java 使用 jtransforms 傅里叶变换库实现删除 wav 歌曲中的人声、提取歌曲旋律功能

引入 maven 依赖：

    net.sourceforge.jtransforms
    jtransforms
    2.4.0

原理：

1. 将音频信号进行分帧处理，将每一帧的数据进行傅里叶变换，得到短时傅里叶变换（STFT）。
2. 对于每一帧的频谱，可以通过观察频谱图的特征来确定人声和旋律所在的频率范围。
3. 根据人声和旋律所在的频率范围，可以将频谱图中对应的频率区域置零，以实现人声的去除。
4. 对处理后的频谱进行逆傅里叶变换，得到去除人声的音频信号。
5. 可以进一步对去除人声的音频信号进行处理，如滤波、增强等，以提取出旋律。

java 代码实现：todo

可能用到的工具类 AudioUtils.java：

import javax.sound.sampled.*;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.util.Arrays;


public class AudioUtils {
    public static void main(String[] args) throws UnsupportedAudioFileException, IOException {
        File file = new File("C:\\E\\素材\\音频\\wav\\一生所爱.wav");
        double[] doubleArray = wavToDoubleArray(file);
        System.out.println( doubleArray.length );

        int partLength = doubleArray.length / 10;


        doubleArrayToWAV(  Arrays.copyOfRange(doubleArray, 0, partLength),new File( "C:\\E\\素材\\音频\\wav\\一生所爱_part1.wav" ) );
        doubleArrayToWAV(  Arrays.copyOfRange(doubleArray, partLength, partLength * 2),new File( "C:\\E\\素材\\音频\\wav\\一生所爱_part2.wav" ) );
        doubleArrayToWAV(  Arrays.copyOfRange(doubleArray, partLength * 2, partLength * 3),new File( "C:\\E\\素材\\音频\\wav\\一生所爱_part3.wav" ) );
        doubleArrayToWAV(  Arrays.copyOfRange(doubleArray, partLength * 3, partLength * 4),new File( "C:\\E\\素材\\音频\\wav\\一生所爱_part4.wav" ) );
        doubleArrayToWAV(  Arrays.copyOfRange(doubleArray, partLength * 4, partLength * 5),new File( "C:\\E\\素材\\音频\\wav\\一生所爱_part5.wav" ) );
        doubleArrayToWAV(  Arrays.copyOfRange(doubleArray, partLength * 5, partLength * 6),new File( "C:\\E\\素材\\音频\\wav\\一生所爱_part6.wav" ) );
    }

    public static double[] wavToDoubleArray(File mp3File) throws UnsupportedAudioFileException, IOException {
        AudioInputStream audioInputStream = AudioSystem.getAudioInputStream(mp3File);
        AudioFormat audioFormat = audioInputStream.getFormat();
        int numChannels = audioFormat.getChannels();
        int sampleSizeInBytes = audioFormat.getSampleSizeInBits() / 8;
        int frameSize = numChannels * sampleSizeInBytes;
        int bufferSize = (int) (audioInputStream.getFrameLength() * frameSize);
        byte[] audioBytes = new byte[bufferSize];
        audioInputStream.read(audioBytes);

        double[] audioData = new double[audioBytes.length / 2];
        for (int i = 0, j = 0; i < audioBytes.length; i += 2, j++) {
            int sample = (audioBytes[i + 1] << 8) | (audioBytes[i] & 0xFF);
            audioData[j] = sample / 32768.0;
        }

        return audioData;
    }

    public static void doubleArrayToWAV(double[] audioData, File outputFile) throws IOException, UnsupportedAudioFileException {
        AudioFormat audioFormat = new AudioFormat(44100, 16, 2, true, false);
        byte[] audioBytes = new byte[audioData.length * 2];
        for (int i = 0, j = 0; i < audioData.length; i++, j += 2) {
            short sample = (short) (audioData[i] * 32767);
            audioBytes[j] = (byte) (sample & 0xFF);
            audioBytes[j + 1] = (byte) ((sample >> 8) & 0xFF);
        }

        AudioInputStream audioInputStream = new AudioInputStream(new ByteArrayInputStream(audioBytes), audioFormat, audioData.length);
        AudioSystem.write(audioInputStream, AudioFileFormat.Type.WAVE, outputFile);
    }
}