AudioRecord 获取录音音量

要获取 AudioRecord 录音音量，您可以在读取音频数据时计算其振幅值，并将其转换为分贝值以显示音量大小。

以下是获取录音音量的示例代码：

// 配置 AudioRecord 对象
int audioSource = MediaRecorder.AudioSource.MIC;
int sampleRate = 44100;
int channelConfig = AudioFormat.CHANNEL_IN_MONO;
int audioFormat = AudioFormat.ENCODING_PCM_16BIT;
int bufferSize = AudioRecord.getMinBufferSize(sampleRate, channelConfig, audioFormat);
AudioRecord recorder = new AudioRecord(audioSource, sampleRate, channelConfig, audioFormat, bufferSize);

// 开始录音
byte[] buffer = new byte[bufferSize];
recorder.startRecording();

// 计算音量大小
while (isRecording) {
    int readSize = recorder.read(buffer, 0, bufferSize);
    double sum = 0;
    for (int i = 0; i < readSize; i++) {
        // 将 byte 转为 short，计算振幅值
        short audioSample = (short) ((buffer[i] & 0xFF) | (buffer[i + 1] << 8));
        sum += audioSample * audioSample;
    }
    // 计算平均振幅值
    double amplitude = Math.sqrt(sum / readSize);
    // 将振幅值转换为分贝值
    double db = 20 * Math.log10(amplitude / 32767.0);
    // 显示分贝值
    Log.d(TAG, "Current volume level: " + db + " dB");
}

// 停止录音并释放资源
recorder.stop();
recorder.release();

注意：为了能够获取录音音量，您需要在 `AndroidManifest.xml` 文件中添加 `android.permission.RECORD_AUDIO` 权限。