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1 /* | 1 /* |
2 * jidctflt.c | 2 * jidctflt.c |
3 * | 3 * |
| 4 * This file was part of the Independent JPEG Group's software: |
4 * Copyright (C) 1994-1998, Thomas G. Lane. | 5 * Copyright (C) 1994-1998, Thomas G. Lane. |
5 * This file is part of the Independent JPEG Group's software. | 6 * Modified 2010 by Guido Vollbeding. |
6 * For conditions of distribution and use, see the accompanying README file. | 7 * libjpeg-turbo Modifications: |
| 8 * Copyright (C) 2014, D. R. Commander. |
| 9 * For conditions of distribution and use, see the accompanying README.ijg |
| 10 * file. |
7 * | 11 * |
8 * This file contains a floating-point implementation of the | 12 * This file contains a floating-point implementation of the |
9 * inverse DCT (Discrete Cosine Transform). In the IJG code, this routine | 13 * inverse DCT (Discrete Cosine Transform). In the IJG code, this routine |
10 * must also perform dequantization of the input coefficients. | 14 * must also perform dequantization of the input coefficients. |
11 * | 15 * |
12 * This implementation should be more accurate than either of the integer | 16 * This implementation should be more accurate than either of the integer |
13 * IDCT implementations. However, it may not give the same results on all | 17 * IDCT implementations. However, it may not give the same results on all |
14 * machines because of differences in roundoff behavior. Speed will depend | 18 * machines because of differences in roundoff behavior. Speed will depend |
15 * on the hardware's floating point capacity. | 19 * on the hardware's floating point capacity. |
16 * | 20 * |
17 * A 2-D IDCT can be done by 1-D IDCT on each column followed by 1-D IDCT | 21 * A 2-D IDCT can be done by 1-D IDCT on each column followed by 1-D IDCT |
18 * on each row (or vice versa, but it's more convenient to emit a row at | 22 * on each row (or vice versa, but it's more convenient to emit a row at |
19 * a time). Direct algorithms are also available, but they are much more | 23 * a time). Direct algorithms are also available, but they are much more |
20 * complex and seem not to be any faster when reduced to code. | 24 * complex and seem not to be any faster when reduced to code. |
21 * | 25 * |
22 * This implementation is based on Arai, Agui, and Nakajima's algorithm for | 26 * This implementation is based on Arai, Agui, and Nakajima's algorithm for |
23 * scaled DCT. Their original paper (Trans. IEICE E-71(11):1095) is in | 27 * scaled DCT. Their original paper (Trans. IEICE E-71(11):1095) is in |
24 * Japanese, but the algorithm is described in the Pennebaker & Mitchell | 28 * Japanese, but the algorithm is described in the Pennebaker & Mitchell |
25 * JPEG textbook (see REFERENCES section in file README). The following code | 29 * JPEG textbook (see REFERENCES section in file README.ijg). The following |
26 * is based directly on figure 4-8 in P&M. | 30 * code is based directly on figure 4-8 in P&M. |
27 * While an 8-point DCT cannot be done in less than 11 multiplies, it is | 31 * While an 8-point DCT cannot be done in less than 11 multiplies, it is |
28 * possible to arrange the computation so that many of the multiplies are | 32 * possible to arrange the computation so that many of the multiplies are |
29 * simple scalings of the final outputs. These multiplies can then be | 33 * simple scalings of the final outputs. These multiplies can then be |
30 * folded into the multiplications or divisions by the JPEG quantization | 34 * folded into the multiplications or divisions by the JPEG quantization |
31 * table entries. The AA&N method leaves only 5 multiplies and 29 adds | 35 * table entries. The AA&N method leaves only 5 multiplies and 29 adds |
32 * to be done in the DCT itself. | 36 * to be done in the DCT itself. |
33 * The primary disadvantage of this method is that with a fixed-point | 37 * The primary disadvantage of this method is that with a fixed-point |
34 * implementation, accuracy is lost due to imprecise representation of the | 38 * implementation, accuracy is lost due to imprecise representation of the |
35 * scaled quantization values. However, that problem does not arise if | 39 * scaled quantization values. However, that problem does not arise if |
36 * we use floating point arithmetic. | 40 * we use floating point arithmetic. |
37 */ | 41 */ |
38 | 42 |
39 #define JPEG_INTERNALS | 43 #define JPEG_INTERNALS |
40 #include "jinclude.h" | 44 #include "jinclude.h" |
41 #include "jpeglib.h" | 45 #include "jpeglib.h" |
42 #include "jdct.h"» » /* Private declarations for DCT subsystem */ | 46 #include "jdct.h" /* Private declarations for DCT subsystem */ |
43 | 47 |
44 #ifdef DCT_FLOAT_SUPPORTED | 48 #ifdef DCT_FLOAT_SUPPORTED |
45 | 49 |
46 | 50 |
47 /* | 51 /* |
48 * This module is specialized to the case DCTSIZE = 8. | 52 * This module is specialized to the case DCTSIZE = 8. |
49 */ | 53 */ |
50 | 54 |
51 #if DCTSIZE != 8 | 55 #if DCTSIZE != 8 |
52 Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */ | 56 Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */ |
53 #endif | 57 #endif |
54 | 58 |
55 | 59 |
56 /* Dequantize a coefficient by multiplying it by the multiplier-table | 60 /* Dequantize a coefficient by multiplying it by the multiplier-table |
57 * entry; produce a float result. | 61 * entry; produce a float result. |
58 */ | 62 */ |
59 | 63 |
60 #define DEQUANTIZE(coef,quantval) (((FAST_FLOAT) (coef)) * (quantval)) | 64 #define DEQUANTIZE(coef,quantval) (((FAST_FLOAT) (coef)) * (quantval)) |
61 | 65 |
62 | 66 |
63 /* | 67 /* |
64 * Perform dequantization and inverse DCT on one block of coefficients. | 68 * Perform dequantization and inverse DCT on one block of coefficients. |
65 */ | 69 */ |
66 | 70 |
67 GLOBAL(void) | 71 GLOBAL(void) |
68 jpeg_idct_float (j_decompress_ptr cinfo, jpeg_component_info * compptr, | 72 jpeg_idct_float (j_decompress_ptr cinfo, jpeg_component_info *compptr, |
69 » » JCOEFPTR coef_block, | 73 JCOEFPTR coef_block, |
70 » » JSAMPARRAY output_buf, JDIMENSION output_col) | 74 JSAMPARRAY output_buf, JDIMENSION output_col) |
71 { | 75 { |
72 FAST_FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7; | 76 FAST_FLOAT tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7; |
73 FAST_FLOAT tmp10, tmp11, tmp12, tmp13; | 77 FAST_FLOAT tmp10, tmp11, tmp12, tmp13; |
74 FAST_FLOAT z5, z10, z11, z12, z13; | 78 FAST_FLOAT z5, z10, z11, z12, z13; |
75 JCOEFPTR inptr; | 79 JCOEFPTR inptr; |
76 FLOAT_MULT_TYPE * quantptr; | 80 FLOAT_MULT_TYPE *quantptr; |
77 FAST_FLOAT * wsptr; | 81 FAST_FLOAT *wsptr; |
78 JSAMPROW outptr; | 82 JSAMPROW outptr; |
79 JSAMPLE *range_limit = IDCT_range_limit(cinfo); | 83 JSAMPLE *range_limit = cinfo->sample_range_limit; |
80 int ctr; | 84 int ctr; |
81 FAST_FLOAT workspace[DCTSIZE2]; /* buffers data between passes */ | 85 FAST_FLOAT workspace[DCTSIZE2]; /* buffers data between passes */ |
82 SHIFT_TEMPS | 86 #define _0_125 ((FLOAT_MULT_TYPE)0.125) |
83 | 87 |
84 /* Pass 1: process columns from input, store into work array. */ | 88 /* Pass 1: process columns from input, store into work array. */ |
85 | 89 |
86 inptr = coef_block; | 90 inptr = coef_block; |
87 quantptr = (FLOAT_MULT_TYPE *) compptr->dct_table; | 91 quantptr = (FLOAT_MULT_TYPE *) compptr->dct_table; |
88 wsptr = workspace; | 92 wsptr = workspace; |
89 for (ctr = DCTSIZE; ctr > 0; ctr--) { | 93 for (ctr = DCTSIZE; ctr > 0; ctr--) { |
90 /* Due to quantization, we will usually find that many of the input | 94 /* Due to quantization, we will usually find that many of the input |
91 * coefficients are zero, especially the AC terms. We can exploit this | 95 * coefficients are zero, especially the AC terms. We can exploit this |
92 * by short-circuiting the IDCT calculation for any column in which all | 96 * by short-circuiting the IDCT calculation for any column in which all |
93 * the AC terms are zero. In that case each output is equal to the | 97 * the AC terms are zero. In that case each output is equal to the |
94 * DC coefficient (with scale factor as needed). | 98 * DC coefficient (with scale factor as needed). |
95 * With typical images and quantization tables, half or more of the | 99 * With typical images and quantization tables, half or more of the |
96 * column DCT calculations can be simplified this way. | 100 * column DCT calculations can be simplified this way. |
97 */ | 101 */ |
98 | 102 |
99 if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*2] == 0 && | 103 if (inptr[DCTSIZE*1] == 0 && inptr[DCTSIZE*2] == 0 && |
100 » inptr[DCTSIZE*3] == 0 && inptr[DCTSIZE*4] == 0 && | 104 inptr[DCTSIZE*3] == 0 && inptr[DCTSIZE*4] == 0 && |
101 » inptr[DCTSIZE*5] == 0 && inptr[DCTSIZE*6] == 0 && | 105 inptr[DCTSIZE*5] == 0 && inptr[DCTSIZE*6] == 0 && |
102 » inptr[DCTSIZE*7] == 0) { | 106 inptr[DCTSIZE*7] == 0) { |
103 /* AC terms all zero */ | 107 /* AC terms all zero */ |
104 FAST_FLOAT dcval = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); | 108 FAST_FLOAT dcval = DEQUANTIZE(inptr[DCTSIZE*0], |
105 | 109 quantptr[DCTSIZE*0] * _0_125); |
| 110 |
106 wsptr[DCTSIZE*0] = dcval; | 111 wsptr[DCTSIZE*0] = dcval; |
107 wsptr[DCTSIZE*1] = dcval; | 112 wsptr[DCTSIZE*1] = dcval; |
108 wsptr[DCTSIZE*2] = dcval; | 113 wsptr[DCTSIZE*2] = dcval; |
109 wsptr[DCTSIZE*3] = dcval; | 114 wsptr[DCTSIZE*3] = dcval; |
110 wsptr[DCTSIZE*4] = dcval; | 115 wsptr[DCTSIZE*4] = dcval; |
111 wsptr[DCTSIZE*5] = dcval; | 116 wsptr[DCTSIZE*5] = dcval; |
112 wsptr[DCTSIZE*6] = dcval; | 117 wsptr[DCTSIZE*6] = dcval; |
113 wsptr[DCTSIZE*7] = dcval; | 118 wsptr[DCTSIZE*7] = dcval; |
114 | 119 |
115 inptr++;» » » /* advance pointers to next column */ | 120 inptr++; /* advance pointers to next column */ |
116 quantptr++; | 121 quantptr++; |
117 wsptr++; | 122 wsptr++; |
118 continue; | 123 continue; |
119 } | 124 } |
120 | 125 |
121 /* Even part */ | 126 /* Even part */ |
122 | 127 |
123 tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]); | 128 tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0] * _0_125); |
124 tmp1 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]); | 129 tmp1 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2] * _0_125); |
125 tmp2 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]); | 130 tmp2 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4] * _0_125); |
126 tmp3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]); | 131 tmp3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6] * _0_125); |
127 | 132 |
128 tmp10 = tmp0 + tmp2;» /* phase 3 */ | 133 tmp10 = tmp0 + tmp2; /* phase 3 */ |
129 tmp11 = tmp0 - tmp2; | 134 tmp11 = tmp0 - tmp2; |
130 | 135 |
131 tmp13 = tmp1 + tmp3;» /* phases 5-3 */ | 136 tmp13 = tmp1 + tmp3; /* phases 5-3 */ |
132 tmp12 = (tmp1 - tmp3) * ((FAST_FLOAT) 1.414213562) - tmp13; /* 2*c4 */ | 137 tmp12 = (tmp1 - tmp3) * ((FAST_FLOAT) 1.414213562) - tmp13; /* 2*c4 */ |
133 | 138 |
134 tmp0 = tmp10 + tmp13;» /* phase 2 */ | 139 tmp0 = tmp10 + tmp13; /* phase 2 */ |
135 tmp3 = tmp10 - tmp13; | 140 tmp3 = tmp10 - tmp13; |
136 tmp1 = tmp11 + tmp12; | 141 tmp1 = tmp11 + tmp12; |
137 tmp2 = tmp11 - tmp12; | 142 tmp2 = tmp11 - tmp12; |
138 | 143 |
139 /* Odd part */ | 144 /* Odd part */ |
140 | 145 |
141 tmp4 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]); | 146 tmp4 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1] * _0_125); |
142 tmp5 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3]); | 147 tmp5 = DEQUANTIZE(inptr[DCTSIZE*3], quantptr[DCTSIZE*3] * _0_125); |
143 tmp6 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5]); | 148 tmp6 = DEQUANTIZE(inptr[DCTSIZE*5], quantptr[DCTSIZE*5] * _0_125); |
144 tmp7 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7]); | 149 tmp7 = DEQUANTIZE(inptr[DCTSIZE*7], quantptr[DCTSIZE*7] * _0_125); |
145 | 150 |
146 z13 = tmp6 + tmp5;» » /* phase 6 */ | 151 z13 = tmp6 + tmp5; /* phase 6 */ |
147 z10 = tmp6 - tmp5; | 152 z10 = tmp6 - tmp5; |
148 z11 = tmp4 + tmp7; | 153 z11 = tmp4 + tmp7; |
149 z12 = tmp4 - tmp7; | 154 z12 = tmp4 - tmp7; |
150 | 155 |
151 tmp7 = z11 + z13;» » /* phase 5 */ | 156 tmp7 = z11 + z13; /* phase 5 */ |
152 tmp11 = (z11 - z13) * ((FAST_FLOAT) 1.414213562); /* 2*c4 */ | 157 tmp11 = (z11 - z13) * ((FAST_FLOAT) 1.414213562); /* 2*c4 */ |
153 | 158 |
154 z5 = (z10 + z12) * ((FAST_FLOAT) 1.847759065); /* 2*c2 */ | 159 z5 = (z10 + z12) * ((FAST_FLOAT) 1.847759065); /* 2*c2 */ |
155 tmp10 = ((FAST_FLOAT) 1.082392200) * z12 - z5; /* 2*(c2-c6) */ | 160 tmp10 = z5 - z12 * ((FAST_FLOAT) 1.082392200); /* 2*(c2-c6) */ |
156 tmp12 = ((FAST_FLOAT) -2.613125930) * z10 + z5; /* -2*(c2+c6) */ | 161 tmp12 = z5 - z10 * ((FAST_FLOAT) 2.613125930); /* 2*(c2+c6) */ |
157 | 162 |
158 tmp6 = tmp12 - tmp7;» /* phase 2 */ | 163 tmp6 = tmp12 - tmp7; /* phase 2 */ |
159 tmp5 = tmp11 - tmp6; | 164 tmp5 = tmp11 - tmp6; |
160 tmp4 = tmp10 + tmp5; | 165 tmp4 = tmp10 - tmp5; |
161 | 166 |
162 wsptr[DCTSIZE*0] = tmp0 + tmp7; | 167 wsptr[DCTSIZE*0] = tmp0 + tmp7; |
163 wsptr[DCTSIZE*7] = tmp0 - tmp7; | 168 wsptr[DCTSIZE*7] = tmp0 - tmp7; |
164 wsptr[DCTSIZE*1] = tmp1 + tmp6; | 169 wsptr[DCTSIZE*1] = tmp1 + tmp6; |
165 wsptr[DCTSIZE*6] = tmp1 - tmp6; | 170 wsptr[DCTSIZE*6] = tmp1 - tmp6; |
166 wsptr[DCTSIZE*2] = tmp2 + tmp5; | 171 wsptr[DCTSIZE*2] = tmp2 + tmp5; |
167 wsptr[DCTSIZE*5] = tmp2 - tmp5; | 172 wsptr[DCTSIZE*5] = tmp2 - tmp5; |
168 wsptr[DCTSIZE*4] = tmp3 + tmp4; | 173 wsptr[DCTSIZE*3] = tmp3 + tmp4; |
169 wsptr[DCTSIZE*3] = tmp3 - tmp4; | 174 wsptr[DCTSIZE*4] = tmp3 - tmp4; |
170 | 175 |
171 inptr++;» » » /* advance pointers to next column */ | 176 inptr++; /* advance pointers to next column */ |
172 quantptr++; | 177 quantptr++; |
173 wsptr++; | 178 wsptr++; |
174 } | 179 } |
175 | 180 |
176 /* Pass 2: process rows from work array, store into output array. */ | 181 /* Pass 2: process rows from work array, store into output array. */ |
177 /* Note that we must descale the results by a factor of 8 == 2**3. */ | |
178 | 182 |
179 wsptr = workspace; | 183 wsptr = workspace; |
180 for (ctr = 0; ctr < DCTSIZE; ctr++) { | 184 for (ctr = 0; ctr < DCTSIZE; ctr++) { |
181 outptr = output_buf[ctr] + output_col; | 185 outptr = output_buf[ctr] + output_col; |
182 /* Rows of zeroes can be exploited in the same way as we did with columns. | 186 /* Rows of zeroes can be exploited in the same way as we did with columns. |
183 * However, the column calculation has created many nonzero AC terms, so | 187 * However, the column calculation has created many nonzero AC terms, so |
184 * the simplification applies less often (typically 5% to 10% of the time). | 188 * the simplification applies less often (typically 5% to 10% of the time). |
185 * And testing floats for zero is relatively expensive, so we don't bother. | 189 * And testing floats for zero is relatively expensive, so we don't bother. |
186 */ | 190 */ |
187 | 191 |
188 /* Even part */ | 192 /* Even part */ |
189 | 193 |
190 tmp10 = wsptr[0] + wsptr[4]; | 194 /* Apply signed->unsigned and prepare float->int conversion */ |
191 tmp11 = wsptr[0] - wsptr[4]; | 195 z5 = wsptr[0] + ((FAST_FLOAT) CENTERJSAMPLE + (FAST_FLOAT) 0.5); |
| 196 tmp10 = z5 + wsptr[4]; |
| 197 tmp11 = z5 - wsptr[4]; |
192 | 198 |
193 tmp13 = wsptr[2] + wsptr[6]; | 199 tmp13 = wsptr[2] + wsptr[6]; |
194 tmp12 = (wsptr[2] - wsptr[6]) * ((FAST_FLOAT) 1.414213562) - tmp13; | 200 tmp12 = (wsptr[2] - wsptr[6]) * ((FAST_FLOAT) 1.414213562) - tmp13; |
195 | 201 |
196 tmp0 = tmp10 + tmp13; | 202 tmp0 = tmp10 + tmp13; |
197 tmp3 = tmp10 - tmp13; | 203 tmp3 = tmp10 - tmp13; |
198 tmp1 = tmp11 + tmp12; | 204 tmp1 = tmp11 + tmp12; |
199 tmp2 = tmp11 - tmp12; | 205 tmp2 = tmp11 - tmp12; |
200 | 206 |
201 /* Odd part */ | 207 /* Odd part */ |
202 | 208 |
203 z13 = wsptr[5] + wsptr[3]; | 209 z13 = wsptr[5] + wsptr[3]; |
204 z10 = wsptr[5] - wsptr[3]; | 210 z10 = wsptr[5] - wsptr[3]; |
205 z11 = wsptr[1] + wsptr[7]; | 211 z11 = wsptr[1] + wsptr[7]; |
206 z12 = wsptr[1] - wsptr[7]; | 212 z12 = wsptr[1] - wsptr[7]; |
207 | 213 |
208 tmp7 = z11 + z13; | 214 tmp7 = z11 + z13; |
209 tmp11 = (z11 - z13) * ((FAST_FLOAT) 1.414213562); | 215 tmp11 = (z11 - z13) * ((FAST_FLOAT) 1.414213562); |
210 | 216 |
211 z5 = (z10 + z12) * ((FAST_FLOAT) 1.847759065); /* 2*c2 */ | 217 z5 = (z10 + z12) * ((FAST_FLOAT) 1.847759065); /* 2*c2 */ |
212 tmp10 = ((FAST_FLOAT) 1.082392200) * z12 - z5; /* 2*(c2-c6) */ | 218 tmp10 = z5 - z12 * ((FAST_FLOAT) 1.082392200); /* 2*(c2-c6) */ |
213 tmp12 = ((FAST_FLOAT) -2.613125930) * z10 + z5; /* -2*(c2+c6) */ | 219 tmp12 = z5 - z10 * ((FAST_FLOAT) 2.613125930); /* 2*(c2+c6) */ |
214 | 220 |
215 tmp6 = tmp12 - tmp7; | 221 tmp6 = tmp12 - tmp7; |
216 tmp5 = tmp11 - tmp6; | 222 tmp5 = tmp11 - tmp6; |
217 tmp4 = tmp10 + tmp5; | 223 tmp4 = tmp10 - tmp5; |
218 | 224 |
219 /* Final output stage: scale down by a factor of 8 and range-limit */ | 225 /* Final output stage: float->int conversion and range-limit */ |
220 | 226 |
221 outptr[0] = range_limit[(int) DESCALE((INT32) (tmp0 + tmp7), 3) | 227 outptr[0] = range_limit[((int) (tmp0 + tmp7)) & RANGE_MASK]; |
222 » » » & RANGE_MASK]; | 228 outptr[7] = range_limit[((int) (tmp0 - tmp7)) & RANGE_MASK]; |
223 outptr[7] = range_limit[(int) DESCALE((INT32) (tmp0 - tmp7), 3) | 229 outptr[1] = range_limit[((int) (tmp1 + tmp6)) & RANGE_MASK]; |
224 » » » & RANGE_MASK]; | 230 outptr[6] = range_limit[((int) (tmp1 - tmp6)) & RANGE_MASK]; |
225 outptr[1] = range_limit[(int) DESCALE((INT32) (tmp1 + tmp6), 3) | 231 outptr[2] = range_limit[((int) (tmp2 + tmp5)) & RANGE_MASK]; |
226 » » » & RANGE_MASK]; | 232 outptr[5] = range_limit[((int) (tmp2 - tmp5)) & RANGE_MASK]; |
227 outptr[6] = range_limit[(int) DESCALE((INT32) (tmp1 - tmp6), 3) | 233 outptr[3] = range_limit[((int) (tmp3 + tmp4)) & RANGE_MASK]; |
228 » » » & RANGE_MASK]; | 234 outptr[4] = range_limit[((int) (tmp3 - tmp4)) & RANGE_MASK]; |
229 outptr[2] = range_limit[(int) DESCALE((INT32) (tmp2 + tmp5), 3) | 235 |
230 » » » & RANGE_MASK]; | 236 wsptr += DCTSIZE; /* advance pointer to next row */ |
231 outptr[5] = range_limit[(int) DESCALE((INT32) (tmp2 - tmp5), 3) | |
232 » » » & RANGE_MASK]; | |
233 outptr[4] = range_limit[(int) DESCALE((INT32) (tmp3 + tmp4), 3) | |
234 » » » & RANGE_MASK]; | |
235 outptr[3] = range_limit[(int) DESCALE((INT32) (tmp3 - tmp4), 3) | |
236 » » » & RANGE_MASK]; | |
237 | |
238 wsptr += DCTSIZE;» » /* advance pointer to next row */ | |
239 } | 237 } |
240 } | 238 } |
241 | 239 |
242 #endif /* DCT_FLOAT_SUPPORTED */ | 240 #endif /* DCT_FLOAT_SUPPORTED */ |
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