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/**
*
* File Name: armVCM4P2_CheckVLCEscapeMode.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 VLC escape mode check
*
*/
#include "omxtypes.h"
#include "armOMX.h"
#include "armVC.h"
#include "armCOMM.h"
/**
* Function: armVCM4P2_CheckVLCEscapeMode
*
* Description:
* Performs escape mode decision based on the run, run+, level, level+ and
* last combinations.
*
* Remarks:
*
* Parameters:
* [in] run Run value (count of zeros) to be encoded
* [in] level Level value (non-zero value) to be encoded
* [in] runPlus Calculated as runPlus = run - (RMAX + 1)
* [in] levelPlus Calculated as
* levelPlus = sign(level)*[abs(level) - LMAX]
* [in] maxStoreRun Max store possible (considering last and inter/intra)
* [in] maxRunForMultipleEntries
* The run value after which level
* will be equal to 1:
* (considering last and inter/intra status)
* [in] pRunIndexTable Run Index table defined in
* armVCM4P2_Huff_Tables_VLC.c
* (considering last and inter/intra status)
*
*
* Return Value:
* Returns an Escape mode which can take values from 0 to 3
* 0 --> no escape mode, 1 --> escape type 1,
* 1 --> escape type 2, 3 --> escape type 3, check section 7.4.1.3
* in the MPEG ISO standard.
*
*/
OMX_U8 armVCM4P2_CheckVLCEscapeMode(
OMX_U32 run,
OMX_U32 runPlus,
OMX_S16 level,
OMX_S16 levelPlus,
OMX_U8 maxStoreRun,
OMX_U8 maxRunForMultipleEntries,
OMX_INT shortVideoHeader,
const OMX_U8 *pRunIndexTable
)
{
OMX_U8 escape = 0, fMode = 0, entries;
level = armAbs (level);
levelPlus = armAbs (levelPlus);
/* Check for a valid entry with run, level and Last combination
Mode 0 check */
if (run <= maxStoreRun)
{
entries = pRunIndexTable[run + 1]
- pRunIndexTable[run];
if (run > maxRunForMultipleEntries)
{
entries = 1;
}
if (level > entries)
{
escape = 1;
}
}
else
{
escape = 1;
}
if(escape && shortVideoHeader)
{
escape = 0;
fMode = 4;
}
/* Check for a valid entry with run, levelPlus and Last combination
Mode 1 check */
if (escape)
{
escape = 0;
fMode = 1;
if (run <= maxStoreRun)
{
entries = pRunIndexTable[run + 1]
- pRunIndexTable[run];
if (run > maxRunForMultipleEntries)
{
entries = 1;
}
if (levelPlus > entries)
{
escape = 1;
}
}
else
{
escape = 1;
}
}
/* Check for a valid entry with runPlus, level and Last combination
Mode 2 check */
if (escape)
{
escape = 0;
fMode = 2;
if (runPlus <= maxStoreRun)
{
entries = pRunIndexTable[runPlus + 1]
- pRunIndexTable[runPlus];
if (runPlus > maxRunForMultipleEntries)
{
entries = 1;
}
if (level > entries)
{
escape = 1;
}
}
else
{
escape = 1;
}
}
/* select mode 3 --> FLC */
if (escape)
{
fMode = 3;
}
return fMode;
}
/*End of File*/
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