mbheaddec.c

au1200 linux2.6.11 硬件解码mae驱动和maiplayer播放器源码

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

This software module was originally developed by 

	Wei-ge Chen ([e-mail]), Microsoft Corporation
	Ming-Chieh Lee ([e-mail]), Microsoft Corporation
	Simon Winder ([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)

and also edited by
	Dick van Smirren ([e-mail]), KPN Research
	Cor Quist ([e-mail]), KPN Research
	(date: July, 1998)

and also edited by
	Yoshinori Suzuki (Hitachi, Ltd.)

and also edited by
	Hideaki Kimata (NTT)

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:

	MBHeadDec.cpp

Abstract:

	MacroBlock overhead decoder

Revision History:

	This software module was edited by

		Hiroyuki Katata ([e-mail]), Sharp Corporation
		Norio Ito ([e-mail]), Sharp Corporation
		Shuichi Watanabe ([e-mail]), Sharp Corporation
		(date: October, 1997)

	for object based temporal scalability.
    
	Dec 20, 1997:	Interlaced tools added by NextLevel Systems (GI)
                    X. Chen ([e-mail]), B. Eifrig ([e-mail])
	Feb. 24, 1999:	GMC added by Y. Suzuki (Hitachi, Ltd.)
	Mar.13	2000 : MB stuffing decoding added by Hideaki Kimata (NTT)
	May.25  2000 : MB stuffing decoding on the last MB by Hideaki Kimata (NTT)

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

#include "typeapi.h"
#include "codehead.h"
#include "mode.h"
#include "global.h"
#ifdef UNDER_CE
#include "bitstrm.h"
#include "huffman.h"
#else
#include "entropy/bitstrm.h"
#include "entropy/huffman.h"
#endif
#include "vopses.h"
#include "vopsedec.h"

//#define USE_BSFAST

// Moved from vopses.cpp
Void setDCVLCMode(CMBMode* pmbmd, Bool *pbBoundary)
{
    if(pmbmd->m_dctMd == INTRA || pmbmd->m_dctMd == INTRAQ || !pmbmd->m_bSkip)
    {
        Int iQP;
        if(*pbBoundary)
        {
            *pbBoundary = FALSE;
            iQP = pmbmd->m_stepSize; // current qp
        }
        else
            iQP = pmbmd->m_stepSize - pmbmd->m_intStepDelta; // previous qp

        if (g_pVOP->iIntraDcSwitchThr != 0) 
        {
            if (g_pVOP->iIntraDcSwitchThr == 7)
                pmbmd->m_bCodeDcAsAc = TRUE;

            else if (iQP >= (2 * g_pVOP->iIntraDcSwitchThr + 11))
                pmbmd->m_bCodeDcAsAc = TRUE;

            else
                pmbmd->m_bCodeDcAsAc = FALSE;
        }

        else
            pmbmd->m_bCodeDcAsAc = FALSE;
    }
}

INLINE Void decodeMBTextureHeadOfIVOP (CMBMode* pmbmd, Int *iCurrentQP, Bool *pbRestart)
{
	Int iBlk = 0, iCBPC = 0, iCBPY = 0, iMCBPC = 8;  

#ifdef USE_BSFAST
    _BSFAST_DECL;
    UInt bitsread;
    _BSFAST_INIT();
#endif

	while (iMCBPC == 8) 
    {
#ifdef USE_BSFAST
         iMCBPC = decodeSymbol_WithFastBS (m_pentrdecMCBPCintra,_BSFastCurrentBits(), &bitsread);
         _BSFastSkipBits(bitsread);
         _BSFastCheckedPreload();
#else
         iMCBPC = decodeSymbol (m_pentrdecMCBPCintra);
#endif  // USE_BSFAST
	}

#ifndef NO_ASSERTS
	assert (iMCBPC >= 0 && iMCBPC <= 8);
#endif

	pmbmd->m_dctMd = INTRA;
	pmbmd->m_bSkip = FALSE;  //reset for direct mode 
	pmbmd->m_bMCSEL = FALSE; //reset for direct mode 
	pmbmd->m_bFieldMV = 0;
	pmbmd->m_intStepDelta = 0;

	if (iMCBPC > 3)
		pmbmd->m_dctMd = INTRAQ;

	iCBPC = iMCBPC % 4;

    if (!main_short_video_header) 
    {
#ifdef USE_BSFAST
        pmbmd->m_bACPrediction =  _BSFastGetBits(1);
#else
        MP4V_RETSINGLEBIT(&pmbmd->m_bACPrediction);
#endif
    }

#ifdef USE_BSFAST
         iCBPY = decodeSymbol_WithFastBS (m_pentrdecCBPY,_BSFastCurrentBits(), &bitsread);
         _BSFastSkipBits(bitsread);
         _BSFastCheckedPreload();
#else
         iCBPY = decodeSymbol (m_pentrdecCBPY);
#endif // USE_BSFAST

	SETCBPYANDC (pmbmd, iCBPC, iCBPY);

	if (pmbmd->m_dctMd == INTRAQ)	
    {
    Int iQuantMax;
    Int iDQUANT;
#ifdef USE_BSFAST
        iDQUANT = _BSFastGetBits(2);
#else
        iDQUANT = getBits (2);
#endif

		switch (iDQUANT) 
        {
		    case 0:
                pmbmd->m_intStepDelta = -1;
			break;

		    case 1:
                pmbmd->m_intStepDelta = -2;
			break;

		    case 2:
                pmbmd->m_intStepDelta = 1;
			break;

		    case 3:
                pmbmd->m_intStepDelta = 2;
			break;

#ifndef NO_ASSERTS
		    default:
                assert (FALSE);
#endif
		}

		(*iCurrentQP) += pmbmd->m_intStepDelta;
		iQuantMax = (1<<g_pVOL->uiQuantPrecision) - 1;
		CHECKRANGE ((*iCurrentQP), 1, iQuantMax);
	}

#ifdef USE_BSFAST
    _BSFAST_DONE();
#endif
	pmbmd->m_stepSize = (*iCurrentQP);

#ifdef ENABLE_INTERLACING
	if (g_pVOP->bInterlace)
		pmbmd->m_bFieldDCT = getSingleBit (); // get dct_type
#endif

	setDCVLCMode(pmbmd, pbRestart);
}

// Inter
INLINE Void decodeMBTextureHeadOfPVOP (CMBMode* pmbmd, Int *iCurrentQP, Bool *pbRestart)
{
	Int iBlk = 0, iCBPC = 0, iCBPY = 0, iMCBPC;

#ifdef USE_BSFAST
    _BSFAST_DECL;
    UInt bitsread;
    _BSFAST_INIT();
#endif

	do 
    {
        if (MP4V_EOF())
            return;
#ifdef USE_BSFAST
        pmbmd->m_bSkip =  _BSFastGetBits(1);
#else
        MP4V_RETSINGLEBIT(&pmbmd->m_bSkip);
#endif

		if (!pmbmd->m_bSkip) 
        {

#ifdef USE_BSFAST
            iMCBPC = decodeSymbol_WithFastBS (m_pentrdecMCBPCinter,_BSFastCurrentBits(), &bitsread);
            _BSFastSkipBits(bitsread);
            _BSFastCheckedPreload();
#else
			iMCBPC = decodeSymbol (m_pentrdecMCBPCinter);
#endif // USE_BSFAST

#ifndef NO_ASSERTS
			assert (iMCBPC >= 0 && iMCBPC <= 20);	
#endif
		}
	} while((!pmbmd->m_bSkip) && (iMCBPC == 20));


	if (!pmbmd->m_bSkip) 
    {
		Int iMBtype = iMCBPC / 4; //per H.263's MBtype
		pmbmd -> m_bFieldMV = FALSE;

		switch (iMBtype) 
        {
		    case 0:
    			pmbmd->m_dctMd = INTER;
    			pmbmd -> m_bhas4MVForward = FALSE;
			break;

		    case 1:
    			pmbmd->m_dctMd = INTERQ;
    			pmbmd -> m_bhas4MVForward = FALSE;
			break;

		    case 2:
    			pmbmd -> m_dctMd = INTER;
    			pmbmd -> m_bhas4MVForward = TRUE;
			break;

		    case 3:
                pmbmd->m_dctMd = INTRA;
			break;

		    case 4:
                pmbmd->m_dctMd = INTRAQ;
			break;

#ifndef NO_ASSERTS
		    default:
                assert (FALSE);
#endif
		}

		iCBPC = iMCBPC % 4;
// GMC
		pmbmd->m_bMCSEL = FALSE;

#ifdef ENABLE_SPRITE
		if((pmbmd->m_dctMd == INTER || pmbmd->m_dctMd == INTERQ) && (pmbmd -> m_bhas4MVForward == FALSE) && (g_pVOP->vopPredType == SPRITE))
		{
#ifdef USE_BSFAST
            pmbmd->m_bMCSEL = _BSFastGetBits(1);
#else
            MP4V_RETSINGLEBIT (&pmbmd->m_bMCSEL);
#endif
		}
#endif
// ~GMC
		if (pmbmd->m_dctMd == INTRA || pmbmd->m_dctMd == INTRAQ)	
        {
			if (!main_short_video_header)
            {
#ifdef USE_BSFAST
                pmbmd->m_bACPrediction = _BSFastGetBits(1);
#else
                MP4V_RETSINGLEBIT(&pmbmd->m_bACPrediction);
#endif
            }

#ifdef USE_BSFAST
            iCBPY = decodeSymbol_WithFastBS (m_pentrdecCBPY,_BSFastCurrentBits(), &bitsread);
#else
            iCBPY = decodeSymbol (m_pentrdecCBPY);
#endif // USE_BSFAST
		}

		else 
        {
#ifdef USE_BSFAST
            iCBPY = 15 - decodeSymbol_WithFastBS (m_pentrdecCBPY,_BSFastCurrentBits(), &bitsread);
#else
            iCBPY = 15 - decodeSymbol (m_pentrdecCBPY);
#endif // USE_BSFAST
		}
#ifdef USE_BSFAST
        _BSFastSkipBits(bitsread);
        _BSFastCheckedPreload();
#endif

#ifndef NO_ASSERTS
		assert (iCBPY >= 0 && iCBPY <= 15);			
#endif
	}

	else
  	{									//skipped
		pmbmd->m_dctMd = INTER;
		pmbmd -> m_bhas4MVForward = FALSE;
		pmbmd -> m_bFieldMV = FALSE;
// GMC
		pmbmd -> m_bMCSEL = FALSE;

#ifdef ENABLE_SPRITE
//		if(g_pVO->m_uiSprite == 2 && g_pVOP->vopPredType == SPRITE)
		if(g_pVOP->vopPredType == SPRITE)
            pmbmd -> m_bMCSEL = TRUE;
#endif
// ~GMC
	}

	SETCBPYANDC (pmbmd, iCBPC, iCBPY);

	pmbmd->m_intStepDelta = 0;

	if (pmbmd->m_dctMd == INTERQ || pmbmd->m_dctMd == INTRAQ) 
    {
        Int iQuantMax;
        Int iDQUANT;

#ifndef NO_ASSERTS
		assert (!pmbmd->m_bSkip);
#endif

#ifdef USE_BSFAST
		iDQUANT = _BSFastGetBits (2);
#else
    iDQUANT = getBits (2);
#endif

		switch (iDQUANT)