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Diffstat (limited to 'media/libstagefright/codecs/on2/h264dec/omxdl/reference/vc/m4p2/src/armVCM4P2_GetVLCBits.c')
| -rw-r--r-- | media/libstagefright/codecs/on2/h264dec/omxdl/reference/vc/m4p2/src/armVCM4P2_GetVLCBits.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/on2/h264dec/omxdl/reference/vc/m4p2/src/armVCM4P2_GetVLCBits.c b/media/libstagefright/codecs/on2/h264dec/omxdl/reference/vc/m4p2/src/armVCM4P2_GetVLCBits.c new file mode 100644 index 0000000..953f597 --- /dev/null +++ b/media/libstagefright/codecs/on2/h264dec/omxdl/reference/vc/m4p2/src/armVCM4P2_GetVLCBits.c @@ -0,0 +1,278 @@ +/** + * + * File Name: armVCM4P2_GetVLCBits.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 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 */ + |