mvdec.cpp

MPEG-4编解码的实现(包括MPEG4视音频编解码)

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

This software module was originally developed by 

	Wei-ge Chen ([e-mail]), Microsoft Corporation
	Ming-Chieh Lee ([e-mail]), Microsoft Corporation
	(date: July, 1997)

and edited by Xuemin Chen ([e-mail]), General Instrument Corp.

in the course of development of the MPEG-4 Video (ISO/IEC 14496-2). 
This software module is an implementation of a part of one or more MPEG-4 Video tools 
as specified by the MPEG-4 Video. 
ISO/IEC gives users of the MPEG-4 Video free license to this software module or modifications 
thereof for use in hardware or software products claiming conformance to the MPEG-4 Video. 
Those intending to use this software module in hardware or software products are advised that its use may infringe existing patents. 
The original developer of this software module and his/her company, 
the subsequent editors and their companies, 
and ISO/IEC have no liability for use of this software module or modifications thereof in an implementation. 
Copyright is not released for non MPEG-4 Video conforming products. 
Microsoft retains full right to use the code for his/her own purpose, 
assign or donate the code to a third party and to inhibit third parties from using the code for non <MPEG standard> conforming products. 
This copyright notice must be included in all copies or derivative works. 

Copyright (c) 1996, 1997.

Module Name:

	mvDec.cpp

Abstract:

	motion vector decoder

Revision History:
	Dec 20, 1997:	Interlaced tools added by General Instrument Corp.

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

#include "typeapi.h"
#include "codehead.h"
#include "mode.hpp"
#include "global.hpp"
#include "entropy/bitstrm.hpp"
#include "entropy/entropy.hpp"
#include "entropy/huffman.hpp"
#include "vopses.hpp"
#include "vopsedec.hpp"

#ifdef __MFC_
#ifdef _DEBUG
#undef THIS_FILE
static char BASED_CODE THIS_FILE[] = __FILE__;
#endif

#define new DEBUG_NEW				   
#endif // __MFC_

Void CVideoObjectDecoder::decodeMV (const CMBMode* pmbmd, CMotionVector* pmv, 
									Bool bLeftBndry, Bool bRightBndry, Bool bTopBndry, 
									Bool bZeroMV, Int iMBX, Int iMBY)
{
	if (pmbmd->m_bSkip || pmbmd->m_dctMd == INTRA || pmbmd->m_dctMd == INTRAQ || bZeroMV)	{
		memset (pmv, 0, PVOP_MV_PER_REF_PER_MB * sizeof (CMotionVector));
		return;
	}
	CVector vctDiff, vctDecode, vctPred;
	if (pmbmd->m_bhas4MVForward)	{
		for (Int iBlk = Y_BLOCK1; iBlk <= Y_BLOCK4; iBlk++)	{
			if (bLeftBndry || bRightBndry || bTopBndry)
				if(short_video_header)
					find8x8MVpredAtBoundary(vctPred, pmv, bLeftBndry, bRightBndry, bTopBndry, (BlockNum) iBlk);
				else
					findMVpredGeneric (vctPred, pmv, pmbmd, iBlk, iMBX, iMBY);
			else 
				find8x8MVpredInterior (vctPred, pmv, (BlockNum) iBlk);
			getDiffMV (vctDiff, m_vopmd.mvInfoForward);
			vctDecode = vctDiff + vctPred;																//fit in range
			fitMvInRange (vctDecode, m_vopmd.mvInfoForward);
			pmv [iBlk] = CMotionVector (vctDecode);		//convert to full pel now
		}
	}
// INTERLACE
	else if ((m_vopmd.bInterlace)&&(pmbmd->m_bFieldMV))	{
		Int iTempX1, iTempY1, iTempX2, iTempY2;
		find16x16MVpred (vctPred, pmv, bLeftBndry, bRightBndry, bTopBndry);
		getDiffMV (vctDiff, m_vopmd.mvInfoForward);
		vctDiff.y *= 2;
		vctPred.y = 2*(vctPred.y / 2);
		vctDecode = vctDiff + vctPred;																//fit in range
		fitMvInRange (vctDecode, m_vopmd.mvInfoForward);
		CMotionVector* pmv16x8 = pmv +5;
		if(pmbmd->m_bForwardTop) {
			pmv16x8++;
			*pmv16x8 = CMotionVector (vctDecode);		//convert to full pel now
			iTempX1 = pmv16x8->m_vctTrueHalfPel.x;
			iTempY1 = pmv16x8->m_vctTrueHalfPel.y;
			pmv16x8++;
		} 
		else
		{
			*pmv16x8 = CMotionVector (vctDecode);		//convert to full pel now
			iTempX1 = pmv16x8->m_vctTrueHalfPel.x;
			iTempY1 = pmv16x8->m_vctTrueHalfPel.y;
			pmv16x8++;
			pmv16x8++;
		}
		getDiffMV (vctDiff, m_vopmd.mvInfoForward);
		vctDiff.y *= 2;
		vctPred.y = 2*(vctPred.y / 2);
		vctDecode = vctDiff + vctPred;																//fit in range
		fitMvInRange (vctDecode, m_vopmd.mvInfoForward);
		if(pmbmd->m_bForwardBottom) {
			pmv16x8++;
			*pmv16x8 = CMotionVector (vctDecode);		//convert to full pel now
			iTempX2 = pmv16x8->m_vctTrueHalfPel.x;
			iTempY2 = pmv16x8->m_vctTrueHalfPel.y;
		}
		else
		{
			*pmv16x8 = CMotionVector (vctDecode);		//convert to full pel now
			iTempX2 = pmv16x8->m_vctTrueHalfPel.x;
			iTempY2 = pmv16x8->m_vctTrueHalfPel.y;
		}

		Int iTemp;
		for (UInt i = 1; i < 5; i++) {
			iTemp = iTempX1 + iTempX2;
			pmv [i].m_vctTrueHalfPel.x = (iTemp & 3) ? ((iTemp>>1) | 1) : (iTemp>>1);
			iTemp = iTempY1 + iTempY2;
			pmv [i].m_vctTrueHalfPel.y = (iTemp & 3) ? ((iTemp>>1) | 1) : (iTemp>>1);
		}
	}
// ~INTERLACE
	else {			//1 mv
		if(short_video_header)
			find16x16MVpred(vctPred, pmv, bLeftBndry, bRightBndry, bTopBndry);
		else
			findMVpredGeneric (vctPred, pmv, pmbmd, ALL_Y_BLOCKS, iMBX, iMBY);
		getDiffMV (vctDiff, m_vopmd.mvInfoForward);
		vctDecode = vctDiff + vctPred;																//fit in range
		fitMvInRange (vctDecode, m_vopmd.mvInfoForward);
		*pmv++ = CMotionVector (vctDecode);			//convert to full pel now
		for (Int i = 0; i < 4; i++) {
			*pmv = *(pmv - 1);
			pmv++;
		}
	}
}

Void CVideoObjectDecoder::decodeMVofBVOP (CMotionVector* pmvForward, CMotionVector* pmvBackward, CMBMode* pmbmd, 
										  Int iMBX, Int iMBY, const CMotionVector* pmvRef, const CMBMode* pmbmdRef)
{
	CVector vctDiff;
	//CVector vctPred;
	CVector vctDecode;
	//UInt nBits = 0;
	if(pmbmd->m_bSkip == TRUE && m_volmd.volType == ENHN_LAYER && m_vopmd.iRefSelectCode == 0)
		return;
	if (pmbmd->m_mbType == FORWARD || pmbmd->m_mbType == INTERPOLATE)	{
		assert (pmbmd->m_bSkip != TRUE);
		assert (pmbmd->m_bhas4MVForward != TRUE);
		getDiffMV (vctDiff, m_vopmd.mvInfoForward);
		// TPS FIX
		if (pmbmd->m_bFieldMV && m_volmd.volType != ENHN_LAYER) {
			vctDecode.x = vctDiff.x + m_vctForwardMvPredBVOP[0].x;
			vctDecode.y = 2 * (vctDiff.y + m_vctForwardMvPredBVOP[0].y / 2);
			fitMvInRange (vctDecode, m_vopmd.mvInfoForward);
			m_vctForwardMvPredBVOP[0] = vctDecode;
			pmvForward[0] = CMotionVector(vctDecode);
			pmvForward[1] = pmvForward[0];
			pmvForward[2] = pmvForward[0];
			getDiffMV(vctDiff, m_vopmd.mvInfoForward);
			vctDecode.x = vctDiff.x + m_vctForwardMvPredBVOP[1].x;
			vctDecode.y = 2 * (vctDiff.y + m_vctForwardMvPredBVOP[1].y / 2);
			fitMvInRange (vctDecode, m_vopmd.mvInfoForward);
			m_vctForwardMvPredBVOP[1] = vctDecode;
			pmvForward[3] = CMotionVector(vctDecode);
			pmvForward[4] = pmvForward[3];
		} else {
			vctDecode = vctDiff + m_vctForwardMvPredBVOP[0];
			fitMvInRange (vctDecode, m_vopmd.mvInfoForward);
			m_vctForwardMvPredBVOP[0] = vctDecode;
			m_vctForwardMvPredBVOP[1] = vctDecode;
			*pmvForward++ = CMotionVector(vctDecode);
			for (Int i = 0; i < 4; i++) {
				*pmvForward = *(pmvForward - 1);
				pmvForward++;
			}
		}
	}
	// TPS FIX
	if ( (pmbmd->m_mbType == BACKWARD || pmbmd->m_mbType == INTERPOLATE)	
		&& (m_volmd.volType != ENHN_LAYER || m_vopmd.iRefSelectCode != 0) ){	// modified by Sharp (98/3/11)
		assert (pmbmd->m_bSkip != TRUE);
		assert (pmbmd->m_bhas4MVBackward != TRUE);
		getDiffMV (vctDiff, m_vopmd.mvInfoBackward);
		if (pmbmd->m_bFieldMV && m_volmd.volType != ENHN_LAYER) {
			vctDecode.x = vctDiff.x + m_vctBackwardMvPredBVOP[0].x;
			vctDecode.y = 2 * (vctDiff.y + m_vctBackwardMvPredBVOP[0].y / 2);
			fitMvInRange (vctDecode, m_vopmd.mvInfoBackward);
			m_vctBackwardMvPredBVOP[0] = vctDecode;
			pmvBackward[0] = CMotionVector(vctDecode);
			pmvBackward[1] = pmvBackward[0];
			pmvBackward[2] = pmvBackward[0];
			getDiffMV(vctDiff, m_vopmd.mvInfoBackward);
			vctDecode.x = vctDiff.x + m_vctBackwardMvPredBVOP[1].x;
			vctDecode.y = 2 * (vctDiff.y + m_vctBackwardMvPredBVOP[1].y / 2);
			fitMvInRange (vctDecode, m_vopmd.mvInfoBackward);
			m_vctBackwardMvPredBVOP[1] = vctDecode;
			pmvBackward[3] = CMotionVector(vctDecode);
			pmvBackward[4] = pmvBackward[3];
		} else {
			vctDecode = vctDiff + m_vctBackwardMvPredBVOP[0];
			fitMvInRange (vctDecode, m_vopmd.mvInfoBackward);
			m_vctBackwardMvPredBVOP[0] = vctDecode;
			m_vctBackwardMvPredBVOP[1] = vctDecode;
			*pmvBackward++ = CMotionVector(vctDecode);
			for (Int i = 0; i < 4; i++) {
				*pmvBackward = *(pmvBackward - 1);
				pmvBackward++;
			}
		}
	}
	if (pmbmd->m_mbType == DIRECT)	{	
		static MVInfo directInfo = { 32, 1, 1};
		assert (pmbmd->m_bhas4MVForward != TRUE);
		/* begin of new changes 02-19-99 
    	if (m_vopmd.bInterlace) {
		    memset (pmvForward, 0, BVOP_MV_PER_REF_PER_MB * sizeof (CMotionVector));	//set forward mv to zero
		    if (!pmbmd->m_bSkip)
			    getDiffMV (pmbmd->m_vctDirectDeltaMV, directInfo);