shpdec.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 

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

and edited by
	Yoshihiro Kikuchi (TOSHIBA CORPORATION)
	Takeshi Nagai (TOSHIBA CORPORATION)
	Toshiaki Watanabe (TOSHIBA CORPORATION)
	Noboru Yamaguchi (TOSHIBA CORPORATION)

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:

	shpdec.cpp

Abstract:

	Block decoding functions

Revision History:

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

#include <stdlib.h>
#include <math.h>
#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 "dct.hpp"
#include "cae.h"
#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::decodeIntraShape (CMBMode* pmbmd, Int iMBX, Int iMBY, PixelC* ppxlcCurrMBBY, PixelC* ppxlcCurrMBBYFrm)
{
	static Int rgiShapeMdCode [3];
	Int iMBnum = VPMBnum(iMBX, iMBY);
	m_bVPNoLeft = bVPNoLeft(iMBnum, iMBX);
	m_bVPNoTop = bVPNoTop(iMBnum);
	m_bVPNoRightTop = bVPNoRightTop(iMBnum, iMBX);
	m_bVPNoLeftTop = bVPNoLeftTop(iMBnum, iMBX);

	//printf("(%d,%d)",iMBX,iMBY);
	Int iTblIndex = shpMdTableIndex (pmbmd, iMBX, iMBY);
	rgiShapeMdCode [ALL_TRANSP] = grgchFirstShpCd [iTblIndex + ALL_TRANSP];
	rgiShapeMdCode [ALL_OPAQUE] = grgchFirstShpCd [iTblIndex + ALL_OPAQUE];
	rgiShapeMdCode [INTRA_CAE]  = grgchFirstShpCd [iTblIndex + INTRA_CAE];
	//	Modified for error resilient mode by Toshiba(1997-11-14)
	//Int iBits = m_pbitstrmIn->peekBits (2);
	//iBits = (iBits > 1) ? m_pbitstrmIn->getBits (2) : m_pbitstrmIn->getBits (1);
	Int iBits = m_pbitstrmIn->peekBits (3);
	assert (iBits != 0);
	if (iBits >= 4) {
		iBits = m_pbitstrmIn->getBits (1);
		iBits = 0;
	}
	else if (iBits >= 2) {
		iBits = m_pbitstrmIn->getBits (2);
		iBits = 2;
	}
	else if (iBits == 1) {
		iBits = m_pbitstrmIn->getBits (3);
		iBits = 3;
	}
	//	End Toshiba(1997-11-14)
	assert (iBits == 0 || iBits == 2 || iBits == 3);
	//printf("[%08x]",m_pbitstrmIn->peekBits(32));
	if (iBits == rgiShapeMdCode [ALL_TRANSP])	{
		pmbmd->m_shpmd = ALL_TRANSP;//printf("_");
		pxlcmemset (ppxlcCurrMBBY, MPEG4_TRANSPARENT, MB_SQUARE_SIZE);
		copyReconShapeToMbAndRef (ppxlcCurrMBBY, ppxlcCurrMBBYFrm, MPEG4_TRANSPARENT);
		pmbmd->m_rgTranspStatus [0] = pmbmd->m_rgTranspStatus [1] = pmbmd->m_rgTranspStatus [2] = pmbmd->m_rgTranspStatus [3] =
		pmbmd->m_rgTranspStatus [4] = pmbmd->m_rgTranspStatus [5] = pmbmd->m_rgTranspStatus [6] = ALL;
	}
	else if (iBits == rgiShapeMdCode [ALL_OPAQUE])	{
		pmbmd->m_shpmd = ALL_OPAQUE;//printf("X");
		copyReconShapeToMbAndRef (ppxlcCurrMBBY, ppxlcCurrMBBYFrm, MPEG4_OPAQUE);
		pmbmd->m_rgTranspStatus [0] = pmbmd->m_rgTranspStatus [1] = pmbmd->m_rgTranspStatus [2] = pmbmd->m_rgTranspStatus [3] =
		pmbmd->m_rgTranspStatus [4] = pmbmd->m_rgTranspStatus [5] = pmbmd->m_rgTranspStatus [6] = NONE;
	}
	else if (iBits == rgiShapeMdCode [INTRA_CAE])	{	
		pmbmd->m_shpmd = INTRA_CAE;//printf("S");
		decodeIntraCaeBAB (ppxlcCurrMBBY, ppxlcCurrMBBYFrm);
		decideTransparencyStatus (pmbmd, ppxlcCurrMBBY);
		assert (pmbmd->m_rgTranspStatus [0] == PARTIAL);
	}
	else
		assert (FALSE);
}

Void CVideoObjectDecoder::decodeInterShape (CVOPU8YUVBA* pvopcRefQ, CMBMode* pmbmd, CoordI iMBX, CoordI iMBY, CoordI iX, CoordI iY, CMotionVector* pmv, CMotionVector* pmvBY, PixelC* ppxlcMBBY, PixelC* ppxlcMBBYFrm, const ShapeMode& shpmdColocatedMB)
{
	assert (shpmdColocatedMB != UNKNOWN);
	//	Added for error resilient mode by Toshiba(1997-11-14)
	//printf("m_iVPMBnum=%d\n",m_iVPMBnum);
	Int iMBnum = VPMBnum(iMBX, iMBY);
	m_bVPNoLeft = bVPNoLeft(iMBnum, iMBX);
	m_bVPNoTop = bVPNoTop(iMBnum);
	m_bVPNoRightTop = bVPNoRightTop(iMBnum, iMBX);
	m_bVPNoLeftTop = bVPNoLeftTop(iMBnum, iMBX);

	//printf("(%d,%d)",iMBX,iMBY);
	CEntropyDecoder* pentrdec = m_pentrdecSet->m_ppentrdecShapeMode [shpmdColocatedMB];
	pmbmd->m_shpmd = (ShapeMode) pentrdec->decodeSymbol ();
	//printf("[%08x]",m_pbitstrmIn->peekBits(32));
	if (pmbmd->m_shpmd == ALL_TRANSP)	{//printf("_");
		copyReconShapeToMbAndRef (ppxlcMBBY, ppxlcMBBYFrm, MPEG4_TRANSPARENT);
		pmbmd->m_rgTranspStatus [0] = pmbmd->m_rgTranspStatus [1] = pmbmd->m_rgTranspStatus [2] = pmbmd->m_rgTranspStatus [3] =
		pmbmd->m_rgTranspStatus [4] = pmbmd->m_rgTranspStatus [5] = pmbmd->m_rgTranspStatus [6] = ALL;
	}
	else if (pmbmd->m_shpmd == ALL_OPAQUE)	{//printf("X");
		copyReconShapeToMbAndRef (ppxlcMBBY, ppxlcMBBYFrm, MPEG4_OPAQUE);
		pmbmd->m_rgTranspStatus [0] = pmbmd->m_rgTranspStatus [1] = pmbmd->m_rgTranspStatus [2] = pmbmd->m_rgTranspStatus [3] =
		pmbmd->m_rgTranspStatus [4] = pmbmd->m_rgTranspStatus [5] = pmbmd->m_rgTranspStatus [6] = NONE;
	}
	else if (pmbmd->m_shpmd == INTRA_CAE)	{//printf("S");
		decodeIntraCaeBAB (ppxlcMBBY, ppxlcMBBYFrm);
		decideTransparencyStatus (pmbmd, ppxlcMBBY);
		assert (pmbmd->m_rgTranspStatus [0] == PARTIAL || pmbmd->m_rgTranspStatus [0] == NONE);
	}
	else {//printf("M");
		CMotionVector mvShapeDiff (0, 0);
		if (pmbmd->m_shpmd == MVDNZ_NOUPDT || pmbmd->m_shpmd == INTER_CAE_MVDNZ)	
			decodeMVDS (mvShapeDiff);
		CMotionVector mvShapeMVP = findShapeMVP (pmv, pmvBY, pmbmd, iMBX, iMBY);
		*pmvBY = mvShapeMVP + mvShapeDiff;
		//printf("(%d,%d)",pmvBY->iMVX*2,pmvBY->iMVY*2);
		//motion comp
		motionCompBY ((PixelC*) m_puciPredBAB->pixels (),
					  (PixelC*) pvopcRefQ->getPlane (BY_PLANE)->pixels (),
					  pmvBY->iMVX + iX - 1,		
					  pmvBY->iMVY + iY - 1);	//-1 due to 18x18 motion comp
		if (pmbmd->m_shpmd == INTER_CAE_MVDZ || pmbmd->m_shpmd == INTER_CAE_MVDNZ)
		{
			m_iInverseCR = 1;
			m_iWidthCurrBAB = BAB_SIZE;
			const PixelC *ppxlcPredBAB = m_puciPredBAB->pixels ();
			if(!m_volmd.bNoCrChange && m_pbitstrmIn->getBits (1) != 0)
			{
				if(m_pbitstrmIn->getBits (1) == 0)
				{
					m_iInverseCR = 2;
					m_iWidthCurrBAB = 12;
					downSampleShapeMCPred(ppxlcPredBAB,m_ppxlcPredBABDown2,2);
					ppxlcPredBAB = m_ppxlcPredBABDown2;
					subsampleLeftTopBorderFromVOP (ppxlcMBBYFrm, m_ppxlcCurrMBBYDown2);
					m_rgpxlcCaeSymbol = m_ppxlcCurrMBBYDown2;
				}
				else
				{
					m_iInverseCR = 4;
					m_iWidthCurrBAB = 8;
					downSampleShapeMCPred(ppxlcPredBAB,m_ppxlcPredBABDown4,4);
					ppxlcPredBAB = m_ppxlcPredBABDown4;
					subsampleLeftTopBorderFromVOP (ppxlcMBBYFrm, m_ppxlcCurrMBBYDown4);
					m_rgpxlcCaeSymbol = m_ppxlcCurrMBBYDown4;
				}	
			}
			else
			{
				copyLeftTopBorderFromVOP (ppxlcMBBYFrm, m_ppxlcReconCurrBAB);  //used for upsample and CAE
				m_rgpxlcCaeSymbol = m_ppxlcReconCurrBAB;		//assign encoding buffer
			}

			if (m_pbitstrmIn->getBits (1) == 1)
				decodeInterCAEH (ppxlcPredBAB);			//right bottom border made on the fly
			else
				decodeInterCAEV (ppxlcPredBAB); 

			if(m_iInverseCR>1)