mbheaddec.c

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

        {
		    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);
	}

	pmbmd->m_stepSize = (*iCurrentQP);

#ifdef ENABLE_INTERLACING
	if (m_vopmd.bInterlace && !pmbmd->m_bSkip) 
    {
		if ((pmbmd->m_dctMd == INTRA) || (pmbmd->m_dctMd == INTRAQ) || (iCBPY || iCBPC)) 
			pmbmd->m_bFieldDCT = getSingleBit (); // get dct_type
		else
			pmbmd->m_bFieldDCT = FALSE;
// GMC
		pmbmd->m_bFieldMV = FALSE;
// ~GMC
		if (((pmbmd->m_dctMd == INTERQ) || (pmbmd->m_dctMd == INTER)) && (pmbmd -> m_bhas4MVForward == FALSE) && (pmbmd -> m_bMCSEL == FALSE)) { // GMC
			pmbmd->m_bFieldMV = getSingleBit (); // get field_prediction
			if (pmbmd->m_bFieldMV == TRUE) {
				pmbmd->m_bForwardTop = getSingleBit (); // get top field reference
				pmbmd->m_bForwardBottom = getSingleBit (); // get bottom field reference
			}
		}
	}
#endif

#ifdef USE_BSFAST
    _BSFAST_DONE();
#endif

	setDCVLCMode(pmbmd, pbRestart);
}

// B-VOP
#ifndef USE_BSFAST
INLINE Void decodeMBTextureHeadOfBVOP (CMBMode* pmbmd, Int *iCurrQP)
{
	Int iBlk = 0, iMODB = 0, iMCBPC = 0, iCBPC = 0, iCBPY = 0, iMbType, uiCBPB = 0;
    Int nNextBit;

	pmbmd->m_bhas4MVForward = pmbmd->m_bhas4MVBackward = FALSE;
	pmbmd->m_bMCSEL = FALSE;
	pmbmd->m_bSkip = FALSE;
	pmbmd->m_dctMd = INTER;
	pmbmd->m_intStepDelta = 0;
	pmbmd->m_bFieldDCT = FALSE;
	pmbmd->m_bFieldMV = FALSE;

    MP4V_RETSINGLEBIT(&nNextBit);

    if (MP4V_EOF())
        return;

	if (nNextBit == 1) //MODB=1 colocated non-skip but curr skip
    {
		pmbmd->m_bSkip = TRUE;  
		iMODB = 0;
		pmbmd->m_mbType = (!(g_pVOL->volType == ENHN_LAYER && g_pVOP->iRefSelectCode == 0))? DIRECT : FORWARD;

#ifdef DUAL_MODE
		if(g_pVOL->volType == ENHN_LAYER && m_vopmd.iRefSelectCode == 0)
			return;
#endif
	}

    else
    {
        MP4V_RETSINGLEBIT(&nNextBit);
        if (nNextBit == 1) //MODB="01"
        {
#ifdef DUAL_MODE
            if (g_pVOL->volType == BASE_LAYER || (g_pVOL->volType == ENHN_LAYER && g_pVOP->iRefSelectCode != 0))
#endif

                iMbType = decodeSymbol (m_pentrdecMbTypeBVOP);

#ifdef DUAL_MODE
    		else	
            {
    			if (getSingleBit () == 1)	
    				iMbType = FORWARD;
    			else if (getSingleBit () == 1)	
    				iMbType = INTERPOLATE;
    			else if (getSingleBit () == 1)
    				iMbType = BACKWARD;
    			else 
                {
    				fprintf(stderr,"MB Type 0000 does not exsit.\n");
    				exit(2);
    			}
    		}
#endif

#ifndef NO_ASSERTS
            assert (iMbType >= 0 && iMbType <= 3);
#endif
    		pmbmd->m_mbType = (MBType) iMbType;
    		iMODB = 1;
        }

        else //MODB="00"
        {
#ifdef DUAL_MODE
            if (g_pVOL->volType == BASE_LAYER || (g_pVOL->volType == ENHN_LAYER && g_pVOP->iRefSelectCode != 0))
#endif
                iMbType = decodeSymbol (m_pentrdecMbTypeBVOP);

#ifdef DUAL_MODE
    		else	
            {
    			if (getSingleBit () == 1)	
    				iMbType = FORWARD;
    			else if (getSingleBit () == 1)	
    				iMbType = INTERPOLATE;
    			else if (getSingleBit () == 1)
    				iMbType = BACKWARD;
    			else
                {
    				fprintf(stderr,"MB Type 0000 is not exsit.\n");
    				exit(2);
    			}
    		}
#endif

#ifndef NO_ASSERTS
            assert (iMbType >= 0 && iMbType <= 3);
#endif
    		pmbmd->m_mbType = (MBType) iMbType;		
    		iMODB = 2;

    		uiCBPB = getBits (6);
    		pmbmd->m_bhas4MVForward = pmbmd->m_bhas4MVBackward = FALSE;	//this is okay; will be reset later
    									//Only one mv for B-VOP except direct mode (will be reset in mvdec.cpp)
    		iCBPC = uiCBPB & 0x0003;
    		iCBPY = (uiCBPB >> 2) & 0x000F;
    		
    		if (pmbmd->m_mbType != DIRECT)	
            {
    			Int DQUANT = 0, iQuantMax;
                MP4V_RETSINGLEBIT(&nNextBit);
    
                if (nNextBit)
                {
                    DQUANT = -2;
                    MP4V_RETSINGLEBIT(&nNextBit);
    
                    if (nNextBit)
                        DQUANT = 2;
                }
    
    			pmbmd->m_intStepDelta = DQUANT;
    			(*iCurrQP) += pmbmd->m_intStepDelta;
    			iQuantMax = (1<<g_pVOL->uiQuantPrecision) - 1;
                CHECKRANGE ((*iCurrQP), 1, iQuantMax); 
    		}
        }
    }

	pmbmd->m_stepSize = (*iCurrQP);

	SETCBPYANDC (pmbmd, iCBPC, iCBPY);

	if (pmbmd->m_mbType == DIRECT)
		pmbmd->m_dctMd = INTER;		//direct mode doesn't have dquant
	else	
		pmbmd->m_dctMd = INTERQ;		//meaningless in B_VOP 'cause DQUANT is always sent

#ifdef ENABLE_INTERLACING
	if (m_vopmd.bInterlace) 
    {
		if (uiCBPB != 0)
			pmbmd->m_bFieldDCT = getSingleBit (); // get dct_type
		if (pmbmd->m_mbType != DIRECT) {
			pmbmd->m_bFieldMV = getSingleBit ();
			if (pmbmd->m_bFieldMV) {
				if (pmbmd->m_mbType != BACKWARD) {
					pmbmd->m_bForwardTop = getSingleBit ();
					pmbmd->m_bForwardBottom = getSingleBit ();
				}
				if (pmbmd->m_mbType != FORWARD) {
					pmbmd->m_bBackwardTop = getSingleBit ();
					pmbmd->m_bBackwardBottom = getSingleBit ();
				}
			}
		}
	}
#endif
}
#else // USE_BSFAST
INLINE Void decodeMBTextureHeadOfBVOP (CMBMode* pmbmd, Int *iCurrQP)
{
	Int iBlk = 0, iMODB = 0, iMCBPC = 0, iCBPC = 0, iCBPY = 0, iMbType, uiCBPB = 0;
    Int nNextBit, nPeakNextBit = 0;

  _BSFAST_DECL;
  UInt bitsread;
  _BSFAST_INIT();

	pmbmd->m_bhas4MVForward = pmbmd->m_bhas4MVBackward = FALSE;
	pmbmd->m_bMCSEL = FALSE;
	pmbmd->m_bSkip = FALSE;
	pmbmd->m_dctMd = INTER;
	pmbmd->m_intStepDelta = 0;
	pmbmd->m_bFieldDCT = FALSE;
	pmbmd->m_bFieldMV = FALSE;

    nNextBit = _BSFastGetBits(1);
    nPeakNextBit = _BSFastPeekBits(1);

    if (MP4V_EOF())
        return;

	if (nNextBit == 1) //MODB=1 colocated non-skip but curr skip
    {
		pmbmd->m_bSkip = TRUE;  
		iMODB = 0;
		pmbmd->m_mbType = (!(g_pVOL->volType == ENHN_LAYER && g_pVOP->iRefSelectCode == 0))? DIRECT : FORWARD;

#ifdef DUAL_MODE
		if(g_pVOL->volType == ENHN_LAYER && m_vopmd.iRefSelectCode == 0)
			return;
#endif
	}

    else if (nPeakNextBit == 1) //MODB="01"
    {
        _BSFastGetBits(1); // now read the actual bit we just peaked

#ifdef DUAL_MODE
		if (g_pVOL->volType == BASE_LAYER || (g_pVOL->volType == ENHN_LAYER && g_pVOP->iRefSelectCode != 0))
#endif

            {
                iMbType = decodeSymbol_WithFastBS (m_pentrdecMbTypeBVOP,_BSFastCurrentBits(), &bitsread);
                _BSFastSkipBits(bitsread);
                _BSFastCheckedPreload();
            }

#ifdef DUAL_MODE
		else	
        {
			if (getSingleBit () == 1)	
				iMbType = FORWARD;
			else if (getSingleBit () == 1)	
				iMbType = INTERPOLATE;
			else if (getSingleBit () == 1)
				iMbType = BACKWARD;
			else 
            {
				fprintf(stderr,"MB Type 0000 does not exsit.\n");
				exit(2);
			}
		}
#endif

#ifndef NO_ASSERTS
		assert (iMbType >= 0 && iMbType <= 3);
#endif
		pmbmd->m_mbType = (MBType) iMbType;
		iMODB = 1;
	}

    else //MODB="00"
    {
        _BSFastGetBits(1); // now read the actual bit we just peaked

#ifdef DUAL_MODE
		if (g_pVOL->volType == BASE_LAYER || (g_pVOL->volType == ENHN_LAYER && g_pVOP->iRefSelectCode != 0))
#endif

            {
                iMbType = decodeSymbol_WithFastBS (m_pentrdecMbTypeBVOP,_BSFastCurrentBits(), &bitsread);
                _BSFastSkipBits(bitsread);
                _BSFastCheckedPreload();
            }

#ifdef DUAL_MODE
		else	
        {
			if (getSingleBit () == 1)	
				iMbType = FORWARD;
			else if (getSingleBit () == 1)	
				iMbType = INTERPOLATE;
			else if (getSingleBit () == 1)
				iMbType = BACKWARD;
			else
            {
				fprintf(stderr,"MB Type 0000 is not exsit.\n");
				exit(2);
			}
		}
#endif

#ifndef NO_ASSERTS
		assert (iMbType >= 0 && iMbType <= 3);
#endif
		pmbmd->m_mbType = (MBType) iMbType;		
		iMODB = 2;
        uiCBPB =_BSFastGetBits(6);
		pmbmd->m_bhas4MVForward = pmbmd->m_bhas4MVBackward = FALSE;	//this is okay; will be reset later
									//Only one mv for B-VOP except direct mode (will be reset in mvdec.cpp)
		iCBPC = uiCBPB & 0x0003;
		iCBPY = (uiCBPB >> 2) & 0x000F;
		
		if (pmbmd->m_mbType != DIRECT)	
        {
			Int DQUANT;
      Int iQuantMax;
            nNextBit = _BSFastGetBits(1);
            if (!nNextBit)
				DQUANT = 0;
            else
            {
                nNextBit = _BSFastGetBits(1);
                if (!nNextBit)
                    DQUANT = -2;
                else
                    DQUANT = 2;
            }

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

	pmbmd->m_stepSize = (*iCurrQP);

	SETCBPYANDC (pmbmd, iCBPC, iCBPY);

	if (pmbmd->m_mbType == DIRECT)
		pmbmd->m_dctMd = INTER;		//direct mode doesn't have dquant
	else	
		pmbmd->m_dctMd = INTERQ;		//meaningless in B_VOP 'cause DQUANT is always sent

#ifdef ENABLE_INTERLACING
	if (m_vopmd.bInterlace) 
    {
		if (uiCBPB != 0)
			pmbmd->m_bFieldDCT = getSingleBit (); // get dct_type
		if (pmbmd->m_mbType != DIRECT) {
			pmbmd->m_bFieldMV = getSingleBit ();
			if (pmbmd->m_bFieldMV) {
				if (pmbmd->m_mbType != BACKWARD) {
					pmbmd->m_bForwardTop = getSingleBit ();
					pmbmd->m_bForwardBottom = getSingleBit ();
				}
				if (pmbmd->m_mbType != FORWARD) {
					pmbmd->m_bBackwardTop = getSingleBit ();
					pmbmd->m_bBackwardBottom = getSingleBit ();
				}
			}
		}
	}
#endif
    _BSFAST_DONE();
}
#endif // USE_BSFAST