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1 /* |
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2 * jdmainct.c |
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3 * |
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4 * Copyright (C) 1994-1996, Thomas G. Lane. |
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5 * This file is part of the Independent JPEG Group's software. |
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6 * For conditions of distribution and use, see the accompanying README file. |
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7 * |
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8 * This file contains the main buffer controller for decompression. |
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9 * The main buffer lies between the JPEG decompressor proper and the |
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10 * post-processor; it holds downsampled data in the JPEG colorspace. |
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11 * |
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12 * Note that this code is bypassed in raw-data mode, since the application |
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13 * supplies the equivalent of the main buffer in that case. |
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14 */ |
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15 |
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16 #define JPEG_INTERNALS |
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17 #include "jinclude.h" |
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18 #include "jpeglib.h" |
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19 |
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20 |
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21 /* |
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22 * In the current system design, the main buffer need never be a full-image |
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23 * buffer; any full-height buffers will be found inside the coefficient or |
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24 * postprocessing controllers. Nonetheless, the main controller is not |
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25 * trivial. Its responsibility is to provide context rows for upsampling/ |
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26 * rescaling, and doing this in an efficient fashion is a bit tricky. |
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27 * |
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28 * Postprocessor input data is counted in "row groups". A row group |
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29 * is defined to be (v_samp_factor * DCT_scaled_size / min_DCT_scaled_size) |
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30 * sample rows of each component. (We require DCT_scaled_size values to be |
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31 * chosen such that these numbers are integers. In practice DCT_scaled_size |
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32 * values will likely be powers of two, so we actually have the stronger |
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33 * condition that DCT_scaled_size / min_DCT_scaled_size is an integer.) |
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34 * Upsampling will typically produce max_v_samp_factor pixel rows from each |
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35 * row group (times any additional scale factor that the upsampler is |
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36 * applying). |
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37 * |
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38 * The coefficient controller will deliver data to us one iMCU row at a time; |
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39 * each iMCU row contains v_samp_factor * DCT_scaled_size sample rows, or |
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40 * exactly min_DCT_scaled_size row groups. (This amount of data corresponds |
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41 * to one row of MCUs when the image is fully interleaved.) Note that the |
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42 * number of sample rows varies across components, but the number of row |
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43 * groups does not. Some garbage sample rows may be included in the last iMCU |
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44 * row at the bottom of the image. |
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45 * |
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46 * Depending on the vertical scaling algorithm used, the upsampler may need |
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47 * access to the sample row(s) above and below its current input row group. |
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48 * The upsampler is required to set need_context_rows TRUE at global selection |
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49 * time if so. When need_context_rows is FALSE, this controller can simply |
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50 * obtain one iMCU row at a time from the coefficient controller and dole it |
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51 * out as row groups to the postprocessor. |
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52 * |
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53 * When need_context_rows is TRUE, this controller guarantees that the buffer |
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54 * passed to postprocessing contains at least one row group's worth of samples |
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55 * above and below the row group(s) being processed. Note that the context |
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56 * rows "above" the first passed row group appear at negative row offsets in |
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57 * the passed buffer. At the top and bottom of the image, the required |
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58 * context rows are manufactured by duplicating the first or last real sample |
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59 * row; this avoids having special cases in the upsampling inner loops. |
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60 * |
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61 * The amount of context is fixed at one row group just because that's a |
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62 * convenient number for this controller to work with. The existing |
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63 * upsamplers really only need one sample row of context. An upsampler |
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64 * supporting arbitrary output rescaling might wish for more than one row |
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65 * group of context when shrinking the image; tough, we don't handle that. |
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66 * (This is justified by the assumption that downsizing will be handled mostly |
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67 * by adjusting the DCT_scaled_size values, so that the actual scale factor at |
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68 * the upsample step needn't be much less than one.) |
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69 * |
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70 * To provide the desired context, we have to retain the last two row groups |
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71 * of one iMCU row while reading in the next iMCU row. (The last row group |
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72 * can't be processed until we have another row group for its below-context, |
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73 * and so we have to save the next-to-last group too for its above-context.) |
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74 * We could do this most simply by copying data around in our buffer, but |
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75 * that'd be very slow. We can avoid copying any data by creating a rather |
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76 * strange pointer structure. Here's how it works. We allocate a workspace |
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77 * consisting of M+2 row groups (where M = min_DCT_scaled_size is the number |
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78 * of row groups per iMCU row). We create two sets of redundant pointers to |
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79 * the workspace. Labeling the physical row groups 0 to M+1, the synthesized |
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80 * pointer lists look like this: |
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81 * M+1 M-1 |
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82 * master pointer --> 0 master pointer --> 0 |
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83 * 1 1 |
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84 * ... ... |
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85 * M-3 M-3 |
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86 * M-2 M |
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87 * M-1 M+1 |
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88 * M M-2 |
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89 * M+1 M-1 |
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90 * 0 0 |
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91 * We read alternate iMCU rows using each master pointer; thus the last two |
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92 * row groups of the previous iMCU row remain un-overwritten in the workspace. |
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93 * The pointer lists are set up so that the required context rows appear to |
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94 * be adjacent to the proper places when we pass the pointer lists to the |
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95 * upsampler. |
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96 * |
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97 * The above pictures describe the normal state of the pointer lists. |
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98 * At top and bottom of the image, we diddle the pointer lists to duplicate |
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99 * the first or last sample row as necessary (this is cheaper than copying |
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100 * sample rows around). |
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101 * |
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102 * This scheme breaks down if M < 2, ie, min_DCT_scaled_size is 1. In that |
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103 * situation each iMCU row provides only one row group so the buffering logic |
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104 * must be different (eg, we must read two iMCU rows before we can emit the |
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105 * first row group). For now, we simply do not support providing context |
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106 * rows when min_DCT_scaled_size is 1. That combination seems unlikely to |
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107 * be worth providing --- if someone wants a 1/8th-size preview, they probably |
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108 * want it quick and dirty, so a context-free upsampler is sufficient. |
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109 */ |
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110 |
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111 |
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112 /* Private buffer controller object */ |
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113 |
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114 typedef struct { |
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115 struct jpeg_d_main_controller pub; /* public fields */ |
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116 |
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117 /* Pointer to allocated workspace (M or M+2 row groups). */ |
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118 JSAMPARRAY buffer[MAX_COMPONENTS]; |
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119 |
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120 boolean buffer_full; /* Have we gotten an iMCU row from decoder? */ |
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121 JDIMENSION rowgroup_ctr; /* counts row groups output to postprocessor */ |
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122 |
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123 /* Remaining fields are only used in the context case. */ |
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124 |
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125 /* These are the master pointers to the funny-order pointer lists. */ |
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126 JSAMPIMAGE xbuffer[2]; /* pointers to weird pointer lists */ |
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127 |
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128 int whichptr; /* indicates which pointer set is now in use */ |
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129 int context_state; /* process_data state machine status */ |
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130 JDIMENSION rowgroups_avail; /* row groups available to postprocessor */ |
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131 JDIMENSION iMCU_row_ctr; /* counts iMCU rows to detect image top/bot */ |
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132 } my_main_controller; |
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133 |
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134 typedef my_main_controller * my_main_ptr; |
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135 |
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136 /* context_state values: */ |
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137 #define CTX_PREPARE_FOR_IMCU 0 /* need to prepare for MCU row */ |
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138 #define CTX_PROCESS_IMCU 1 /* feeding iMCU to postprocessor */ |
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139 #define CTX_POSTPONED_ROW 2 /* feeding postponed row group */ |
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140 |
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141 |
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142 /* Forward declarations */ |
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143 METHODDEF(void) process_data_simple_main |
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144 JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf, |
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145 JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail)); |
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146 METHODDEF(void) process_data_context_main |
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147 JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf, |
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148 JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail)); |
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149 #ifdef QUANT_2PASS_SUPPORTED |
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150 METHODDEF(void) process_data_crank_post |
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151 JPP((j_decompress_ptr cinfo, JSAMPARRAY output_buf, |
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152 JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail)); |
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153 #endif |
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154 |
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155 |
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156 LOCAL(void) |
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157 alloc_funny_pointers (j_decompress_ptr cinfo) |
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158 /* Allocate space for the funny pointer lists. |
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159 * This is done only once, not once per pass. |
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160 */ |
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161 { |
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162 my_main_ptr main = (my_main_ptr) cinfo->main; |
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163 int ci, rgroup; |
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164 int M = cinfo->min_DCT_scaled_size; |
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165 jpeg_component_info *compptr; |
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166 JSAMPARRAY xbuf; |
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167 |
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168 /* Get top-level space for component array pointers. |
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169 * We alloc both arrays with one call to save a few cycles. |
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170 */ |
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171 main->xbuffer[0] = (JSAMPIMAGE) |
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172 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
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173 cinfo->num_components * 2 * SIZEOF(JSAMPARRAY)); |
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174 main->xbuffer[1] = main->xbuffer[0] + cinfo->num_components; |
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175 |
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176 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; |
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177 ci++, compptr++) { |
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178 rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) / |
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179 cinfo->min_DCT_scaled_size; /* height of a row group of component */ |
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180 /* Get space for pointer lists --- M+4 row groups in each list. |
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181 * We alloc both pointer lists with one call to save a few cycles. |
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182 */ |
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183 xbuf = (JSAMPARRAY) |
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184 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
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185 2 * (rgroup * (M + 4)) * SIZEOF(JSAMPROW)); |
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186 xbuf += rgroup; /* want one row group at negative offsets */ |
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187 main->xbuffer[0][ci] = xbuf; |
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188 xbuf += rgroup * (M + 4); |
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189 main->xbuffer[1][ci] = xbuf; |
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190 } |
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191 } |
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192 |
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193 |
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194 LOCAL(void) |
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195 make_funny_pointers (j_decompress_ptr cinfo) |
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196 /* Create the funny pointer lists discussed in the comments above. |
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197 * The actual workspace is already allocated (in main->buffer), |
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198 * and the space for the pointer lists is allocated too. |
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199 * This routine just fills in the curiously ordered lists. |
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200 * This will be repeated at the beginning of each pass. |
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201 */ |
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202 { |
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203 my_main_ptr main = (my_main_ptr) cinfo->main; |
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204 int ci, i, rgroup; |
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205 int M = cinfo->min_DCT_scaled_size; |
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206 jpeg_component_info *compptr; |
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207 JSAMPARRAY buf, xbuf0, xbuf1; |
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208 |
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209 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; |
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210 ci++, compptr++) { |
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211 rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) / |
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212 cinfo->min_DCT_scaled_size; /* height of a row group of component */ |
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213 xbuf0 = main->xbuffer[0][ci]; |
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214 xbuf1 = main->xbuffer[1][ci]; |
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215 /* First copy the workspace pointers as-is */ |
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216 buf = main->buffer[ci]; |
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217 for (i = 0; i < rgroup * (M + 2); i++) { |
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218 xbuf0[i] = xbuf1[i] = buf[i]; |
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219 } |
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220 /* In the second list, put the last four row groups in swapped order */ |
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221 for (i = 0; i < rgroup * 2; i++) { |
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222 xbuf1[rgroup*(M-2) + i] = buf[rgroup*M + i]; |
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223 xbuf1[rgroup*M + i] = buf[rgroup*(M-2) + i]; |
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224 } |
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225 /* The wraparound pointers at top and bottom will be filled later |
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226 * (see set_wraparound_pointers, below). Initially we want the "above" |
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227 * pointers to duplicate the first actual data line. This only needs |
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228 * to happen in xbuffer[0]. |
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229 */ |
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230 for (i = 0; i < rgroup; i++) { |
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231 xbuf0[i - rgroup] = xbuf0[0]; |
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232 } |
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233 } |
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234 } |
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235 |
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236 |
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237 LOCAL(void) |
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238 set_wraparound_pointers (j_decompress_ptr cinfo) |
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239 /* Set up the "wraparound" pointers at top and bottom of the pointer lists. |
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240 * This changes the pointer list state from top-of-image to the normal state. |
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241 */ |
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242 { |
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243 my_main_ptr main = (my_main_ptr) cinfo->main; |
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244 int ci, i, rgroup; |
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245 int M = cinfo->min_DCT_scaled_size; |
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246 jpeg_component_info *compptr; |
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247 JSAMPARRAY xbuf0, xbuf1; |
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248 |
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249 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; |
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250 ci++, compptr++) { |
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251 rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) / |
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252 cinfo->min_DCT_scaled_size; /* height of a row group of component */ |
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253 xbuf0 = main->xbuffer[0][ci]; |
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254 xbuf1 = main->xbuffer[1][ci]; |
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255 for (i = 0; i < rgroup; i++) { |
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256 xbuf0[i - rgroup] = xbuf0[rgroup*(M+1) + i]; |
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257 xbuf1[i - rgroup] = xbuf1[rgroup*(M+1) + i]; |
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258 xbuf0[rgroup*(M+2) + i] = xbuf0[i]; |
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259 xbuf1[rgroup*(M+2) + i] = xbuf1[i]; |
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260 } |
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261 } |
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262 } |
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263 |
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264 |
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265 LOCAL(void) |
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266 set_bottom_pointers (j_decompress_ptr cinfo) |
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267 /* Change the pointer lists to duplicate the last sample row at the bottom |
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268 * of the image. whichptr indicates which xbuffer holds the final iMCU row. |
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269 * Also sets rowgroups_avail to indicate number of nondummy row groups in row. |
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270 */ |
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271 { |
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272 my_main_ptr main = (my_main_ptr) cinfo->main; |
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273 int ci, i, rgroup, iMCUheight, rows_left; |
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274 jpeg_component_info *compptr; |
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275 JSAMPARRAY xbuf; |
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276 |
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277 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; |
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278 ci++, compptr++) { |
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279 /* Count sample rows in one iMCU row and in one row group */ |
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280 iMCUheight = compptr->v_samp_factor * compptr->DCT_scaled_size; |
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281 rgroup = iMCUheight / cinfo->min_DCT_scaled_size; |
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282 /* Count nondummy sample rows remaining for this component */ |
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283 rows_left = (int) (compptr->downsampled_height % (JDIMENSION) iMCUheight); |
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284 if (rows_left == 0) rows_left = iMCUheight; |
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285 /* Count nondummy row groups. Should get same answer for each component, |
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286 * so we need only do it once. |
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287 */ |
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288 if (ci == 0) { |
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289 main->rowgroups_avail = (JDIMENSION) ((rows_left-1) / rgroup + 1); |
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290 } |
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291 /* Duplicate the last real sample row rgroup*2 times; this pads out the |
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292 * last partial rowgroup and ensures at least one full rowgroup of context. |
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293 */ |
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294 xbuf = main->xbuffer[main->whichptr][ci]; |
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295 for (i = 0; i < rgroup * 2; i++) { |
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296 xbuf[rows_left + i] = xbuf[rows_left-1]; |
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297 } |
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298 } |
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299 } |
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300 |
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301 |
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302 /* |
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303 * Initialize for a processing pass. |
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304 */ |
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305 |
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306 METHODDEF(void) |
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307 start_pass_main (j_decompress_ptr cinfo, J_BUF_MODE pass_mode) |
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308 { |
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309 my_main_ptr main = (my_main_ptr) cinfo->main; |
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310 |
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311 switch (pass_mode) { |
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312 case JBUF_PASS_THRU: |
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313 if (cinfo->upsample->need_context_rows) { |
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314 main->pub.process_data = process_data_context_main; |
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315 make_funny_pointers(cinfo); /* Create the xbuffer[] lists */ |
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316 main->whichptr = 0; /* Read first iMCU row into xbuffer[0] */ |
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317 main->context_state = CTX_PREPARE_FOR_IMCU; |
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318 main->iMCU_row_ctr = 0; |
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319 } else { |
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320 /* Simple case with no context needed */ |
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321 main->pub.process_data = process_data_simple_main; |
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322 } |
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323 main->buffer_full = FALSE; /* Mark buffer empty */ |
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324 main->rowgroup_ctr = 0; |
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325 break; |
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326 #ifdef QUANT_2PASS_SUPPORTED |
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327 case JBUF_CRANK_DEST: |
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328 /* For last pass of 2-pass quantization, just crank the postprocessor */ |
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329 main->pub.process_data = process_data_crank_post; |
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330 break; |
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331 #endif |
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332 default: |
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333 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); |
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334 break; |
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335 } |
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336 } |
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337 |
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338 |
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339 /* |
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340 * Process some data. |
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341 * This handles the simple case where no context is required. |
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342 */ |
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343 |
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344 METHODDEF(void) |
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345 process_data_simple_main (j_decompress_ptr cinfo, |
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346 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, |
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347 JDIMENSION out_rows_avail) |
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348 { |
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349 my_main_ptr main = (my_main_ptr) cinfo->main; |
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350 JDIMENSION rowgroups_avail; |
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351 |
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352 /* Read input data if we haven't filled the main buffer yet */ |
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353 if (! main->buffer_full) { |
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354 if (! (*cinfo->coef->decompress_data) (cinfo, main->buffer)) |
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355 return; /* suspension forced, can do nothing more */ |
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356 main->buffer_full = TRUE; /* OK, we have an iMCU row to work with */ |
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357 } |
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358 |
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359 /* There are always min_DCT_scaled_size row groups in an iMCU row. */ |
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360 rowgroups_avail = (JDIMENSION) cinfo->min_DCT_scaled_size; |
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361 /* Note: at the bottom of the image, we may pass extra garbage row groups |
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362 * to the postprocessor. The postprocessor has to check for bottom |
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363 * of image anyway (at row resolution), so no point in us doing it too. |
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364 */ |
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365 |
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366 /* Feed the postprocessor */ |
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367 (*cinfo->post->post_process_data) (cinfo, main->buffer, |
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368 &main->rowgroup_ctr, rowgroups_avail, |
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369 output_buf, out_row_ctr, out_rows_avail); |
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370 |
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371 /* Has postprocessor consumed all the data yet? If so, mark buffer empty */ |
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372 if (main->rowgroup_ctr >= rowgroups_avail) { |
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373 main->buffer_full = FALSE; |
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374 main->rowgroup_ctr = 0; |
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375 } |
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376 } |
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377 |
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378 |
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379 /* |
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380 * Process some data. |
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381 * This handles the case where context rows must be provided. |
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382 */ |
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383 |
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384 METHODDEF(void) |
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385 process_data_context_main (j_decompress_ptr cinfo, |
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386 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, |
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387 JDIMENSION out_rows_avail) |
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388 { |
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389 my_main_ptr main = (my_main_ptr) cinfo->main; |
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390 |
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391 /* Read input data if we haven't filled the main buffer yet */ |
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392 if (! main->buffer_full) { |
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393 if (! (*cinfo->coef->decompress_data) (cinfo, |
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394 main->xbuffer[main->whichptr])) |
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395 return; /* suspension forced, can do nothing more */ |
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396 main->buffer_full = TRUE; /* OK, we have an iMCU row to work with */ |
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397 main->iMCU_row_ctr++; /* count rows received */ |
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398 } |
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399 |
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400 /* Postprocessor typically will not swallow all the input data it is handed |
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401 * in one call (due to filling the output buffer first). Must be prepared |
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402 * to exit and restart. This switch lets us keep track of how far we got. |
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403 * Note that each case falls through to the next on successful completion. |
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404 */ |
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405 switch (main->context_state) { |
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406 case CTX_POSTPONED_ROW: |
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407 /* Call postprocessor using previously set pointers for postponed row */ |
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408 (*cinfo->post->post_process_data) (cinfo, main->xbuffer[main->whichptr], |
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409 &main->rowgroup_ctr, main->rowgroups_avail, |
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410 output_buf, out_row_ctr, out_rows_avail); |
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411 if (main->rowgroup_ctr < main->rowgroups_avail) |
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412 return; /* Need to suspend */ |
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413 main->context_state = CTX_PREPARE_FOR_IMCU; |
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414 if (*out_row_ctr >= out_rows_avail) |
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415 return; /* Postprocessor exactly filled output buf */ |
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416 /*FALLTHROUGH*/ |
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417 case CTX_PREPARE_FOR_IMCU: |
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418 /* Prepare to process first M-1 row groups of this iMCU row */ |
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419 main->rowgroup_ctr = 0; |
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420 main->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_scaled_size - 1); |
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421 /* Check for bottom of image: if so, tweak pointers to "duplicate" |
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422 * the last sample row, and adjust rowgroups_avail to ignore padding rows. |
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423 */ |
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424 if (main->iMCU_row_ctr == cinfo->total_iMCU_rows) |
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425 set_bottom_pointers(cinfo); |
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426 main->context_state = CTX_PROCESS_IMCU; |
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427 /*FALLTHROUGH*/ |
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428 case CTX_PROCESS_IMCU: |
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429 /* Call postprocessor using previously set pointers */ |
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430 (*cinfo->post->post_process_data) (cinfo, main->xbuffer[main->whichptr], |
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431 &main->rowgroup_ctr, main->rowgroups_avail, |
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432 output_buf, out_row_ctr, out_rows_avail); |
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433 if (main->rowgroup_ctr < main->rowgroups_avail) |
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434 return; /* Need to suspend */ |
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435 /* After the first iMCU, change wraparound pointers to normal state */ |
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436 if (main->iMCU_row_ctr == 1) |
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437 set_wraparound_pointers(cinfo); |
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438 /* Prepare to load new iMCU row using other xbuffer list */ |
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439 main->whichptr ^= 1; /* 0=>1 or 1=>0 */ |
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440 main->buffer_full = FALSE; |
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441 /* Still need to process last row group of this iMCU row, */ |
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442 /* which is saved at index M+1 of the other xbuffer */ |
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443 main->rowgroup_ctr = (JDIMENSION) (cinfo->min_DCT_scaled_size + 1); |
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444 main->rowgroups_avail = (JDIMENSION) (cinfo->min_DCT_scaled_size + 2); |
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445 main->context_state = CTX_POSTPONED_ROW; |
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446 } |
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447 } |
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448 |
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449 |
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450 /* |
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451 * Process some data. |
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452 * Final pass of two-pass quantization: just call the postprocessor. |
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453 * Source data will be the postprocessor controller's internal buffer. |
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454 */ |
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455 |
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456 #ifdef QUANT_2PASS_SUPPORTED |
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457 |
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458 METHODDEF(void) |
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459 process_data_crank_post (j_decompress_ptr cinfo, |
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460 JSAMPARRAY output_buf, JDIMENSION *out_row_ctr, |
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461 JDIMENSION out_rows_avail) |
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462 { |
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463 (*cinfo->post->post_process_data) (cinfo, (JSAMPIMAGE) NULL, |
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464 (JDIMENSION *) NULL, (JDIMENSION) 0, |
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465 output_buf, out_row_ctr, out_rows_avail); |
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466 } |
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467 |
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468 #endif /* QUANT_2PASS_SUPPORTED */ |
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469 |
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470 |
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471 /* |
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472 * Initialize main buffer controller. |
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473 */ |
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474 |
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475 GLOBAL(void) |
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476 jinit_d_main_controller (j_decompress_ptr cinfo, boolean need_full_buffer) |
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477 { |
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478 my_main_ptr main; |
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479 int ci, rgroup, ngroups; |
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480 jpeg_component_info *compptr; |
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481 |
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482 main = (my_main_ptr) |
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483 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
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484 SIZEOF(my_main_controller)); |
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485 cinfo->main = (struct jpeg_d_main_controller *) main; |
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486 main->pub.start_pass = start_pass_main; |
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487 |
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488 if (need_full_buffer) /* shouldn't happen */ |
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489 ERREXIT(cinfo, JERR_BAD_BUFFER_MODE); |
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490 |
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491 /* Allocate the workspace. |
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492 * ngroups is the number of row groups we need. |
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493 */ |
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494 if (cinfo->upsample->need_context_rows) { |
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495 if (cinfo->min_DCT_scaled_size < 2) /* unsupported, see comments above */ |
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496 ERREXIT(cinfo, JERR_NOTIMPL); |
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497 alloc_funny_pointers(cinfo); /* Alloc space for xbuffer[] lists */ |
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498 ngroups = cinfo->min_DCT_scaled_size + 2; |
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499 } else { |
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500 ngroups = cinfo->min_DCT_scaled_size; |
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501 } |
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502 |
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503 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; |
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504 ci++, compptr++) { |
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505 rgroup = (compptr->v_samp_factor * compptr->DCT_scaled_size) / |
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506 cinfo->min_DCT_scaled_size; /* height of a row group of component */ |
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507 main->buffer[ci] = (*cinfo->mem->alloc_sarray) |
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508 ((j_common_ptr) cinfo, JPOOL_IMAGE, |
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509 compptr->width_in_blocks * compptr->DCT_scaled_size, |
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510 (JDIMENSION) (rgroup * ngroups)); |
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511 } |
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512 } |