pcm是原始的無(wú)損音頻數(shù)據(jù),但是在安卓手機(jī)上,播放起來(lái)并不是很方便,這里就演示如何把pcm轉(zhuǎn)為wav。
只需一個(gè)工具類即可實(shí)現(xiàn),原理其實(shí)很簡(jiǎn)單,就在pcm文件的文件頭,加上wav的文件頭屬性即可。為什么這么簡(jiǎn)單還要寫(xiě),因?yàn)榫W(wǎng)上所找到的答案實(shí)在是亂七八糟,什么都有,所以特此記錄,直接上代碼:
package com.north.light.libaudio.utils;
import android.media.AudioFormat;
import android.media.AudioRecord;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
/**
* Created by lzt
* time 2021/6/9 15:42
*
* @author lizhengting
* 描述:pcm格式的音頻轉(zhuǎn)換為wav格式的工具類
*/
public class PcmToWavUtil {
private int mBufferSize; //緩存的音頻大小
private int mSampleRate = 8000;// 8000|16000
private int mChannel = AudioFormat.CHANNEL_IN_STEREO; //立體聲
private int mEncoding = AudioFormat.ENCODING_PCM_16BIT;
private static class SingleHolder {
static PcmToWavUtil mInstance = new PcmToWavUtil();
}
public static PcmToWavUtil getInstance() {
return SingleHolder.mInstance;
}
public PcmToWavUtil() {
this.mBufferSize = AudioRecord.getMinBufferSize(mSampleRate, mChannel, mEncoding);
}
/**
* @param sampleRate sample rate、采樣率
* @param channel channel、聲道
* @param encoding Audio data format、音頻格式
*/
public PcmToWavUtil(int sampleRate, int channel, int encoding) {
this.mSampleRate = sampleRate;
this.mChannel = channel;
this.mEncoding = encoding;
this.mBufferSize = AudioRecord.getMinBufferSize(mSampleRate, mChannel, mEncoding);
}
/**
* pcm文件轉(zhuǎn)wav文件
*
* @param inFilename 源文件路徑
* @param outFilename 目標(biāo)文件路徑
* @param deleteOrg 是否刪除源文件
*/
public void pcmToWav(String inFilename, String outFilename, boolean deleteOrg) {
FileInputStream in;
FileOutputStream out;
long totalAudioLen;
long totalDataLen;
long longSampleRate = mSampleRate;
int channels = 2;
long byteRate = 16 * mSampleRate * channels / 8;
byte[] data = new byte[mBufferSize];
try {
in = new FileInputStream(inFilename);
out = new FileOutputStream(outFilename);
totalAudioLen = in.getChannel().size();
totalDataLen = totalAudioLen + 36;
writeWaveFileHeader(out, totalAudioLen, totalDataLen,
longSampleRate, channels, byteRate);
while (in.read(data) != -1) {
out.write(data);
}
in.close();
out.close();
if (deleteOrg) {
new File(inFilename).delete();
}
} catch (IOException e) {
e.printStackTrace();
}
}
public void pcmToWav(String inFilename, String outFilename) {
pcmToWav(inFilename, outFilename, false);
}
/**
* 加入wav文件頭
*/
private void writeWaveFileHeader(FileOutputStream out, long totalAudioLen,
long totalDataLen, long longSampleRate, int channels, long byteRate)
throws IOException {
byte[] header = new byte[44];
header[0] = 'R'; // RIFF/WAVE header
header[1] = 'I';
header[2] = 'F';
header[3] = 'F';
header[4] = (byte) (totalDataLen & 0xff);
header[5] = (byte) ((totalDataLen >> 8) & 0xff);
header[6] = (byte) ((totalDataLen >> 16) & 0xff);
header[7] = (byte) ((totalDataLen >> 24) & 0xff);
header[8] = 'W'; //WAVE
header[9] = 'A';
header[10] = 'V';
header[11] = 'E';
header[12] = 'f'; // 'fmt ' chunk
header[13] = 'm';
header[14] = 't';
header[15] = ' ';
header[16] = 16; // 4 bytes: size of 'fmt ' chunk
header[17] = 0;
header[18] = 0;
header[19] = 0;
header[20] = 1; // format = 1
header[21] = 0;
header[22] = (byte) channels;
header[23] = 0;
header[24] = (byte) (longSampleRate & 0xff);
header[25] = (byte) ((longSampleRate >> 8) & 0xff);
header[26] = (byte) ((longSampleRate >> 16) & 0xff);
header[27] = (byte) ((longSampleRate >> 24) & 0xff);
header[28] = (byte) (byteRate & 0xff);
header[29] = (byte) ((byteRate >> 8) & 0xff);
header[30] = (byte) ((byteRate >> 16) & 0xff);
header[31] = (byte) ((byteRate >> 24) & 0xff);
header[32] = (byte) (2 * 16 / 8); // block align
header[33] = 0;
header[34] = 16; // bits per sample
header[35] = 0;
header[36] = 'd'; //data
header[37] = 'a';
header[38] = 't';
header[39] = 'a';
header[40] = (byte) (totalAudioLen & 0xff);
header[41] = (byte) ((totalAudioLen >> 8) & 0xff);
header[42] = (byte) ((totalAudioLen >> 16) & 0xff);
header[43] = (byte) ((totalAudioLen >> 24) & 0xff);
out.write(header, 0, 44);
}
}
that‘s all----------------------------------------------------------------------------------