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_factors.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 39 mp3ScaleFactors *scalefac, 40 mp3SideInfo *si, side information 41 int32 gr, granule 42 int32 ch, channel 43 mp3Header *info, mp3 header information 44 uint32 *scalefac_IIP_buffer, auxiliary scale data 45 tbits *pMainData bit stream Data 46 47 Returns 48 49 III_scalefac_t *scalefac, scale factor 50 51 52 ------------------------------------------------------------------------------ 53 FUNCTION DESCRIPTION 54 55 get scale factor for mpe2 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_factors.h" 79 #include "pvmp3_mpeg2_get_scale_data.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 /*---------------------------------------------------------------------------- 105 ; EXTERNAL FUNCTION REFERENCES 106 ; Declare functions defined elsewhere and referenced in this module 107 ----------------------------------------------------------------------------*/ 108 109 /*---------------------------------------------------------------------------- 110 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES 111 ; Declare variables used in this module but defined elsewhere 112 ----------------------------------------------------------------------------*/ 113 114 /*---------------------------------------------------------------------------- 115 ; FUNCTION CODE 116 ----------------------------------------------------------------------------*/ 117 118 void pvmp3_mpeg2_get_scale_factors(mp3ScaleFactors *scalefac, 119 mp3SideInfo *si, 120 int32 gr, 121 int32 ch, 122 mp3Header *info, 123 uint32 *scalefac_IIP_buffer, 124 tmp3Bits *pMainData) 125 { 126 127 int32 sfb; 128 int32 k = 0; 129 int32 window; 130 uint32 *scalefac_buffer = &scalefac_IIP_buffer[56]; 131 132 granuleInfo *gr_info = &(si->ch[ch].gran[gr]); 133 134 pvmp3_mpeg2_get_scale_data(si, 135 gr, 136 ch, 137 info, 138 (uint32 *)scalefac_buffer, 139 (uint32 *)scalefac_IIP_buffer, 140 pMainData); 141 142 143 if (gr_info->window_switching_flag && (gr_info->block_type == 2)) 144 { 145 if (gr_info->mixed_block_flag) 146 { 147 for (sfb = 0; sfb < 6; sfb++) 148 { 149 scalefac->l[sfb] = scalefac_buffer[sfb]; 150 } 151 152 153 k = 6; 154 for (sfb = 3; sfb < 12; sfb++) 155 { 156 for (window = 0; window < 3; window++) 157 { 158 scalefac->s[window][sfb] = scalefac_buffer[k]; 159 k++; 160 } 161 } 162 163 164 /* adjust position of "illegal position" information in scalefac_IIP_buffer[] */ 165 /* in mixed blocks mode for short sfb, move them 3 places up. efs 3002-07-04 */ 166 for (sfb = 11; sfb >= 3; sfb--) 167 { 168 scalefac_IIP_buffer[3*sfb + 2] = scalefac_IIP_buffer[3*sfb - 1]; 169 scalefac_IIP_buffer[3*sfb + 1] = scalefac_IIP_buffer[3*sfb - 2]; 170 scalefac_IIP_buffer[3*sfb ] = scalefac_IIP_buffer[3*sfb - 3]; 171 172 } 173 } 174 else 175 { /* SHORT*/ 176 for (sfb = 0; sfb < 12; sfb++) 177 { 178 for (window = 0; window < 3; window++) 179 { 180 scalefac->s[window][sfb] = scalefac_buffer[k]; 181 k++; 182 } 183 } 184 } 185 186 scalefac->s[0][12] = 0; 187 scalefac->s[1][12] = 0; 188 scalefac->s[2][12] = 0; 189 190 } 191 else 192 { /* LONG types 0,1,3 */ 193 for (sfb = 0; sfb < 21; sfb++) 194 { 195 scalefac->l[sfb] = scalefac_buffer[sfb]; 196 } 197 scalefac->l[21] = 0; 198 scalefac->l[22] = 0; 199 200 } 201 } 202 203
