我需要将音频文件从μ-law转换为PCM。

Question

我需要将wav文件从格式1转换为格式2

格式1 :μ-law，8000 64，64 kbps，mono

格式2 :容器WAV编码PCM速率16K样例格式16位通道单通道

下面是代码片段:

File file = new File("audio_before_conversion.wav");
AudioFormat audioFormat = new AudioFormat(16000, 16, 1, true , true);
AudioInputStream audioInputStream1 = new AudioInputStream(
     new FileInputStream(file), audioFormat, numFrames);
AudioSystem.write(audioInputStream1, Type.WAVE, 
     new File("audio_after_conversion.wav"));

问题:，但是，这是行不通的。它播放一些噪音，也减少了我的音频文件长度。

编辑1:到μ-law

Answer 1

下面的代码为我工作--

File sourceFile = new File("<Source_Path>.wav");

        File targetFile = new File("<Destination_Path>.wav");

        AudioInputStream sourceAudioInputStream = AudioSystem.getAudioInputStream(sourceFile);


        AudioInputStream targetAudioInputStream=AudioSystem.getAudioInputStream(AudioFormat.Encoding.PCM_SIGNED, sourceAudioInputStream);
        System.out.println("Sample Rate1 "+targetAudioInputStream.getFormat().getFrameRate());
    AudioFormat targetFormat = new AudioFormat(new AudioFormat.Encoding("PCM_SIGNED"), 16000, 16, 1, 2, 8000, false);



        AudioInputStream targetAudioInputStream1 = AudioSystem.getAudioInputStream(targetFormat, targetAudioInputStream);
        System.out.println("Sample Rate "+targetAudioInputStream1.getFormat().getFrameRate());

        try {
            AudioSystem.write(targetAudioInputStream1, AudioFileFormat.Type.WAVE, targetFile);
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

Answer 2

您需要使用AudioSystem并将格式转换和音频写入分为两个不同的步骤：

final File file = new File("audio_before_conversion.wav");
// open the audio stream
final AudioInputStream pcmStream8k = AudioSystem.getAudioInputStream(file);
// specify target format
final AudioFormat targetFormat = new AudioFormat(16000, 16, 1, true , true);
// this converts your audio stream
final AudioInputStream pcmStream16k = AudioSystem.getAudioInputStream(targetFormat, pcmStream8k);
// this writes the audio stream
AudioSystem.write(pcmStream16k, AudioFileFormat.Type.WAVE, new File("audio_after_conversion.wav"));