1 /****************************************************************************** 2 * 3 * Copyright (C) 2015 The Android Open Source Project 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at: 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 ***************************************************************************** 18 * Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore 19 */ 20 21 #ifndef _IH264D_BITSTRM_H_ 22 #define _IH264D_BITSTRM_H_ 23 /*! 24 ************************************************************************* 25 * \file ih264d_bitstrm.h 26 * 27 * \brief 28 * Contains all the declarations of bitstream reading routines 29 * 30 * \date 31 * 20/11/2002 32 * 33 * \author AI 34 ************************************************************************* 35 */ 36 37 /* Includes */ 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include "ih264_typedefs.h" 41 #include "ih264_macros.h" 42 #include "ih264_platform_macros.h" 43 44 #define INT_IN_BYTES 4 45 #define INT_IN_BITS 32 46 47 /* Based on level 1.2 of baseline profile */ 48 /* 396[MAX_FS] * 128 * 1.5 [ChromaFormatParameter] / sizeof(UWORD32) 49 i.e 396 * 128 * 1.5 / 4 = 19008 */ 50 /* Based on level 3 of main profile */ 51 /* 1620[MAX_FS] * 128 * 1.5 [ChromaFormatParameter] / sizeof(UWORD32) 52 i.e 1620 * 128 * 1.5 / 4= 77760 */ 53 #define SIZE_OF_BUFFER 77760 54 55 /* Structure for the ps_bitstrm */ 56 typedef struct 57 { 58 UWORD32 u4_ofst; /* Offset in the buffer for the current bit */ 59 UWORD32 *pu4_buffer; /* Bitstream Buffer */ 60 UWORD32 u4_max_ofst; /* Position of the last bit read in the current buffer */ 61 void * pv_codec_handle; /* For Error Handling */ 62 } dec_bit_stream_t; 63 64 /* To read the next bit */ 65 UWORD8 ih264d_get_bit_h264(dec_bit_stream_t *); 66 67 /* To read the next specified number of bits */ 68 UWORD32 ih264d_get_bits_h264(dec_bit_stream_t *, UWORD32); 69 70 /* To see the next specified number of bits */ 71 UWORD32 ih264d_next_bits_h264(dec_bit_stream_t *, UWORD32); 72 73 /* To flush a specified number of bits*/ 74 WORD32 ih264d_flush_bits_h264(dec_bit_stream_t *, WORD32); 75 76 /*! 77 ************************************************************************** 78 * \if Function name : MoreRbspData \endif 79 * 80 * \brief 81 * Determines whether there is more data in RBSP or not. 82 * 83 * \param ps_bitstrm : Pointer to bitstream 84 * 85 * \return 86 * Returns 1 if there is more data in RBSP before rbsp_trailing_bits(). 87 * Otherwise it returns FALSE. 88 ************************************************************************** 89 */ 90 91 #define MORE_RBSP_DATA(ps_bitstrm) \ 92 (ps_bitstrm->u4_ofst < ps_bitstrm->u4_max_ofst) 93 #define EXCEED_OFFSET(ps_bitstrm) \ 94 (ps_bitstrm->u4_ofst > ps_bitstrm->u4_max_ofst) 95 96 void GoToByteBoundary(dec_bit_stream_t * ps_bitstrm); 97 UWORD8 ih264d_check_byte_aligned(dec_bit_stream_t * ps_bitstrm); 98 99 /*****************************************************************************/ 100 /* Define a macro for inlining of GETBIT: */ 101 /*****************************************************************************/ 102 #define GETBIT(u4_code, u4_offset, pu4_bitstream) \ 103 { \ 104 UWORD32 *pu4_buf = (pu4_bitstream); \ 105 UWORD32 u4_word_off = ((u4_offset) >> 5); \ 106 UWORD32 u4_bit_off = (u4_offset) & 0x1F; \ 107 u4_code = pu4_buf[u4_word_off] << u4_bit_off; \ 108 (u4_offset)++; \ 109 u4_code = (u4_code >> 31); \ 110 } 111 112 113 114 /*****************************************************************************/ 115 /* Define a macro for inlining of GETBITS: u4_no_bits shall not exceed 32 */ 116 /*****************************************************************************/ 117 #define GETBITS(u4_code, u4_offset, pu4_bitstream, u4_no_bits) \ 118 { \ 119 UWORD32 *pu4_buf = (pu4_bitstream); \ 120 UWORD32 u4_word_off = ((u4_offset) >> 5); \ 121 UWORD32 u4_bit_off = (u4_offset) & 0x1F; \ 122 u4_code = pu4_buf[u4_word_off++] << u4_bit_off; \ 123 \ 124 if(u4_bit_off) \ 125 u4_code |= (pu4_buf[u4_word_off] >> (INT_IN_BITS - u4_bit_off)); \ 126 u4_code = u4_code >> (INT_IN_BITS - u4_no_bits); \ 127 (u4_offset) += u4_no_bits; \ 128 } \ 129 \ 130 131 /*****************************************************************************/ 132 /* Define a macro for inlining of NEXTBITS */ 133 /*****************************************************************************/ 134 #define NEXTBITS(u4_word, u4_offset, pu4_bitstream, u4_no_bits) \ 135 { \ 136 UWORD32 *pu4_buf = (pu4_bitstream); \ 137 UWORD32 u4_word_off = ((u4_offset) >> 5); \ 138 UWORD32 u4_bit_off = (u4_offset) & 0x1F; \ 139 u4_word = pu4_buf[u4_word_off++] << u4_bit_off; \ 140 if(u4_bit_off) \ 141 u4_word |= (pu4_buf[u4_word_off] >> (INT_IN_BITS - u4_bit_off)); \ 142 u4_word = u4_word >> (INT_IN_BITS - u4_no_bits); \ 143 } 144 /*****************************************************************************/ 145 /* Define a macro for inlining of NEXTBITS_32 */ 146 /*****************************************************************************/ 147 #define NEXTBITS_32(u4_word, u4_offset, pu4_bitstream) \ 148 { \ 149 UWORD32 *pu4_buf = (pu4_bitstream); \ 150 UWORD32 u4_word_off = ((u4_offset) >> 5); \ 151 UWORD32 u4_bit_off = (u4_offset) & 0x1F; \ 152 \ 153 u4_word = pu4_buf[u4_word_off++] << u4_bit_off; \ 154 if(u4_bit_off) \ 155 u4_word |= (pu4_buf[u4_word_off] >> (INT_IN_BITS - u4_bit_off)); \ 156 } 157 158 159 /*****************************************************************************/ 160 /* Define a macro for inlining of FIND_ONE_IN_STREAM_32 */ 161 /*****************************************************************************/ 162 #define FIND_ONE_IN_STREAM_32(u4_ldz, u4_offset, pu4_bitstream) \ 163 { \ 164 UWORD32 u4_word; \ 165 NEXTBITS_32(u4_word, u4_offset, pu4_bitstream); \ 166 u4_ldz = CLZ(u4_word); \ 167 (u4_offset) += (u4_ldz + 1); \ 168 } 169 170 /*****************************************************************************/ 171 /* Define a macro for inlining of FIND_ONE_IN_STREAM_LEN */ 172 /*****************************************************************************/ 173 #define FIND_ONE_IN_STREAM_LEN(u4_ldz, u4_offset, pu4_bitstream, u4_len) \ 174 { \ 175 UWORD32 u4_word; \ 176 NEXTBITS_32(u4_word, u4_offset, pu4_bitstream); \ 177 u4_ldz = CLZ(u4_word); \ 178 if(u4_ldz < u4_len) \ 179 (u4_offset) += (u4_ldz + 1); \ 180 else \ 181 { \ 182 u4_ldz = u4_len; \ 183 (u4_offset) += u4_ldz; \ 184 } \ 185 } 186 187 /*****************************************************************************/ 188 /* Define a macro for inlining of FLUSHBITS */ 189 /*****************************************************************************/ 190 #define FLUSHBITS(u4_offset, u4_no_bits) \ 191 { \ 192 (u4_offset) += (u4_no_bits); \ 193 } 194 195 #endif /* _BITSTREAM_H_ */ 196
