umc_vc1_dec_ipic.cpp

audio-video-codecs.rar语音编解码器

/* /////////////////////////////////////////////////////////////////////////////
//
//                  INTEL CORPORATION PROPRIETARY INFORMATION
//     This software is supplied under the terms of a license agreement or
//     nondisclosure agreement with Intel Corporation and may not be copied
//     or disclosed except in accordance with the terms of that agreement.
//          Copyright(c) 2004-2007 Intel Corporation. All Rights Reserved.
//
//
//          VC-1 (VC1) decoder, I picture layer for simple\main profiles
//
*/
#include "umc_defs.h"

#if defined (UMC_ENABLE_VC1_VIDEO_DECODER)

#include <memory.h>

#include "umc_vc1_dec_seq.h"

#include "umc_vc1_dec_time_statistics.h"

//Simplw/Main profiles I picture
VC1Status DecodePictureLayer_ProgressiveIpicture(VC1Context* pContext)
{
    VC1Status vc1Res = VC1_OK;
    Ipp32u tempValue;

    VC1PictureLayerHeader* picLayerHeader = pContext->m_picLayerHeader;
    VC1SequenceLayerHeader* seqLayerHeader = pContext->m_seqLayerHeader;


    seqLayerHeader->RNDCTRL = 1;
    pContext->interp_params_luma.roundControl = seqLayerHeader->RNDCTRL;
    pContext->interp_params_chroma.roundControl = seqLayerHeader->RNDCTRL;


    if (picLayerHeader->PTYPE == VC1_I_FRAME)
        memset(pContext->savedMV,VC1_MVINTRA,sizeof(Ipp16s)*seqLayerHeader->heightMB*seqLayerHeader->widthMB*4*2);

    //4.1.1.1 The BF field is currently undefined
    //3.2.1.6 BF is a 7-bit field that is only present in I-picture
    //headers.
    VC1_GET_BITS(7, tempValue);   //BF

    //PQINDEX is a 5-bit field that signals the quantizer scale index
    //for the entire frame. It is present in all picture types.  If the
    //implicit quantizer is used (signaled by sequence field
    //QUANTIZER = 00, see section 3.1.19) then PQINDEX specifies both
    //the picture quantizer scale (PQUANT) and the quantizer
    //(3QP or 5QP deadzone) used for the frame. Table 5 shows how
    //PQINDEX is translated to PQUANT and the quantizer for implicit mode.
    //If the quantizer is signaled explicitly at the sequence or frame
    //level (signaled by sequence field QUANTIZER = 01, 10 or 11 see
    //section 3.1.19) then PQINDEX is translated to the picture quantizer
    //stepsize PQUANT as indicated by Table 6.
    VC1_GET_BITS(5, picLayerHeader->PQINDEX);
    CalculatePQuant(pContext);

    if(picLayerHeader->PQINDEX <= 8)
    {
        //3.2.1.8
        //HALFQP is a 1bit field present in all frame types if QPINDEX
        //is less than or equal to 8. The HALFQP field allows the picture
        //quantizer to be expressed in half step increments over the low
        //PQUANT range. If HALFQP = 1 then the picture quantizer stepsize
        //is PQUANT + ?. If HALFQP = 0 then the picture quantizer
        //stepize is PQUANT. Therefore, if the 3QP deadzone quantizer
        //is used then half stepsizes are possible up to PQUANT = 9
        //(i.e., PQUANT = 1, 1.5, 2, 2.5