21 |
21 |
22 typedef struct { |
22 typedef struct { |
23 struct jpeg_forward_dct pub; /* public fields */ |
23 struct jpeg_forward_dct pub; /* public fields */ |
24 |
24 |
25 /* Pointer to the DCT routine actually in use */ |
25 /* Pointer to the DCT routine actually in use */ |
26 forward_DCT_method_ptr do_dct; |
26 forward_DCT_method_ptr do_dct[MAX_COMPONENTS]; |
27 |
27 |
28 /* The actual post-DCT divisors --- not identical to the quant table |
28 /* The actual post-DCT divisors --- not identical to the quant table |
29 * entries, because of scaling (especially for an unnormalized DCT). |
29 * entries, because of scaling (especially for an unnormalized DCT). |
30 * Each table is given in normal array order. |
30 * Each table is given in normal array order. |
31 */ |
31 */ |
32 DCTELEM * divisors[NUM_QUANT_TBLS]; |
32 DCTELEM * divisors[NUM_QUANT_TBLS]; |
33 |
33 |
34 #ifdef DCT_FLOAT_SUPPORTED |
34 #ifdef DCT_FLOAT_SUPPORTED |
35 /* Same as above for the floating-point case. */ |
35 /* Same as above for the floating-point case. */ |
36 float_DCT_method_ptr do_float_dct; |
36 float_DCT_method_ptr do_float_dct[MAX_COMPONENTS]; |
37 FAST_FLOAT * float_divisors[NUM_QUANT_TBLS]; |
37 FAST_FLOAT * float_divisors[NUM_QUANT_TBLS]; |
38 #endif |
38 #endif |
39 } my_fdct_controller; |
39 } my_fdct_controller; |
40 |
40 |
41 typedef my_fdct_controller * my_fdct_ptr; |
41 typedef my_fdct_controller * my_fdct_ptr; |
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42 |
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43 |
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44 /* The current scaled-DCT routines require ISLOW-style divisor tables, |
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45 * so be sure to compile that code if either ISLOW or SCALING is requested. |
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46 */ |
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47 #ifdef DCT_ISLOW_SUPPORTED |
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48 #define PROVIDE_ISLOW_TABLES |
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49 #else |
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50 #ifdef DCT_SCALING_SUPPORTED |
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51 #define PROVIDE_ISLOW_TABLES |
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52 #endif |
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53 #endif |
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54 |
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55 |
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56 /* |
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57 * Perform forward DCT on one or more blocks of a component. |
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58 * |
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59 * The input samples are taken from the sample_data[] array starting at |
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60 * position start_row/start_col, and moving to the right for any additional |
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61 * blocks. The quantized coefficients are returned in coef_blocks[]. |
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62 */ |
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63 |
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64 METHODDEF(void) |
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65 forward_DCT (j_compress_ptr cinfo, jpeg_component_info * compptr, |
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66 JSAMPARRAY sample_data, JBLOCKROW coef_blocks, |
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67 JDIMENSION start_row, JDIMENSION start_col, |
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68 JDIMENSION num_blocks) |
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69 /* This version is used for integer DCT implementations. */ |
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70 { |
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71 /* This routine is heavily used, so it's worth coding it tightly. */ |
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72 my_fdct_ptr fdct = (my_fdct_ptr) cinfo->fdct; |
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73 forward_DCT_method_ptr do_dct = fdct->do_dct[compptr->component_index]; |
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74 DCTELEM * divisors = fdct->divisors[compptr->quant_tbl_no]; |
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75 DCTELEM workspace[DCTSIZE2]; /* work area for FDCT subroutine */ |
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76 JDIMENSION bi; |
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77 |
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78 sample_data += start_row; /* fold in the vertical offset once */ |
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79 |
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80 for (bi = 0; bi < num_blocks; bi++, start_col += compptr->DCT_h_scaled_size) { |
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81 /* Perform the DCT */ |
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82 (*do_dct) (workspace, sample_data, start_col); |
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83 |
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84 /* Quantize/descale the coefficients, and store into coef_blocks[] */ |
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85 { register DCTELEM temp, qval; |
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86 register int i; |
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87 register JCOEFPTR output_ptr = coef_blocks[bi]; |
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88 |
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89 for (i = 0; i < DCTSIZE2; i++) { |
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90 qval = divisors[i]; |
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91 temp = workspace[i]; |
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92 /* Divide the coefficient value by qval, ensuring proper rounding. |
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93 * Since C does not specify the direction of rounding for negative |
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94 * quotients, we have to force the dividend positive for portability. |
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95 * |
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96 * In most files, at least half of the output values will be zero |
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97 * (at default quantization settings, more like three-quarters...) |
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98 * so we should ensure that this case is fast. On many machines, |
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99 * a comparison is enough cheaper than a divide to make a special test |
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100 * a win. Since both inputs will be nonnegative, we need only test |
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101 * for a < b to discover whether a/b is 0. |
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102 * If your machine's division is fast enough, define FAST_DIVIDE. |
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103 */ |
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104 #ifdef FAST_DIVIDE |
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105 #define DIVIDE_BY(a,b) a /= b |
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106 #else |
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107 #define DIVIDE_BY(a,b) if (a >= b) a /= b; else a = 0 |
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108 #endif |
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109 if (temp < 0) { |
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110 temp = -temp; |
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111 temp += qval>>1; /* for rounding */ |
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112 DIVIDE_BY(temp, qval); |
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113 temp = -temp; |
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114 } else { |
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115 temp += qval>>1; /* for rounding */ |
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116 DIVIDE_BY(temp, qval); |
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117 } |
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118 output_ptr[i] = (JCOEF) temp; |
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119 } |
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120 } |
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121 } |
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122 } |
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123 |
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124 |
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125 #ifdef DCT_FLOAT_SUPPORTED |
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126 |
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127 METHODDEF(void) |
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128 forward_DCT_float (j_compress_ptr cinfo, jpeg_component_info * compptr, |
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129 JSAMPARRAY sample_data, JBLOCKROW coef_blocks, |
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130 JDIMENSION start_row, JDIMENSION start_col, |
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131 JDIMENSION num_blocks) |
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132 /* This version is used for floating-point DCT implementations. */ |
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133 { |
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134 /* This routine is heavily used, so it's worth coding it tightly. */ |
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135 my_fdct_ptr fdct = (my_fdct_ptr) cinfo->fdct; |
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136 float_DCT_method_ptr do_dct = fdct->do_float_dct[compptr->component_index]; |
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137 FAST_FLOAT * divisors = fdct->float_divisors[compptr->quant_tbl_no]; |
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138 FAST_FLOAT workspace[DCTSIZE2]; /* work area for FDCT subroutine */ |
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139 JDIMENSION bi; |
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140 |
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141 sample_data += start_row; /* fold in the vertical offset once */ |
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142 |
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143 for (bi = 0; bi < num_blocks; bi++, start_col += compptr->DCT_h_scaled_size) { |
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144 /* Perform the DCT */ |
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145 (*do_dct) (workspace, sample_data, start_col); |
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146 |
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147 /* Quantize/descale the coefficients, and store into coef_blocks[] */ |
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148 { register FAST_FLOAT temp; |
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149 register int i; |
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150 register JCOEFPTR output_ptr = coef_blocks[bi]; |
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151 |
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152 for (i = 0; i < DCTSIZE2; i++) { |
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153 /* Apply the quantization and scaling factor */ |
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154 temp = workspace[i] * divisors[i]; |
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155 /* Round to nearest integer. |
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156 * Since C does not specify the direction of rounding for negative |
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157 * quotients, we have to force the dividend positive for portability. |
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158 * The maximum coefficient size is +-16K (for 12-bit data), so this |
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159 * code should work for either 16-bit or 32-bit ints. |
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160 */ |
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161 output_ptr[i] = (JCOEF) ((int) (temp + (FAST_FLOAT) 16384.5) - 16384); |
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162 } |
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163 } |
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164 } |
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165 } |
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166 |
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167 #endif /* DCT_FLOAT_SUPPORTED */ |
42 |
168 |
43 |
169 |
44 /* |
170 /* |
45 * Initialize for a processing pass. |
171 * Initialize for a processing pass. |
46 * Verify that all referenced Q-tables are present, and set up |
172 * Verify that all referenced Q-tables are present, and set up |
54 start_pass_fdctmgr (j_compress_ptr cinfo) |
180 start_pass_fdctmgr (j_compress_ptr cinfo) |
55 { |
181 { |
56 my_fdct_ptr fdct = (my_fdct_ptr) cinfo->fdct; |
182 my_fdct_ptr fdct = (my_fdct_ptr) cinfo->fdct; |
57 int ci, qtblno, i; |
183 int ci, qtblno, i; |
58 jpeg_component_info *compptr; |
184 jpeg_component_info *compptr; |
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185 int method = 0; |
59 JQUANT_TBL * qtbl; |
186 JQUANT_TBL * qtbl; |
60 DCTELEM * dtbl; |
187 DCTELEM * dtbl; |
61 |
188 |
62 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; |
189 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; |
63 ci++, compptr++) { |
190 ci++, compptr++) { |
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191 /* Select the proper DCT routine for this component's scaling */ |
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192 switch ((compptr->DCT_h_scaled_size << 8) + compptr->DCT_v_scaled_size) { |
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193 #ifdef DCT_SCALING_SUPPORTED |
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194 case ((1 << 8) + 1): |
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195 fdct->do_dct[ci] = jpeg_fdct_1x1; |
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196 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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197 break; |
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198 case ((2 << 8) + 2): |
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199 fdct->do_dct[ci] = jpeg_fdct_2x2; |
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200 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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201 break; |
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202 case ((3 << 8) + 3): |
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203 fdct->do_dct[ci] = jpeg_fdct_3x3; |
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204 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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205 break; |
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206 case ((4 << 8) + 4): |
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207 fdct->do_dct[ci] = jpeg_fdct_4x4; |
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208 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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209 break; |
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210 case ((5 << 8) + 5): |
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211 fdct->do_dct[ci] = jpeg_fdct_5x5; |
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212 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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213 break; |
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214 case ((6 << 8) + 6): |
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215 fdct->do_dct[ci] = jpeg_fdct_6x6; |
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216 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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217 break; |
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218 case ((7 << 8) + 7): |
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219 fdct->do_dct[ci] = jpeg_fdct_7x7; |
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220 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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221 break; |
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222 case ((9 << 8) + 9): |
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223 fdct->do_dct[ci] = jpeg_fdct_9x9; |
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224 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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225 break; |
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226 case ((10 << 8) + 10): |
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227 fdct->do_dct[ci] = jpeg_fdct_10x10; |
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228 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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229 break; |
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230 case ((11 << 8) + 11): |
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231 fdct->do_dct[ci] = jpeg_fdct_11x11; |
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232 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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233 break; |
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234 case ((12 << 8) + 12): |
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235 fdct->do_dct[ci] = jpeg_fdct_12x12; |
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236 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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237 break; |
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238 case ((13 << 8) + 13): |
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239 fdct->do_dct[ci] = jpeg_fdct_13x13; |
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240 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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241 break; |
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242 case ((14 << 8) + 14): |
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243 fdct->do_dct[ci] = jpeg_fdct_14x14; |
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244 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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245 break; |
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246 case ((15 << 8) + 15): |
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247 fdct->do_dct[ci] = jpeg_fdct_15x15; |
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248 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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249 break; |
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250 case ((16 << 8) + 16): |
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251 fdct->do_dct[ci] = jpeg_fdct_16x16; |
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252 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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253 break; |
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254 case ((16 << 8) + 8): |
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255 fdct->do_dct[ci] = jpeg_fdct_16x8; |
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256 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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257 break; |
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258 case ((14 << 8) + 7): |
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259 fdct->do_dct[ci] = jpeg_fdct_14x7; |
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260 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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261 break; |
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262 case ((12 << 8) + 6): |
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263 fdct->do_dct[ci] = jpeg_fdct_12x6; |
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264 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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265 break; |
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266 case ((10 << 8) + 5): |
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267 fdct->do_dct[ci] = jpeg_fdct_10x5; |
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268 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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269 break; |
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270 case ((8 << 8) + 4): |
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271 fdct->do_dct[ci] = jpeg_fdct_8x4; |
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272 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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273 break; |
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274 case ((6 << 8) + 3): |
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275 fdct->do_dct[ci] = jpeg_fdct_6x3; |
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276 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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277 break; |
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278 case ((4 << 8) + 2): |
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279 fdct->do_dct[ci] = jpeg_fdct_4x2; |
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280 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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281 break; |
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282 case ((2 << 8) + 1): |
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283 fdct->do_dct[ci] = jpeg_fdct_2x1; |
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284 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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285 break; |
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286 case ((8 << 8) + 16): |
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287 fdct->do_dct[ci] = jpeg_fdct_8x16; |
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288 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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289 break; |
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290 case ((7 << 8) + 14): |
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291 fdct->do_dct[ci] = jpeg_fdct_7x14; |
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292 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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293 break; |
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294 case ((6 << 8) + 12): |
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295 fdct->do_dct[ci] = jpeg_fdct_6x12; |
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296 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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297 break; |
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298 case ((5 << 8) + 10): |
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299 fdct->do_dct[ci] = jpeg_fdct_5x10; |
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300 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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301 break; |
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302 case ((4 << 8) + 8): |
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303 fdct->do_dct[ci] = jpeg_fdct_4x8; |
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304 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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305 break; |
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306 case ((3 << 8) + 6): |
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307 fdct->do_dct[ci] = jpeg_fdct_3x6; |
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308 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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309 break; |
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310 case ((2 << 8) + 4): |
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311 fdct->do_dct[ci] = jpeg_fdct_2x4; |
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312 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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313 break; |
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314 case ((1 << 8) + 2): |
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315 fdct->do_dct[ci] = jpeg_fdct_1x2; |
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316 method = JDCT_ISLOW; /* jfdctint uses islow-style table */ |
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317 break; |
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318 #endif |
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319 case ((DCTSIZE << 8) + DCTSIZE): |
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320 switch (cinfo->dct_method) { |
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321 #ifdef DCT_ISLOW_SUPPORTED |
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322 case JDCT_ISLOW: |
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323 fdct->do_dct[ci] = jpeg_fdct_islow; |
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324 method = JDCT_ISLOW; |
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325 break; |
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326 #endif |
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327 #ifdef DCT_IFAST_SUPPORTED |
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328 case JDCT_IFAST: |
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329 fdct->do_dct[ci] = jpeg_fdct_ifast; |
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330 method = JDCT_IFAST; |
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331 break; |
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332 #endif |
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333 #ifdef DCT_FLOAT_SUPPORTED |
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334 case JDCT_FLOAT: |
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335 fdct->do_float_dct[ci] = jpeg_fdct_float; |
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336 method = JDCT_FLOAT; |
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337 break; |
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338 #endif |
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339 default: |
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340 ERREXIT(cinfo, JERR_NOT_COMPILED); |
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341 break; |
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342 } |
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343 break; |
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344 default: |
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345 ERREXIT2(cinfo, JERR_BAD_DCTSIZE, |
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346 compptr->DCT_h_scaled_size, compptr->DCT_v_scaled_size); |
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347 break; |
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348 } |
64 qtblno = compptr->quant_tbl_no; |
349 qtblno = compptr->quant_tbl_no; |
65 /* Make sure specified quantization table is present */ |
350 /* Make sure specified quantization table is present */ |
66 if (qtblno < 0 || qtblno >= NUM_QUANT_TBLS || |
351 if (qtblno < 0 || qtblno >= NUM_QUANT_TBLS || |
67 cinfo->quant_tbl_ptrs[qtblno] == NULL) |
352 cinfo->quant_tbl_ptrs[qtblno] == NULL) |
68 ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, qtblno); |
353 ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, qtblno); |
69 qtbl = cinfo->quant_tbl_ptrs[qtblno]; |
354 qtbl = cinfo->quant_tbl_ptrs[qtblno]; |
70 /* Compute divisors for this quant table */ |
355 /* Compute divisors for this quant table */ |
71 /* We may do this more than once for same table, but it's not a big deal */ |
356 /* We may do this more than once for same table, but it's not a big deal */ |
72 switch (cinfo->dct_method) { |
357 switch (method) { |
73 #ifdef DCT_ISLOW_SUPPORTED |
358 #ifdef PROVIDE_ISLOW_TABLES |
74 case JDCT_ISLOW: |
359 case JDCT_ISLOW: |
75 /* For LL&M IDCT method, divisors are equal to raw quantization |
360 /* For LL&M IDCT method, divisors are equal to raw quantization |
76 * coefficients multiplied by 8 (to counteract scaling). |
361 * coefficients multiplied by 8 (to counteract scaling). |
77 */ |
362 */ |
78 if (fdct->divisors[qtblno] == NULL) { |
363 if (fdct->divisors[qtblno] == NULL) { |
156 aanscalefactor[row] * aanscalefactor[col] * 8.0))); |
443 aanscalefactor[row] * aanscalefactor[col] * 8.0))); |
157 i++; |
444 i++; |
158 } |
445 } |
159 } |
446 } |
160 } |
447 } |
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448 fdct->pub.forward_DCT[ci] = forward_DCT_float; |
161 break; |
449 break; |
162 #endif |
450 #endif |
163 default: |
451 default: |
164 ERREXIT(cinfo, JERR_NOT_COMPILED); |
452 ERREXIT(cinfo, JERR_NOT_COMPILED); |
165 break; |
453 break; |
166 } |
454 } |
167 } |
455 } |
168 } |
456 } |
169 |
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170 |
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171 /* |
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172 * Perform forward DCT on one or more blocks of a component. |
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173 * |
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174 * The input samples are taken from the sample_data[] array starting at |
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175 * position start_row/start_col, and moving to the right for any additional |
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176 * blocks. The quantized coefficients are returned in coef_blocks[]. |
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177 */ |
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178 |
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179 METHODDEF(void) |
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180 forward_DCT (j_compress_ptr cinfo, jpeg_component_info * compptr, |
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181 JSAMPARRAY sample_data, JBLOCKROW coef_blocks, |
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182 JDIMENSION start_row, JDIMENSION start_col, |
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183 JDIMENSION num_blocks) |
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184 /* This version is used for integer DCT implementations. */ |
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185 { |
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186 /* This routine is heavily used, so it's worth coding it tightly. */ |
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187 my_fdct_ptr fdct = (my_fdct_ptr) cinfo->fdct; |
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188 forward_DCT_method_ptr do_dct = fdct->do_dct; |
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189 DCTELEM * divisors = fdct->divisors[compptr->quant_tbl_no]; |
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190 DCTELEM workspace[DCTSIZE2]; /* work area for FDCT subroutine */ |
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191 JDIMENSION bi; |
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192 |
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193 sample_data += start_row; /* fold in the vertical offset once */ |
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194 |
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195 for (bi = 0; bi < num_blocks; bi++, start_col += DCTSIZE) { |
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196 /* Load data into workspace, applying unsigned->signed conversion */ |
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197 { register DCTELEM *workspaceptr; |
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198 register JSAMPROW elemptr; |
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199 register int elemr; |
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200 |
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201 workspaceptr = workspace; |
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202 for (elemr = 0; elemr < DCTSIZE; elemr++) { |
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203 elemptr = sample_data[elemr] + start_col; |
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204 #if DCTSIZE == 8 /* unroll the inner loop */ |
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205 *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
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206 *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
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207 *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
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208 *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
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209 *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
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210 *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
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211 *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
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212 *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
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213 #else |
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214 { register int elemc; |
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215 for (elemc = DCTSIZE; elemc > 0; elemc--) { |
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216 *workspaceptr++ = GETJSAMPLE(*elemptr++) - CENTERJSAMPLE; |
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217 } |
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218 } |
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219 #endif |
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220 } |
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221 } |
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222 |
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223 /* Perform the DCT */ |
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224 (*do_dct) (workspace); |
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225 |
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226 /* Quantize/descale the coefficients, and store into coef_blocks[] */ |
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227 { register DCTELEM temp, qval; |
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228 register int i; |
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229 register JCOEFPTR output_ptr = coef_blocks[bi]; |
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230 |
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231 for (i = 0; i < DCTSIZE2; i++) { |
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232 qval = divisors[i]; |
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233 temp = workspace[i]; |
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234 /* Divide the coefficient value by qval, ensuring proper rounding. |
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235 * Since C does not specify the direction of rounding for negative |
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236 * quotients, we have to force the dividend positive for portability. |
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237 * |
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238 * In most files, at least half of the output values will be zero |
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239 * (at default quantization settings, more like three-quarters...) |
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240 * so we should ensure that this case is fast. On many machines, |
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241 * a comparison is enough cheaper than a divide to make a special test |
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242 * a win. Since both inputs will be nonnegative, we need only test |
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243 * for a < b to discover whether a/b is 0. |
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244 * If your machine's division is fast enough, define FAST_DIVIDE. |
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245 */ |
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246 #ifdef FAST_DIVIDE |
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247 #define DIVIDE_BY(a,b) a /= b |
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248 #else |
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249 #define DIVIDE_BY(a,b) if (a >= b) a /= b; else a = 0 |
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250 #endif |
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251 if (temp < 0) { |
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252 temp = -temp; |
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253 temp += qval>>1; /* for rounding */ |
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254 DIVIDE_BY(temp, qval); |
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255 temp = -temp; |
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256 } else { |
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257 temp += qval>>1; /* for rounding */ |
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258 DIVIDE_BY(temp, qval); |
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259 } |
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260 output_ptr[i] = (JCOEF) temp; |
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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 |
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266 |
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267 #ifdef DCT_FLOAT_SUPPORTED |
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268 |
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269 METHODDEF(void) |
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270 forward_DCT_float (j_compress_ptr cinfo, jpeg_component_info * compptr, |
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271 JSAMPARRAY sample_data, JBLOCKROW coef_blocks, |
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272 JDIMENSION start_row, JDIMENSION start_col, |
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273 JDIMENSION num_blocks) |
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274 /* This version is used for floating-point DCT implementations. */ |
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275 { |
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276 /* This routine is heavily used, so it's worth coding it tightly. */ |
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277 my_fdct_ptr fdct = (my_fdct_ptr) cinfo->fdct; |
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278 float_DCT_method_ptr do_dct = fdct->do_float_dct; |
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279 FAST_FLOAT * divisors = fdct->float_divisors[compptr->quant_tbl_no]; |
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280 FAST_FLOAT workspace[DCTSIZE2]; /* work area for FDCT subroutine */ |
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281 JDIMENSION bi; |
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282 |
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283 sample_data += start_row; /* fold in the vertical offset once */ |
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284 |
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285 for (bi = 0; bi < num_blocks; bi++, start_col += DCTSIZE) { |
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286 /* Load data into workspace, applying unsigned->signed conversion */ |
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287 { register FAST_FLOAT *workspaceptr; |
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288 register JSAMPROW elemptr; |
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289 register int elemr; |
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290 |
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291 workspaceptr = workspace; |
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292 for (elemr = 0; elemr < DCTSIZE; elemr++) { |
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293 elemptr = sample_data[elemr] + start_col; |
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294 #if DCTSIZE == 8 /* unroll the inner loop */ |
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295 *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
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296 *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
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297 *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
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298 *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
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299 *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
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300 *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
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301 *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
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302 *workspaceptr++ = (FAST_FLOAT)(GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
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303 #else |
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304 { register int elemc; |
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305 for (elemc = DCTSIZE; elemc > 0; elemc--) { |
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306 *workspaceptr++ = (FAST_FLOAT) |
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307 (GETJSAMPLE(*elemptr++) - CENTERJSAMPLE); |
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308 } |
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309 } |
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310 #endif |
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311 } |
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312 } |
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313 |
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314 /* Perform the DCT */ |
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315 (*do_dct) (workspace); |
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316 |
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317 /* Quantize/descale the coefficients, and store into coef_blocks[] */ |
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318 { register FAST_FLOAT temp; |
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319 register int i; |
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320 register JCOEFPTR output_ptr = coef_blocks[bi]; |
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321 |
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322 for (i = 0; i < DCTSIZE2; i++) { |
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323 /* Apply the quantization and scaling factor */ |
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324 temp = workspace[i] * divisors[i]; |
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325 /* Round to nearest integer. |
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326 * Since C does not specify the direction of rounding for negative |
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327 * quotients, we have to force the dividend positive for portability. |
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328 * The maximum coefficient size is +-16K (for 12-bit data), so this |
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329 * code should work for either 16-bit or 32-bit ints. |
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330 */ |
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331 output_ptr[i] = (JCOEF) ((int) (temp + (FAST_FLOAT) 16384.5) - 16384); |
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332 } |
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333 } |
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334 } |
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335 } |
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336 |
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337 #endif /* DCT_FLOAT_SUPPORTED */ |
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338 |
457 |
339 |
458 |
340 /* |
459 /* |
341 * Initialize FDCT manager. |
460 * Initialize FDCT manager. |
342 */ |
461 */ |
351 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
470 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
352 SIZEOF(my_fdct_controller)); |
471 SIZEOF(my_fdct_controller)); |
353 cinfo->fdct = (struct jpeg_forward_dct *) fdct; |
472 cinfo->fdct = (struct jpeg_forward_dct *) fdct; |
354 fdct->pub.start_pass = start_pass_fdctmgr; |
473 fdct->pub.start_pass = start_pass_fdctmgr; |
355 |
474 |
356 switch (cinfo->dct_method) { |
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357 #ifdef DCT_ISLOW_SUPPORTED |
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358 case JDCT_ISLOW: |
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359 fdct->pub.forward_DCT = forward_DCT; |
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360 fdct->do_dct = jpeg_fdct_islow; |
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361 break; |
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362 #endif |
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363 #ifdef DCT_IFAST_SUPPORTED |
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364 case JDCT_IFAST: |
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365 fdct->pub.forward_DCT = forward_DCT; |
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366 fdct->do_dct = jpeg_fdct_ifast; |
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367 break; |
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368 #endif |
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369 #ifdef DCT_FLOAT_SUPPORTED |
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370 case JDCT_FLOAT: |
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371 fdct->pub.forward_DCT = forward_DCT_float; |
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372 fdct->do_float_dct = jpeg_fdct_float; |
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373 break; |
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374 #endif |
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375 default: |
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376 ERREXIT(cinfo, JERR_NOT_COMPILED); |
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377 break; |
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378 } |
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379 |
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380 /* Mark divisor tables unallocated */ |
475 /* Mark divisor tables unallocated */ |
381 for (i = 0; i < NUM_QUANT_TBLS; i++) { |
476 for (i = 0; i < NUM_QUANT_TBLS; i++) { |
382 fdct->divisors[i] = NULL; |
477 fdct->divisors[i] = NULL; |
383 #ifdef DCT_FLOAT_SUPPORTED |
478 #ifdef DCT_FLOAT_SUPPORTED |
384 fdct->float_divisors[i] = NULL; |
479 fdct->float_divisors[i] = NULL; |