Pedal Point源码发布及说明（6）[1]

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/*/////////////////////////////////////////////////////////////////////

  文件：waverecorder.cpp

  描述：录音类实现文件

  作者：张友邦

  时间：2004-09-10

  声明：本文件系作者辛苦熬夜的产物，任何人使用本文件请保留本描述文本。

  历史：

/*/////////////////////////////////////////////////////////////////////

//////////////////////////////////////////////////////////////////////
#include "stdafx.h"
#include "waverecorder.h"
#include "graphseed.h"

//////////////////////////////////////////////////////////////////////
// constructions/destruction
namespace wa
{
//////////////////////////////////////////////////////////////////////

#define maxinputbuffers 25
#define buffersize 1024 * 1

float waverecorder::samplecoef = 1.0;

waverecorder::waverecorder()
{
 memset(&waveformat, 0x00, sizeof(waveformatex));
 waveformat.wformattag = wave_format_pcm;
 waveformat.nchannels = 1;
 waveformat.wbitspersample = 8;
 waveformat.cbsize = 0;
 waveformat.nsamplespersec = 44100;
 waveformat.navgbytespersec = waveformat.nsamplespersec
  *(waveformat.wbitspersample>>3);
 waveformat.nblockalign =
  (waveformat.wbitspersample>>3)*
  waveformat.nchannels;

 status = e_status_stoped;
 samplecoef = 1.0;
}

waverecorder::waverecorder(const waveformatex& waveformatconfig)
{
 waveformat = waveformatconfig;

 status = e_status_stoped;
 samplecoef = 1.0;
}

waverecorder::waverecorder(const int& frequency, const int& channels)
{
 memset(&waveformat, 0x00, sizeof(waveformatex));
 waveformat.wformattag = wave_format_pcm;
 waveformat.nchannels = channels;
 waveformat.wbitspersample = 16;
 waveformat.cbsize = 0;
 waveformat.nsamplespersec = frequency;
 waveformat.navgbytespersec = waveformat.nsamplespersec
  *(waveformat.wbitspersample>>3);
 waveformat.nblockalign =
  (waveformat.wbitspersample>>3)*
  waveformat.nchannels;

 status = e_status_stoped;
 samplecoef = 1.0;
}

waverecorder::~waverecorder()
{
 try
 {
  stop();
 }
 catch (...)
 {
 }
}

float waverecorder::constraint(char v)
{
 if (v == -128)
  return 127.0 * samplecoef;

 return float(v) * samplecoef;
}

void waverecorder::smooth(char* input, int* output, int length,
        double smoothness/* = 0.8*/, int scale /*= 100*/)
{
 double a = 1.0 - (2.4 / scale);
 double b = smoothness;
 double acoef = a;
 double bcoef = a * b;
 double ccoef = a * b * b;
 double mastergain = 1.0 / (-1.0 / (log(a) + 2.0 * log(b)) +
  2.0 / (log(a) + log(b)) - 1.0 / log(a));
 double again = mastergain;
 double bgain = mastergain * (log(a * b * b) * (log(a) - log(a * b)) /
  ((log(a * b * b) - log(a * b)) * log(a * b))
  - log(a) / log(a * b));
 double cgain = mastergain * (-(log(a) - log(a * b)) /
  (log(a * b * b) - log(a * b)));

 double areg = 0;
 double breg = 0;
 double creg = 0;

 //第一次循环，取得reg的平均值
 for (int j = 0; j < length; ++j)
 {
  float v = constraint(input[j]);

  areg = acoef * areg + v;
  breg = bcoef * breg + v;
  creg = ccoef * creg + v;
 }

 //得到基音
 float base = again * areg + bgain * breg + cgain * creg;
 output[0] = base;

 //用基音作为其始作循环得到其他数据
 for (int i = 1; i < length; ++i)
 {
  int v = constraint(input[i - 1]);

  areg = acoef * areg + v;
  breg = bcoef * breg + v;
  creg = ccoef * creg + v;

  output[i] = again * areg + bgain * breg + cgain * creg - base;
 }
}

void callback waverecorder::waveinproc
(
 hwavein hwi,       //音频设备句柄
 uint umsg,         //消息标识
 dword dwinstance,  //用户定义数据
 dword dwparam1,    //消息参数
 dword dwparam2     //消息参数
)
{
 //过滤消息(只处理数据消息)