corrade-vassal – Blame information for rev 1
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1 | vero | 1 | /* |
2 | * CVS identifier: |
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3 | * |
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4 | * $Id: LayersInfo.java,v 1.7 2001/04/15 14:31:22 grosbois Exp $ |
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5 | * |
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6 | * Class: LayersInfo |
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7 | * |
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8 | * Description: Specification of a layer |
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9 | * |
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10 | * |
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11 | * |
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12 | * COPYRIGHT: |
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13 | * |
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14 | * This software module was originally developed by Raphaël Grosbois and |
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15 | * Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel |
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16 | * Askelöf (Ericsson Radio Systems AB); and Bertrand Berthelot, David |
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17 | * Bouchard, Félix Henry, Gerard Mozelle and Patrice Onno (Canon Research |
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18 | * Centre France S.A) in the course of development of the JPEG2000 |
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19 | * standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This |
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20 | * software module is an implementation of a part of the JPEG 2000 |
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21 | * Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio |
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22 | * Systems AB and Canon Research Centre France S.A (collectively JJ2000 |
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23 | * Partners) agree not to assert against ISO/IEC and users of the JPEG |
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24 | * 2000 Standard (Users) any of their rights under the copyright, not |
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25 | * including other intellectual property rights, for this software module |
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26 | * with respect to the usage by ISO/IEC and Users of this software module |
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27 | * or modifications thereof for use in hardware or software products |
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28 | * claiming conformance to the JPEG 2000 Standard. Those intending to use |
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29 | * this software module in hardware or software products are advised that |
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30 | * their use may infringe existing patents. The original developers of |
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31 | * this software module, JJ2000 Partners and ISO/IEC assume no liability |
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32 | * for use of this software module or modifications thereof. No license |
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33 | * or right to this software module is granted for non JPEG 2000 Standard |
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34 | * conforming products. JJ2000 Partners have full right to use this |
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35 | * software module for his/her own purpose, assign or donate this |
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36 | * software module to any third party and to inhibit third parties from |
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37 | * using this software module for non JPEG 2000 Standard conforming |
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38 | * products. This copyright notice must be included in all copies or |
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39 | * derivative works of this software module. |
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40 | * |
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41 | * Copyright (c) 1999/2000 JJ2000 Partners. |
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42 | * */ |
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43 | using System; |
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44 | namespace CSJ2K.j2k.entropy.encoder |
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45 | { |
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46 | |||
47 | /// <summary> This class stores the specification of a layer distribution in the bit |
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48 | /// stream. The specification is made of optimization points and a number of |
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49 | /// extra layers to add between the optimization points. Each optimization |
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50 | /// point creates a layer which is optimized by the rate allocator to the |
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51 | /// specified target bitrate. The extra layers are added by the rate allocator |
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52 | /// between the optimized layers, with the difference that they are not |
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53 | /// optimized (i.e. they have no precise target bitrate). |
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54 | /// |
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55 | /// <p>The overall target bitrate for the bit stream is always added as the |
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56 | /// last optimization point without any extra layers after it. If there are |
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57 | /// some optimization points whose target bitrate is larger than the overall |
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58 | /// target bitrate, the overall target bitrate will still appear as the last |
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59 | /// optimization point, even though it does not follow the increasing target |
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60 | /// bitrate order of the other optimization points. The rate allocator is |
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61 | /// responsible for eliminating layers that have target bitrates larger than |
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62 | /// the overall target bitrate.</p> |
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63 | /// |
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64 | /// <p>Optimization points can be added with the addOptPoint() method. It takes |
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65 | /// the target bitrate for the optimized layer and the number of extra layers |
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66 | /// to add after it.</p> |
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67 | /// |
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68 | /// <p>Information about the total number of layers, total number of |
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69 | /// optimization points, target bitrates, etc. can be obtained with the other |
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70 | /// methods.</p> |
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71 | /// |
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72 | /// </summary> |
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73 | public class LayersInfo |
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74 | { |
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75 | /// <summary> Returns the overall target bitrate for the entire bit stream. |
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76 | /// |
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77 | /// </summary> |
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78 | /// <returns> The overall target bitrate |
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79 | /// |
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80 | /// </returns> |
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81 | virtual public float TotBitrate |
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82 | { |
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83 | get |
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84 | { |
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85 | return totbrate; |
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86 | } |
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87 | |||
88 | } |
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89 | /// <summary> Returns the total number of layers, according to the layer |
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90 | /// specification of this object and the overall target bitrate. |
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91 | /// |
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92 | /// </summary> |
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93 | /// <returns> The total number of layers, according to the layer spec. |
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94 | /// |
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95 | /// </returns> |
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96 | virtual public int TotNumLayers |
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97 | { |
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98 | get |
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99 | { |
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100 | return totlyrs; |
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101 | } |
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102 | |||
103 | } |
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104 | /// <summary> Returns the number of layers to optimize, or optimization points, as |
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105 | /// specified by this object. |
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106 | /// |
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107 | /// </summary> |
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108 | /// <returns> The number of optimization points |
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109 | /// |
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110 | /// </returns> |
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111 | virtual public int NOptPoints |
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112 | { |
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113 | get |
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114 | { |
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115 | // overall target bitrate is counted as extra |
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116 | return nopt + 1; |
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117 | } |
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118 | |||
119 | } |
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120 | |||
121 | /// <summary>The initial size for the arrays: 10 </summary> |
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122 | private const int SZ_INIT = 10; |
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123 | |||
124 | /// <summary>The size increment for the arrays </summary> |
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125 | private const int SZ_INCR = 5; |
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126 | |||
127 | /// <summary>The total number of layers </summary> |
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128 | // Starts at 1: overall target bitrate is always an extra optimized layer |
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129 | internal int totlyrs = 1; |
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130 | |||
131 | /// <summary>The overall target bitrate, for the whole bit stream </summary> |
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132 | internal float totbrate; |
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133 | |||
134 | /// <summary>The number of optimized layers, or optimization points, without |
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135 | /// counting the extra one coming from the overall target bitrate |
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136 | /// </summary> |
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137 | internal int nopt; |
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138 | |||
139 | /// <summary>The target bitrate to which specified layers should be optimized. </summary> |
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140 | internal float[] optbrate = new float[SZ_INIT]; |
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141 | |||
142 | /// <summary>The number of extra layers to be added after an optimized layer. After |
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143 | /// the layer that is optimized to optbrate[i], extralyrs[i] extra layers |
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144 | /// should be added. These layers are allocated between the bitrate |
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145 | /// optbrate[i] and the next optimized bitrate optbrate[i+1] or, if it does |
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146 | /// not exist, the overall target bitrate. |
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147 | /// </summary> |
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148 | internal int[] extralyrs = new int[SZ_INIT]; |
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149 | |||
150 | /// <summary> Creates a new LayersInfo object. The overall target bitrate 'brate' is |
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151 | /// always an extra optimization point, with no extra layers are after |
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152 | /// it. Note that any optimization points that are added with addOptPoint() |
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153 | /// are always added before the overall target bitrate. |
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154 | /// |
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155 | /// </summary> |
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156 | /// <param name="brate">The overall target bitrate for the bit stream |
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157 | /// |
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158 | /// </param> |
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159 | public LayersInfo(float brate) |
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160 | { |
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161 | if (brate <= 0) |
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162 | { |
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163 | throw new System.ArgumentException("Overall target bitrate must " + "be a positive number"); |
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164 | } |
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165 | totbrate = brate; |
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166 | } |
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167 | |||
168 | /// <summary> Returns the target bitrate of the optmimization point 'n'. |
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169 | /// |
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170 | /// </summary> |
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171 | /// <param name="n">The optimization point index (starts at 0). |
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172 | /// |
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173 | /// </param> |
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174 | /// <returns> The target bitrate (in bpp) for the optimization point 'n'. |
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175 | /// |
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176 | /// </returns> |
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177 | public virtual float getTargetBitrate(int n) |
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178 | { |
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179 | // overall target bitrate is counted as extra |
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180 | return (n < nopt)?optbrate[n]:totbrate; |
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181 | } |
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182 | |||
183 | /// <summary> Returns the number of extra layers to add after the optimization point |
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184 | /// 'n', but before optimization point 'n+1'. If there is no optimization |
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185 | /// point 'n+1' then they should be added before the overall target |
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186 | /// bitrate. |
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187 | /// |
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188 | /// </summary> |
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189 | /// <param name="n">The optimization point index (starts at 0). |
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190 | /// |
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191 | /// </param> |
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192 | /// <returns> The number of extra (unoptimized) layers to add after the |
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193 | /// optimization point 'n' |
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194 | /// |
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195 | /// </returns> |
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196 | public virtual int getExtraLayers(int n) |
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197 | { |
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198 | // overall target bitrate is counted as extra |
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199 | return (n < nopt)?extralyrs[n]:0; |
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200 | } |
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201 | |||
202 | /// <summary> Adds a new optimization point, with target bitrate 'brate' and with |
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203 | /// 'elyrs' (unoptimized) extra layers after it. The target bitrate 'brate' |
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204 | /// must be larger than the previous optimization point. The arguments are |
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205 | /// checked and IllegalArgumentException is thrown if they are not correct. |
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206 | /// |
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207 | /// </summary> |
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208 | /// <param name="brate">The target bitrate for the optimized layer. |
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209 | /// |
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210 | /// </param> |
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211 | /// <param name="elyrs">The number of extra (unoptimized) layers to add after the |
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212 | /// optimized layer. |
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213 | /// |
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214 | /// </param> |
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215 | public virtual void addOptPoint(float brate, int elyrs) |
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216 | { |
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217 | // Check validity of arguments |
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218 | if (brate <= 0) |
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219 | { |
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220 | throw new System.ArgumentException("Target bitrate must be positive"); |
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221 | } |
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222 | if (elyrs < 0) |
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223 | { |
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224 | throw new System.ArgumentException("The number of extra layers " + "must be 0 or more"); |
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225 | } |
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226 | if (nopt > 0 && optbrate[nopt - 1] >= brate) |
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227 | { |
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228 | throw new System.ArgumentException("New optimization point must have " + "a target bitrate higher than the " + "preceding one"); |
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229 | } |
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230 | // Check room for new optimization point |
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231 | if (optbrate.Length == nopt) |
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232 | { |
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233 | // Need more room |
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234 | float[] tbr = optbrate; |
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235 | int[] tel = extralyrs; |
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236 | // both arrays always have same size |
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237 | optbrate = new float[optbrate.Length + SZ_INCR]; |
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238 | extralyrs = new int[extralyrs.Length + SZ_INCR]; |
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239 | Array.Copy(tbr, 0, optbrate, 0, nopt); |
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240 | Array.Copy(tel, 0, extralyrs, 0, nopt); |
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241 | } |
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242 | // Add new optimization point |
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243 | optbrate[nopt] = brate; |
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244 | extralyrs[nopt] = elyrs; |
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245 | nopt++; |
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246 | // Update total number of layers |
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247 | totlyrs += 1 + elyrs; |
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248 | } |
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249 | } |
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250 | } |