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_mpeg2_get_scale_data.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, side information 39 int32 gr, granule 40 int32 ch, channel 41 mp3Header *info, mp3 header information 42 uint32 *scalefac_buffer, 43 uint32 *scalefac_IIP_buffer, 44 tbits *pMainData bit stream Data 45 46 Returns 47 48 uint32 *scalefac_buffer, acquired scale band data 49 uint32 *scalefac_IIP_buffer, auxiliary scale data 50 51 52 ------------------------------------------------------------------------------ 53 FUNCTION DESCRIPTION 54 55 get scale data for mpeg2 layer III LSF extension 56 57 ------------------------------------------------------------------------------ 58 REQUIREMENTS 59 60 61 ------------------------------------------------------------------------------ 62 REFERENCES 63 64 [1] ISO MPEG Audio Subgroup Software Simulation Group (1996) 65 ISO 13818-3 MPEG-2 Audio Decoder - Lower Sampling Frequency Extension 66 67 ------------------------------------------------------------------------------ 68 PSEUDO-CODE 69 70 ------------------------------------------------------------------------------ 71 */ 72 73 74 /*---------------------------------------------------------------------------- 75 ; INCLUDES 76 ----------------------------------------------------------------------------*/ 77 78 #include "pvmp3_mpeg2_get_scale_data.h" 79 #include "pvmp3_getbits.h" 80 81 82 /*---------------------------------------------------------------------------- 83 ; MACROS 84 ; Define module specific macros here 85 ----------------------------------------------------------------------------*/ 86 87 88 /*---------------------------------------------------------------------------- 89 ; DEFINES 90 ; Include all pre-processor statements here. Include conditional 91 ; compile variables also. 92 ----------------------------------------------------------------------------*/ 93 94 /*---------------------------------------------------------------------------- 95 ; LOCAL FUNCTION DEFINITIONS 96 ; Function Prototype declaration 97 ----------------------------------------------------------------------------*/ 98 99 /*---------------------------------------------------------------------------- 100 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS 101 ; Variable declaration - defined here and used outside this module 102 ----------------------------------------------------------------------------*/ 103 104 const uint32 nr_of_sfb_block[6][3][4] = 105 { {{ 6, 5, 5, 5}, { 9, 9, 9, 9}, { 6, 9, 9, 9}}, 106 {{ 6, 5, 7, 3}, { 9, 9, 12, 6}, { 6, 9, 12, 6}}, 107 {{11, 10, 0, 0}, { 18, 18, 0, 0}, {15, 18, 0, 0}}, 108 {{ 7, 7, 7, 0}, { 12, 12, 12, 0}, { 6, 15, 12, 0}}, 109 {{ 6, 6, 6, 3}, { 12, 9, 9, 6}, { 6, 12, 9, 6}}, 110 {{ 8, 8, 5, 0}, { 15, 12, 9, 0}, { 6, 18, 9, 0}} 111 }; 112 113 /*---------------------------------------------------------------------------- 114 ; EXTERNAL FUNCTION REFERENCES 115 ; Declare functions defined elsewhere and referenced in this module 116 ----------------------------------------------------------------------------*/ 117 118 /*---------------------------------------------------------------------------- 119 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES 120 ; Declare variables used in this module but defined elsewhere 121 ----------------------------------------------------------------------------*/ 122 123 /*---------------------------------------------------------------------------- 124 ; FUNCTION CODE 125 ----------------------------------------------------------------------------*/ 126 127 void pvmp3_mpeg2_get_scale_data(mp3SideInfo *si, 128 int32 gr, 129 int32 ch, 130 mp3Header *info, 131 uint32 *scalefac_buffer, 132 uint32 *scalefac_IIP_buffer, 133 tmp3Bits *pMainData) 134 { 135 int16 i; 136 int16 j; 137 int16 k; 138 int16 blocktypenumber = 0; 139 int16 blocknumber = 0; 140 141 granuleInfo *gr_info = &(si->ch[ch].gran[gr]); 142 uint32 scalefac_comp, int_scalefac_comp, new_slen[4] = { 0,0,0,0 }; 143 144 scalefac_comp = gr_info->scalefac_compress; 145 146 147 148 if ((((info->mode_ext &1)) && (ch == 1))) 149 { 150 /* intensity_scale = scalefac_comp %2; */ 151 int_scalefac_comp = scalefac_comp >> 1; 152 153 if (int_scalefac_comp < 180) 154 { 155 new_slen[0] = int_scalefac_comp / 36; 156 new_slen[1] = (int_scalefac_comp % 36) / 6; 157 new_slen[2] = int_scalefac_comp % 6; 158 blocknumber = 3; 159 } 160 else if (int_scalefac_comp < 244) 161 { 162 int_scalefac_comp -= 180; 163 new_slen[0] = (int_scalefac_comp & 63) >> 4; 164 new_slen[1] = (int_scalefac_comp & 15) >> 2; 165 new_slen[2] = int_scalefac_comp & 3; 166 blocknumber = 4; 167 } 168 else if (int_scalefac_comp <= 255) 169 { 170 int_scalefac_comp -= 244; 171 new_slen[0] = (int_scalefac_comp) / 3; 172 new_slen[1] = (int_scalefac_comp) % 3; 173 new_slen[2] = 0; 174 blocknumber = 5; 175 } 176 new_slen[3] = 0; 177 si->ch[ch].gran[gr].preflag = 0; 178 } 179 else 180 { 181 if (scalefac_comp < 400) 182 { 183 new_slen[0] = (scalefac_comp >> 4) / 5; 184 new_slen[1] = (scalefac_comp >> 4) % 5; 185 new_slen[2] = (scalefac_comp & 15) >> 2 ; 186 new_slen[3] = (scalefac_comp & 3); 187 si->ch[ch].gran[gr].preflag = 0; 188 189 blocknumber = 0; 190 } 191 else if (scalefac_comp < 500) 192 { 193 scalefac_comp -= 400; 194 new_slen[0] = (scalefac_comp >> 2) / 5; 195 new_slen[1] = (scalefac_comp >> 2) % 5; 196 new_slen[2] = scalefac_comp & 3; 197 new_slen[3] = 0; 198 si->ch[ch].gran[gr].preflag = 0; 199 blocknumber = 1; 200 } 201 else if (scalefac_comp < 512) 202 { 203 scalefac_comp -= 500; 204 new_slen[0] = scalefac_comp / 3; 205 new_slen[1] = scalefac_comp % 3; 206 new_slen[2] = 0 ; 207 new_slen[3] = 0; 208 si->ch[ch].gran[gr].preflag = 1; 209 blocknumber = 2; 210 } 211 } 212 213 if (gr_info->block_type == 2) 214 { 215 if (gr_info->mixed_block_flag) 216 { 217 blocktypenumber = 2; 218 } 219 else 220 { 221 blocktypenumber = 1; 222 } 223 } 224 225 k = 0; 226 for (i = 0; i < 4; i++) 227 { 228 if (new_slen[i]) 229 { 230 for (j = 0; j < (int16)nr_of_sfb_block[blocknumber][blocktypenumber][i]; j++) 231 { 232 scalefac_buffer[k] = getNbits(pMainData, new_slen[i]); 233 scalefac_IIP_buffer[k] = (1L << new_slen[i]) - 1; 234 k++; 235 } 236 } 237 else 238 { 239 for (j = 0; j < (int16)nr_of_sfb_block[blocknumber][blocktypenumber][i]; j++) 240 { 241 scalefac_buffer[k] = 0; 242 scalefac_IIP_buffer[k] = 0; 243 k++; 244 } 245 } 246 } 247 } 248
