java实现wav的重采样

news2024/11/23 23:48:36

在处理一些用户上传的音频的时候，往往根据用户的设备不通，文件格式难以统一，尤其是涉及到算法模型相关的，更是令人头疼，这里提供两种思路解决这个问题。

不借助三方库

这种采用的是javax.sound.sampled下的包来实现，缺点是需要预先知道目标的采样率等信息。

工具类

import com.example.phoneme.constant.WavConstant;
import lombok.extern.slf4j.Slf4j;

import javax.sound.sampled.*;
import java.io.*;
import java.util.Arrays;

@Slf4j
public class WavUtils {

    public static byte[] toPCM(byte[] src) {
        if (src.length > 44) {
            return Arrays.copyOfRange(src, 44, src.length);
        }
        return new byte[0];
    }

    public static byte[] convertTo16kHzMono16bitPCM(byte[] audioData,int sampleRate,int sampleSizeBits,int channels,boolean signed,boolean bigEndian) {
        try{
            // 创建输入字节数组流
            ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(audioData);

            // 创建目标音频格式
            AudioFormat targetFormat = new AudioFormat(WavConstant.SAMPLE_RATE, WavConstant.BIT_DEPTH, WavConstant.CHANNELS, WavConstant.SIGNED, WavConstant.BIG_ENDIAN);

            // 创建目标音频输入流
            AudioInputStream audioInputStream = new AudioInputStream(byteArrayInputStream, new AudioFormat(sampleRate, sampleSizeBits, channels, signed, bigEndian), audioData.length / 4);

            // 转换音频格式
            AudioInputStream convertedAudioInputStream = AudioSystem.getAudioInputStream(targetFormat, audioInputStream);

            // 将转换后的音频数据写入字节数组
            ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
            AudioSystem.write(convertedAudioInputStream, AudioFileFormat.Type.WAVE, byteArrayOutputStream);

            // 将字节数组返回
            byte[] convertedAudioData = byteArrayOutputStream.toByteArray();

            // 关闭流
            audioInputStream.close();
            convertedAudioInputStream.close();
            byteArrayOutputStream.close();

            return convertedAudioData;

        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }

    public static boolean checkVideo(byte[] fileBytes) {

        try (InputStream inputStream = new ByteArrayInputStream(fileBytes)) {
            // 使用AudioSystem类获取音频文件的格式
            AudioFileFormat audioFileFormat = AudioSystem.getAudioFileFormat(inputStream);
            // 判断文件格式是否为WAV
            if (audioFileFormat.getType() == AudioFileFormat.Type.WAVE) {
                // 获取WAV文件的属性信息
                AudioFormat audioFormat = audioFileFormat.getFormat();
                double sampleRate = audioFormat.getSampleRate();
                int channels = audioFormat.getChannels();
                int bitDepth = audioFormat.getSampleSizeInBits();

                log.info("上传的音频格式为:Sample Rate:{},Channels:{},Bit Depth:{}", sampleRate, channels, bitDepth);
                if (sampleRate == WavConstant.SAMPLE_RATE
                        && channels == WavConstant.CHANNELS
                        && bitDepth == WavConstant.BIT_DEPTH) {
                    log.info("校验通过");
                    return true;
                }
            } else {
                log.info("不是WAV文件");
                return false;
            }
        } catch (UnsupportedAudioFileException | IOException e) {
            log.info("不是WAV文件");
            return false;
        }
        log.info("不是WAV文件");
        return false;
    }
}

常量类

public interface WavConstant {

    float SAMPLE_RATE = 16000.0;
    int CHANNELS = 1;
    int BIT_DEPTH = 16;
    boolean SIGNED = true;
    boolean BIG_ENDIAN = false;
}

测试类

@Test
public void testTransform(){
    try (FileInputStream fis=new FileInputStream("/path/to/file")){
        byte[] buffer = new byte[1024];
            int bytesRead;
            ByteArrayOutputStream stream = new ByteArrayOutputStream();
            while ((bytesRead = fis.read(buffer)) != -1) {
                stream.write(buffer);
            }
            byte[] streamByteArray = stream.toByteArray();
            boolean b1 = checkVideo(streamByteArray);
            log.info("文件是否符合要求: {}", b1);
            byte[] bytes = WavUtils.convertTo16kHzMono16bitPCM(streamByteArray,16000,16,2,true,false);
            log.info("开始转换");
            boolean b2 = checkVideo(bytes);
            log.info("文件的字节长度是: {}", bytes.length);
            log.info("文件是否符合要求: {}", b2);
    }catch (IOException ioe){
        ioe.printStackTrace();
    }
}

运行结果

在这里插入图片描述

借助三方库

比较通用的解决方案是ffmpeg，这里提供一种方法，借助命令行实现，缺点也很明显，就是命令行对于代码来说可控程度不高，依赖环境，不好迁移，需要保存中间文件，但是优点是处理音频更灵活

工具类

import lombok.extern.slf4j.Slf4j;

import java.io.IOException;

@Slf4j
public class FfmpegUtil {

    public static void toWav(String flvPath, int sampleRate, int channel, int bitrate, String fileType, String targetFilename) {
        try {
            String command = "ffmpeg -i " + flvPath + " -vn " + " -ar " + sampleRate + " -ac " + channel + " -ab " + bitrate + "k" + " -f " + fileType + " " + targetFilename;
            Runtime.getRuntime().exec(new String[]{"sh", "-c", command});
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}