/******************************************************************************
*
* Copyright (C) 2012 Ittiam Systems Pvt Ltd, Bangalore
*
* 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
* ihevcd_bitps_bitstrm.h
*
* @brief
* Header for bitps_bitstrm access functions
*
* @author
* Harish
*
* @par List of Functions:
*
* @remarks
* None
*
*******************************************************************************
*/
#ifndef _IHEVCD_BITSTREAM_H_
#define _IHEVCD_BITSTREAM_H_
/**
* @brief defines the maximum number of bits in a bitstream word
*/
#define WORD_SIZE 32
/**
* @brief Twice the WORD_SIZE
*/
#define DBL_WORD_SIZE (2 * (WORD_SIZE))
/**
* @brief WORD_SIZE - 1
*/
#define WORD_SIZE_MINUS1 (WORD_SIZE - 1)
/**
******************************************************************************
* @brief Macro used to copy elements in bistream structure to local variables.
******************************************************************************
*/
#define GET_STREAM(m_ps_bitstrm, m_pu4_buf, m_u4_bit_ofst, \
m_u4_cur_word, m_u4_nxt_word) \
{ \
m_pu4_buf = m_ps_bitstrm->pu4_buf; \
m_u4_bit_ofst = m_ps_bitstrm->u4_bit_ofst; \
m_u4_cur_word = m_ps_bitstrm->u4_cur_word; \
m_u4_nxt_word = m_ps_bitstrm->u4_nxt_word; \
}
/**
******************************************************************************
* @brief Macro used to copy local variables to elements in bistream structure.
******************************************************************************
*/
#define SET_STREAM(m_ps_bitstrm, m_pu4_buf, m_u4_bit_ofst, \
m_u4_cur_word, m_u4_nxt_word) \
{ \
m_ps_bitstrm->pu4_buf = m_pu4_buf; \
m_ps_bitstrm->u4_bit_ofst = m_u4_bit_ofst; \
m_ps_bitstrm->u4_cur_word = m_u4_cur_word; \
m_ps_bitstrm->u4_nxt_word = m_u4_nxt_word; \
}
/**
******************************************************************************
* @brief Snoop next m_cnt bits without updating offsets or buffer increments.
* Data is not consumed in this call
******************************************************************************
*/
#define BITS_NXT(m_u4_bits, m_pu4_buf, m_u4_bit_ofst, \
m_u4_cur_word, m_u4_nxt_word, m_cnt) \
{ \
m_u4_bits = (m_u4_cur_word << m_u4_bit_ofst) >> \
(WORD_SIZE - m_cnt); \
\
if(m_u4_bit_ofst > (WORD_SIZE - m_cnt)) \
{ \
m_u4_bits |= SHR(m_u4_nxt_word, \
(WORD_SIZE + WORD_SIZE - m_cnt \
- m_u4_bit_ofst)); \
} \
}
/**
******************************************************************************
* @brief Snoop next 32 bits without updating offsets or buffer increments.
* Data is not consumed in this call
******************************************************************************
*/
#define BITS_NXT32(m_u4_bits, m_pu4_buf, m_u4_bit_ofst, \
m_u4_cur_word, m_u4_nxt_word) \
{ \
m_u4_bits = (m_u4_cur_word << m_u4_bit_ofst); \
\
m_u4_bits |= SHR(m_u4_nxt_word, (WORD_SIZE - m_u4_bit_ofst)); \
}
/**
******************************************************************************
* @brief Flush m_u4_bits and updated the buffer pointer.
* Data is consumed
******************************************************************************
*/
#define BITS_FLUSH(m_pu4_buf, m_u4_bit_ofst, m_u4_cur_word, \
m_u4_nxt_word, m_cnt) \
{ \
UWORD32 temp; \
\
m_u4_bit_ofst += m_cnt; \
if( m_u4_bit_ofst >= WORD_SIZE ) \
{ \
m_u4_cur_word = m_u4_nxt_word; \
/* Getting the next word */ \
temp = *(m_pu4_buf++); \
\
m_u4_bit_ofst -= WORD_SIZE; \
/* Swapping little endian to big endian conversion*/\
m_u4_nxt_word = ITT_BIG_ENDIAN(temp); \
} \
}
/**
******************************************************************************
* @brief Get m_cnt number of bits and update bffer pointers and offset.
* Data is consumed
******************************************************************************
*/
#define BITS_GET(m_u4_bits, m_pu4_buf, m_u4_bit_ofst, \
m_u4_cur_word,m_u4_nxt_word, m_cnt) \
{ \
m_u4_bits = (m_u4_cur_word << m_u4_bit_ofst) \
>> (WORD_SIZE - m_cnt); \
m_u4_bit_ofst += m_cnt; \
if(m_u4_bit_ofst > WORD_SIZE) \
{ \
m_u4_bits |= SHR(m_u4_nxt_word, \
(DBL_WORD_SIZE - m_u4_bit_ofst)); \
} \
\
if( m_u4_bit_ofst >= WORD_SIZE ) \
{ \
UWORD32 pu4_word_tmp; \
m_u4_cur_word = m_u4_nxt_word; \
/* Getting the next word */ \
pu4_word_tmp = *(m_pu4_buf++); \
\
m_u4_bit_ofst -= WORD_SIZE; \
/* Swapping little endian to big endian conversion*/ \
m_u4_nxt_word = ITT_BIG_ENDIAN(pu4_word_tmp); \
} \
}
/**
******************************************************************************
* @brief Get 1 bit and update buffer pointers and offset.
* Data is consumed
******************************************************************************
*/
#define BIT_GET(m_u4_bits,m_pu4_buf,m_u4_bit_ofst, \
m_u4_cur_word,m_u4_nxt_word) \
{ \
m_u4_bits = (m_u4_cur_word << m_u4_bit_ofst) \
>> (WORD_SIZE_MINUS1); \
m_u4_bit_ofst++; \
\
if(m_u4_bit_ofst == WORD_SIZE) \
{ \
UWORD32 pu4_word_tmp; \
m_u4_cur_word = m_u4_nxt_word; \
/* Getting the next word */ \
pu4_word_tmp = *m_pu4_buf++; \
\
m_u4_bit_ofst = 0; \
/* Swapping little endian to big endian conversion*/ \
m_u4_nxt_word = ITT_BIG_ENDIAN(pu4_word_tmp); \
} \
}
void ihevcd_bits_init(bitstrm_t *ps_bitstrm,
UWORD8 *pu1_buf,
UWORD32 u4_numbytes);
void ihevcd_bits_flush(bitstrm_t *ps_bitstrm, UWORD32 u4_numbits);
void ihevcd_bits_flush_to_byte_boundary(bitstrm_t *ps_bitstrm);
UWORD32 ihevcd_bits_nxt(bitstrm_t *ps_bitstrm, UWORD32 u4_numbits);
UWORD32 ihevcd_bits_nxt32(bitstrm_t *ps_bitstrm, UWORD32 u4_numbits);
UWORD32 ihevcd_bits_get(bitstrm_t *ps_bitstrm, UWORD32 u4_numbits);
UWORD32 ihevcd_bits_num_bits_remaining(bitstrm_t *ps_bitstrm);
UWORD32 ihevcd_bits_num_bits_consumed(bitstrm_t *ps_bitstrm);
UWORD32 ihevcd_uev(bitstrm_t *ps_bitstrm);
WORD32 ihevcd_sev(bitstrm_t *ps_bitstrm);
void ihevcd_bits_seek(bitstrm_t *ps_bitstrm, WORD32 numbits);
#endif /* _IHEVCD_BITSTREAM_H_ */