使用Java实现将多声道音频转换为单声道文件的转换方案

    public static void convertOneChannel(String origin, AudioSampleRate audioSampleRate,
                                         String target) throws IOException {

        File sourceFile = new File(origin);
        File targetFile = new File(target);

        try (AudioInputStream originalStream = AudioSystem.getAudioInputStream(sourceFile)) {

            AudioFormat originalFormat = originalStream.getFormat();
            // 使用 PCM_SIGNED
            int sampleSizeInBits = originalFormat.getSampleSizeInBits() > 0 ? originalFormat.getSampleSizeInBits() : 16;

            // 目标格式：单声道
            AudioFormat targetFormat = new AudioFormat(
                AudioFormat.Encoding.PCM_SIGNED,
                audioSampleRate.value,              // 新采样率
                sampleSizeInBits,                   // 位深
                1,                                  // 单声道
                (sampleSizeInBits / 8) * 1,         // frameSize = 位深/8 * 声道数
                audioSampleRate.value,                   // frameRate
                false                               // 小端序（WAV 常用）
            );

            AudioInputStream convertedStream;
            if (AudioSystem.isConversionSupported(targetFormat, originalFormat)) {
                // 支持直接转换
                convertedStream = AudioSystem.getAudioInputStream(targetFormat, originalStream);
            } else {
                // 不支持直接转换，先转 PCM_SIGNED，再转换采样率和声道
                AudioFormat intermediateFormat = new AudioFormat(
                    AudioFormat.Encoding.PCM_SIGNED,
                    originalFormat.getSampleRate(),
                    sampleSizeInBits,
                    originalFormat.getChannels(),
                    (sampleSizeInBits / 8) * originalFormat.getChannels(),
                    originalFormat.getFrameRate(),
                    false
                );
                AudioInputStream pcmStream = AudioSystem.getAudioInputStream(intermediateFormat, originalStream);
                convertedStream = AudioSystem.getAudioInputStream(targetFormat, pcmStream);
            }

            AudioSystem.write(convertedStream, AudioFileFormat.Type.WAVE, targetFile);
            convertedStream.close();
        } catch (UnsupportedAudioFileException e) {
            throw new RuntimeException(e);
        }
    }

int sampleSizeInBits = originalFormat.getSampleSizeInBits() > 0 ? originalFormat.getSampleSizeInBits() : 16;

1, // 单声道
(sampleSizeInBits / 8) * 1, // frameSize = 位深/8 * 声道数

AudioInputStream pcmStream = AudioSystem.getAudioInputStream(intermediateFormat, originalStream);

public static void main(String[] args) throws IOException {
    convertOneChannel(
        "D:/input/stereo.wav",
        AudioSampleRate._16k,
        "D:/output/mono.wav"
    );
}