1 /* ------------------------------------------------------------------ 2 * Copyright (C) 1998-2009 PacketVideo 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either 13 * express or implied. 14 * See the License for the specific language governing permissions 15 * and limitations under the License. 16 * ------------------------------------------------------------------- 17 */ 18 /* 19 ------------------------------------------------------------------------------ 20 21 PacketVideo Corp. 22 MP3 Decoder Library 23 24 Filename: pvmp3_get_side_info.cpp 25 26 Date: 09/21/2007 27 28 ------------------------------------------------------------------------------ 29 REVISION HISTORY 30 31 32 Description: 33 34 ------------------------------------------------------------------------------ 35 INPUT AND OUTPUT DEFINITIONS 36 37 Input 38 mp3SideInfo *si, 39 mp3Header *info, mp3 header information 40 uint32 *crc initialized crc value (if enabled) 41 42 43 Returns 44 45 mp3SideInfo *si, side information 46 47 48 ------------------------------------------------------------------------------ 49 FUNCTION DESCRIPTION 50 51 acquires side information 52 53 ------------------------------------------------------------------------------ 54 REQUIREMENTS 55 56 57 ------------------------------------------------------------------------------ 58 REFERENCES 59 60 [1] ISO MPEG Audio Subgroup Software Simulation Group (1996) 61 ISO 13818-3 MPEG-2 Audio Decoder - Lower Sampling Frequency Extension 62 63 ------------------------------------------------------------------------------ 64 PSEUDO-CODE 65 66 ------------------------------------------------------------------------------ 67 */ 68 69 70 /*---------------------------------------------------------------------------- 71 ; INCLUDES 72 ----------------------------------------------------------------------------*/ 73 74 #include "pvmp3_get_side_info.h" 75 #include "pvmp3_crc.h" 76 77 78 /*---------------------------------------------------------------------------- 79 ; MACROS 80 ; Define module specific macros here 81 ----------------------------------------------------------------------------*/ 82 83 84 /*---------------------------------------------------------------------------- 85 ; DEFINES 86 ; Include all pre-processor statements here. Include conditional 87 ; compile variables also. 88 ----------------------------------------------------------------------------*/ 89 90 /*---------------------------------------------------------------------------- 91 ; LOCAL FUNCTION DEFINITIONS 92 ; Function Prototype declaration 93 ----------------------------------------------------------------------------*/ 94 95 /*---------------------------------------------------------------------------- 96 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS 97 ; Variable declaration - defined here and used outside this module 98 ----------------------------------------------------------------------------*/ 99 100 /*---------------------------------------------------------------------------- 101 ; EXTERNAL FUNCTION REFERENCES 102 ; Declare functions defined elsewhere and referenced in this module 103 ----------------------------------------------------------------------------*/ 104 105 /*---------------------------------------------------------------------------- 106 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES 107 ; Declare variables used in this module but defined elsewhere 108 ----------------------------------------------------------------------------*/ 109 110 /*---------------------------------------------------------------------------- 111 ; FUNCTION CODE 112 ----------------------------------------------------------------------------*/ 113 114 ERROR_CODE pvmp3_get_side_info(tmp3Bits *inputStream, 115 mp3SideInfo *si, 116 mp3Header *info, 117 uint32 *crc) 118 { 119 int32 ch, gr; 120 uint32 tmp; 121 122 int stereo = (info->mode == MPG_MD_MONO) ? 1 : 2; 123 124 if (info->version_x == MPEG_1) 125 { 126 if (stereo == 1) 127 { 128 tmp = getbits_crc(inputStream, 14, crc, info->error_protection); 129 si->main_data_begin = (tmp << 18) >> 23; /* 9 */ 130 si->private_bits = (tmp << 23) >> 27; /* 5 */ 131 } 132 else 133 { 134 tmp = getbits_crc(inputStream, 12, crc, info->error_protection); 135 si->main_data_begin = (tmp << 20) >> 23; /* 9 */ 136 si->private_bits = (tmp << 23) >> 29; /* 3 */ 137 138 } 139 140 for (ch = 0; ch < stereo; ch++) 141 { 142 tmp = getbits_crc(inputStream, 4, crc, info->error_protection); 143 si->ch[ch].scfsi[0] = (tmp << 28) >> 31; /* 1 */ 144 si->ch[ch].scfsi[1] = (tmp << 29) >> 31; /* 1 */ 145 si->ch[ch].scfsi[2] = (tmp << 30) >> 31; /* 1 */ 146 si->ch[ch].scfsi[3] = tmp & 1; /* 1 */ 147 } 148 149 for (gr = 0; gr < 2 ; gr++) 150 { 151 for (ch = 0; ch < stereo; ch++) 152 { 153 si->ch[ch].gran[gr].part2_3_length = getbits_crc(inputStream, 12, crc, info->error_protection); 154 tmp = getbits_crc(inputStream, 22, crc, info->error_protection); 155 156 si->ch[ch].gran[gr].big_values = (tmp << 10) >> 23; /* 9 */ 157 si->ch[ch].gran[gr].global_gain = ((tmp << 19) >> 24) - 210; /* 8 */ 158 si->ch[ch].gran[gr].scalefac_compress = (tmp << 27) >> 28; /* 4 */ 159 si->ch[ch].gran[gr].window_switching_flag = tmp & 1; /* 1 */ 160 161 if (si->ch[ch].gran[gr].window_switching_flag) 162 { 163 tmp = getbits_crc(inputStream, 22, crc, info->error_protection); 164 165 si->ch[ch].gran[gr].block_type = (tmp << 10) >> 30; /* 2 */; 166 si->ch[ch].gran[gr].mixed_block_flag = (tmp << 12) >> 31; /* 1 */; 167 168 si->ch[ch].gran[gr].table_select[0] = (tmp << 13) >> 27; /* 5 */; 169 si->ch[ch].gran[gr].table_select[1] = (tmp << 18) >> 27; /* 5 */; 170 171 si->ch[ch].gran[gr].subblock_gain[0] = (tmp << 23) >> 29; /* 3 */; 172 si->ch[ch].gran[gr].subblock_gain[1] = (tmp << 26) >> 29; /* 3 */; 173 si->ch[ch].gran[gr].subblock_gain[2] = (tmp << 29) >> 29; /* 3 */; 174 175 /* Set region_count parameters since they are implicit in this case. */ 176 177 if (si->ch[ch].gran[gr].block_type == 0) 178 { 179 return(SIDE_INFO_ERROR); 180 } 181 else if ((si->ch[ch].gran[gr].block_type == 2) 182 && (si->ch[ch].gran[gr].mixed_block_flag == 0)) 183 { 184 si->ch[ch].gran[gr].region0_count = 8; /* MI 9; */ 185 si->ch[ch].gran[gr].region1_count = 12; 186 } 187 else 188 { 189 si->ch[ch].gran[gr].region0_count = 7; /* MI 8; */ 190 si->ch[ch].gran[gr].region1_count = 13; 191 } 192 } 193 else 194 { 195 tmp = getbits_crc(inputStream, 22, crc, info->error_protection); 196 197 si->ch[ch].gran[gr].table_select[0] = (tmp << 10) >> 27; /* 5 */; 198 si->ch[ch].gran[gr].table_select[1] = (tmp << 15) >> 27; /* 5 */; 199 si->ch[ch].gran[gr].table_select[2] = (tmp << 20) >> 27; /* 5 */; 200 201 si->ch[ch].gran[gr].region0_count = (tmp << 25) >> 28; /* 4 */; 202 si->ch[ch].gran[gr].region1_count = (tmp << 29) >> 29; /* 3 */; 203 204 si->ch[ch].gran[gr].block_type = 0; 205 } 206 207 tmp = getbits_crc(inputStream, 3, crc, info->error_protection); 208 si->ch[ch].gran[gr].preflag = (tmp << 29) >> 31; /* 1 */ 209 si->ch[ch].gran[gr].scalefac_scale = (tmp << 30) >> 31; /* 1 */ 210 si->ch[ch].gran[gr].count1table_select = tmp & 1; /* 1 */ 211 } 212 } 213 } 214 else /* Layer 3 LSF */ 215 { 216 si->main_data_begin = getbits_crc(inputStream, 8, crc, info->error_protection); 217 si->private_bits = getbits_crc(inputStream, stereo, crc, info->error_protection); 218 219 for (ch = 0; ch < stereo; ch++) 220 { 221 tmp = getbits_crc(inputStream, 21, crc, info->error_protection); 222 si->ch[ch].gran[0].part2_3_length = (tmp << 11) >> 20; /* 12 */ 223 si->ch[ch].gran[0].big_values = (tmp << 23) >> 23; /* 9 */ 224 225 tmp = getbits_crc(inputStream, 18, crc, info->error_protection); 226 si->ch[ch].gran[0].global_gain = ((tmp << 14) >> 24) - 210; /* 8 */ 227 si->ch[ch].gran[0].scalefac_compress = (tmp << 22) >> 23; /* 9 */ 228 si->ch[ch].gran[0].window_switching_flag = tmp & 1; /* 1 */ 229 230 if (si->ch[ch].gran[0].window_switching_flag) 231 { 232 233 tmp = getbits_crc(inputStream, 22, crc, info->error_protection); 234 235 si->ch[ch].gran[0].block_type = (tmp << 10) >> 30; /* 2 */; 236 si->ch[ch].gran[0].mixed_block_flag = (tmp << 12) >> 31; /* 1 */; 237 238 si->ch[ch].gran[0].table_select[0] = (tmp << 13) >> 27; /* 5 */; 239 si->ch[ch].gran[0].table_select[1] = (tmp << 18) >> 27; /* 5 */; 240 241 si->ch[ch].gran[0].subblock_gain[0] = (tmp << 23) >> 29; /* 3 */; 242 si->ch[ch].gran[0].subblock_gain[1] = (tmp << 26) >> 29; /* 3 */; 243 si->ch[ch].gran[0].subblock_gain[2] = (tmp << 29) >> 29; /* 3 */; 244 245 /* Set region_count parameters since they are implicit in this case. */ 246 247 if (si->ch[ch].gran[0].block_type == 0) 248 { 249 return(SIDE_INFO_ERROR); 250 } 251 else if ((si->ch[ch].gran[0].block_type == 2) 252 && (si->ch[ch].gran[0].mixed_block_flag == 0)) 253 { 254 si->ch[ch].gran[0].region0_count = 8; /* MI 9; */ 255 si->ch[ch].gran[0].region1_count = 12; 256 } 257 else 258 { 259 si->ch[ch].gran[0].region0_count = 7; /* MI 8; */ 260 si->ch[ch].gran[0].region1_count = 13; 261 } 262 } 263 else 264 { 265 tmp = getbits_crc(inputStream, 22, crc, info->error_protection); 266 267 si->ch[ch].gran[0].table_select[0] = (tmp << 10) >> 27; /* 5 */; 268 si->ch[ch].gran[0].table_select[1] = (tmp << 15) >> 27; /* 5 */; 269 si->ch[ch].gran[0].table_select[2] = (tmp << 20) >> 27; /* 5 */; 270 271 si->ch[ch].gran[0].region0_count = (tmp << 25) >> 28; /* 4 */; 272 si->ch[ch].gran[0].region1_count = (tmp << 29) >> 29; /* 3 */; 273 274 si->ch[ch].gran[0].block_type = 0; 275 } 276 277 tmp = getbits_crc(inputStream, 2, crc, info->error_protection); 278 si->ch[ch].gran[0].scalefac_scale = tmp >> 1; /* 1 */ 279 si->ch[ch].gran[0].count1table_select = tmp & 1; /* 1 */ 280 281 } 282 } 283 return (NO_DECODING_ERROR); 284 } 285 286
