我需要将音频文件从μ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律，8000Hz，64 kbps，单声道

格式2：集装箱波浪 编码 PCM 速率 16K 示例格式 16 位 通道单声道

以下是代码片段：

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，这不起作用。它播放了一些噪音，也减少了我的音频文件长度。

编辑1：木法到μ法

Answer 1

以下代码对我有用——

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"));