streamRipper for Winamp

/*
** Copyright (C) 2006 Kannan Krishnamoorthy.
**
** This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held 
** liable for any damages arising from the use of this software. 
**
** Permission is granted to anyone to use this software for any purpose, including commercial applications, and to 
** alter it and redistribute it freely, subject to the following restrictions:
**
**   1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. 
**      If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
**
**   2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
**
**   3. This notice may not be removed or altered from any source distribution.
**
*/
///////////////////////////////////////////////////////////////////////////////
/// @file     Wave.cpp
/// 
/// @author   Kannan K
/// 
/// @brief    implementation of CWave class
/// 
/// @note     
/// @verbatim
/// ___________________________________________________________________________
/// Revision History
/// Kannan K       05-Dec-2005     Created.
/// @endverbatim
///////////////////////////////////////////////////////////////////////////////

#include "Wave.h"

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CWave::CWave()
{
	//initialize the wave header buffer
    ZeroMemory((void*)&m_pcmWF, sizeof(m_pcmWF));
	m_pcmWF.wFormatTag = 1;
}

CWave::~CWave()
{
	//close file handle
    m_file.close();
}
/////////////////////////////////////////////////////////////////////////////////
/// @b             setFilename
/// 
/// @fn            void CWave::setFilename(TCHAR * strFilename)
/// 
/// @brief         initialize new wav file
/// 
/// @param         TCHAR * strFilename (wav file name)                                                       
/// 
/// @return        Nil                                                       
/// 
/// @author        Kannan K                                                    
/////////////////////////////////////////////////////////////////////////////////
void CWave::setFilename(TCHAR * strFilename)
{
	// create the wav file
    m_file.open(strFilename,ios::in|ios::out|ios::binary|ios::trunc);
	//add wav file signature
    m_file.write("RIFF", 4);
    DWORD dwFileSize = 36;
	m_file.write((char*)&dwFileSize, sizeof(dwFileSize)) ;
	m_file.write("WAVEfmt ", 8) ;
	DWORD dwFmtSize = 16L;
	//add wav data info
	m_file.write((char*)&dwFmtSize, sizeof(dwFmtSize)) ;
	m_file.write((char*)&m_pcmWF.wFormatTag, sizeof(m_pcmWF.wFormatTag)) ;
	m_file.write((char*)&m_pcmWF.nChannels, sizeof(m_pcmWF.nChannels)) ;
	m_file.write((char*)&m_pcmWF.nSamplesPerSec, sizeof(m_pcmWF.nSamplesPerSec)) ;
	m_file.write((char*)&m_pcmWF.nAvgBytesPerSec, sizeof(m_pcmWF.nAvgBytesPerSec)) ;
	m_file.write((char*)&m_pcmWF.nBlockAlign, sizeof(m_pcmWF.nBlockAlign)) ;
	m_file.write((char*)&m_pcmWF.wBitsPerSample, sizeof(m_pcmWF.wBitsPerSample)) ;
	m_file.write("data", 4) ;
	DWORD dwNum = 0;
	m_file.write((char*)&dwNum, sizeof(dwNum)) ;
}
/////////////////////////////////////////////////////////////////////////////////
/// @b             buildFormat
/// 
/// @fn            void CWave::buildFormat(WORD nChannels, DWORD nFrequency, WORD nBits)
/// 
/// @brief         builds the wav file format based on the given three value
/// 
/// @param         WORD nChannels (audio number of channels),
///                     DWORD nFrequency (samples per second), WORD nBits  (bits per sample)                                                     
/// 
/// @return        Nil                                                       
/// 
/// @author        Kannan K                                                    
/////////////////////////////////////////////////////////////////////////////////
void CWave::buildFormat(WORD nChannels, DWORD nFrequency, WORD nBits)
{
    m_pcmWF.wFormatTag = WAVE_FORMAT_PCM;
	m_pcmWF.nChannels = nChannels;
	m_pcmWF.nSamplesPerSec = nFrequency;
	m_pcmWF.nAvgBytesPerSec = nFrequency * nChannels * nBits / 8;
	m_pcmWF.nBlockAlign = nChannels * nBits / 8;
	m_pcmWF.wBitsPerSample = nBits;
}
/////////////////////////////////////////////////////////////////////////////////
/// @b             addSamples
/// 
/// @fn            void CWave::addSamples(void * pSamples,WORD nSamples)
/// 
/// @brief         add sub-sequent samples to the wav file
/// 
/// @param         void * pSamples (samples pointer),WORD nSamples  (number of samples)                                                     
/// 
/// @return        Nil                                                       
/// 
/// @author        Kannan K                                                    
/////////////////////////////////////////////////////////////////////////////////
void CWave::addSamples(void * pSamples,WORD nSamples)
{
    DWORD nSamplesSize = nSamples * m_pcmWF.nBlockAlign;
    DWORD nTemp;

// 4-RIFF
// 4-filesize 36 + data size
// 8-WAVEfmt
// 4-dwFmtSize
// 2-wFormatTag
// 2-nChannels
// 4-nSamplesPerSec
// 4-nAvgBytesPerSec
// 2-nBlockAlign
// 2-wBitsPerSample
// 4-data
// 4-data size = numSamples + nBlockAlign

	//read the existing data length
    m_file.seekg(4,ios::beg);
    m_file.read((char*)&nTemp,sizeof(nTemp));
    m_file.seekg(4,ios::beg);
	//calculate new length
    nTemp += nSamplesSize;
	//write new data length to file
    m_file.write((char*)&nTemp,sizeof(nTemp));

	//read the existing samplesize
    m_file.seekg(40,ios::beg);
    m_file.read((char*)&nTemp,sizeof(nTemp));
    m_file.seekg(40,ios::beg);
	//calculate new samplesize 
    nTemp += nSamplesSize;
	//write to file
    m_file.write((char*)&nTemp,sizeof(nTemp));
	//seek file to end of file
    m_file.seekg(0,ios::end);
    //write current samples at the end of file
    m_file.write((char*)pSamples,nSamplesSize);
}