Android之录音工具类

/**
 * 录音工具类
 * 
 * @author rendongwei
 * 
 */
public class RecordUtil {
    private static final int SAMPLE_RATE_IN_HZ = 8000;
    private MediaRecorder recorder = new MediaRecorder();
    // 录音的路径
    private String mPath;

    public RecordUtil(String path) {
        mPath = path;
    }

    /**
     * 开始录音
     * 
     * @throws IOException
     */
    public void start() throws IOException {
        String state = android.os.Environment.getExternalStorageState();
        if (!state.equals(android.os.Environment.MEDIA_MOUNTED)) {
            throw new IOException("SD Card is not mounted,It is  " + state
                    + ".");
        }
        File directory = new File(mPath).getParentFile();
        if (!directory.exists() && !directory.mkdirs()) {
            throw new IOException("Path to file could not be created");
        }
        recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
        recorder.setOutputFormat(MediaRecorder.OutputFormat.RAW_AMR);
        recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
        recorder.setAudioSamplingRate(SAMPLE_RATE_IN_HZ);
        recorder.setOutputFile(mPath);
        recorder.prepare();
        recorder.start();
    }

    /**
     * 结束录音
     * 
     * @throws IOException
     */
    public void stop() throws IOException {
        recorder.stop();
        recorder.release();
    }

    /**
     * 获取录音时间
     * 
     * @return
     */
    public double getAmplitude() {
        if (recorder != null) {
            return (recorder.getMaxAmplitude());
        }
        return 0;
    }
}