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1 #if !defined(_FX_JPEG_TURBO_)
2 /*
3  * jcsample.c
4  *
5  * Copyright (C) 1991-1996, Thomas G. Lane.
6  * This file is part of the Independent JPEG Group's software.
7  * For conditions of distribution and use, see the accompanying README file.
8  *
9  * This file contains downsampling routines.
10  *
11  * Downsampling input data is counted in "row groups".  A row group
12  * is defined to be max_v_samp_factor pixel rows of each component,
13  * from which the downsampler produces v_samp_factor sample rows.
14  * A single row group is processed in each call to the downsampler module.
15  *
16  * The downsampler is responsible for edge-expansion of its output data
17  * to fill an integral number of DCT blocks horizontally.  The source buffer
18  * may be modified if it is helpful for this purpose (the source buffer is
19  * allocated wide enough to correspond to the desired output width).
20  * The caller (the prep controller) is responsible for vertical padding.
21  *
22  * The downsampler may request "context rows" by setting need_context_rows
23  * during startup.  In this case, the input arrays will contain at least
24  * one row group's worth of pixels above and below the passed-in data;
25  * the caller will create dummy rows at image top and bottom by replicating
26  * the first or last real pixel row.
27  *
28  * An excellent reference for image resampling is
29  *   Digital Image Warping, George Wolberg, 1990.
30  *   Pub. by IEEE Computer Society Press, Los Alamitos, CA. ISBN 0-8186-8944-7.
31  *
32  * The downsampling algorithm used here is a simple average of the source
33  * pixels covered by the output pixel.  The hi-falutin sampling literature
34  * refers to this as a "box filter".  In general the characteristics of a box
35  * filter are not very good, but for the specific cases we normally use (1:1
36  * and 2:1 ratios) the box is equivalent to a "triangle filter" which is not
37  * nearly so bad.  If you intend to use other sampling ratios, you'd be well
38  * advised to improve this code.
39  *
40  * A simple input-smoothing capability is provided.  This is mainly intended
41  * for cleaning up color-dithered GIF input files (if you find it inadequate,
42  * we suggest using an external filtering program such as pnmconvol).  When
43  * enabled, each input pixel P is replaced by a weighted sum of itself and its
44  * eight neighbors.  P's weight is 1-8*SF and each neighbor's weight is SF,
45  * where SF = (smoothing_factor / 1024).
46  * Currently, smoothing is only supported for 2h2v sampling factors.
47  */
48 
49 #define JPEG_INTERNALS
50 #include "jinclude.h"
51 #include "jpeglib.h"
52 
53 
54 /* Pointer to routine to downsample a single component */
55 typedef JMETHOD(void, downsample1_ptr,
56 		(j_compress_ptr cinfo, jpeg_component_info * compptr,
57 		 JSAMPARRAY input_data, JSAMPARRAY output_data));
58 
59 /* Private subobject */
60 
61 typedef struct {
62   struct jpeg_downsampler pub;	/* public fields */
63 
64   /* Downsampling method pointers, one per component */
65   downsample1_ptr methods[MAX_COMPONENTS];
66 } my_downsampler;
67 
68 typedef my_downsampler * my_downsample_ptr;
69 
70 
71 /*
72  * Initialize for a downsampling pass.
73  */
74 
75 METHODDEF(void)
start_pass_downsample(j_compress_ptr cinfo)76 start_pass_downsample (j_compress_ptr cinfo)
77 {
78   /* no work for now */
79 }
80 
81 
82 /*
83  * Expand a component horizontally from width input_cols to width output_cols,
84  * by duplicating the rightmost samples.
85  */
86 
87 LOCAL(void)
expand_right_edge(JSAMPARRAY image_data,int num_rows,JDIMENSION input_cols,JDIMENSION output_cols)88 expand_right_edge (JSAMPARRAY image_data, int num_rows,
89 		   JDIMENSION input_cols, JDIMENSION output_cols)
90 {
91   register JSAMPROW ptr;
92   register JSAMPLE pixval;
93   register int count;
94   int row;
95   int numcols = (int) (output_cols - input_cols);
96 
97   if (numcols > 0) {
98     for (row = 0; row < num_rows; row++) {
99       ptr = image_data[row] + input_cols;
100       pixval = ptr[-1];		/* don't need GETJSAMPLE() here */
101       for (count = numcols; count > 0; count--)
102 	*ptr++ = pixval;
103     }
104   }
105 }
106 
107 
108 /*
109  * Do downsampling for a whole row group (all components).
110  *
111  * In this version we simply downsample each component independently.
112  */
113 
114 METHODDEF(void)
sep_downsample(j_compress_ptr cinfo,JSAMPIMAGE input_buf,JDIMENSION in_row_index,JSAMPIMAGE output_buf,JDIMENSION out_row_group_index)115 sep_downsample (j_compress_ptr cinfo,
116 		JSAMPIMAGE input_buf, JDIMENSION in_row_index,
117 		JSAMPIMAGE output_buf, JDIMENSION out_row_group_index)
118 {
119   my_downsample_ptr downsample = (my_downsample_ptr) cinfo->downsample;
120   int ci;
121   jpeg_component_info * compptr;
122   JSAMPARRAY in_ptr, out_ptr;
123 
124   for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
125        ci++, compptr++) {
126     in_ptr = input_buf[ci] + in_row_index;
127     out_ptr = output_buf[ci] + (out_row_group_index * compptr->v_samp_factor);
128     (*downsample->methods[ci]) (cinfo, compptr, in_ptr, out_ptr);
129   }
130 }
131 
132 
133 /*
134  * Downsample pixel values of a single component.
135  * One row group is processed per call.
136  * This version handles arbitrary integral sampling ratios, without smoothing.
137  * Note that this version is not actually used for customary sampling ratios.
138  */
139 
140 METHODDEF(void)
int_downsample(j_compress_ptr cinfo,jpeg_component_info * compptr,JSAMPARRAY input_data,JSAMPARRAY output_data)141 int_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
142 		JSAMPARRAY input_data, JSAMPARRAY output_data)
143 {
144   int inrow, outrow, h_expand, v_expand, numpix, numpix2, h, v;
145   JDIMENSION outcol, outcol_h;	/* outcol_h == outcol*h_expand */
146   JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
147   JSAMPROW inptr, outptr;
148   INT32 outvalue;
149 
150   h_expand = cinfo->max_h_samp_factor / compptr->h_samp_factor;
151   v_expand = cinfo->max_v_samp_factor / compptr->v_samp_factor;
152   numpix = h_expand * v_expand;
153   numpix2 = numpix/2;
154 
155   /* Expand input data enough to let all the output samples be generated
156    * by the standard loop.  Special-casing padded output would be more
157    * efficient.
158    */
159   expand_right_edge(input_data, cinfo->max_v_samp_factor,
160 		    cinfo->image_width, output_cols * h_expand);
161 
162   inrow = 0;
163   for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
164     outptr = output_data[outrow];
165     for (outcol = 0, outcol_h = 0; outcol < output_cols;
166 	 outcol++, outcol_h += h_expand) {
167       outvalue = 0;
168       for (v = 0; v < v_expand; v++) {
169 	inptr = input_data[inrow+v] + outcol_h;
170 	for (h = 0; h < h_expand; h++) {
171 	  outvalue += (INT32) GETJSAMPLE(*inptr++);
172 	}
173       }
174       *outptr++ = (JSAMPLE) ((outvalue + numpix2) / numpix);
175     }
176     inrow += v_expand;
177   }
178 }
179 
180 
181 /*
182  * Downsample pixel values of a single component.
183  * This version handles the special case of a full-size component,
184  * without smoothing.
185  */
186 
187 METHODDEF(void)
fullsize_downsample(j_compress_ptr cinfo,jpeg_component_info * compptr,JSAMPARRAY input_data,JSAMPARRAY output_data)188 fullsize_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
189 		     JSAMPARRAY input_data, JSAMPARRAY output_data)
190 {
191   /* Copy the data */
192   jcopy_sample_rows(input_data, 0, output_data, 0,
193 		    cinfo->max_v_samp_factor, cinfo->image_width);
194   /* Edge-expand */
195   expand_right_edge(output_data, cinfo->max_v_samp_factor,
196 		    cinfo->image_width, compptr->width_in_blocks * DCTSIZE);
197 }
198 
199 
200 /*
201  * Downsample pixel values of a single component.
202  * This version handles the common case of 2:1 horizontal and 1:1 vertical,
203  * without smoothing.
204  *
205  * A note about the "bias" calculations: when rounding fractional values to
206  * integer, we do not want to always round 0.5 up to the next integer.
207  * If we did that, we'd introduce a noticeable bias towards larger values.
208  * Instead, this code is arranged so that 0.5 will be rounded up or down at
209  * alternate pixel locations (a simple ordered dither pattern).
210  */
211 
212 METHODDEF(void)
h2v1_downsample(j_compress_ptr cinfo,jpeg_component_info * compptr,JSAMPARRAY input_data,JSAMPARRAY output_data)213 h2v1_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
214 		 JSAMPARRAY input_data, JSAMPARRAY output_data)
215 {
216   int outrow;
217   JDIMENSION outcol;
218   JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
219   register JSAMPROW inptr, outptr;
220   register int bias;
221 
222   /* Expand input data enough to let all the output samples be generated
223    * by the standard loop.  Special-casing padded output would be more
224    * efficient.
225    */
226   expand_right_edge(input_data, cinfo->max_v_samp_factor,
227 		    cinfo->image_width, output_cols * 2);
228 
229   for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
230     outptr = output_data[outrow];
231     inptr = input_data[outrow];
232     bias = 0;			/* bias = 0,1,0,1,... for successive samples */
233     for (outcol = 0; outcol < output_cols; outcol++) {
234       *outptr++ = (JSAMPLE) ((GETJSAMPLE(*inptr) + GETJSAMPLE(inptr[1])
235 			      + bias) >> 1);
236       bias ^= 1;		/* 0=>1, 1=>0 */
237       inptr += 2;
238     }
239   }
240 }
241 
242 
243 /*
244  * Downsample pixel values of a single component.
245  * This version handles the standard case of 2:1 horizontal and 2:1 vertical,
246  * without smoothing.
247  */
248 
249 METHODDEF(void)
h2v2_downsample(j_compress_ptr cinfo,jpeg_component_info * compptr,JSAMPARRAY input_data,JSAMPARRAY output_data)250 h2v2_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
251 		 JSAMPARRAY input_data, JSAMPARRAY output_data)
252 {
253   int inrow, outrow;
254   JDIMENSION outcol;
255   JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
256   register JSAMPROW inptr0, inptr1, outptr;
257   register int bias;
258 
259   /* Expand input data enough to let all the output samples be generated
260    * by the standard loop.  Special-casing padded output would be more
261    * efficient.
262    */
263   expand_right_edge(input_data, cinfo->max_v_samp_factor,
264 		    cinfo->image_width, output_cols * 2);
265 
266   inrow = 0;
267   for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
268     outptr = output_data[outrow];
269     inptr0 = input_data[inrow];
270     inptr1 = input_data[inrow+1];
271     bias = 1;			/* bias = 1,2,1,2,... for successive samples */
272     for (outcol = 0; outcol < output_cols; outcol++) {
273       *outptr++ = (JSAMPLE) ((GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) +
274 			      GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1])
275 			      + bias) >> 2);
276       bias ^= 3;		/* 1=>2, 2=>1 */
277       inptr0 += 2; inptr1 += 2;
278     }
279     inrow += 2;
280   }
281 }
282 
283 
284 #ifdef INPUT_SMOOTHING_SUPPORTED
285 
286 /*
287  * Downsample pixel values of a single component.
288  * This version handles the standard case of 2:1 horizontal and 2:1 vertical,
289  * with smoothing.  One row of context is required.
290  */
291 
292 METHODDEF(void)
h2v2_smooth_downsample(j_compress_ptr cinfo,jpeg_component_info * compptr,JSAMPARRAY input_data,JSAMPARRAY output_data)293 h2v2_smooth_downsample (j_compress_ptr cinfo, jpeg_component_info * compptr,
294 			JSAMPARRAY input_data, JSAMPARRAY output_data)
295 {
296   int inrow, outrow;
297   JDIMENSION colctr;
298   JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
299   register JSAMPROW inptr0, inptr1, above_ptr, below_ptr, outptr;
300   INT32 membersum, neighsum, memberscale, neighscale;
301 
302   /* Expand input data enough to let all the output samples be generated
303    * by the standard loop.  Special-casing padded output would be more
304    * efficient.
305    */
306   expand_right_edge(input_data - 1, cinfo->max_v_samp_factor + 2,
307 		    cinfo->image_width, output_cols * 2);
308 
309   /* We don't bother to form the individual "smoothed" input pixel values;
310    * we can directly compute the output which is the average of the four
311    * smoothed values.  Each of the four member pixels contributes a fraction
312    * (1-8*SF) to its own smoothed image and a fraction SF to each of the three
313    * other smoothed pixels, therefore a total fraction (1-5*SF)/4 to the final
314    * output.  The four corner-adjacent neighbor pixels contribute a fraction
315    * SF to just one smoothed pixel, or SF/4 to the final output; while the
316    * eight edge-adjacent neighbors contribute SF to each of two smoothed
317    * pixels, or SF/2 overall.  In order to use integer arithmetic, these
318    * factors are scaled by 2^16 = 65536.
319    * Also recall that SF = smoothing_factor / 1024.
320    */
321 
322   memberscale = 16384 - cinfo->smoothing_factor * 80; /* scaled (1-5*SF)/4 */
323   neighscale = cinfo->smoothing_factor * 16; /* scaled SF/4 */
324 
325   inrow = 0;
326   for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
327     outptr = output_data[outrow];
328     inptr0 = input_data[inrow];
329     inptr1 = input_data[inrow+1];
330     above_ptr = input_data[inrow-1];
331     below_ptr = input_data[inrow+2];
332 
333     /* Special case for first column: pretend column -1 is same as column 0 */
334     membersum = GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) +
335 		GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1]);
336     neighsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[1]) +
337 	       GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[1]) +
338 	       GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[2]) +
339 	       GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[2]);
340     neighsum += neighsum;
341     neighsum += GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[2]) +
342 		GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[2]);
343     membersum = membersum * memberscale + neighsum * neighscale;
344     *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16);
345     inptr0 += 2; inptr1 += 2; above_ptr += 2; below_ptr += 2;
346 
347     for (colctr = output_cols - 2; colctr > 0; colctr--) {
348       /* sum of pixels directly mapped to this output element */
349       membersum = GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) +
350 		  GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1]);
351       /* sum of edge-neighbor pixels */
352       neighsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[1]) +
353 		 GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[1]) +
354 		 GETJSAMPLE(inptr0[-1]) + GETJSAMPLE(inptr0[2]) +
355 		 GETJSAMPLE(inptr1[-1]) + GETJSAMPLE(inptr1[2]);
356       /* The edge-neighbors count twice as much as corner-neighbors */
357       neighsum += neighsum;
358       /* Add in the corner-neighbors */
359       neighsum += GETJSAMPLE(above_ptr[-1]) + GETJSAMPLE(above_ptr[2]) +
360 		  GETJSAMPLE(below_ptr[-1]) + GETJSAMPLE(below_ptr[2]);
361       /* form final output scaled up by 2^16 */
362       membersum = membersum * memberscale + neighsum * neighscale;
363       /* round, descale and output it */
364       *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16);
365       inptr0 += 2; inptr1 += 2; above_ptr += 2; below_ptr += 2;
366     }
367 
368     /* Special case for last column */
369     membersum = GETJSAMPLE(*inptr0) + GETJSAMPLE(inptr0[1]) +
370 		GETJSAMPLE(*inptr1) + GETJSAMPLE(inptr1[1]);
371     neighsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(above_ptr[1]) +
372 	       GETJSAMPLE(*below_ptr) + GETJSAMPLE(below_ptr[1]) +
373 	       GETJSAMPLE(inptr0[-1]) + GETJSAMPLE(inptr0[1]) +
374 	       GETJSAMPLE(inptr1[-1]) + GETJSAMPLE(inptr1[1]);
375     neighsum += neighsum;
376     neighsum += GETJSAMPLE(above_ptr[-1]) + GETJSAMPLE(above_ptr[1]) +
377 		GETJSAMPLE(below_ptr[-1]) + GETJSAMPLE(below_ptr[1]);
378     membersum = membersum * memberscale + neighsum * neighscale;
379     *outptr = (JSAMPLE) ((membersum + 32768) >> 16);
380 
381     inrow += 2;
382   }
383 }
384 
385 
386 /*
387  * Downsample pixel values of a single component.
388  * This version handles the special case of a full-size component,
389  * with smoothing.  One row of context is required.
390  */
391 
392 METHODDEF(void)
fullsize_smooth_downsample(j_compress_ptr cinfo,jpeg_component_info * compptr,JSAMPARRAY input_data,JSAMPARRAY output_data)393 fullsize_smooth_downsample (j_compress_ptr cinfo, jpeg_component_info *compptr,
394 			    JSAMPARRAY input_data, JSAMPARRAY output_data)
395 {
396   int outrow;
397   JDIMENSION colctr;
398   JDIMENSION output_cols = compptr->width_in_blocks * DCTSIZE;
399   register JSAMPROW inptr, above_ptr, below_ptr, outptr;
400   INT32 membersum, neighsum, memberscale, neighscale;
401   int colsum, lastcolsum, nextcolsum;
402 
403   /* Expand input data enough to let all the output samples be generated
404    * by the standard loop.  Special-casing padded output would be more
405    * efficient.
406    */
407   expand_right_edge(input_data - 1, cinfo->max_v_samp_factor + 2,
408 		    cinfo->image_width, output_cols);
409 
410   /* Each of the eight neighbor pixels contributes a fraction SF to the
411    * smoothed pixel, while the main pixel contributes (1-8*SF).  In order
412    * to use integer arithmetic, these factors are multiplied by 2^16 = 65536.
413    * Also recall that SF = smoothing_factor / 1024.
414    */
415 
416   memberscale = 65536L - cinfo->smoothing_factor * 512L; /* scaled 1-8*SF */
417   neighscale = cinfo->smoothing_factor * 64; /* scaled SF */
418 
419   for (outrow = 0; outrow < compptr->v_samp_factor; outrow++) {
420     outptr = output_data[outrow];
421     inptr = input_data[outrow];
422     above_ptr = input_data[outrow-1];
423     below_ptr = input_data[outrow+1];
424 
425     /* Special case for first column */
426     colsum = GETJSAMPLE(*above_ptr++) + GETJSAMPLE(*below_ptr++) +
427 	     GETJSAMPLE(*inptr);
428     membersum = GETJSAMPLE(*inptr++);
429     nextcolsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(*below_ptr) +
430 		 GETJSAMPLE(*inptr);
431     neighsum = colsum + (colsum - membersum) + nextcolsum;
432     membersum = membersum * memberscale + neighsum * neighscale;
433     *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16);
434     lastcolsum = colsum; colsum = nextcolsum;
435 
436     for (colctr = output_cols - 2; colctr > 0; colctr--) {
437       membersum = GETJSAMPLE(*inptr++);
438       above_ptr++; below_ptr++;
439       nextcolsum = GETJSAMPLE(*above_ptr) + GETJSAMPLE(*below_ptr) +
440 		   GETJSAMPLE(*inptr);
441       neighsum = lastcolsum + (colsum - membersum) + nextcolsum;
442       membersum = membersum * memberscale + neighsum * neighscale;
443       *outptr++ = (JSAMPLE) ((membersum + 32768) >> 16);
444       lastcolsum = colsum; colsum = nextcolsum;
445     }
446 
447     /* Special case for last column */
448     membersum = GETJSAMPLE(*inptr);
449     neighsum = lastcolsum + (colsum - membersum) + colsum;
450     membersum = membersum * memberscale + neighsum * neighscale;
451     *outptr = (JSAMPLE) ((membersum + 32768) >> 16);
452 
453   }
454 }
455 
456 #endif /* INPUT_SMOOTHING_SUPPORTED */
457 
458 
459 /*
460  * Module initialization routine for downsampling.
461  * Note that we must select a routine for each component.
462  */
463 
464 GLOBAL(void)
jinit_downsampler(j_compress_ptr cinfo)465 jinit_downsampler (j_compress_ptr cinfo)
466 {
467   my_downsample_ptr downsample;
468   int ci;
469   jpeg_component_info * compptr;
470   boolean smoothok = TRUE;
471 
472   downsample = (my_downsample_ptr)
473     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
474 				SIZEOF(my_downsampler));
475   cinfo->downsample = (struct jpeg_downsampler *) downsample;
476   downsample->pub.start_pass = start_pass_downsample;
477   downsample->pub.downsample = sep_downsample;
478   downsample->pub.need_context_rows = FALSE;
479 
480   if (cinfo->CCIR601_sampling)
481     ERREXIT(cinfo, JERR_CCIR601_NOTIMPL);
482 
483   /* Verify we can handle the sampling factors, and set up method pointers */
484   for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
485        ci++, compptr++) {
486     if (compptr->h_samp_factor == cinfo->max_h_samp_factor &&
487 	compptr->v_samp_factor == cinfo->max_v_samp_factor) {
488 #ifdef INPUT_SMOOTHING_SUPPORTED
489       if (cinfo->smoothing_factor) {
490 	downsample->methods[ci] = fullsize_smooth_downsample;
491 	downsample->pub.need_context_rows = TRUE;
492       } else
493 #endif
494 	downsample->methods[ci] = fullsize_downsample;
495     } else if (compptr->h_samp_factor * 2 == cinfo->max_h_samp_factor &&
496 	       compptr->v_samp_factor == cinfo->max_v_samp_factor) {
497       smoothok = FALSE;
498       downsample->methods[ci] = h2v1_downsample;
499     } else if (compptr->h_samp_factor * 2 == cinfo->max_h_samp_factor &&
500 	       compptr->v_samp_factor * 2 == cinfo->max_v_samp_factor) {
501 #ifdef INPUT_SMOOTHING_SUPPORTED
502       if (cinfo->smoothing_factor) {
503 	downsample->methods[ci] = h2v2_smooth_downsample;
504 	downsample->pub.need_context_rows = TRUE;
505       } else
506 #endif
507 	downsample->methods[ci] = h2v2_downsample;
508     } else if ((cinfo->max_h_samp_factor % compptr->h_samp_factor) == 0 &&
509 	       (cinfo->max_v_samp_factor % compptr->v_samp_factor) == 0) {
510       smoothok = FALSE;
511       downsample->methods[ci] = int_downsample;
512     } else
513       ERREXIT(cinfo, JERR_FRACT_SAMPLE_NOTIMPL);
514   }
515 
516 #ifdef INPUT_SMOOTHING_SUPPORTED
517   if (cinfo->smoothing_factor && !smoothok)
518     TRACEMS(cinfo, 0, JTRC_SMOOTH_NOTIMPL);
519 #endif
520 }
521 
522 #endif //_FX_JPEG_TURBO_
523