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/**
*
* File Name: omxVCM4P2_DecodePadMV_PVOP.c
* OpenMAX DL: v1.0.2
* Revision: 9641
* Date: Thursday, February 7, 2008
*
* (c) Copyright 2007-2008 ARM Limited. All Rights Reserved.
*
*
*
* Description:
* Contains module for decoding MV and padding the same
*
*/
#include "omxtypes.h"
#include "armOMX.h"
#include "omxVC.h"
#include "armCOMM_Bitstream.h"
#include "armCOMM.h"
#include "armVCM4P2_Huff_Tables_VLC.h"
/**
* Function: omxVCM4P2_DecodePadMV_PVOP (6.2.5.1.1)
*
* Description:
* Decodes and pads the four motion vectors associated with a non-intra P-VOP
* macroblock. For macroblocks of type OMX_VC_INTER4V, the output MV is
* padded as specified in [ISO14496-2], subclause 7.6.1.6. Otherwise, for
* macroblocks of types other than OMX_VC_INTER4V, the decoded MV is copied to
* all four output MV buffer entries.
*
* Input Arguments:
*
* ppBitStream - pointer to the pointer to the current byte in the bit
* stream buffer
* pBitOffset - pointer to the bit position in the byte pointed to by
* *ppBitStream. *pBitOffset is valid within [0-7].
* pSrcMVLeftMB, pSrcMVUpperMB, and pSrcMVUpperRightMB - pointers to the
* motion vector buffers of the macroblocks specially at the left,
* upper, and upper-right side of the current macroblock,
* respectively; a value of NULL indicates unavailability. Note:
* Any neighborhood macroblock outside the current VOP or video
* packet or outside the current GOB (when short_video_header is
* 1 ) for which gob_header_empty is 0 is treated as
* transparent, according to [ISO14496-2], subclause 7.6.5.
* fcodeForward - a code equal to vop_fcode_forward in MPEG-4 bit stream
* syntax
* MBType - the type of the current macroblock. If MBType is not equal to
* OMX_VC_INTER4V, the destination motion vector buffer is still
* filled with the same decoded vector.
*
* Output Arguments:
*
* ppBitStream - *ppBitStream is updated after the block is decoded, so
* that it points to the current byte in the bit stream buffer
* pBitOffset - *pBitOffset is updated so that it points to the current bit
* position in the byte pointed by *ppBitStream
* pDstMVCurMB - pointer to the motion vector buffer for the current
* macroblock; contains four decoded motion vectors
*
* Return Value:
*
* OMX_Sts_NoErr - no error
* OMX_Sts_BadArgErr - bad arguments:
* - At least one of the following pointers is NULL:
* ppBitStream, *ppBitStream, pBitOffset, pDstMVCurMB
* - *pBitOffset exceeds [0,7]
* - fcodeForward exceeds (0,7]
* - MBType less than zero
* - motion vector buffer is not 4-byte aligned.
* OMX_Sts_Err - status error
*
*/
OMXResult omxVCM4P2_DecodePadMV_PVOP(
const OMX_U8 ** ppBitStream,
OMX_INT * pBitOffset,
OMXVCMotionVector * pSrcMVLeftMB,
OMXVCMotionVector *pSrcMVUpperMB,
OMXVCMotionVector * pSrcMVUpperRightMB,
OMXVCMotionVector * pDstMVCurMB,
OMX_INT fcodeForward,
OMXVCM4P2MacroblockType MBType
)
{
OMXVCMotionVector diffMV;
OMXVCMotionVector dstMVPredME[12];
OMX_INT iBlk, i, count = 1;
OMX_S32 mvHorResidual = 1, mvVerResidual = 1, mvHorData, mvVerData;
OMX_S8 scaleFactor, index;
OMX_S16 high, low, range;
/* Argument error checks */
armRetArgErrIf(ppBitStream == NULL, OMX_Sts_BadArgErr);
armRetArgErrIf(*ppBitStream == NULL, OMX_Sts_BadArgErr);
armRetArgErrIf(pBitOffset == NULL, OMX_Sts_BadArgErr);
armRetArgErrIf(pDstMVCurMB == NULL, OMX_Sts_BadArgErr);
armRetArgErrIf(((*pBitOffset < 0) || (*pBitOffset > 7)), OMX_Sts_BadArgErr);
armRetArgErrIf(((fcodeForward < 1) || (fcodeForward > 7)), \
OMX_Sts_BadArgErr);
armRetArgErrIf(!armIs4ByteAligned(pDstMVCurMB), OMX_Sts_BadArgErr);
if ((MBType == OMX_VC_INTRA) ||
(MBType == OMX_VC_INTRA_Q)
)
{
/* All MV's are zero */
for (i = 0; i < 4; i++)
{
pDstMVCurMB[i].dx = 0;
pDstMVCurMB[i].dy = 0;
}
return OMX_Sts_NoErr;
}
if ((MBType == OMX_VC_INTER4V) || (MBType == OMX_VC_INTER4V_Q))
{
count = 4;
}
else if ((MBType == OMX_VC_INTER) || (MBType == OMX_VC_INTER_Q))
{
count = 1;
}
/* Calculating the scale factor */
scaleFactor = 1 << (fcodeForward -1);
high = ( 32 * scaleFactor) - 1;
low = ( (-32) * scaleFactor);
range = ( 64 * scaleFactor);
/* Huffman decoding and MV reconstruction */
for (iBlk = 0; iBlk < count; iBlk++)
{
/* Huffman decoding to get Horizontal data and residual */
index = armUnPackVLC32(ppBitStream, pBitOffset,
armVCM4P2_aVlcMVD);
armRetDataErrIf(index == -1, OMX_Sts_Err);
mvHorData = index - 32;
if ((fcodeForward > 1) && (mvHorData != 0))
{
mvHorResidual = (OMX_S32) armGetBits(ppBitStream,
pBitOffset, (fcodeForward -1));
}
/* Huffman decoding to get Vertical data and residual */
index = armUnPackVLC32(ppBitStream, pBitOffset, armVCM4P2_aVlcMVD);
armRetDataErrIf(index == -1, OMX_Sts_Err);
mvVerData = index - 32;
if ((fcodeForward > 1) && (mvVerData != 0))
{
mvVerResidual = (OMX_S32) armGetBits(ppBitStream,
pBitOffset, (fcodeForward -1));
}
/* Calculating the differtial MV */
if ( (scaleFactor == 1) || (mvHorData == 0) )
{
diffMV.dx = mvHorData;
}
else
{
diffMV.dx = ((armAbs(mvHorData) - 1) * fcodeForward)
+ mvHorResidual + 1;
if (mvHorData < 0)
{
diffMV.dx = -diffMV.dx;
}
}
if ( (scaleFactor == 1) || (mvVerData == 0) )
{
diffMV.dy = mvVerData;
}
else
{
diffMV.dy = ((armAbs(mvVerData) - 1) * fcodeForward)
+ mvVerResidual + 1;
if (mvVerData < 0)
{
diffMV.dy = -diffMV.dy;
}
}
/* Find the predicted vector */
omxVCM4P2_FindMVpred (
pDstMVCurMB,
pSrcMVLeftMB,
pSrcMVUpperMB,
pSrcMVUpperRightMB,
&pDstMVCurMB[iBlk],
dstMVPredME,
iBlk);
/* Adding the difference to the predicted MV to reconstruct MV */
pDstMVCurMB[iBlk].dx += diffMV.dx;
pDstMVCurMB[iBlk].dy += diffMV.dy;
/* Checking the range and keeping it within the limits */
if ( pDstMVCurMB[iBlk].dx < low )
{
pDstMVCurMB[iBlk].dx += range;
}
if (pDstMVCurMB[iBlk].dx > high)
{
pDstMVCurMB[iBlk].dx -= range;
}
if ( pDstMVCurMB[iBlk].dy < low )
{
pDstMVCurMB[iBlk].dy += range;
}
if (pDstMVCurMB[iBlk].dy > high)
{
pDstMVCurMB[iBlk].dy -= range;
}
}
if ((MBType == OMX_VC_INTER) || (MBType == OMX_VC_INTER_Q))
{
pDstMVCurMB[1] = pDstMVCurMB[0];
pDstMVCurMB[2] = pDstMVCurMB[0];
pDstMVCurMB[3] = pDstMVCurMB[0];
}
return OMX_Sts_NoErr;
}
/* End of file */
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