xref: /frameworks/av/media/libstagefright/codecs/on2/h264dec/omxdl/reference/vc/m4p10/src/armVCM4P10_UnpackBlock2x2.c

/*
 * Copyright (C) 2007-2008 ARM Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
/* ----------------------------------------------------------------
 *
 *
 * File Name:  armVCM4P10_UnpackBlock2x2.c
 * OpenMAX DL: v1.0.2
 * Revision:   9641
 * Date:       Thursday, February 7, 2008
 *
 *
 *
 *
 * H.264 inverse quantize and transform helper module
 *
 */

#include "omxtypes.h"
#include "armOMX.h"
#include "omxVC.h"

#include "armVC.h"

/*
 * Description
 * Unpack a 2x2 block of coefficient-residual pair values
 *
 * Parameters:
 * [in]	ppSrc	Double pointer to residual coefficient-position pair
 *						buffer output by CALVC decoding
 * [out]	ppSrc	*ppSrc is updated to the start of next non empty block
 * [out]	pDst	Pointer to unpacked 4x4 block
 */

void armVCM4P10_UnpackBlock2x2(
     const OMX_U8 **ppSrc,
     OMX_S16* pDst
)
{
    const OMX_U8 *pSrc = *ppSrc;
    int i;
    int Flag, Value;

    for (i=0; i<4; i++)
    {
        pDst[i] = 0;
    }

    do
    {
        Flag  = *pSrc++;
        if (Flag & 0x10)
        {
            /* 16 bit */
            Value = *pSrc++;
            Value = Value | ((*pSrc++)<<8);
            if (Value & 0x8000)
            {
                Value -= 0x10000;
            }
        }
        else
        {
            /* 8 bit */
            Value = *pSrc++;
            if (Value & 0x80)
            {
                Value -= 0x100;
            }
        }
        i = Flag & 15;
        pDst[i] = (OMX_S16)Value;
    }
    while ((Flag & 0x20)==0);

    *ppSrc = pSrc;
}

/* End of file */