前言
wav音频添加自定义时长静音的工具类
Maven依赖
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>30.1.1-jre</version>
</dependency>
<dependency>
<groupId>cn.hutool</groupId>
<artifactId>hutool-all</artifactId>
<version>5.5.2</version>
</dependency>
代码
package ai.guiji.csdn.tools;
import cn.hutool.core.io.FileUtil;
import cn.hutool.core.io.IoUtil;
import cn.hutool.core.util.IdUtil;
import cn.hutool.core.util.URLUtil;
import com.google.common.base.Joiner;
import com.google.common.primitives.Bytes;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.stream.LongStream;
/** java项目 fhadmin.cn **/
public class WavAddSilenceUtils {
/**
* 根据PCM文件构建wav的header字段
*
* @param srate Sample rate - 8000, 16000, etc.
* @param channel Number of channels - Mono = 1, Stereo = 2, etc..
* @param format Number of bits per sample (16 here)
* @throws IOException
*/
public static byte[] buildWavHeader(int dataLength, int srate, int channel, int format)
throws IOException {
byte[] header = new byte[44];
long totalDataLen = dataLength + 36;
long bitrate = srate * channel * format;
header[0] = 'R';
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';
header[9] = 'A';
header[10] = 'V';
header[11] = 'E';
header[12] = 'f';
header[13] = 'm';
header[14] = 't';
header[15] = ' ';
header[16] = (byte) format;
header[17] = 0;
header[18] = 0;
header[19] = 0;
header[20] = 1;
header[21] = 0;
header[22] = (byte) channel;
header[23] = 0;
header[24] = (byte) (srate & 0xff);
header[25] = (byte) ((srate >> 8) & 0xff);
header[26] = (byte) ((srate >> 16) & 0xff);
header[27] = (byte) ((srate >> 24) & 0xff);
header[28] = (byte) ((bitrate / 8) & 0xff);
header[29] = (byte) (((bitrate / 8) >> 8) & 0xff);
header[30] = (byte) (((bitrate / 8) >> 16) & 0xff);
header[31] = (byte) (((bitrate / 8) >> 24) & 0xff);
header[32] = (byte) ((channel * format) / 8);
header[33] = 0;
header[34] = 16;
header[35] = 0;
header[36] = 'd';
header[37] = 'a';
header[38] = 't';
header[39] = 'a';
header[40] = (byte) (dataLength & 0xff);
header[41] = (byte) ((dataLength >> 8) & 0xff);
header[42] = (byte) ((dataLength >> 16) & 0xff);
header[43] = (byte) ((dataLength >> 24) & 0xff);
return header;
}
/**
* 默认写入的pcm数据是16000采样率，16bit，可以按照需要修改
*
* @param filePath
* @param pcmData
*/
public static boolean writeToFile(String filePath, byte[] pcmData) {
BufferedOutputStream bos = null;
try {
bos = new BufferedOutputStream(new FileOutputStream(filePath));
byte[] header = buildWavHeader(pcmData.length, 16000, 1, 16);
bos.write(header, 0, 44);
bos.write(pcmData);
bos.close();
return true;
} catch (Exception e) {
e.printStackTrace();
} finally {
if (bos != null) {
try {
bos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return false;
}
/**
* 增加延时静音
*
* @param filePath 音频地址
* @param tmpDirPath 临时目录地址
* @param delayTime 延时时长，单位毫秒
* @return 最终文件地址
* @throws Exception 异常
*/
public static String delayWav(String filePath, String tmpDirPath, Long delayTime)
throws Exception {
byte[] bytes;
if (filePath.startsWith("http")) {
bytes = IoUtil.readBytes(URLUtil.getStream(new URL(filePath)));
} else {
bytes = FileUtil.readBytes(filePath);
}
List<Byte> resultByte =
new ArrayList<>(Bytes.asList(Arrays.copyOfRange(bytes, 44, bytes.length)));
LongStream.range(0, (long) (delayTime * 32)).forEach(x -> resultByte.add((byte) 0));
String resultPath =
Joiner.on(File.separator).join(Arrays.asList(tmpDirPath, IdUtil.simpleUUID() + ".wav"));
writeToFile(resultPath, Bytes.toArray(resultByte));
return resultPath;
}
public static void main(String[] args) throws Exception {
System.out.println(delayWav("http://xxxx/xxx.wav", "C:\\Users\\huyi\\Desktop\\", 10000L));
}
}
代码说明：
1、delayWav方法参数分别为wav音频文件地址（可以支持http的url地址）、临时文件目录地址、延时静音时长（单位毫秒）
2、对wav的要求默认为：采样率16K、单声道。
对需要处理的音频参数调整。
3、生成uuid的随机文件名，避免重复。
