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/**
*
* File Name: omxVCM4P2_EncodeVLCZigzag_IntraACVLC.c
* OpenMAX DL: v1.0.2
* Revision: 9641
* Date: Thursday, February 7, 2008
*
* (c) Copyright 2007-2008 ARM Limited. All Rights Reserved.
*
*
*
* Description:
* Contains modules for zigzag scanning and VLC encoding
* for intra block.
*
*/
#include "omxtypes.h"
#include "armOMX.h"
#include "omxVC.h"
#include "armVC.h"
/**
* Function: omxVCM4P2_EncodeVLCZigzag_IntraACVLC (6.2.4.5.2)
*
* Description:
* Performs zigzag scan and VLC encoding of AC and DC coefficients for one
* intra block. Two versions of the function (DCVLC and ACVLC) are provided
* in order to support the two different methods of processing DC
* coefficients, as described in [ISO14496-2], subclause 7.4.1.4, Intra DC
* Coefficient Decoding for the Case of Switched VLC Encoding.
*
* Input Arguments:
*
* ppBitStream - double pointer to the current byte in the bitstream
* pBitOffset - pointer to the bit position in the byte pointed by
* *ppBitStream. Valid within 0 to 7.
* pQDctBlkCoef - pointer to the quantized DCT coefficient
* predDir - AC prediction direction, which is used to decide the zigzag
* scan pattern; takes one of the following values:
* - OMX_VC_NONE - AC prediction not used.
* Performs classical zigzag scan.
* - OMX_VC_HORIZONTAL - Horizontal prediction.
* Performs alternate-vertical zigzag scan.
* - OMX_VC_VERTICAL - Vertical prediction.
* Performs alternate-horizontal zigzag scan.
* pattern - block pattern which is used to decide whether this block is
* encoded
* shortVideoHeader - binary flag indicating presence of
* short_video_header; escape modes 0-3 are used if
* shortVideoHeader==0, and escape mode 4 is used when
* shortVideoHeader==1.
*
* Output Arguments:
*
* ppBitStream - *ppBitStream is updated after the block is encoded, 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.
*
* Return Value:
*
* OMX_Sts_NoErr - no error
* OMX_Sts_BadArgErr - Bad arguments:
* - At least one of the following pointers is NULL: ppBitStream,
* *ppBitStream, pBitOffset, pQDctBlkCoef.
* - *pBitOffset < 0, or *pBitOffset >7.
* - PredDir is not one of: OMX_VC_NONE, OMX_VC_HORIZONTAL, or
* OMX_VC_VERTICAL.
* - VideoComp is not one component of enum OMXVCM4P2VideoComponent.
*
*/
OMXResult omxVCM4P2_EncodeVLCZigzag_IntraACVLC(
OMX_U8 **ppBitStream,
OMX_INT *pBitOffset,
const OMX_S16 *pQDctBlkCoef,
OMX_U8 predDir,
OMX_U8 pattern,
OMX_INT shortVideoHeader
)
{
OMX_U8 start = 0;
return armVCM4P2_EncodeVLCZigzag_Intra(
ppBitStream,
pBitOffset,
pQDctBlkCoef,
predDir,
pattern,
shortVideoHeader,
start);
}
/* End of file */
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