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/*
* 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: armVCM4P2_GetVLCBits.c
* OpenMAX DL: v1.0.2
* Revision: 9641
* Date: Thursday, February 7, 2008
*
*
*
*
* Description:
* Contains module for VLC get bits from the stream
*
*/
#include "omxtypes.h"
#include "armOMX.h"
#include "armVC.h"
#include "armCOMM.h"
#include "armCOMM_Bitstream.h"
#include "armVCM4P2_ZigZag_Tables.h"
#include "armVCM4P2_Huff_Tables_VLC.h"
/**
* Function: armVCM4P2_GetVLCBits
*
* Description:
* Performs escape mode decision based on the run, run+, level, level+ and
* last combinations.
*
* Remarks:
*
* Parameters:
* [in] ppBitStream pointer to the pointer to the current byte in
* the bit stream
* [in] pBitOffset pointer to the bit position in the byte pointed
* by *ppBitStream. Valid within 0 to 7
* [in] start start indicates whether the encoding begins with
* 0th element or 1st.
* [in/out] pLast pointer to last status flag
* [in] runBeginSingleLevelEntriesL0 The run value from which level
* will be equal to 1: last == 0
* [in] IndexBeginSingleLevelEntriesL0 Array index in the VLC table
* pointing to the
* runBeginSingleLevelEntriesL0
* [in] runBeginSingleLevelEntriesL1 The run value from which level
* will be equal to 1: last == 1
* [in] IndexBeginSingleLevelEntriesL1 Array index in the VLC table
* pointing to the
* runBeginSingleLevelEntriesL0
* [in] pRunIndexTableL0 Run Index table defined in
* armVCM4P2_Huff_Tables_VLC.c for last == 0
* [in] pVlcTableL0 VLC table for last == 0
* [in] pRunIndexTableL1 Run Index table defined in
* armVCM4P2_Huff_Tables_VLC.c for last == 1
* [in] pVlcTableL1 VLC table for last == 1
* [in] pLMAXTableL0 Level MAX table defined in
* armVCM4P2_Huff_Tables_VLC.c for last == 0
* [in] pLMAXTableL1 Level MAX table defined in
* armVCM4P2_Huff_Tables_VLC.c for last == 1
* [in] pRMAXTableL0 Run MAX table defined in
* armVCM4P2_Huff_Tables_VLC.c for last == 0
* [in] pRMAXTableL1 Run MAX table defined in
* armVCM4P2_Huff_Tables_VLC.c for last == 1
* [out]pDst pointer to the coefficient buffer of current
* block. Should be 32-bit aligned
*
* Return Value:
* Standard OMXResult result. See enumeration for possible result codes.
*
*/
OMXResult armVCM4P2_GetVLCBits (
const OMX_U8 **ppBitStream,
OMX_INT * pBitOffset,
OMX_S16 * pDst,
OMX_INT shortVideoHeader,
OMX_U8 start,
OMX_U8 * pLast,
OMX_U8 runBeginSingleLevelEntriesL0,
OMX_U8 maxIndexForMultipleEntriesL0,
OMX_U8 maxRunForMultipleEntriesL1,
OMX_U8 maxIndexForMultipleEntriesL1,
const OMX_U8 * pRunIndexTableL0,
const ARM_VLC32 *pVlcTableL0,
const OMX_U8 * pRunIndexTableL1,
const ARM_VLC32 *pVlcTableL1,
const OMX_U8 * pLMAXTableL0,
const OMX_U8 * pLMAXTableL1,
const OMX_U8 * pRMAXTableL0,
const OMX_U8 * pRMAXTableL1,
const OMX_U8 * pZigzagTable
)
{
OMX_U32 storeRun;
OMX_U8 tabIndex, markerBit;
OMX_S16 storeLevel;
OMX_U16 unpackRetIndex;
OMX_U8 i, fType, escape;
OMX_U8 sign = 0;
/* Unpacking the bitstream and RLD */
for (i = start; i < 64;)
{
escape = armLookAheadBits(ppBitStream, pBitOffset, 7);
if (escape != 3)
{
fType = 0; /* Not in escape mode */
}
else
{
armSkipBits (ppBitStream, pBitOffset, 7);
if(shortVideoHeader)
{
*pLast = armGetBits(ppBitStream, pBitOffset, 1);
storeRun = armGetBits(ppBitStream, pBitOffset, 6);
storeLevel = armGetBits(ppBitStream, pBitOffset, 8);
/* Ref to Table B-18 (c) in MPEG4 Standard- FLC code for */
/* LEVEL when short_video_header is 1, the storeLevel is */
/* a signed value and the sign and the unsigned value for */
/* storeLevel need to be extracted and passed to arm */
/* FillVLDBuffer function */
sign = (storeLevel & 0x80);
if(sign==0x80)
{
storeLevel=(storeLevel^0xff)+1;
sign=1;
}
armRetDataErrIf( storeLevel == 0 || sign*storeLevel == 128 , OMX_Sts_Err); /* Invalid FLC */
armRetDataErrIf((i + storeRun) >= 64, OMX_Sts_Err);
armVCM4P2_FillVLDBuffer(
storeRun,
pDst,
storeLevel,
sign,
*pLast,
&i,
pZigzagTable);
return OMX_Sts_NoErr;
}
if (armGetBits(ppBitStream, pBitOffset, 1))
{
if (armGetBits(ppBitStream, pBitOffset, 1))
{
fType = 3;
}
else
{
fType = 2;
}
}
else
{
fType = 1;
}
}
if (fType < 3)
{
unpackRetIndex = armUnPackVLC32(ppBitStream, pBitOffset,
pVlcTableL0);
if (unpackRetIndex != ARM_NO_CODEBOOK_INDEX)
{
/* Decode run and level from the index */
/* last = 0 */
*pLast = 0;
if (unpackRetIndex > maxIndexForMultipleEntriesL0)
{
storeLevel = 1;
storeRun = (unpackRetIndex - maxIndexForMultipleEntriesL0)
+ runBeginSingleLevelEntriesL0;
}
else
{
tabIndex = 1;
while (pRunIndexTableL0[tabIndex] <= unpackRetIndex)
{
tabIndex++;
}
storeRun = tabIndex - 1;
storeLevel = unpackRetIndex - pRunIndexTableL0[tabIndex - 1] + 1;
}
sign = (OMX_U8) armGetBits(ppBitStream, pBitOffset, 1);
if (fType == 1)
{
storeLevel = (armAbs(storeLevel) + pLMAXTableL0[storeRun]);
}
else if (fType == 2)
{
storeRun = storeRun + pRMAXTableL0[storeLevel-1] + 1;
}
}
else
{
unpackRetIndex = armUnPackVLC32(ppBitStream, pBitOffset,
pVlcTableL1);
armRetDataErrIf(unpackRetIndex == ARM_NO_CODEBOOK_INDEX, OMX_Sts_Err);
/* Decode run and level from the index */
/* last = 1 */
*pLast = 1;
if (unpackRetIndex > maxIndexForMultipleEntriesL1)
{
storeLevel = 1;
storeRun = (unpackRetIndex - maxIndexForMultipleEntriesL1)
+ maxRunForMultipleEntriesL1;
}
else
{
tabIndex = 1;
while (pRunIndexTableL1[tabIndex] <= unpackRetIndex)
{
tabIndex++;
}
storeRun = tabIndex - 1;
storeLevel = unpackRetIndex - pRunIndexTableL1[tabIndex - 1] + 1;
}
sign = (OMX_U8) armGetBits(ppBitStream, pBitOffset, 1);
if (fType == 1)
{
storeLevel = (armAbs(storeLevel) + pLMAXTableL1[storeRun]);
}
else if (fType == 2)
{
storeRun = storeRun + pRMAXTableL1[storeLevel-1] + 1;
}
}
armRetDataErrIf((i + storeRun) >= 64, OMX_Sts_Err);
armVCM4P2_FillVLDBuffer(
storeRun,
pDst,
storeLevel,
sign,
*pLast,
&i,
pZigzagTable);
}
else
{
*pLast = armGetBits(ppBitStream, pBitOffset, 1);
storeRun = armGetBits(ppBitStream, pBitOffset, 6);
armRetDataErrIf((i + storeRun) >= 64, OMX_Sts_Err);
markerBit = armGetBits(ppBitStream, pBitOffset, 1);
armRetDataErrIf( markerBit == 0, OMX_Sts_Err);
storeLevel = armGetBits(ppBitStream, pBitOffset, 12);
if (storeLevel & 0x800)
{
storeLevel -= 4096;
}
armRetDataErrIf( storeLevel == 0 || storeLevel == -2048 , OMX_Sts_Err); /* Invalid FLC */
armGetBits(ppBitStream, pBitOffset, 1);
armVCM4P2_FillVLDBuffer(
storeRun,
pDst,
storeLevel,
0, /* Sign is not used, preprocessing done */
*pLast,
&i,
pZigzagTable);
}
} /* End of forloop for i */
return OMX_Sts_NoErr;
}
/* End of File */
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