frameworks/base/media/libstagefright/codecs/mp3dec/src/pvmp3_mpeg2_get_scale_factors.cpp

   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