/******************************************************************************
*
* Copyright (C) 2015 The Android Open Source Project
*
* 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.
*
*****************************************************************************
* Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore
*/
#ifndef _IH264D_BITSTRM_H_
#define _IH264D_BITSTRM_H_
/*!
*************************************************************************
* \file ih264d_bitstrm.h
*
* \brief
* Contains all the declarations of bitstream reading routines
*
* \date
* 20/11/2002
*
* \author AI
*************************************************************************
*/
/* Includes */
#include <stdio.h>
#include <stdlib.h>
#include "ih264_typedefs.h"
#include "ih264_macros.h"
#include "ih264_platform_macros.h"
#define INT_IN_BYTES 4
#define INT_IN_BITS 32
/* Based on level 1.2 of baseline profile */
/* 396[MAX_FS] * 128 * 1.5 [ChromaFormatParameter] / sizeof(UWORD32)
i.e 396 * 128 * 1.5 / 4 = 19008 */
/* Based on level 3 of main profile */
/* 1620[MAX_FS] * 128 * 1.5 [ChromaFormatParameter] / sizeof(UWORD32)
i.e 1620 * 128 * 1.5 / 4= 77760 */
#define SIZE_OF_BUFFER 77760
/* Structure for the ps_bitstrm */
typedef struct
{
UWORD32 u4_ofst; /* Offset in the buffer for the current bit */
UWORD32 *pu4_buffer; /* Bitstream Buffer */
UWORD32 u4_max_ofst; /* Position of the last bit read in the current buffer */
void * pv_codec_handle; /* For Error Handling */
} dec_bit_stream_t;
/* To read the next bit */
UWORD8 ih264d_get_bit_h264(dec_bit_stream_t *);
/* To read the next specified number of bits */
UWORD32 ih264d_get_bits_h264(dec_bit_stream_t *, UWORD32);
/* To see the next specified number of bits */
UWORD32 ih264d_next_bits_h264(dec_bit_stream_t *, UWORD32);
/* To flush a specified number of bits*/
WORD32 ih264d_flush_bits_h264(dec_bit_stream_t *, WORD32);
/*!
**************************************************************************
* \if Function name : MoreRbspData \endif
*
* \brief
* Determines whether there is more data in RBSP or not.
*
* \param ps_bitstrm : Pointer to bitstream
*
* \return
* Returns 1 if there is more data in RBSP before rbsp_trailing_bits().
* Otherwise it returns FALSE.
**************************************************************************
*/
#define MORE_RBSP_DATA(ps_bitstrm) \
(ps_bitstrm->u4_ofst < ps_bitstrm->u4_max_ofst)
#define EXCEED_OFFSET(ps_bitstrm) \
(ps_bitstrm->u4_ofst > ps_bitstrm->u4_max_ofst)
void GoToByteBoundary(dec_bit_stream_t * ps_bitstrm);
UWORD8 ih264d_check_byte_aligned(dec_bit_stream_t * ps_bitstrm);
/*****************************************************************************/
/* Define a macro for inlining of GETBIT: */
/*****************************************************************************/
#define GETBIT(u4_code, u4_offset, pu4_bitstream) \
{ \
UWORD32 *pu4_buf = (pu4_bitstream); \
UWORD32 u4_word_off = ((u4_offset) >> 5); \
UWORD32 u4_bit_off = (u4_offset) & 0x1F; \
u4_code = pu4_buf[u4_word_off] << u4_bit_off; \
(u4_offset)++; \
u4_code = (u4_code >> 31); \
}
/*****************************************************************************/
/* Define a macro for inlining of GETBITS: u4_no_bits shall not exceed 32 */
/*****************************************************************************/
#define GETBITS(u4_code, u4_offset, pu4_bitstream, u4_no_bits) \
{ \
UWORD32 *pu4_buf = (pu4_bitstream); \
UWORD32 u4_word_off = ((u4_offset) >> 5); \
UWORD32 u4_bit_off = (u4_offset) & 0x1F; \
u4_code = pu4_buf[u4_word_off++] << u4_bit_off; \
\
if(u4_bit_off) \
u4_code |= (pu4_buf[u4_word_off] >> (INT_IN_BITS - u4_bit_off)); \
u4_code = u4_code >> (INT_IN_BITS - u4_no_bits); \
(u4_offset) += u4_no_bits; \
} \
\
/*****************************************************************************/
/* Define a macro for inlining of NEXTBITS */
/*****************************************************************************/
#define NEXTBITS(u4_word, u4_offset, pu4_bitstream, u4_no_bits) \
{ \
UWORD32 *pu4_buf = (pu4_bitstream); \
UWORD32 u4_word_off = ((u4_offset) >> 5); \
UWORD32 u4_bit_off = (u4_offset) & 0x1F; \
u4_word = pu4_buf[u4_word_off++] << u4_bit_off; \
if(u4_bit_off) \
u4_word |= (pu4_buf[u4_word_off] >> (INT_IN_BITS - u4_bit_off)); \
u4_word = u4_word >> (INT_IN_BITS - u4_no_bits); \
}
/*****************************************************************************/
/* Define a macro for inlining of NEXTBITS_32 */
/*****************************************************************************/
#define NEXTBITS_32(u4_word, u4_offset, pu4_bitstream) \
{ \
UWORD32 *pu4_buf = (pu4_bitstream); \
UWORD32 u4_word_off = ((u4_offset) >> 5); \
UWORD32 u4_bit_off = (u4_offset) & 0x1F; \
\
u4_word = pu4_buf[u4_word_off++] << u4_bit_off; \
if(u4_bit_off) \
u4_word |= (pu4_buf[u4_word_off] >> (INT_IN_BITS - u4_bit_off)); \
}
/*****************************************************************************/
/* Define a macro for inlining of FIND_ONE_IN_STREAM_32 */
/*****************************************************************************/
#define FIND_ONE_IN_STREAM_32(u4_ldz, u4_offset, pu4_bitstream) \
{ \
UWORD32 u4_word; \
NEXTBITS_32(u4_word, u4_offset, pu4_bitstream); \
u4_ldz = CLZ(u4_word); \
(u4_offset) += (u4_ldz + 1); \
}
/*****************************************************************************/
/* Define a macro for inlining of FIND_ONE_IN_STREAM_LEN */
/*****************************************************************************/
#define FIND_ONE_IN_STREAM_LEN(u4_ldz, u4_offset, pu4_bitstream, u4_len) \
{ \
UWORD32 u4_word; \
NEXTBITS_32(u4_word, u4_offset, pu4_bitstream); \
u4_ldz = CLZ(u4_word); \
if(u4_ldz < u4_len) \
(u4_offset) += (u4_ldz + 1); \
else \
{ \
u4_ldz = u4_len; \
(u4_offset) += u4_ldz; \
} \
}
/*****************************************************************************/
/* Define a macro for inlining of FLUSHBITS */
/*****************************************************************************/
#define FLUSHBITS(u4_offset, u4_no_bits) \
{ \
(u4_offset) += (u4_no_bits); \
}
#endif /* _BITSTREAM_H_ */