【android】Java实现PCM格式音频转MP3或WAV

最近做语音合成的项目，需要把PCM格式的音频文件转换成MP3或WAV，记录一下。

Java实现的PCM格式音频文件转换MP3格式

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
 
/**
 * PCM 转 MP3
 *
 * @author QC班长
 * @since 2020-02-02
 */
public class PcmToMp3 {
 
    public static void main(String[] agrs) throws Exception {
        //convertAudioFiles("resource/茯茶素是什么，有什么效果，生产工艺有哪些？.pcm", "resource/茯茶素是什么，有什么效果，生产工艺有哪些？.mp3");
        convertAudioFiles("tnafcs.pcm", "tnafcs.mp3");
    }
 
    /**
     * @param src    待转换文件路径
     * @param target 目标文件路径
     * @throws IOException 抛出异常
     */
    public static String convertAudioFiles(String src, String target) throws IOException {
        FileInputStream fis = new FileInputStream(src);
        FileOutputStream fos = new FileOutputStream(target);
 
        //计算长度
        byte[] buf = new byte[1024 * 4];
        int size = fis.read(buf);
        int PCMSize = 0;
        while (size != -1) {
            PCMSize += size;
            size = fis.read(buf);
        }
        fis.close();
        
        //填入参数，比特率等等。这里用的是16位单声道 8000 hz
        WaveHeader header = new WaveHeader();
        //长度字段 = 内容的大小（PCMSize) + 头部字段的大小(不包括前面4字节的标识符RIFF以及fileLength本身的4字节)
        header.fileLength = PCMSize + (44 - 8);
        header.FmtHdrLeth = 16;
        header.BitsPerSample = 16;
        header.Channels = 1;
        header.FormatTag = 0x0001;
        header.SamplesPerSec = 16000;//正常速度是8000，这里写成了16000，速度加快一倍
        header.BlockAlign = (short) (header.Channels * header.BitsPerSample / 8);
        header.AvgBytesPerSec = header.BlockAlign * header.SamplesPerSec;
        header.DataHdrLeth = PCMSize;
 
        byte[] h = header.getHeader();
 
        assert h.length == 44; //WAV标准，头部应该是44字节
        //write header
        fos.write(h, 0, h.length);
        //write data stream
        fis = new FileInputStream(src);
        size = fis.read(buf);
        while (size != -1) {
            fos.write(buf, 0, size);
            size = fis.read(buf);
        }
        fis.close();
        fos.close();
        System.out.println("PCM Convert to MP3 OK!");
        return "ok";
    }
}

Java实现的PCM格式音频文件转换WAV格式

 
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
 
/**
 * PCM 转 WAV
 *
 * @author QC班长
 * @since 2020-02-02
 */
public class PcmToWav {
    public static void main(String[] agrs) throws Exception {
        //convertAudioFiles("resource/茯茶素是什么，有什么效果，生产工艺有哪些？.pcm", "resource/茯茶素是什么，有什么效果，生产工艺有哪些？.mp3");
        convertAudioFiles("tnafcs.pcm", "tnafcs.mp3");
    }
    /**
     * @param src    待转换文件路径
     * @param target 目标文件路径
     * @throws IOException 抛出异常
     */
    public static void convertAudioFiles(String src, String target) throws IOException {
 
        FileInputStream fis = new FileInputStream(src);
        FileOutputStream fos = new FileOutputStream(target);
 
        //计算长度
        byte[] buf = new byte[1024 * 4];
        int size = fis.read(buf);
        int PCMSize = 0;
        while (size != -1) {
            PCMSize += size;
            size = fis.read(buf);
        }
        fis.close();
 
        //填入参数，比特率等等。这里用的是16位单声道 8000 hz
        WaveHeader header = new WaveHeader();
        //长度字段 = 内容的大小（PCMSize) + 头部字段的大小(不包括前面4字节的标识符RIFF以及fileLength本身的4字节)
        header.fileLength = PCMSize + (44 - 8);
        header.FmtHdrLeth = 16;
        header.BitsPerSample = 16;
        header.Channels = 2;
        header.FormatTag = 0x0001;
        header.SamplesPerSec = 8000;
        header.BlockAlign = (short) (header.Channels * header.BitsPerSample / 8);
        header.AvgBytesPerSec = header.BlockAlign * header.SamplesPerSec;
        header.DataHdrLeth = PCMSize;
 
        byte[] h = header.getHeader();
 
        assert h.length == 44; //WAV标准，头部应该是44字节
        // write header
        fos.write(h, 0, h.length);
        // write data stream
        fis = new FileInputStream(src);
        size = fis.read(buf);
        while (size != -1) {
            fos.write(buf, 0, size);
            size = fis.read(buf);
        }
        fis.close();
        fos.close();
        System.out.println("Convert OK!");
    }
}

WaveHeader类

import java.io.ByteArrayOutputStream;
import java.io.IOException;
 
/**
 * WaveHeader
 *
 * @author QC班长
 * @since 2020-04-03
 */
public class WaveHeader {
    public final char fileID[] = {'R', 'I', 'F', 'F'};
    public int fileLength;
    public char wavTag[] = {'W', 'A', 'V', 'E'};
    public char FmtHdrID[] = {'f', 'm', 't', ' '};
    public int FmtHdrLeth;
    public short FormatTag;
    public short Channels;
    public int SamplesPerSec;
    public int AvgBytesPerSec;
    public short BlockAlign;
    public short BitsPerSample;
    public char DataHdrID[] = {'d', 'a', 't', 'a'};
    public int DataHdrLeth;
 
    public byte[] getHeader() throws IOException {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        WriteChar(bos, fileID);
        WriteInt(bos, fileLength);
        WriteChar(bos, wavTag);
        WriteChar(bos, FmtHdrID);
        WriteInt(bos, FmtHdrLeth);
        WriteShort(bos, FormatTag);
        WriteShort(bos, Channels);
        WriteInt(bos, SamplesPerSec);
        WriteInt(bos, AvgBytesPerSec);
        WriteShort(bos, BlockAlign);
        WriteShort(bos, BitsPerSample);
        WriteChar(bos, DataHdrID);
        WriteInt(bos, DataHdrLeth);
        bos.flush();
        byte[] r = bos.toByteArray();
        bos.close();
        return r;
    }
 
    private void WriteShort(ByteArrayOutputStream bos, int s) throws IOException {
        byte[] mybyte = new byte[2];
        mybyte[1] = (byte) ((s << 16) >> 24);
        mybyte[0] = (byte) ((s << 24) >> 24);
        bos.write(mybyte);
    }
 
    private void WriteInt(ByteArrayOutputStream bos, int n) throws IOException {
        byte[] buf = new byte[4];
        buf[3] = (byte) (n >> 24);
        buf[2] = (byte) ((n << 8) >> 24);
        buf[1] = (byte) ((n << 16) >> 24);
        buf[0] = (byte) ((n << 24) >> 24);
        bos.write(buf);
    }
 
    private void WriteChar(ByteArrayOutputStream bos, char[] id) {
        for (char c : id) {
            bos.write(c);
        }
    }
 
}