0.00001) {
            if (getFrameRate() == (float) AudioSystem.NOT_SPECIFIED) {
                sFrameRate = "unknown frame rate, ";
            } else {
                sFrameRate = getFrameRate() + " frames/second, ";
            }
        }

        String sEndian = "";
        if ((getEncoding().equals(Encoding.PCM_SIGNED)
             || getEncoding().equals(Encoding.PCM_UNSIGNED))
            && ((getSampleSizeInBits() > 8)
                || (getSampleSizeInBits() == AudioSystem.NOT_SPECIFIED))) {
            if (isBigEndian()) {
                sEndian = "big-endian";
            } else {
                sEndian = "little-endian";
            }
        }

        return sEncoding
            + sSampleRate
            + sSampleSizeInBits
            + sChannels
            + sFrameSize
            + sFrameRate
            + sEndian;

    }

    
The Encoding class names the specific type of data representation used for an audio stream. The encoding includes aspects of the sound format other than the number of channels, sample rate, sample size, frame rate, frame size, and byte order. 

One ubiquitous type of audio encoding is pulse-code modulation (PCM),
which is simply a linear (proportional) representation of the sound
waveform. With PCM, the number stored in each sample is proportional to
the instantaneous amplitude of the sound pressure at that point in time.
The numbers may be signed or unsigned integers or floats. Besides PCM,
other encodings include mu-law and a-law, which are nonlinear mappings of
the sound amplitude that are often used for recording speech.

 You can use a predefined encoding by referring to one of the static objects created by this class, such as PCM_SIGNED or PCM_UNSIGNED. Service providers can create new encodings, such as compressed audio formats, and make these available through the AudioSystem class. 
 The Encoding class is static, so that all AudioFormat objects that have the same encoding will refer to the same object (rather than different instances of the same class). This allows matches to be made by checking that two format's encodings are equal. 
Author:Kara Kytle
See Also:
Since:1.3
/**
     * The {@code Encoding} class names the specific type of data representation
     * used for an audio stream. The encoding includes aspects of the sound
     * format other than the number of channels, sample rate, sample size, frame
     * rate, frame size, and byte order.
     * <p>
     * One ubiquitous type of audio encoding is pulse-code modulation (PCM),
     * which is simply a linear (proportional) representation of the sound
     * waveform. With PCM, the number stored in each sample is proportional to
     * the instantaneous amplitude of the sound pressure at that point in time.
     * The numbers may be signed or unsigned integers or floats. Besides PCM,
     * other encodings include mu-law and a-law, which are nonlinear mappings of
     * the sound amplitude that are often used for recording speech.
     * <p>
     * You can use a predefined encoding by referring to one of the static
     * objects created by this class, such as {@code PCM_SIGNED} or
     * {@code PCM_UNSIGNED}. Service providers can create new encodings, such as
     * compressed audio formats, and make these available through the
     * {@link AudioSystem} class.
     * <p>
     * The {@code Encoding} class is static, so that all {@code AudioFormat}
     * objects that have the same encoding will refer to the same object (rather
     * than different instances of the same class). This allows matches to be
     * made by checking that two format's encodings are equal.
     *
     * @author Kara Kytle
     * @see AudioFormat
     * @see javax.sound.sampled.spi.FormatConversionProvider
     * @since 1.3
     */
    public static class Encoding {

        
Specifies signed, linear PCM data.

/**
         * Specifies signed, linear PCM data.
         */
        public static final Encoding PCM_SIGNED = new Encoding("PCM_SIGNED");

        
Specifies unsigned, linear PCM data.

/**
         * Specifies unsigned, linear PCM data.
         */
        public static final Encoding PCM_UNSIGNED = new Encoding("PCM_UNSIGNED");

        
Specifies floating-point PCM data.

Since:1.7
/**
         * Specifies floating-point PCM data.
         *
         * @since 1.7
         */
        public static final Encoding PCM_FLOAT = new Encoding("PCM_FLOAT");

        
Specifies u-law encoded data.

/**
         * Specifies u-law encoded data.
         */
        public static final Encoding ULAW = new Encoding("ULAW");

        
Specifies a-law encoded data.

/**
         * Specifies a-law encoded data.
         */
        public static final Encoding ALAW = new Encoding("ALAW");

        
Encoding name.

/**
         * Encoding name.
         */
        private final String name;

        
Constructs a new encoding.

Params:
  • name – the name of the new type of encoding
/**
         * Constructs a new encoding.
         *
         * @param  name the name of the new type of encoding
         */
        public Encoding(final String name) {
            this.name = name;
        }

        
Indicates whether the specified object is equal to this encoding, returning true if the objects are equal. 
Params:
  • obj – the reference object with which to compare
Returns:true if the specified object is equal to this encoding; false otherwise
/**
         * Indicates whether the specified object is equal to this encoding,
         * returning {@code true} if the objects are equal.
         *
         * @param  obj the reference object with which to compare
         * @return {@code true} if the specified object is equal to this
         *         encoding; {@code false} otherwise
         */
        @Override
        public final boolean equals(final Object obj) {
            if (this == obj) {
                return true;
            }
            if (!(obj instanceof Encoding)) {
                return false;
            }
            return Objects.equals(name, ((Encoding) obj).name);
        }

        
Returns a hash code value for this encoding.

Returns:a hash code value for this encoding
/**
         * Returns a hash code value for this encoding.
         *
         * @return a hash code value for this encoding
         */
        @Override
        public final int hashCode() {
            return name != null ? name.hashCode() : 0;
        }

        
Provides the String representation of the encoding. This String is the same name that was passed to the constructor. For the predefined encodings, the name is similar to the encoding's variable (field) name. For example, PCM_SIGNED.toString() returns the name "PCM_SIGNED". 
Returns:the encoding name
/**
         * Provides the {@code String} representation of the encoding. This
         * {@code String} is the same name that was passed to the constructor.
         * For the predefined encodings, the name is similar to the encoding's
         * variable (field) name. For example, {@code PCM_SIGNED.toString()}
         * returns the name "PCM_SIGNED".
         *
         * @return the encoding name
         */
        @Override
        public final String toString() {
            return name;
        }
    }
}