1 /* |
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2 * Copyright (c) 2010 Ixonos Plc. |
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3 * All rights reserved. |
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4 * This component and the accompanying materials are made available |
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5 * under the terms of the "Eclipse Public License v1.0" |
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6 * which accompanies this distribution, and is available |
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7 * at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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8 * |
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9 * Initial Contributors: |
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10 * Nokia Corporation - Initial contribution |
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11 * |
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12 * Contributors: |
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13 * Ixonos Plc |
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14 * |
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15 * Description: |
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16 * |
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17 */ |
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18 |
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19 |
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20 /************************************************************************** |
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21 huffdec1.cpp - Bit parsing routines for decoding LFE, SCE and CPE audio elements. |
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22 |
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23 Author(s): Juha Ojanpera |
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24 Copyright (c) 2000-2004 by Nokia Research Center, Speech and Audio Systems. |
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25 *************************************************************************/ |
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26 |
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27 /*-- Project Headers. --*/ |
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28 #include "tool.h" |
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29 #include "tool2.h" |
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30 |
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31 #define SCE_START_BITS (LEN_TAG + LEN_SCL_PCM) |
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32 #define CPE_START_BITS (LEN_TAG + LEN_COM_WIN) |
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33 |
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34 /************************************************************************** |
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35 Title: getmask |
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36 |
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37 Purpose: Reads MS mask and MS flag bits from the bitstream. |
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38 |
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39 Usage: y = getmask(bs, info, group, max_sfb, mask) |
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40 |
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41 Input: bs - bitstream parameters |
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42 info - block (long/short) parameters |
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43 group - grouping info for short blocks |
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44 max_sfb - # of sfb's present in the channel pair |
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45 |
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46 Output: y - value of MS mask in the bitstream |
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47 mask - flag bit for each sfb (only if y == 1) |
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48 |
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49 Author(s): Juha Ojanpera |
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50 *************************************************************************/ |
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51 |
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52 INLINE int16 |
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53 getmask(TBitStream *bs, CInfo *info, uint8 *group, uint8 max_sfb, uint8 *mask) |
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54 { |
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55 int16 b, i, mp; |
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56 |
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57 mp = (int16) BsGetBits(bs, LEN_MASK_PRES); |
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58 |
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59 /*--Get mask. --*/ |
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60 if(mp == 1) |
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61 { |
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62 for(b = 0; b < info->nsbk; b = *group++) |
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63 { |
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64 int16 sfb; |
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65 uint32 tmp, flag; |
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66 |
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67 #if 1 |
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68 /* |
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69 * Speed up the reading of the flags. |
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70 */ |
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71 sfb = max_sfb; |
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72 if(sfb > 32) sfb = 32; |
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73 flag = 1 << (sfb - 1); |
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74 tmp = BsGetBits(bs, sfb); |
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75 |
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76 for(i = 0; i < sfb; i++, mask++, flag >>= 1) |
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77 *mask = (tmp & flag) ? (uint8) 1 : (uint8) 0; |
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78 |
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79 if(sfb == 32) |
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80 { |
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81 sfb = int16(max_sfb - 32); |
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82 flag = 1 << (sfb - 1); |
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83 tmp = BsGetBits(bs, sfb); |
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84 |
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85 for( ; i < max_sfb; i++, mask++, flag >>= 1) |
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86 *mask = (tmp & flag) ? (uint8) 1 : (uint8) 0; |
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87 } |
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88 |
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89 #else |
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90 for(i = 0; i < max_sfb; i++, mask++) |
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91 *mask = (uint8) BsGetBits(bs, LEN_MASK); |
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92 mask += info->sfb_per_sbk[0] - i; |
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93 #endif |
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94 } |
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95 } |
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96 else if(mp == 2) |
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97 { |
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98 for(b = 0; b < info->nsbk; b = *group++) |
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99 { |
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100 SET_MEMORY(mask, max_sfb, 1); |
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101 mask += info->sfb_per_sbk[0]; |
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102 } |
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103 } |
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104 else |
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105 { |
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106 for(b = 0; b < info->nsbk; b = *group++) |
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107 { |
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108 ZERO_MEMORY(mask, max_sfb); |
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109 mask += info->sfb_per_sbk[0]; |
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110 } |
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111 } |
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112 |
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113 return (mp); |
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114 } |
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115 |
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116 /************************************************************************** |
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117 Object Definitions |
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118 *************************************************************************/ |
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119 |
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120 /************************************************************************** |
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121 Title: GetSCE |
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122 |
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123 Purpose: Decodes LFE/SCE audio element from the bitstream. |
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124 |
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125 Usage: y = GetSCE(aac, bs, mip, gains, gainPos, bufBitOffset) |
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126 |
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127 Input: bs - bitstream parameters |
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128 bufBitOffset - # of bits read read so far |
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129 |
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130 Output: y - 0 on success, -1 otherwise |
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131 mip |
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132 ch_info - channel mapping parameters |
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133 aac |
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134 winInfo - block/window parameters for each channel |
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135 toolInfo |
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136 quant - quantized spectral coefficients |
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137 gains - 'global_gain' bitstream element |
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138 gainPos - location of 'global_gain' within the bitstream |
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139 |
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140 Author(s): Juha Ojanpera |
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141 *************************************************************************/ |
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142 |
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143 int16 |
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144 GetSCE(CAACAudDec *aac, TBitStream *bs, CMC_Info *mip, uint8 *gains, |
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145 uint32 *gainPos, uint32 bufBitOffset) |
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146 { |
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147 int16 ch, global_gain; |
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148 CWindowInfo **winInfo; |
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149 CToolInfo **toolInfo; |
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150 CWindowInfo *win; |
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151 CToolInfo *tool; |
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152 TCh_Info *cip; |
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153 uint32 tmp; |
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154 |
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155 toolInfo = aac->tool; |
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156 winInfo = aac->winInfo; |
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157 |
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158 tmp = BsGetBits(bs, SCE_START_BITS); |
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159 |
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160 ch = ChIndex(1, (int16) (tmp >> LEN_SCL_PCM), 0, mip); |
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161 cip = &mip->ch_info[ch]; |
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162 tool = toolInfo[ch]; |
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163 win = winInfo[ch]; |
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164 |
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165 /*-- Global gain. --*/ |
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166 global_gain = (int16) (tmp & 0xFF); |
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167 |
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168 /*-- Save global gain element and its position. --*/ |
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169 if(gainPos) |
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170 { |
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171 gains[0] = (uint8) global_gain; |
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172 gainPos[0] = BsGetBitsRead(bs) - bufBitOffset - LEN_SCL_PCM; |
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173 } |
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174 |
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175 if(!GetICSInfo(bs, win, tool->ltp, NULL)) return (-1); |
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176 |
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177 cip->info = mip->sfbInfo->winmap[win->wnd]; |
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178 |
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179 win->hasmask = 0; |
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180 tool = toolInfo[ch]; |
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181 |
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182 if(!GetICS(bs, cip, win->group, win->max_sfb, win->cb_map, |
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183 tool->quant, global_gain, win->sfac)) |
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184 return (-1); |
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185 |
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186 return (0); |
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187 } |
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188 |
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189 /************************************************************************** |
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190 Title: GetCPE |
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191 |
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192 Purpose: Decodes CPE audio element from the bitstream. |
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193 |
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194 Usage: y = GetCPE(aac, bs, mip, gains, gainPos, bufBitOffset |
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195 |
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196 Input: bs - bitstream parameters |
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197 bufBitOffset - # of bits read read so far |
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198 |
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199 Output: y - 0 on success, -1 otherwise |
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200 mip |
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201 ch_info - channel mapping parameters |
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202 aac |
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203 winInfo - block/window parameters for each channel |
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204 toolInfo |
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205 quant - quantized spectral coefficients |
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206 gains - 'global_gain' bitstream element |
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207 gainPos - location of 'global_gain' within the bitstream |
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208 |
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209 Author(s): Juha Ojanpera |
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210 *************************************************************************/ |
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211 |
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212 int16 |
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213 GetCPE(CAACAudDec *aac, TBitStream *bs, CMC_Info *mip, uint8 *gains, |
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214 uint32 *gainPos, uint32 bufBitOffset) |
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215 { |
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216 int16 i, common_window, ch; |
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217 CWindowInfo **winInfo; |
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218 CToolInfo **toolInfo; |
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219 int16 global_gain; |
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220 CWindowInfo *win; |
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221 CToolInfo **tool; |
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222 TCh_Info *cip; |
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223 |
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224 toolInfo = aac->tool; |
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225 winInfo = aac->winInfo; |
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226 |
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227 uint16 tmp = (uint16) BsGetBits(bs, CPE_START_BITS); |
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228 |
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229 common_window = (int16) (tmp & 0x1); |
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230 |
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231 ch = ChIndex(2, (int16) (tmp >> 1), common_window, mip); |
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232 |
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233 if(common_window) |
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234 { |
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235 win = winInfo[ch]; |
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236 |
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237 if(!GetICSInfo(bs, win, toolInfo[ch]->ltp, toolInfo[ch + 1]->ltp)) |
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238 return (-1); |
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239 |
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240 win->hasmask = (uint8) getmask(bs, mip->sfbInfo->winmap[win->wnd], win->group, win->max_sfb, win->mask); |
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241 } |
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242 else |
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243 winInfo[ch]->hasmask = winInfo[ch + 1]->hasmask = 0; |
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244 |
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245 tool = toolInfo + ch; |
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246 cip = &mip->ch_info[ch]; |
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247 for(i = ch; i < ch + 2; i++, cip++, tool++) |
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248 { |
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249 CWindowInfo *wi = winInfo[i]; |
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250 |
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251 win = winInfo[cip->widx]; |
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252 |
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253 /*-- Global gain. --*/ |
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254 global_gain = (int16) BsGetBits(bs, LEN_SCL_PCM); |
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255 |
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256 /*-- Save global gain element and its position. --*/ |
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257 if(gainPos) |
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258 { |
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259 gains[i - ch] = (uint8) global_gain; |
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260 gainPos[i - ch] = BsGetBitsRead(bs) - bufBitOffset - LEN_SCL_PCM; |
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261 bufBitOffset = BsGetBitsRead(bs); |
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262 } |
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263 |
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264 if(!common_window) |
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265 if(!GetICSInfo(bs, win, (*tool)->ltp, NULL)) |
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266 return (-1); |
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267 |
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268 cip->info = mip->sfbInfo->winmap[win->wnd]; |
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269 |
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270 if(!GetICS(bs, cip, win->group, win->max_sfb, wi->cb_map, |
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271 (*tool)->quant, global_gain, wi->sfac)) |
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272 return (-1); |
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273 } |
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274 |
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275 return (0); |
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276 } |
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277 |
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278 /************************************************************************** |
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279 Title : LTP_Decode |
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280 |
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281 Purpose : Decodes the bitstream elements for LTP tool. |
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282 |
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283 Usage : LTP_Decode(bs, ltp_info, max_sfb) |
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284 |
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285 Input : bs - input bitstream |
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286 max_sfb - # scalefactor bands to be used for current frame |
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287 |
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288 Output : ltp_info - LTP parameters for this channel |
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289 |
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290 Author(s) : Juha Ojanpera |
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291 *************************************************************************/ |
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292 |
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293 INLINE void |
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294 LTP_Decode(TBitStream *bs, CLTP_Info *ltp_info, int16 max_sfb) |
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295 { |
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296 /* |
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297 Purpose: 1 bits is used to indicate the presence of LTP. */ |
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298 #define LEN_LTP_DATA_PRESENT 1 |
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299 |
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300 /* |
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301 Purpose: # of bits used for the pitch lag. */ |
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302 #define LEN_LTP_LAG 11 |
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303 |
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304 /* |
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305 Purpose: # of bits used for the gain value. */ |
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306 #define LEN_LTP_COEF 3 |
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307 |
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308 ltp_info->ltp_present = (uint8) BsGetBits(bs, LEN_LTP_DATA_PRESENT); |
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309 if(ltp_info->ltp_present) |
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310 { |
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311 uint32 bits = BsGetBits(bs, LEN_LTP_LAG + LEN_LTP_COEF); |
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312 |
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313 /*-- LTP lag. --*/ |
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314 ltp_info->delay[0] = (int16) (bits >> LEN_LTP_COEF); |
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315 |
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316 /*-- LTP gain. --*/ |
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317 ltp_info->cbIdx = (uint8) (bits & 0x7); |
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318 |
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319 /*-- Sfb flags. --*/ |
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320 ltp_info->max_sfb = max_sfb; |
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321 if(max_sfb < 33) |
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322 ltp_info->sfbflags[0] = BsGetBits(bs, max_sfb); |
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323 else |
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324 { |
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325 ltp_info->sfbflags[0] = BsGetBits(bs, 32); |
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326 ltp_info->sfbflags[1] = BsGetBits(bs, (int16) (max_sfb - 32)); |
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327 } |
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328 } |
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329 } |
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330 |
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331 /************************************************************************** |
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332 Title: GetICSInfo |
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333 |
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334 Purpose: Reads side information for individual channel element. |
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335 Individual channel elements within channel pair element may |
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336 share this information. |
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337 |
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338 Usage: y = GetICSInfo(bs, winInfo, ltp_left, ltp_right) |
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339 |
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340 Input: bs - bitstream parameters |
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341 |
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342 Output: y - # of sfb's present in this channel |
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343 winInfo : |
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344 wnd - window type for this channel |
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345 wshape - window shape for this channel |
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346 group - grouping of short blocks |
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347 lpflag - BWAP prediction flags for each sfb |
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348 prstflag - reset flags for BWAP |
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349 ltp_left - LTP parameters for left channel of the audio element |
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350 ltp_right - LTP parameters for right channel of the audio element |
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351 |
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352 Author(s): Juha Ojanpera |
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353 *************************************************************************/ |
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354 |
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355 int16 |
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356 GetICSInfo(TBitStream *bs, CWindowInfo *winInfo, CLTP_Info *ltp_left, CLTP_Info *ltp_right) |
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357 { |
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358 #define INFO_BITS (LEN_ICS_RESERV + LEN_WIN_SEQ + LEN_WIN_SH + LEN_MAX_SFBL + LEN_PRED_PRES) |
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359 int16 i, j; |
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360 uint32 tmp; |
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361 |
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362 tmp = BsGetBits(bs, INFO_BITS); |
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363 winInfo->wnd = (uint8) ((tmp >> 8) & 0x3); |
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364 winInfo->wshape[0].this_bk = (uint8) ((tmp >> 7) & 0x1); |
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365 |
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366 /*-- Max scalefactor, scalefactor grouping and prediction flags. --*/ |
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367 winInfo->prstflag[0] = 0; |
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368 if(winInfo->wnd == 2) |
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369 { |
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370 tmp <<= 4; |
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371 tmp |= BsGetBits(bs, 4); |
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372 winInfo->max_sfb = (uint8) ((tmp >> 7) & 0xF); |
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373 if(winInfo->max_sfb > MAXLONGSFBBANDS) return (FALSE); |
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374 |
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375 /*-- Get grouping info for short blocks. --*/ |
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376 j = 0; |
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377 if(!(tmp & 64)) winInfo->group[j++] = 1; |
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378 if(!(tmp & 32)) winInfo->group[j++] = 2; |
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379 if(!(tmp & 16)) winInfo->group[j++] = 3; |
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380 if(!(tmp & 8)) winInfo->group[j++] = 4; |
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381 if(!(tmp & 4)) winInfo->group[j++] = 5; |
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382 if(!(tmp & 2)) winInfo->group[j++] = 6; |
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383 if(!(tmp & 1)) winInfo->group[j++] = 7; |
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384 winInfo->group[j] = NSHORT; |
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385 |
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386 /*-- Prediction (BWAP) is disabled. --*/ |
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387 winInfo->lpflag[0] = 0; |
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388 } |
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389 else |
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390 { |
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391 winInfo->group[0] = 1; |
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392 winInfo->max_sfb = (uint8) ((tmp >> 1) & 0x3F); |
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393 if(winInfo->max_sfb > MAXLONGSFBBANDS) return (FALSE); |
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394 |
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395 if(winInfo->predType == BWAP_PRED) |
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396 { |
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397 /*-- Read BWAP predictor parameters. --*/ |
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398 winInfo->lpflag[0] = (uint8) (tmp & 0x1); |
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399 if(winInfo->lpflag[0]) |
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400 { |
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401 /*-- Predictor reset pattern. --*/ |
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402 winInfo->prstflag[0] = (uint8) BsGetBits(bs, LEN_PRED_RST); |
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403 if(winInfo->prstflag[0]) |
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404 winInfo->prstflag[1] = (uint8) BsGetBits(bs, LEN_PRED_RSTGRP); |
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405 |
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406 /*-- Sfb flags for each predictor band. --*/ |
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407 j = (winInfo->max_sfb < winInfo->predBands) ? winInfo->max_sfb : winInfo->predBands; |
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408 |
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409 for(i = 1; i < j + 1; i++) |
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410 winInfo->lpflag[i] = (uint8) BsGetBits(bs, LEN_PRED_ENAB); |
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411 |
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412 for(; i < winInfo->predBands + 1; i++) |
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413 winInfo->lpflag[i] = 0; |
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414 } |
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415 } |
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416 |
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417 else if(winInfo->predType == LTP_PRED) |
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418 { |
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419 /*-- Is LTP used in this channel ? --*/ |
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420 ltp_left->ltp_present = (uint8) (tmp & 1); |
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421 if(ltp_left->ltp_present) |
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422 { |
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423 int16 nbands = MIN(winInfo->max_sfb, winInfo->predBands); |
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424 LTP_Decode(bs, ltp_left, nbands); |
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425 if(ltp_right) |
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426 LTP_Decode(bs, ltp_right, nbands); |
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427 } |
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428 else if(ltp_right) ltp_right->ltp_present = 0; |
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429 } |
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430 |
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431 /*-- Bitstream syntax error. --*/ |
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432 else if(tmp & 0x1) return (FALSE); |
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433 } |
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434 |
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435 return (TRUE); |
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436 } |
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437 |
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438 /* |
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439 * Retrieves 'global_gain' bitstream elements from single channel element. |
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440 */ |
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441 int16 |
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442 GetSCEGain(CAACAudDec *aac, TBitStream *bs, uint8 *gains, uint32 *gainPos, uint32 bufBitOffset) |
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443 { |
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444 return GetSCE(aac, bs, aac->mc_info, gains, gainPos, bufBitOffset); |
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445 } |
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446 |
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447 /* |
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448 * Retrieves 'global_gain' bitstream elements from channel pair element. |
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449 */ |
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450 int16 |
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451 GetCPEGain(CAACAudDec *aac, TBitStream *bs, uint8 *gains, uint32 *gainPos, uint32 bufBitOffset) |
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452 { |
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453 return GetCPE(aac, bs, aac->mc_info, gains, gainPos, bufBitOffset); |
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454 } |
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