swdec_vop.c

freescale i.mx31 BSP CE5.0全部源码

/*------------------------------------------------------------------------------
--                                                                            --
--       This software is confidential and proprietary and may be used        --
--        only as expressly authorized by a licensing agreement from          --
--                                                                            --
--                            Hantro Products Oy.                             --
--                                                                            --
--      In the event of publication, the following notice is applicable:      --
--                                                                            --
--                   (C) COPYRIGHT 2004 HANTRO PRODUCTS OY                    --
--                            ALL RIGHTS RESERVED                             --
--                                                                            --
--         The entire notice above must be reproduced on all copies.          --
--                                                                            --
--------------------------------------------------------------------------------
--
--  Abstract : VOP decoding functionality 
--
-------------------------------------------------------------------------------*/


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

    Table of contents
   
     1. Include headers
     2. External identifiers
     3. Module defines
     4. Module identifiers
     5. Fuctions
        5.1     SwDec_DecodeVopHeader
        5.2     SwDec_DecodeVop
        5.3     SwDec_ReadVopComplexity

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


/*------------------------------------------------------------------------------
    1. Include headers
------------------------------------------------------------------------------*/

#include "SwDec_Vop.h"
#include "SwDec_Utils.h"
#include "SwDec_MotionTexture.h"
#include "MP4SwDecApi.h" /* for Memcpy */

/*------------------------------------------------------------------------------
    2. External identifiers 
------------------------------------------------------------------------------*/

#ifndef MP4DEC_H263_ONLY

/*------------------------------------------------------------------------------
    3. Module defines 
------------------------------------------------------------------------------*/

/*------------------------------------------------------------------------------
    4. Module indentifiers 
------------------------------------------------------------------------------*/

static const u32 stuffingTable[8] = {0x0,0x1,0x3,0x7,0xF,0x1F,0x3F,0x7F};

STATIC u32 SwDec_DecodeVopHeader(decContainer_t *pDecContainer);
STATIC u32 SwDec_ReadVopComplexity(decContainer_t *pDecContainer);

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

   5.1  Function name: SwDec_DecodeVopHeader

        Purpose: Decode VideoObjectPlane header
                 
        Input: 
            Pointer to decContainer_t structure

        Output:
            HANTRO_OK/HANTRO_NOK/END_OF_STREAM

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

u32 SwDec_DecodeVopHeader(decContainer_t *pDecContainer)
{

    u32 i,tmp;
    i32 itmp;
    u32 moduloTimeBase,vopTimeIncrement;
    u32 status = HANTRO_OK;

    /* check that previous vop was finished, if it wasnt't return start code
     * into the stream and get away */
    if (pDecContainer->StrmStorage.vpMbNumber)
    {
        (void)SwDec_UnFlushBits(pDecContainer,32);
        pDecContainer->StrmStorage.pLastSync =
            pDecContainer->StrmDesc.pStrmCurrPos;
        return(HANTRO_NOK);
    }

    /* vop header is non valid until successively decoded */
    pDecContainer->StrmStorage.validVopHeader = 0;

    pDecContainer->StrmStorage.vpMbNumber = 0;
    pDecContainer->StrmStorage.vpNumMbs = 0;

    pDecContainer->StrmStorage.resyncMarkerLength = 0;

    tmp = SwDec_GetBits(pDecContainer,2); /* vop coding type */
    CHECK_END_OF_STREAM(tmp);

    if ( (tmp != IVOP) && (tmp != PVOP) )
    {
        return(HANTRO_NOK);
    }

    pDecContainer->VopDesc.vopCodingType = tmp;

    /* Time codes updated at the end of function so that they won't be updated
     * twice if header is lost (updated if vop header lost and header extension
     * received in video packet header) */

    /* modulo time base */
    moduloTimeBase = 0;
    while ((tmp = SwDec_GetOneBit(pDecContainer)) == 1) 
        moduloTimeBase++;

    CHECK_END_OF_STREAM(tmp);

    /* marker */
    tmp = SwDec_GetOneBit(pDecContainer);
    CHECK_END_OF_STREAM(tmp);
    if (tmp == 0) 
    {
        return(HANTRO_NOK);
    }

    /* number of bits needed to represent [0,vop_time_increment_resolution) */
    i = SwDec_NumBits(pDecContainer->Hdrs.vopTimeIncrementResolution - 1);
    vopTimeIncrement = SwDec_GetBits(pDecContainer, i);
    CHECK_END_OF_STREAM(vopTimeIncrement);

    if (vopTimeIncrement >=
        pDecContainer->Hdrs.vopTimeIncrementResolution)
    {
        return(HANTRO_NOK);
    }

    /* marker */
    tmp = SwDec_GetOneBit(pDecContainer);
    CHECK_END_OF_STREAM(tmp);
    if (tmp == 0)
    {
        return(HANTRO_NOK);
    }

    /* vop coded */
    tmp = SwDec_GetOneBit(pDecContainer);
    CHECK_END_OF_STREAM(tmp);
    pDecContainer->VopDesc.vopCoded = tmp;

    if (pDecContainer->VopDesc.vopCoded)
    {
        /* vop rounding type */
        if (pDecContainer->VopDesc.vopCodingType == PVOP)
        {
            tmp = SwDec_GetOneBit(pDecContainer);
            CHECK_END_OF_STREAM(tmp);
        }
        else
        {
            tmp = 0;
        }
        pDecContainer->VopDesc.vopRoundingType = tmp;

        if (!pDecContainer->Hdrs.complexityEstimationDisable)
        {
            status = SwDec_ReadVopComplexity(pDecContainer);
            if (status != HANTRO_OK) return(status);
        }

        tmp = SwDec_GetBits(pDecContainer,3);
        CHECK_END_OF_STREAM(tmp);
        pDecContainer->VopDesc.intraDcVlcThr = tmp;

        pDecContainer->VopDesc.QP = SwDec_GetBits(pDecContainer,5);
        CHECK_END_OF_STREAM(pDecContainer->VopDesc.QP);
        if (pDecContainer->VopDesc.QP == 0)
        {
            return(HANTRO_NOK);
        }
        pDecContainer->StrmStorage.QP = pDecContainer->VopDesc.QP;
        pDecContainer->StrmStorage.prevQP = pDecContainer->VopDesc.QP;
        pDecContainer->StrmStorage.vpQP = pDecContainer->VopDesc.QP;

        if (pDecContainer->VopDesc.vopCodingType == PVOP)
        {
            tmp = SwDec_GetBits(pDecContainer,3);
            CHECK_END_OF_STREAM(tmp);
            if (tmp == 0)
            {
                return(HANTRO_NOK);
            }
            pDecContainer->VopDesc.fcodeFwd = tmp;
        }
        else
        {
            /* set vop_fcode_fwd of intra VOP to 1 for resync marker length
             * computation */
            pDecContainer->VopDesc.fcodeFwd = 1;
        }
        pDecContainer->StrmStorage.resyncMarkerLength = 
            pDecContainer->VopDesc.fcodeFwd + 16;
    }


    /* update time codes */
    pDecContainer->VopDesc.timeCodeSeconds += moduloTimeBase;
    /* to support modulo_time_base values higher than 60 -> while */
    while (pDecContainer->VopDesc.timeCodeSeconds >= 60)
    {
        pDecContainer->VopDesc.timeCodeSeconds -= 60;
        pDecContainer->VopDesc.timeCodeMinutes++;
        if (pDecContainer->VopDesc.timeCodeMinutes >= 60)
        {
            pDecContainer->VopDesc.timeCodeMinutes -= 60;
            pDecContainer->VopDesc.timeCodeHours++;
        }
    }
    /* compute tics since previous picture */
    itmp = (i32)vopTimeIncrement -
        (i32)pDecContainer->VopDesc.vopTimeIncrement +
        (i32)moduloTimeBase*
        (i32)pDecContainer->Hdrs.vopTimeIncrementResolution;
    pDecContainer->VopDesc.ticsFromPrev = (itmp >= 0) ? (u32)itmp:
        (u32)(itmp + (i32)pDecContainer->Hdrs.vopTimeIncrementResolution);
    pDecContainer->VopDesc.vopTimeIncrement = vopTimeIncrement;
    pDecContainer->VopDesc.moduloTimeBase = moduloTimeBase;

    /* everything ok this far -> set vop header valid. If vop was not coded
     * don't set the flag -> if there were errors in vop header decoding they
     * don't limit decoding of header extension in video packets. */
    if (pDecContainer->VopDesc.vopCoded)
    {
        pDecContainer->StrmStorage.validVopHeader = 1;
    }

    return(HANTRO_OK);
}
	
/*------------------------------------------------------------------------------

   5.2  Function name: SwDec_DecodeVop

        Purpose: Decode VideoObjectPlane
                 
        Input: 
            Pointer to decContainer_t structure