android腾讯微博吹一吹实现原理

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http://www.eoeandroid.com/thread-211137-1-1.html

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最近研究腾讯吹一吹，写了一个dome 贴出核心的线程代码，那么吹一吹的原理是什么呢？声音 对 就是声音.
1.当用户到吹一吹界面之后 有一个核心的线程便开启一直在读取麦克风的声音信息.
2.当500毫秒以内或者读取的5次数据的平均值超过某一个值的时候 则就可以触发吹一吹事件
3.通知界面，界面接受到之后 响应响应的动画。
以下是线程的代码：

package com.bshark.letmessage.server;

import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Message;

import com.bshark.letmessage.ui.BlowActivity.MyHandler;
import com.bshark.letmessage.util.Parameter;

public class RecordThread extends Thread {
        private AudioRecord ar;
        private int bs = 100;
        private static int SAMPLE_RATE_IN_HZ = 8000;
        private Message msg;
        private int number = 1;
        private int tal = 1;
        private MyHandler handler;
        private long currenttime;
        private long endtime;
        private long time = 1;
        //到达该值之后 触发事件
        private static int BLOW_ACTIVI=2620;

        public RecordThread(MyHandler myHandler) {
                super();
                bs = AudioRecord.getMinBufferSize(SAMPLE_RATE_IN_HZ,
                                AudioFormat.CHANNEL_CONFIGURATION_MONO,
                                AudioFormat.ENCODING_PCM_16BIT);
                ar = new AudioRecord(MediaRecorder.AudioSource.MIC, SAMPLE_RATE_IN_HZ,
                                AudioFormat.CHANNEL_CONFIGURATION_MONO,
                                AudioFormat.ENCODING_PCM_16BIT, bs);
                handler = myHandler;
        }

        @Override
        public void run() {
                try {

                        ar.startRecording();
                        Parameter.isblow = true;
                        // 用于读取的 buffer
                        byte[] buffer = new byte[bs];
                        while (Parameter.isblow) {
                                number++;
                                sleep(8);
                                currenttime = System.currentTimeMillis();
                                int r = ar.read(buffer, 0, bs) + 1;
                                int v = 0;
                                for (int i = 0; i < buffer.length; i++) {
                                        v += buffer * buffer;
                                }
                                int value = Integer.valueOf(v / (int) r);
                                tal = tal + value;
                                endtime = System.currentTimeMillis();
                                time = time + (endtime - currenttime);
                
                                if (time >= 500 || number > 5) {

                                        int total = tal / number;
                                        if (total > BLOW_ACTIVI) {
                                                //发送消息通知到界面 触发动画
                                                
                                                //利用传入的handler 给界面发送通知


                                                //
                                                number = 1;
                                                tal = 1;
                                                time = 1;
                                        }
                                }

                        }
                        ar.stop();
                        ar.release();
                        bs=100;
                        
                } catch (Exception e) {
                        e.printStackTrace();
                }
        }
}