swdec_vop.c

freescale i.mx31 BSP CE5.0全部源码

        Output:
            HANTRO_OK/HANTRO_NOK/END_OF_STREAM

------------------------------------------------------------------------------*/

u32 SwDec_DecodeVop(decContainer_t *pDecContainer)
{

    u32 tmp;
    u32 isEndOfVop;
    u32 stuffingLength;
    u32 isResyncMarker = 0;
    u32 status = HANTRO_OK;

    ASSERT(pDecContainer);
    ASSERT(!pDecContainer->StrmStorage.shortVideo);

    status = SwDec_DecodeVopHeader(pDecContainer);
    if (status != HANTRO_OK) return(status);

    if (pDecContainer->VopDesc.vopCoded)
    {
        status = SwDec_DecodeMotionTexture(pDecContainer);
        if (status != HANTRO_OK) return(status);
    }
    else
    {
        pDecContainer->StrmStorage.vpNumMbs =
            pDecContainer->VopDesc.totalMbInVop;
        
        /* copy previous picture if external memory allocation used */
        if (pDecContainer->StrmStorage.extPicBufAlloc)
        {
            MP4SwDecMemcpy(pDecContainer->pOut, pDecContainer->pRef, 
                (384 * pDecContainer->VopDesc.totalMbInVop));
        }
        else
        {
            tmp = (u32)pDecContainer->pRef;
            pDecContainer->pRef = pDecContainer->pOut;
            pDecContainer->pOut = (u8*)tmp;
        }
    }
    isEndOfVop = (pDecContainer->StrmStorage.vpMbNumber +
                  pDecContainer->StrmStorage.vpNumMbs) ==
                 pDecContainer->VopDesc.totalMbInVop;

    status = SwDec_GetStuffing(pDecContainer);
    if (status != HANTRO_OK)
    {
        /* NOT coded vop and problem in stuffing or next startcode
         * --> prevent concealing current vop */
        if (!pDecContainer->VopDesc.vopCoded)
        {
            pDecContainer->StrmStorage.vpMbNumber +=
                pDecContainer->StrmStorage.vpNumMbs;
            pDecContainer->StrmStorage.vpQP = pDecContainer->StrmStorage.QP;
            pDecContainer->StrmStorage.vpNumMbs = 0;
            
            return (HANTRO_OK);
        }
        else if (isEndOfVop)
        {
            /* read stuffing until stream ends or resync marker or
             * startcode found */
            while( !IS_END_OF_STREAM(pDecContainer) )
            {
                tmp = SwDec_ShowBits(pDecContainer,32);
                isResyncMarker = 
                    (tmp>>(32-pDecContainer->StrmStorage.resyncMarkerLength));
                
                /* break if there is resync marker or startcode */
                if ( (isResyncMarker == 0x1) || ((tmp>>8) == 0x1) )
                    break;
                /* read stuffing byte */
                stuffingLength = 8-pDecContainer->StrmDesc.bitPosInWord;
                tmp = SwDec_GetBits(pDecContainer,stuffingLength);

                /* check that stuffing is valid H.263 or MPEG-4 stuffing */
                if ( (tmp != 0) && (tmp != stuffingTable[stuffingLength - 1]))
                    return (HANTRO_NOK);
            }
        }
        else
            return(status);
    }

    /* there might be extra stuffing byte if next start code is video
     * object sequence start or end code */
    tmp = SwDec_ShowBitsAligned(pDecContainer,32,1);
    if ((tmp == SC_VOS_START) || (tmp == SC_VOS_END))
    {
        tmp = SwDec_GetStuffing(pDecContainer);
        if (tmp != HANTRO_OK)
        {
            /* NOT coded vop and problem in stuffing or next startcode
            * --> prevent concealing current vop */
            if (!pDecContainer->VopDesc.vopCoded)
            {
                pDecContainer->StrmStorage.vpMbNumber +=
                    pDecContainer->StrmStorage.vpNumMbs;
                pDecContainer->StrmStorage.vpQP = pDecContainer->StrmStorage.QP;
                pDecContainer->StrmStorage.vpNumMbs = 0;
                
                return (HANTRO_OK);
            }
            else
                return(tmp);
        }
    }

    /* skip all extra zero bits, not according to standard
     * but some encoders put zero bytes to stream */
    tmp = SwDec_ShowBits(pDecContainer, 24);
    if (tmp == 0)
    {
        /* while startcode prefix found or end of stream */
        while ( (tmp != 0x1) && !IS_END_OF_STREAM(pDecContainer))
        {
            SwDec_FlushBits(pDecContainer, 8);
            tmp = SwDec_ShowBits(pDecContainer, 24);
        }
    }
    
    /* stuffing ok -> check that there is proper start code or marker or
     * stream ends */
    tmp = SwDec_ShowBits(pDecContainer,32);
    if (/* END_OF_STREAM */
        (IS_END_OF_STREAM(pDecContainer)) ||
        /* RESYNC_MARKER (if enabled) */
        (((tmp>>(32-pDecContainer->StrmStorage.resyncMarkerLength)) == 0x01) &&
         !isEndOfVop) || 
        /* end of VOP and START_CODE or SC_ERROR (i.e. at least 23 zeros) */
        (isEndOfVop && !(tmp>>9))) 
    {
        /* whole video packet decoded and stuffing ok -> set vpMbNumber in
        * StrmStorage so that this video packet won't be touched/concealed
        * anymore. Also set VpQP to QP so that concealment will use qp of last
        * decoded macro block */
        pDecContainer->StrmStorage.vpMbNumber +=
            pDecContainer->StrmStorage.vpNumMbs;
        pDecContainer->StrmStorage.vpQP = pDecContainer->StrmStorage.QP;

        pDecContainer->StrmStorage.vpNumMbs = 0;

        return(HANTRO_OK);

    }
    else
    {
        /* NOT coded vop and problem in stuffing or next startcode
         * --> prevent concealing current vop */
        if (!pDecContainer->VopDesc.vopCoded)
        {
            pDecContainer->StrmStorage.vpMbNumber +=
                pDecContainer->StrmStorage.vpNumMbs;
            pDecContainer->StrmStorage.vpQP = pDecContainer->StrmStorage.QP;

            pDecContainer->StrmStorage.vpNumMbs = 0;
    
            return (HANTRO_OK);
        }
        else
            return(HANTRO_NOK);
    }

}
	
/*------------------------------------------------------------------------------

   5.3  Function name: SwDec_ReadVopComplexity

        Purpose: read vop complexity estimation header
                 
        Input: 
            Pointer to decContainer_t structure

        Output:
            HANTRO_OK/END_OF_STREAM

------------------------------------------------------------------------------*/

u32 SwDec_ReadVopComplexity(decContainer_t *pDecContainer)
{

    u32 tmp;

    ASSERT(pDecContainer);
    ASSERT((pDecContainer->VopDesc.vopCodingType == IVOP) ||
           (pDecContainer->VopDesc.vopCodingType == PVOP));

    tmp = 0;
    if (pDecContainer->Hdrs.estimationMethod == 0)
    {
        /* common stuff for I- and P-VOPs */
        if (pDecContainer->Hdrs.opaque)
            tmp = SwDec_GetBits(pDecContainer,8);
        if (pDecContainer->Hdrs.transparent)
            tmp = SwDec_GetBits(pDecContainer,8);
        if (pDecContainer->Hdrs.intraCae)
            tmp = SwDec_GetBits(pDecContainer,8);
        if (pDecContainer->Hdrs.interCae)
            tmp = SwDec_GetBits(pDecContainer,8);
        if (pDecContainer->Hdrs.noUpdate)
            tmp = SwDec_GetBits(pDecContainer,8);
        if (pDecContainer->Hdrs.upsampling)
            tmp = SwDec_GetBits(pDecContainer,8);
        if (pDecContainer->Hdrs.intraBlocks)
            tmp = SwDec_GetBits(pDecContainer,8);
        if (pDecContainer->Hdrs.notCodedBlocks)
            tmp = SwDec_GetBits(pDecContainer,8);
        if (pDecContainer->Hdrs.dctCoefs)
            tmp = SwDec_GetBits(pDecContainer,8);
        if (pDecContainer->Hdrs.dctLines)
            tmp = SwDec_GetBits(pDecContainer,8);
        if (pDecContainer->Hdrs.vlcSymbols)
            tmp = SwDec_GetBits(pDecContainer,8);
        /* NOTE that this is just 4 bits long */
        if (pDecContainer->Hdrs.vlcBits)
            tmp = SwDec_GetBits(pDecContainer,4);

        if (pDecContainer->VopDesc.vopCodingType == IVOP)
        {
            if (pDecContainer->Hdrs.sadct)
                tmp = SwDec_GetBits(pDecContainer,8);
        }
        else /* PVOP */
        {
            if (pDecContainer->Hdrs.interBlocks)
                tmp = SwDec_GetBits(pDecContainer,8);
            if (pDecContainer->Hdrs.inter4vBlocks)
                tmp = SwDec_GetBits(pDecContainer,8);
            if (pDecContainer->Hdrs.apm)
                tmp = SwDec_GetBits(pDecContainer,8);
            if (pDecContainer->Hdrs.npm)
                tmp = SwDec_GetBits(pDecContainer,8);
            if (pDecContainer->Hdrs.forwBackMcQ)
                tmp = SwDec_GetBits(pDecContainer,8);
            if (pDecContainer->Hdrs.halfpel2)
                tmp = SwDec_GetBits(pDecContainer,8);
            if (pDecContainer->Hdrs.halfpel4)
                tmp = SwDec_GetBits(pDecContainer,8);
            if (pDecContainer->Hdrs.sadct)
                tmp = SwDec_GetBits(pDecContainer,8);
            if (pDecContainer->Hdrs.quarterpel)
                tmp = SwDec_GetBits(pDecContainer,8);
        }
    }
    CHECK_END_OF_STREAM(tmp);

    return(HANTRO_OK);

}
#endif