1 /****************************************************************************** 2 * 3 * Copyright (C) 2012 Ittiam Systems Pvt Ltd, Bangalore 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 /** 19 ******************************************************************************* 20 * @file 21 * ihevcd_bitps_bitstrm.h 22 * 23 * @brief 24 * Header for bitps_bitstrm access functions 25 * 26 * @author 27 * Harish 28 * 29 * @par List of Functions: 30 * 31 * @remarks 32 * None 33 * 34 ******************************************************************************* 35 */ 36 37 #ifndef _IHEVCD_BITSTREAM_H_ 38 #define _IHEVCD_BITSTREAM_H_ 39 /** 40 * @brief defines the maximum number of bits in a bitstream word 41 */ 42 #define WORD_SIZE 32 43 /** 44 * @brief Twice the WORD_SIZE 45 */ 46 #define DBL_WORD_SIZE (2 * (WORD_SIZE)) 47 48 /** 49 * @brief WORD_SIZE - 1 50 */ 51 #define WORD_SIZE_MINUS1 (WORD_SIZE - 1) 52 53 /** 54 ****************************************************************************** 55 * @brief Macro used to copy elements in bistream structure to local variables. 56 ****************************************************************************** 57 */ 58 59 #define GET_STREAM(m_ps_bitstrm, m_pu4_buf, m_u4_bit_ofst, \ 60 m_u4_cur_word, m_u4_nxt_word) \ 61 { \ 62 m_pu4_buf = m_ps_bitstrm->pu4_buf; \ 63 m_u4_bit_ofst = m_ps_bitstrm->u4_bit_ofst; \ 64 m_u4_cur_word = m_ps_bitstrm->u4_cur_word; \ 65 m_u4_nxt_word = m_ps_bitstrm->u4_nxt_word; \ 66 } 67 68 /** 69 ****************************************************************************** 70 * @brief Macro used to copy local variables to elements in bistream structure. 71 ****************************************************************************** 72 */ 73 #define SET_STREAM(m_ps_bitstrm, m_pu4_buf, m_u4_bit_ofst, \ 74 m_u4_cur_word, m_u4_nxt_word) \ 75 { \ 76 m_ps_bitstrm->pu4_buf = m_pu4_buf; \ 77 m_ps_bitstrm->u4_bit_ofst = m_u4_bit_ofst; \ 78 m_ps_bitstrm->u4_cur_word = m_u4_cur_word; \ 79 m_ps_bitstrm->u4_nxt_word = m_u4_nxt_word; \ 80 } 81 82 83 84 /** 85 ****************************************************************************** 86 * @brief Snoop next m_cnt bits without updating offsets or buffer increments. 87 * Data is not consumed in this call 88 ****************************************************************************** 89 */ 90 #define BITS_NXT(m_u4_bits, m_pu4_buf, m_u4_bit_ofst, \ 91 m_u4_cur_word, m_u4_nxt_word, m_cnt) \ 92 { \ 93 m_u4_bits = (m_u4_cur_word << m_u4_bit_ofst) >> \ 94 (WORD_SIZE - m_cnt); \ 95 \ 96 if(m_u4_bit_ofst > (WORD_SIZE - m_cnt)) \ 97 { \ 98 m_u4_bits |= SHR(m_u4_nxt_word, \ 99 (WORD_SIZE + WORD_SIZE - m_cnt \ 100 - m_u4_bit_ofst)); \ 101 } \ 102 } 103 104 105 /** 106 ****************************************************************************** 107 * @brief Snoop next 32 bits without updating offsets or buffer increments. 108 * Data is not consumed in this call 109 ****************************************************************************** 110 */ 111 #define BITS_NXT32(m_u4_bits, m_pu4_buf, m_u4_bit_ofst, \ 112 m_u4_cur_word, m_u4_nxt_word) \ 113 { \ 114 m_u4_bits = (m_u4_cur_word << m_u4_bit_ofst); \ 115 \ 116 m_u4_bits |= SHR(m_u4_nxt_word, (WORD_SIZE - m_u4_bit_ofst)); \ 117 } 118 119 120 /** 121 ****************************************************************************** 122 * @brief Flush m_u4_bits and updated the buffer pointer. 123 * Data is consumed 124 ****************************************************************************** 125 */ 126 #define BITS_FLUSH(m_pu4_buf, m_u4_bit_ofst, m_u4_cur_word, \ 127 m_u4_nxt_word, m_cnt) \ 128 { \ 129 UWORD32 temp; \ 130 \ 131 m_u4_bit_ofst += m_cnt; \ 132 if( m_u4_bit_ofst >= WORD_SIZE ) \ 133 { \ 134 m_u4_cur_word = m_u4_nxt_word; \ 135 /* Getting the next word */ \ 136 temp = *(m_pu4_buf++); \ 137 \ 138 m_u4_bit_ofst -= WORD_SIZE; \ 139 /* Swapping little endian to big endian conversion*/\ 140 m_u4_nxt_word = ITT_BIG_ENDIAN(temp); \ 141 } \ 142 } 143 /** 144 ****************************************************************************** 145 * @brief Get m_cnt number of bits and update bffer pointers and offset. 146 * Data is consumed 147 ****************************************************************************** 148 */ 149 #define BITS_GET(m_u4_bits, m_pu4_buf, m_u4_bit_ofst, \ 150 m_u4_cur_word,m_u4_nxt_word, m_cnt) \ 151 { \ 152 m_u4_bits = (m_u4_cur_word << m_u4_bit_ofst) \ 153 >> (WORD_SIZE - m_cnt); \ 154 m_u4_bit_ofst += m_cnt; \ 155 if(m_u4_bit_ofst > WORD_SIZE) \ 156 { \ 157 m_u4_bits |= SHR(m_u4_nxt_word, \ 158 (DBL_WORD_SIZE - m_u4_bit_ofst)); \ 159 } \ 160 \ 161 if( m_u4_bit_ofst >= WORD_SIZE ) \ 162 { \ 163 UWORD32 pu4_word_tmp; \ 164 m_u4_cur_word = m_u4_nxt_word; \ 165 /* Getting the next word */ \ 166 pu4_word_tmp = *(m_pu4_buf++); \ 167 \ 168 m_u4_bit_ofst -= WORD_SIZE; \ 169 /* Swapping little endian to big endian conversion*/ \ 170 m_u4_nxt_word = ITT_BIG_ENDIAN(pu4_word_tmp); \ 171 } \ 172 } 173 174 /** 175 ****************************************************************************** 176 * @brief Get 1 bit and update buffer pointers and offset. 177 * Data is consumed 178 ****************************************************************************** 179 */ 180 181 #define BIT_GET(m_u4_bits,m_pu4_buf,m_u4_bit_ofst, \ 182 m_u4_cur_word,m_u4_nxt_word) \ 183 { \ 184 m_u4_bits = (m_u4_cur_word << m_u4_bit_ofst) \ 185 >> (WORD_SIZE_MINUS1); \ 186 m_u4_bit_ofst++; \ 187 \ 188 if(m_u4_bit_ofst == WORD_SIZE) \ 189 { \ 190 UWORD32 pu4_word_tmp; \ 191 m_u4_cur_word = m_u4_nxt_word; \ 192 /* Getting the next word */ \ 193 pu4_word_tmp = *m_pu4_buf++; \ 194 \ 195 m_u4_bit_ofst = 0; \ 196 /* Swapping little endian to big endian conversion*/ \ 197 m_u4_nxt_word = ITT_BIG_ENDIAN(pu4_word_tmp); \ 198 } \ 199 } 200 201 void ihevcd_bits_init(bitstrm_t *ps_bitstrm, 202 UWORD8 *pu1_buf, 203 UWORD32 u4_numbytes); 204 void ihevcd_bits_flush(bitstrm_t *ps_bitstrm, UWORD32 u4_numbits); 205 206 void ihevcd_bits_flush_to_byte_boundary(bitstrm_t *ps_bitstrm); 207 208 UWORD32 ihevcd_bits_nxt(bitstrm_t *ps_bitstrm, UWORD32 u4_numbits); 209 210 UWORD32 ihevcd_bits_nxt32(bitstrm_t *ps_bitstrm, UWORD32 u4_numbits); 211 212 213 UWORD32 ihevcd_bits_get(bitstrm_t *ps_bitstrm, UWORD32 u4_numbits); 214 215 UWORD32 ihevcd_bits_num_bits_remaining(bitstrm_t *ps_bitstrm); 216 217 218 UWORD32 ihevcd_bits_num_bits_consumed(bitstrm_t *ps_bitstrm); 219 220 UWORD32 ihevcd_uev(bitstrm_t *ps_bitstrm); 221 222 WORD32 ihevcd_sev(bitstrm_t *ps_bitstrm); 223 224 void ihevcd_bits_seek(bitstrm_t *ps_bitstrm, WORD32 numbits); 225 226 #endif /* _IHEVCD_BITSTREAM_H_ */ 227
