tconverter_fxp.cpp

linux下的一款播放器

/* ***** BEGIN LICENSE BLOCK *****
 * Source last modified: $Id: tconverter_fxp.cpp,v 1.1.42.3 2004/07/09 01:48:09 hubbe Exp $
 * 
 * Portions Copyright (c) 1995-2004 RealNetworks, Inc. All Rights Reserved.
 * 
 * The contents of this file, and the files included with this file,
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 * Source License (the "RPSL") available at
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 * the file under the current version of the RealNetworks Community
 * Source License (the "RCSL") available at
 * http://www.helixcommunity.org/content/rcsl, in which case the RCSL
 * will apply. You may also obtain the license terms directly from
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 * This file is part of the Helix DNA Technology. RealNetworks is the
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 * ***** END LICENSE BLOCK ***** */


/*****************************************************************************
 *  Includes
 */
#include "tconverter_fxp.h"


/*****************************************************************************
 *  CHXTimestampConverterFXP Class
 */
/*****************************************************************************
 *  ReInit
 *	if CvtType == FACTORS, ulVal1 is HXA Factor, ulVal2 is RTP Factor
 *	if CvtType == SAMPLES, ulVal1 is Sample Rate
 */
void CHXTimestampConverterFXP::ReInit(ConversionType cvtType,
			     UINT32 ulVal1, 
			     UINT32 ulVal2)
{
    if (cvtType == FACTORS)
    {
	m_hxaTime.ulBase = ulVal1;	// HXFactor
	m_rtpTime.ulBase = ulVal2;	// RTPFactor  
    }
    else
    {
	m_hxaTime.ulBase = 1000;	// HXFactor = 1000 samples/sec
	m_rtpTime.ulBase = ulVal1;	// RTPFactor
    }
    
    m_hxaTime.lQ = 0;
    m_hxaTime.lR = 0;
    m_hxaTime.ulRef = 0;
    m_hxaTime.ulAnchor = 0;
    m_hxaTime.ulHalfBase = m_hxaTime.ulBase / 2;
    
    m_rtpTime.lQ = 0;
    m_rtpTime.lR = 0;
    m_rtpTime.ulRef = 0;
    m_rtpTime.ulAnchor = 0;
    m_rtpTime.ulHalfBase = m_rtpTime.ulBase / 2;
}

/*****************************************************************************
 *  timeConvert
 */
ULONG32 CHXTimestampConverterFXP::timeConvert(ULONG32 ulT1, 
					      TimeCoordinate& T1, 
					      TimeCoordinate& T2)
{
    LONG32 lSamples;
    LONG32 ldQ;
    LONG32 ldR;

    // Compute the change in samples (+ or -)
    lSamples = ulT1 - T1.ulRef;
    T1.ulRef = ulT1;

    // Compute the Quant in Common Base (+ or -) 
    // and remainder in samples (always +)
    T1.lR += lSamples;	// Could become - at this moment
    
    ldQ = ((LONG32) (T1.lR - T1.ulBase)) / ((LONG32) T1.ulBase);
    ldR = ldQ * ((LONG32) T1.ulBase);
    T1.lR -= ldR;	// Always yields +
    T1.lQ += ldQ;	// + or -

    // Convert the number of samples accumulate from anchor point to 
    // other timebase
    return ((ULONG32) (T2.ulAnchor +
		       (T1.lQ * T2.ulBase) + 
		       (T1.lR * T2.ulBase + T1.ulHalfBase) / T1.ulBase));
}

/*****************************************************************************
 *  setAnchor
 */
void CHXTimestampConverterFXP::setHXAnchor(UINT32 ulHXAnchor)
{
    m_hxaTime.ulRef = m_hxaTime.ulAnchor = ulHXAnchor;
    m_rtpTime.ulRef = m_rtpTime.ulAnchor = timeConvertRaw(ulHXAnchor, m_hxaTime, m_rtpTime);
    m_rtpTime.lQ = m_rtpTime.lR = 0;
    m_hxaTime.lQ = m_hxaTime.lR = 0;
}

void CHXTimestampConverterFXP::setRTPAnchor(UINT32 ulRTPAnchor)
{
    m_rtpTime.ulRef = m_rtpTime.ulAnchor = ulRTPAnchor;
    m_hxaTime.ulRef = m_hxaTime.ulAnchor = timeConvertRaw(ulRTPAnchor, m_rtpTime, m_hxaTime);
    m_rtpTime.lQ = m_rtpTime.lR = 0;
    m_hxaTime.lQ = m_hxaTime.lR = 0;
}

void CHXTimestampConverterFXP::setAnchor(UINT32 ulHXAnchor, UINT32 ulRTPAnchor)
{
    m_hxaTime.ulRef = m_hxaTime.ulAnchor = ulHXAnchor;
    m_rtpTime.ulRef = m_rtpTime.ulAnchor = ulRTPAnchor;
    m_rtpTime.lQ = m_rtpTime.lR = 0;
    m_hxaTime.lQ = m_hxaTime.lR = 0;
}

/*****************************************************************************
 *  assignment
 */
CHXTimestampConverterFXP& CHXTimestampConverterFXP::operator=(const CHXTimestampConverterFXP& lhs)
{
    m_hxaTime = lhs.m_hxaTime;
    m_rtpTime = lhs.m_rtpTime;
    
    return *this;
}