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Diffstat (limited to 'media/libstagefright/codecs/on2/h264dec/omxdl/arm_neon/src/armCOMM_Bitstream.c')
| -rwxr-xr-x | media/libstagefright/codecs/on2/h264dec/omxdl/arm_neon/src/armCOMM_Bitstream.c | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/on2/h264dec/omxdl/arm_neon/src/armCOMM_Bitstream.c b/media/libstagefright/codecs/on2/h264dec/omxdl/arm_neon/src/armCOMM_Bitstream.c new file mode 100755 index 0000000..9ef9319 --- /dev/null +++ b/media/libstagefright/codecs/on2/h264dec/omxdl/arm_neon/src/armCOMM_Bitstream.c @@ -0,0 +1,329 @@ +/** + * + * File Name: armCOMM_Bitstream.c + * OpenMAX DL: v1.0.2 + * Revision: 9641 + * Date: Thursday, February 7, 2008 + * + * (c) Copyright 2007-2008 ARM Limited. All Rights Reserved. + * + * + * + * Defines bitstream encode and decode functions common to all codecs + */ + +#include "omxtypes.h" +#include "armCOMM.h" +#include "armCOMM_Bitstream.h" + +/*************************************** + * Fixed bit length Decode + ***************************************/ + +/** + * Function: armLookAheadBits() + * + * Description: + * Get the next N bits from the bitstream without advancing the bitstream pointer + * + * Parameters: + * [in] **ppBitStream + * [in] *pOffset + * [in] N=1...32 + * + * Returns Value + */ + +OMX_U32 armLookAheadBits(const OMX_U8 **ppBitStream, OMX_INT *pOffset, OMX_INT N) +{ + const OMX_U8 *pBitStream = *ppBitStream; + OMX_INT Offset = *pOffset; + OMX_U32 Value; + + armAssert(Offset>=0 && Offset<=7); + armAssert(N>=1 && N<=32); + + /* Read next 32 bits from stream */ + Value = (pBitStream[0] << 24 ) | ( pBitStream[1] << 16) | (pBitStream[2] << 8 ) | (pBitStream[3]) ; + Value = (Value << Offset ) | (pBitStream[4] >> (8-Offset)); + + /* Return N bits */ + return Value >> (32-N); +} + + +/** + * Function: armGetBits() + * + * Description: + * Read N bits from the bitstream + * + * Parameters: + * [in] *ppBitStream + * [in] *pOffset + * [in] N=1..32 + * + * [out] *ppBitStream + * [out] *pOffset + * Returns Value + */ + + +OMX_U32 armGetBits(const OMX_U8 **ppBitStream, OMX_INT *pOffset, OMX_INT N) +{ + const OMX_U8 *pBitStream = *ppBitStream; + OMX_INT Offset = *pOffset; + OMX_U32 Value; + + if(N == 0) + { + return 0; + } + + armAssert(Offset>=0 && Offset<=7); + armAssert(N>=1 && N<=32); + + /* Read next 32 bits from stream */ + Value = (pBitStream[0] << 24 ) | ( pBitStream[1] << 16) | (pBitStream[2] << 8 ) | (pBitStream[3]) ; + Value = (Value << Offset ) | (pBitStream[4] >> (8-Offset)); + + /* Advance bitstream pointer by N bits */ + Offset += N; + *ppBitStream = pBitStream + (Offset>>3); + *pOffset = Offset & 7; + + /* Return N bits */ + return Value >> (32-N); +} + +/** + * Function: armByteAlign() + * + * Description: + * Align the pointer *ppBitStream to the next byte boundary + * + * Parameters: + * [in] *ppBitStream + * [in] *pOffset + * + * [out] *ppBitStream + * [out] *pOffset + * + **/ + +OMXVoid armByteAlign(const OMX_U8 **ppBitStream,OMX_INT *pOffset) +{ + if(*pOffset > 0) + { + *ppBitStream += 1; + *pOffset = 0; + } +} + +/** + * Function: armSkipBits() + * + * Description: + * Skip N bits from the value at *ppBitStream + * + * Parameters: + * [in] *ppBitStream + * [in] *pOffset + * [in] N + * + * [out] *ppBitStream + * [out] *pOffset + * + **/ + + +OMXVoid armSkipBits(const OMX_U8 **ppBitStream,OMX_INT *pOffset,OMX_INT N) +{ + OMX_INT Offset = *pOffset; + const OMX_U8 *pBitStream = *ppBitStream; + + /* Advance bitstream pointer by N bits */ + Offset += N; + *ppBitStream = pBitStream + (Offset>>3); + *pOffset = Offset & 7; +} + +/*************************************** + * Variable bit length Decode + ***************************************/ + +/** + * Function: armUnPackVLC32() + * + * Description: + * Variable length decode of variable length symbol (max size 32 bits) read from + * the bit stream pointed by *ppBitStream at *pOffset by using the table + * pointed by pCodeBook + * + * Parameters: + * [in] *pBitStream + * [in] *pOffset + * [in] pCodeBook + * + * [out] *pBitStream + * [out] *pOffset + * + * Returns : Code Book Index if successfull. + * : ARM_NO_CODEBOOK_INDEX = -1 if search fails. + **/ +#ifndef C_OPTIMIZED_IMPLEMENTATION + +OMX_U16 armUnPackVLC32( + const OMX_U8 **ppBitStream, + OMX_INT *pOffset, + const ARM_VLC32 *pCodeBook +) +{ + const OMX_U8 *pBitStream = *ppBitStream; + OMX_INT Offset = *pOffset; + OMX_U32 Value; + OMX_INT Index; + + armAssert(Offset>=0 && Offset<=7); + + /* Read next 32 bits from stream */ + Value = (pBitStream[0] << 24 ) | ( pBitStream[1] << 16) | (pBitStream[2] << 8 ) | (pBitStream[3]) ; + Value = (Value << Offset ) | (pBitStream[4] >> (8-Offset)); + + /* Search through the codebook */ + for (Index=0; pCodeBook->codeLen != 0; Index++) + { + if (pCodeBook->codeWord == (Value >> (32 - pCodeBook->codeLen))) + { + Offset = Offset + pCodeBook->codeLen; + *ppBitStream = pBitStream + (Offset >> 3) ; + *pOffset = Offset & 7; + + return Index; + } + pCodeBook++; + } + + /* No code match found */ + return ARM_NO_CODEBOOK_INDEX; +} + +#endif + +/*************************************** + * Fixed bit length Encode + ***************************************/ + +/** + * Function: armPackBits + * + * Description: + * Pack a VLC code word into the bitstream + * + * Remarks: + * + * Parameters: + * [in] ppBitStream pointer to the pointer to the current byte + * in the bit stream. + * [in] pOffset pointer to the bit position in the byte + * pointed by *ppBitStream. Valid within 0 + * to 7. + * [in] codeWord Code word that need to be inserted in to the + * bitstream + * [in] codeLength Length of the code word valid range 1...32 + * + * [out] ppBitStream *ppBitStream is updated after the block is encoded, + * so that it points to the current byte in the bit + * stream buffer. + * [out] pBitOffset *pBitOffset is updated so that it points to the + * current bit position in the byte pointed by + * *ppBitStream. + * + * Return Value: + * Standard OMX_RESULT result. See enumeration for possible result codes. + * + */ + +OMXResult armPackBits ( + OMX_U8 **ppBitStream, + OMX_INT *pOffset, + OMX_U32 codeWord, + OMX_INT codeLength +) +{ + OMX_U8 *pBitStream = *ppBitStream; + OMX_INT Offset = *pOffset; + OMX_U32 Value; + + /* checking argument validity */ + armRetArgErrIf(Offset < 0, OMX_Sts_BadArgErr); + armRetArgErrIf(Offset > 7, OMX_Sts_BadArgErr); + armRetArgErrIf(codeLength < 1, OMX_Sts_BadArgErr); + armRetArgErrIf(codeLength > 32, OMX_Sts_BadArgErr); + + /* Prepare the first byte */ + codeWord = codeWord << (32-codeLength); + Value = (pBitStream[0] >> (8-Offset)) << (8-Offset); + Value = Value | (codeWord >> (24+Offset)); + + /* Write out whole bytes */ + while (8-Offset <= codeLength) + { + *pBitStream++ = (OMX_U8)Value; + codeWord = codeWord << (8-Offset); + codeLength = codeLength - (8-Offset); + Offset = 0; + Value = codeWord >> 24; + } + + /* Write out final partial byte */ + *pBitStream = (OMX_U8)Value; + *ppBitStream = pBitStream; + *pOffset = Offset + codeLength; + + return OMX_Sts_NoErr; +} + +/*************************************** + * Variable bit length Encode + ***************************************/ + +/** + * Function: armPackVLC32 + * + * Description: + * Pack a VLC code word into the bitstream + * + * 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] code VLC code word that need to be inserted in to the + * bitstream + * + * [out] ppBitStream *ppBitStream is updated after the block is encoded, + * so that it points to the current byte in the bit + * stream buffer. + * [out] pBitOffset *pBitOffset is updated so that it points to the + * current bit position in the byte pointed by + * *ppBitStream. + * + * Return Value: + * Standard OMX_RESULT result. See enumeration for possible result codes. + * + */ + +OMXResult armPackVLC32 ( + OMX_U8 **ppBitStream, + OMX_INT *pBitOffset, + ARM_VLC32 code +) +{ + return (armPackBits(ppBitStream, pBitOffset, code.codeWord, code.codeLen)); +} + +/*End of File*/ |