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## jAudioFeatureExtractor.jAudioTools
クラス DSPMethods

    java.lang.Object
      jAudioFeatureExtractor.jAudioTools.DSPMethods

    public class DSPMethods

extends java.lang.Object

A holder class for general static methods relating to processing signals in the form of samples stored as arrays of doubles.

作成者:
  Cory McKay

コンストラクタの概要
`DSPMethods()`

メソッドの概要
`static double[][]` | `applyGain(double[][] samples, double gain)` Applies a gain to the given samples.
`static double` | `convertSampleToTime(int sample, float sampling_rate)` Returns the time corresponding to the given sample indice with the given sampling rate.
`static int` | `convertTimeToSample(double time, float sampling_rate)` Returns the sample corresponding to the given time with the given sampling rate.
`static double[]` | `getAutoCorrelation(double[] signal, int min_lag, int max_lag)` Calculates the auto-correlation of the given signal.
`static double[]` | `getAutoCorrelationLabels(double sampling_rate, int min_lag, int max_lag)` Returns the bin labels for each bin of an auto-correlation calculation that involved the given paremeters (most likely using the getAutoCorrelation method).
`static double[][]` | `getCopyOfSamples(double[][] original_samples)` Returns a copy of the given array of samples.
`static double[]` | `getSamplesMixedDownIntoOneChannel(double[][] audio_samples)` Returns the given set of samples as a set of samples mixed down into one channel.
`static double[]` | `normalizeSamples(double[] samples_to_normalize)` Normalizes the given samples so that the absolute value of the highest sample amplitude is 1.
`static double[][]` | `normalizeSamples(double[][] samples_to_normalize)` Normalizes the given samples dependantly so that the absolute value of the highest sample amplitude is 1.

クラス java.lang.Object から継承されたメソッド
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

コンストラクタの詳細

### DSPMethods

    public DSPMethods()

メソッドの詳細

### applyGain

    public static double[][] applyGain(double[][] samples,
                                       double gain)

  Applies a gain to the given samples. Note that a negative gain effectively applies a phase shift of pi. There is no guarantee that the returned samples will be between -1 and +1. The returned samples are copies, so changes to them will not affect the original samples.

  パラメータ:
    `samples` - Audio samles to modify, usually with a minimum value of -1 and a maximum value of +1. The first indice corresponds to the channel and the second indice corresponds to the sample number.
    `gain` - The gain to apply.
  戻り値:
    The given audio samples after the application of the given gain.

### getSamplesMixedDownIntoOneChannel

    public static double[] getSamplesMixedDownIntoOneChannel(double[][] audio_samples)

  Returns the given set of samples as a set of samples mixed down into one channel.

  パラメータ:
    `audio_samples` - Audio samles to modify, with a minimum value of -1 and a maximum value of +1. The first indice corresponds to the channel and the second indice corresponds to the sample number.
  戻り値:
    The given audio samples mixed down, with equal gain, into one channel.

### normalizeSamples

    public static double[] normalizeSamples(double[] samples_to_normalize)

  Normalizes the given samples so that the absolute value of the highest sample amplitude is 1. Does nothing if also samples are 0.

  パラメータ:
    `samples_to_normalize` - The samples to normalize.
  戻り値:
    Returns a copy of the given samples after normalization.

### normalizeSamples

    public static double[][] normalizeSamples(double[][] samples_to_normalize)

  Normalizes the given samples dependantly so that the absolute value of the highest sample amplitude is 1. Does nothing if all samples are 0.

  パラメータ:
    `samples_to_normalize` - The samples to normalize. The first indice denotes channel and the second denotes sample number.
  戻り値:
    Returns a copy of the given samples after normalization.

### getCopyOfSamples

    public static double[][] getCopyOfSamples(double[][] original_samples)

  Returns a copy of the given array of samples.

  パラメータ:
    `original_samples` - Audio samles to modify, usually with a minimum value of value of- 1 and a maximum value of +1. The first indice corresponds to the channel and the second indice corresponds to the sample number.
  戻り値:
    A copy of the original_samples parameter.

### convertTimeToSample

    public static int convertTimeToSample(double time,
                                          float sampling_rate)

  Returns the sample corresponding to the given time with the given sampling rate.

  パラメータ:
    `time` - The time in seconds to convert to a sample indice.
    `sampling_rate` - The sampling rate of the audio in question.
  戻り値:
    The corresponding sample indice.

### convertSampleToTime

    public static double convertSampleToTime(int sample,
                                             float sampling_rate)

  Returns the time corresponding to the given sample indice with the given sampling rate.

  パラメータ:
    `sample` - The sample indice to convert to time.
    `sampling_rate` - The sampling rate of the audio in question.
  戻り値:
    The corresponding time in seconds.

### getAutoCorrelation

    public static double[] getAutoCorrelation(double[] signal,
                                              int min_lag,
                                              int max_lag)

  Calculates the auto-correlation of the given signal. The auto-correlation is only calculated between the given lags.

  The getAutoCorrelationLabels method can be called to find the labels in Hz for each of the returned bins.

  パラメータ:
    `signal` - The digital signal to auto-correlate.
    `min_lag` - The minimum lag in samples to look for in the auto-correlation.
    `max_lag` - The maximum lag in samples to look for in the auto-correaltion.
  戻り値:
    The auto-correlation for each lag from min_lag to max_lag. Entry 0 corresponds to min_lag, and the last entry corresponds to max_lag.

### getAutoCorrelationLabels

    public static double[] getAutoCorrelationLabels(double sampling_rate,
                                                    int min_lag,
                                                    int max_lag)

  Returns the bin labels for each bin of an auto-correlation calculation that involved the given paremeters (most likely using the getAutoCorrelation method).

  パラメータ:
    `sampling_rate` - The sampling rate that was used to encode the signal that was auto-correlated.
    `min_lag` - The minimum lag in samples that was used in the auto-correlation.
    `max_lag` - The maximum lag in samples that was used in the auto-correlation.
  戻り値:
    The labels, in Hz, for the corresponding bins produced by the getAutoCorrelation method.

概要 | パッケージ | クラス | 階層ツリー | 非推奨 API | 索引 | ヘルプ
前のクラス 次のクラス | フレームあり フレームなし
概要: 入れ子 | フィールド | コンストラクタ | メソッド | 詳細: フィールド | コンストラクタ | メソッド