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[1]获取IE默认代理配置

BOOL GetWinetProxy(LPSTR lpszProxy, UINT nProxyLen)
{
unsigned long        nSize = 4096;
char                 szBuf[4096] = { 0 };
INTERNET_PROXY_INFO* pProxyInfo = (INTERNET_PROXY_INFO*)szBuf;
if(!InternetQueryOption(NULL, INTERNET_OPTION_PROXY, pProxyInfo, &nSize))
{
return FALSE;
}
if (pProxyInfo->dwAccessType == INTERNET_OPEN_TYPE_DIRECT)
{
return FALSE;

}

//这里是代理列表，以\0分隔，结束处两个\0\0，一般我们取第一条代理就够了

LPCSTR lpszProxyList = (LPCSTR)(pProxyInfo + 1);
int nLen = strlen(lpszProxyList);
if (lpszProxy)
{
nProxyLen = min(nLen, nProxyLen-1);
strncpy(lpszProxy, lpszProxyList, nProxyLen);
lpszProxy[nProxyLen] = 0;
}
return nLen;



/*INTERNET_PER_CONN_OPTION_LISTA    List;
INTERNET_PER_CONN_OPTIONA         Option[1];
unsigned long                    nSize = sizeof(INTERNET_PER_CONN_OPTION_LISTA);


Option[0].dwOption = INTERNET_PER_CONN_PROXY_SERVER;
List.dwSize = sizeof(INTERNET_PER_CONN_OPTION_LIST);
List.pszConnection = NULL;
List.dwOptionCount = 1;
List.dwOptionError = 0;
List.pOptions = Option;


if(!InternetQueryOptionA(NULL, INTERNET_OPTION_PER_CONNECTION_OPTION, &List, &nSize))
{
return FALSE;
}
if(Option[0].Value.pszValue != NULL) 
{
int nLen = strlen(Option[0].Value.pszValue);
if (lpszProxy)
{
nProxyLen = min(nLen, nProxyLen-1);
strncpy(lpszProxy, Option[0].Value.pszValue, nProxyLen);
lpszProxy[nProxyLen] = 0;
}
GlobalFree(Option[0].Value.pszValue);
return nLen;
}*/
return FALSE;
}

[2]Hadoop 类Grep源代码注释

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.tdxx.hadoop.example;

import java.util.Random;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.*;
import org.apache.hadoop.mapred.lib.*;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;


/**
 * 从input中提取与表达式相符的单词并计算词频
 * 
 * 继承自配置基类Configured,并扩展接口Tool
 * Configured类中有一个变量conf用于存储配置文件
 * Tool中只有一个方法需要实现
 * int run(String [] args)用于运行输入参数
 * hadoop jar Grep.jar /user/hadoop/20130704/grep.txt /user/hadoop/output/ 'aaa.*'
 * hadoop jar Grep.jar /user/hadoop/20130704/grep.txt /user/hadoop/output/ '[a-z.]+'
 */
public class Grep extends Configured implements Tool {
	// singleton
	private Grep() {
	} 

	public int run(String[] args) throws Exception {
		if (args.length < 3) {
			System.out.println("Grep <inDir> <outDir> <regex> [<group>]");
			ToolRunner.printGenericCommandUsage(System.out);
			return -1;
		}

		Path tempDir = new Path("grep-temp-"
				+ Integer.toString(new Random().nextInt(Integer.MAX_VALUE)));

		//创建job
		JobConf grepJob = new JobConf(getConf(), Grep.class);

		try {
			//job命名
			grepJob.setJobName("grep-search");

			//设置job的输入路径
			FileInputFormat.setInputPaths(grepJob, args[0]);
			
			//设置Mapper类
			grepJob.setMapperClass(RegexMapper.class);
			
			grepJob.set("mapred.mapper.regex", args[2]);
			if (args.length == 4)
				grepJob.set("mapred.mapper.regex.group", args[3]);

			//设置Combiner类
			grepJob.setCombinerClass(LongSumReducer.class);
			
			//设置Reducer类
			grepJob.setReducerClass(LongSumReducer.class);

			//设置输出路径
			FileOutputFormat.setOutputPath(grepJob, tempDir);
			
			//设置输出格式
			grepJob.setOutputFormat(SequenceFileOutputFormat.class);
			
			//设置输出键的类
			grepJob.setOutputKeyClass(Text.class);
			
			//设置输出值的类
			grepJob.setOutputValueClass(LongWritable.class);

			//运行
			JobClient.runJob(grepJob);

			JobConf sortJob = new JobConf(getConf(), Grep.class);
			sortJob.setJobName("grep-sort");

			FileInputFormat.setInputPaths(sortJob, tempDir);
			sortJob.setInputFormat(SequenceFileInputFormat.class);

			sortJob.setMapperClass(InverseMapper.class);

			sortJob.setNumReduceTasks(1); // write a single file
			FileOutputFormat.setOutputPath(sortJob, new Path(args[1]));
			sortJob.setOutputKeyComparatorClass // sort by decreasing freq
					(LongWritable.DecreasingComparator.class);

			JobClient.runJob(sortJob);
		} finally {
			FileSystem.get(grepJob).delete(tempDir, true);
		}
		return 0;
	}

	public static void main(String[] args) throws Exception {
		int res = ToolRunner.run(new Configuration(), new Grep(), args);
		System.exit(res);
	}

}

[3]Speex Acoustic Echo Cancellation (AEC) 回声消除模块的使用

背景：回声与啸叫的产生  http://blog.csdn.net/u011202336/article/details/9238397

参考资料：  http://www.speex.org/docs/manual   

从代码分析，下边是Speex test demo

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "speex/speex_echo.h"
#include "speex/speex_preprocess.h"


#define NN 128
#define TAIL 1024

int main(int argc, char **argv)
{
   FILE *echo_fd, *ref_fd, *e_fd;
   short echo_buf[NN], ref_buf[NN], e_buf[NN];
   SpeexEchoState *st;
   SpeexPreprocessState *den;
   int sampleRate = 8000;

   if (argc != 4)
   {
      fprintf(stderr, "testecho mic_signal.sw speaker_signal.sw output.sw\n");
      exit(1);
   }
   echo_fd = fopen(argv[2], "rb");
   ref_fd  = fopen(argv[1],  "rb");
   e_fd    = fopen(argv[3], "wb");
   // Step1: 初始化结构
     st = speex_echo_state_init(NN, TAIL);
   den = speex_preprocess_state_init(NN, sampleRate);

   //Step2: 设置相关参数
   speex_echo_ctl(st, SPEEX_ECHO_SET_SAMPLING_RATE, &sampleRate);
   speex_preprocess_ctl(den, SPEEX_PREPROCESS_SET_ECHO_STATE, st);

   while (!feof(ref_fd) && !feof(echo_fd))
   {
      fread(ref_buf, sizeof(short), NN, ref_fd);
      fread(echo_buf, sizeof(short), NN, echo_fd);
      
      //Step3: 调用Api回声消除，ref_buf是麦克采集到的数据
      // echo_buf：是从speaker处获取到的数据
      // e_buf: 是回声消除后的数据
      speex_echo_cancellation(st, ref_buf, echo_buf, e_buf);
      speex_preprocess_run(den, e_buf);
      fwrite(e_buf, sizeof(short), NN, e_fd);
   }

   //Step4: 销毁结构 释放资源
   speex_echo_state_destroy(st);
   speex_preprocess_state_destroy(den);
   fclose(e_fd);
   fclose(echo_fd);
   fclose(ref_fd);
   return 0;
}

Speex 源码中附带的这个例子，只适合于串行的链式媒体流，当媒体播放、媒体采集、媒体网络数据接口分属在不同现成时，就会存在同步问题，异步线程会导致信号延迟加大，回声消除收敛效果不好。其中Speex 回声消除必须按照建议的流程：

write_to_soundcard(echo_frame, frame_size);     //播放音频数据，并从声卡获得播放的数据echo_frame.
read_from_soundcard(input_frame, frame_size);   //在数据播放后，从声卡麦克获取采集到的数据input_frame.
speex_echo_cancellation(echo_state, input_frame, echo_frame, output_frame); //调用Api消除噪声，输入input_frame,echo_frame，输出out_frame

在典型的VOIP类型应用中：

echo_frame: 从RTP接收的数据包解码后，送入声卡播放，获取的数据。

input_frame: 本地麦克采集到的数据

output_frame: 回声消除后的数据，送入encodec，并构造rtp数据包，传输到远端。

典型的应用模式： 

Thread A:  接收audio rtp -> decodec -----> sound card 

                                                                    |__> echo_frame queue

Thread B: 获取麦克数据input_frame --> speex_echo_cancellation( speex_state, input_frame, echo_frame,out_frame ) -> rtp packet -> network 

也可以将rtp packet 与network 传输放到另外一个线程。