1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/libs/libjpeg/jdsample.c	Sat Feb 01 19:58:19 2014 +0200
     1.3 @@ -0,0 +1,478 @@
     1.4 +/*
     1.5 + * jdsample.c
     1.6 + *
     1.7 + * Copyright (C) 1991-1996, Thomas G. Lane.
     1.8 + * This file is part of the Independent JPEG Group's software.
     1.9 + * For conditions of distribution and use, see the accompanying README file.
    1.10 + *
    1.11 + * This file contains upsampling routines.
    1.12 + *
    1.13 + * Upsampling input data is counted in "row groups".  A row group
    1.14 + * is defined to be (v_samp_factor * DCT_scaled_size / min_DCT_scaled_size)
    1.15 + * sample rows of each component.  Upsampling will normally produce
    1.16 + * max_v_samp_factor pixel rows from each row group (but this could vary
    1.17 + * if the upsampler is applying a scale factor of its own).
    1.18 + *
    1.19 + * An excellent reference for image resampling is
    1.20 + *   Digital Image Warping, George Wolberg, 1990.
    1.21 + *   Pub. by IEEE Computer Society Press, Los Alamitos, CA. ISBN 0-8186-8944-7.
    1.22 + */
    1.23 +
    1.24 +#define JPEG_INTERNALS
    1.25 +#include "jinclude.h"
    1.26 +#include "jpeglib.h"
    1.27 +
    1.28 +
    1.29 +/* Pointer to routine to upsample a single component */
    1.30 +typedef JMETHOD(void, upsample1_ptr,
    1.31 +		(j_decompress_ptr cinfo, jpeg_component_info * compptr,
    1.32 +		 JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr));
    1.33 +
    1.34 +/* Private subobject */
    1.35 +
    1.36 +typedef struct {
    1.37 +  struct jpeg_upsampler pub;	/* public fields */
    1.38 +
    1.39 +  /* Color conversion buffer.  When using separate upsampling and color
    1.40 +   * conversion steps, this buffer holds one upsampled row group until it
    1.41 +   * has been color converted and output.
    1.42 +   * Note: we do not allocate any storage for component(s) which are full-size,
    1.43 +   * ie do not need rescaling.  The corresponding entry of color_buf[] is
    1.44 +   * simply set to point to the input data array, thereby avoiding copying.
    1.45 +   */
    1.46 +  JSAMPARRAY color_buf[MAX_COMPONENTS];
    1.47 +
    1.48 +  /* Per-component upsampling method pointers */
    1.49 +  upsample1_ptr methods[MAX_COMPONENTS];
    1.50 +
    1.51 +  int next_row_out;		/* counts rows emitted from color_buf */
    1.52 +  JDIMENSION rows_to_go;	/* counts rows remaining in image */
    1.53 +
    1.54 +  /* Height of an input row group for each component. */
    1.55 +  int rowgroup_height[MAX_COMPONENTS];
    1.56 +
    1.57 +  /* These arrays save pixel expansion factors so that int_expand need not
    1.58 +   * recompute them each time.  They are unused for other upsampling methods.
    1.59 +   */
    1.60 +  UINT8 h_expand[MAX_COMPONENTS];
    1.61 +  UINT8 v_expand[MAX_COMPONENTS];
    1.62 +} my_upsampler;
    1.63 +
    1.64 +typedef my_upsampler * my_upsample_ptr;
    1.65 +
    1.66 +
    1.67 +/*
    1.68 + * Initialize for an upsampling pass.
    1.69 + */
    1.70 +
    1.71 +METHODDEF(void)
    1.72 +start_pass_upsample (j_decompress_ptr cinfo)
    1.73 +{
    1.74 +  my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
    1.75 +
    1.76 +  /* Mark the conversion buffer empty */
    1.77 +  upsample->next_row_out = cinfo->max_v_samp_factor;
    1.78 +  /* Initialize total-height counter for detecting bottom of image */
    1.79 +  upsample->rows_to_go = cinfo->output_height;
    1.80 +}
    1.81 +
    1.82 +
    1.83 +/*
    1.84 + * Control routine to do upsampling (and color conversion).
    1.85 + *
    1.86 + * In this version we upsample each component independently.
    1.87 + * We upsample one row group into the conversion buffer, then apply
    1.88 + * color conversion a row at a time.
    1.89 + */
    1.90 +
    1.91 +METHODDEF(void)
    1.92 +sep_upsample (j_decompress_ptr cinfo,
    1.93 +	      JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
    1.94 +	      JDIMENSION in_row_groups_avail,
    1.95 +	      JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
    1.96 +	      JDIMENSION out_rows_avail)
    1.97 +{
    1.98 +  my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
    1.99 +  int ci;
   1.100 +  jpeg_component_info * compptr;
   1.101 +  JDIMENSION num_rows;
   1.102 +
   1.103 +  /* Fill the conversion buffer, if it's empty */
   1.104 +  if (upsample->next_row_out >= cinfo->max_v_samp_factor) {
   1.105 +    for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
   1.106 +	 ci++, compptr++) {
   1.107 +      /* Invoke per-component upsample method.  Notice we pass a POINTER
   1.108 +       * to color_buf[ci], so that fullsize_upsample can change it.
   1.109 +       */
   1.110 +      (*upsample->methods[ci]) (cinfo, compptr,
   1.111 +	input_buf[ci] + (*in_row_group_ctr * upsample->rowgroup_height[ci]),
   1.112 +	upsample->color_buf + ci);
   1.113 +    }
   1.114 +    upsample->next_row_out = 0;
   1.115 +  }
   1.116 +
   1.117 +  /* Color-convert and emit rows */
   1.118 +
   1.119 +  /* How many we have in the buffer: */
   1.120 +  num_rows = (JDIMENSION) (cinfo->max_v_samp_factor - upsample->next_row_out);
   1.121 +  /* Not more than the distance to the end of the image.  Need this test
   1.122 +   * in case the image height is not a multiple of max_v_samp_factor:
   1.123 +   */
   1.124 +  if (num_rows > upsample->rows_to_go) 
   1.125 +    num_rows = upsample->rows_to_go;
   1.126 +  /* And not more than what the client can accept: */
   1.127 +  out_rows_avail -= *out_row_ctr;
   1.128 +  if (num_rows > out_rows_avail)
   1.129 +    num_rows = out_rows_avail;
   1.130 +
   1.131 +  (*cinfo->cconvert->color_convert) (cinfo, upsample->color_buf,
   1.132 +				     (JDIMENSION) upsample->next_row_out,
   1.133 +				     output_buf + *out_row_ctr,
   1.134 +				     (int) num_rows);
   1.135 +
   1.136 +  /* Adjust counts */
   1.137 +  *out_row_ctr += num_rows;
   1.138 +  upsample->rows_to_go -= num_rows;
   1.139 +  upsample->next_row_out += num_rows;
   1.140 +  /* When the buffer is emptied, declare this input row group consumed */
   1.141 +  if (upsample->next_row_out >= cinfo->max_v_samp_factor)
   1.142 +    (*in_row_group_ctr)++;
   1.143 +}
   1.144 +
   1.145 +
   1.146 +/*
   1.147 + * These are the routines invoked by sep_upsample to upsample pixel values
   1.148 + * of a single component.  One row group is processed per call.
   1.149 + */
   1.150 +
   1.151 +
   1.152 +/*
   1.153 + * For full-size components, we just make color_buf[ci] point at the
   1.154 + * input buffer, and thus avoid copying any data.  Note that this is
   1.155 + * safe only because sep_upsample doesn't declare the input row group
   1.156 + * "consumed" until we are done color converting and emitting it.
   1.157 + */
   1.158 +
   1.159 +METHODDEF(void)
   1.160 +fullsize_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
   1.161 +		   JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
   1.162 +{
   1.163 +  *output_data_ptr = input_data;
   1.164 +}
   1.165 +
   1.166 +
   1.167 +/*
   1.168 + * This is a no-op version used for "uninteresting" components.
   1.169 + * These components will not be referenced by color conversion.
   1.170 + */
   1.171 +
   1.172 +METHODDEF(void)
   1.173 +noop_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
   1.174 +	       JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
   1.175 +{
   1.176 +  *output_data_ptr = NULL;	/* safety check */
   1.177 +}
   1.178 +
   1.179 +
   1.180 +/*
   1.181 + * This version handles any integral sampling ratios.
   1.182 + * This is not used for typical JPEG files, so it need not be fast.
   1.183 + * Nor, for that matter, is it particularly accurate: the algorithm is
   1.184 + * simple replication of the input pixel onto the corresponding output
   1.185 + * pixels.  The hi-falutin sampling literature refers to this as a
   1.186 + * "box filter".  A box filter tends to introduce visible artifacts,
   1.187 + * so if you are actually going to use 3:1 or 4:1 sampling ratios
   1.188 + * you would be well advised to improve this code.
   1.189 + */
   1.190 +
   1.191 +METHODDEF(void)
   1.192 +int_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
   1.193 +	      JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
   1.194 +{
   1.195 +  my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
   1.196 +  JSAMPARRAY output_data = *output_data_ptr;
   1.197 +  register JSAMPROW inptr, outptr;
   1.198 +  register JSAMPLE invalue;
   1.199 +  register int h;
   1.200 +  JSAMPROW outend;
   1.201 +  int h_expand, v_expand;
   1.202 +  int inrow, outrow;
   1.203 +
   1.204 +  h_expand = upsample->h_expand[compptr->component_index];
   1.205 +  v_expand = upsample->v_expand[compptr->component_index];
   1.206 +
   1.207 +  inrow = outrow = 0;
   1.208 +  while (outrow < cinfo->max_v_samp_factor) {
   1.209 +    /* Generate one output row with proper horizontal expansion */
   1.210 +    inptr = input_data[inrow];
   1.211 +    outptr = output_data[outrow];
   1.212 +    outend = outptr + cinfo->output_width;
   1.213 +    while (outptr < outend) {
   1.214 +      invalue = *inptr++;	/* don't need GETJSAMPLE() here */
   1.215 +      for (h = h_expand; h > 0; h--) {
   1.216 +	*outptr++ = invalue;
   1.217 +      }
   1.218 +    }
   1.219 +    /* Generate any additional output rows by duplicating the first one */
   1.220 +    if (v_expand > 1) {
   1.221 +      jcopy_sample_rows(output_data, outrow, output_data, outrow+1,
   1.222 +			v_expand-1, cinfo->output_width);
   1.223 +    }
   1.224 +    inrow++;
   1.225 +    outrow += v_expand;
   1.226 +  }
   1.227 +}
   1.228 +
   1.229 +
   1.230 +/*
   1.231 + * Fast processing for the common case of 2:1 horizontal and 1:1 vertical.
   1.232 + * It's still a box filter.
   1.233 + */
   1.234 +
   1.235 +METHODDEF(void)
   1.236 +h2v1_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
   1.237 +	       JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
   1.238 +{
   1.239 +  JSAMPARRAY output_data = *output_data_ptr;
   1.240 +  register JSAMPROW inptr, outptr;
   1.241 +  register JSAMPLE invalue;
   1.242 +  JSAMPROW outend;
   1.243 +  int inrow;
   1.244 +
   1.245 +  for (inrow = 0; inrow < cinfo->max_v_samp_factor; inrow++) {
   1.246 +    inptr = input_data[inrow];
   1.247 +    outptr = output_data[inrow];
   1.248 +    outend = outptr + cinfo->output_width;
   1.249 +    while (outptr < outend) {
   1.250 +      invalue = *inptr++;	/* don't need GETJSAMPLE() here */
   1.251 +      *outptr++ = invalue;
   1.252 +      *outptr++ = invalue;
   1.253 +    }
   1.254 +  }
   1.255 +}
   1.256 +
   1.257 +
   1.258 +/*
   1.259 + * Fast processing for the common case of 2:1 horizontal and 2:1 vertical.
   1.260 + * It's still a box filter.
   1.261 + */
   1.262 +
   1.263 +METHODDEF(void)
   1.264 +h2v2_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
   1.265 +	       JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
   1.266 +{
   1.267 +  JSAMPARRAY output_data = *output_data_ptr;
   1.268 +  register JSAMPROW inptr, outptr;
   1.269 +  register JSAMPLE invalue;
   1.270 +  JSAMPROW outend;
   1.271 +  int inrow, outrow;
   1.272 +
   1.273 +  inrow = outrow = 0;
   1.274 +  while (outrow < cinfo->max_v_samp_factor) {
   1.275 +    inptr = input_data[inrow];
   1.276 +    outptr = output_data[outrow];
   1.277 +    outend = outptr + cinfo->output_width;
   1.278 +    while (outptr < outend) {
   1.279 +      invalue = *inptr++;	/* don't need GETJSAMPLE() here */
   1.280 +      *outptr++ = invalue;
   1.281 +      *outptr++ = invalue;
   1.282 +    }
   1.283 +    jcopy_sample_rows(output_data, outrow, output_data, outrow+1,
   1.284 +		      1, cinfo->output_width);
   1.285 +    inrow++;
   1.286 +    outrow += 2;
   1.287 +  }
   1.288 +}
   1.289 +
   1.290 +
   1.291 +/*
   1.292 + * Fancy processing for the common case of 2:1 horizontal and 1:1 vertical.
   1.293 + *
   1.294 + * The upsampling algorithm is linear interpolation between pixel centers,
   1.295 + * also known as a "triangle filter".  This is a good compromise between
   1.296 + * speed and visual quality.  The centers of the output pixels are 1/4 and 3/4
   1.297 + * of the way between input pixel centers.
   1.298 + *
   1.299 + * A note about the "bias" calculations: when rounding fractional values to
   1.300 + * integer, we do not want to always round 0.5 up to the next integer.
   1.301 + * If we did that, we'd introduce a noticeable bias towards larger values.
   1.302 + * Instead, this code is arranged so that 0.5 will be rounded up or down at
   1.303 + * alternate pixel locations (a simple ordered dither pattern).
   1.304 + */
   1.305 +
   1.306 +METHODDEF(void)
   1.307 +h2v1_fancy_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
   1.308 +		     JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
   1.309 +{
   1.310 +  JSAMPARRAY output_data = *output_data_ptr;
   1.311 +  register JSAMPROW inptr, outptr;
   1.312 +  register int invalue;
   1.313 +  register JDIMENSION colctr;
   1.314 +  int inrow;
   1.315 +
   1.316 +  for (inrow = 0; inrow < cinfo->max_v_samp_factor; inrow++) {
   1.317 +    inptr = input_data[inrow];
   1.318 +    outptr = output_data[inrow];
   1.319 +    /* Special case for first column */
   1.320 +    invalue = GETJSAMPLE(*inptr++);
   1.321 +    *outptr++ = (JSAMPLE) invalue;
   1.322 +    *outptr++ = (JSAMPLE) ((invalue * 3 + GETJSAMPLE(*inptr) + 2) >> 2);
   1.323 +
   1.324 +    for (colctr = compptr->downsampled_width - 2; colctr > 0; colctr--) {
   1.325 +      /* General case: 3/4 * nearer pixel + 1/4 * further pixel */
   1.326 +      invalue = GETJSAMPLE(*inptr++) * 3;
   1.327 +      *outptr++ = (JSAMPLE) ((invalue + GETJSAMPLE(inptr[-2]) + 1) >> 2);
   1.328 +      *outptr++ = (JSAMPLE) ((invalue + GETJSAMPLE(*inptr) + 2) >> 2);
   1.329 +    }
   1.330 +
   1.331 +    /* Special case for last column */
   1.332 +    invalue = GETJSAMPLE(*inptr);
   1.333 +    *outptr++ = (JSAMPLE) ((invalue * 3 + GETJSAMPLE(inptr[-1]) + 1) >> 2);
   1.334 +    *outptr++ = (JSAMPLE) invalue;
   1.335 +  }
   1.336 +}
   1.337 +
   1.338 +
   1.339 +/*
   1.340 + * Fancy processing for the common case of 2:1 horizontal and 2:1 vertical.
   1.341 + * Again a triangle filter; see comments for h2v1 case, above.
   1.342 + *
   1.343 + * It is OK for us to reference the adjacent input rows because we demanded
   1.344 + * context from the main buffer controller (see initialization code).
   1.345 + */
   1.346 +
   1.347 +METHODDEF(void)
   1.348 +h2v2_fancy_upsample (j_decompress_ptr cinfo, jpeg_component_info * compptr,
   1.349 +		     JSAMPARRAY input_data, JSAMPARRAY * output_data_ptr)
   1.350 +{
   1.351 +  JSAMPARRAY output_data = *output_data_ptr;
   1.352 +  register JSAMPROW inptr0, inptr1, outptr;
   1.353 +#if BITS_IN_JSAMPLE == 8
   1.354 +  register int thiscolsum, lastcolsum, nextcolsum;
   1.355 +#else
   1.356 +  register INT32 thiscolsum, lastcolsum, nextcolsum;
   1.357 +#endif
   1.358 +  register JDIMENSION colctr;
   1.359 +  int inrow, outrow, v;
   1.360 +
   1.361 +  inrow = outrow = 0;
   1.362 +  while (outrow < cinfo->max_v_samp_factor) {
   1.363 +    for (v = 0; v < 2; v++) {
   1.364 +      /* inptr0 points to nearest input row, inptr1 points to next nearest */
   1.365 +      inptr0 = input_data[inrow];
   1.366 +      if (v == 0)		/* next nearest is row above */
   1.367 +	inptr1 = input_data[inrow-1];
   1.368 +      else			/* next nearest is row below */
   1.369 +	inptr1 = input_data[inrow+1];
   1.370 +      outptr = output_data[outrow++];
   1.371 +
   1.372 +      /* Special case for first column */
   1.373 +      thiscolsum = GETJSAMPLE(*inptr0++) * 3 + GETJSAMPLE(*inptr1++);
   1.374 +      nextcolsum = GETJSAMPLE(*inptr0++) * 3 + GETJSAMPLE(*inptr1++);
   1.375 +      *outptr++ = (JSAMPLE) ((thiscolsum * 4 + 8) >> 4);
   1.376 +      *outptr++ = (JSAMPLE) ((thiscolsum * 3 + nextcolsum + 7) >> 4);
   1.377 +      lastcolsum = thiscolsum; thiscolsum = nextcolsum;
   1.378 +
   1.379 +      for (colctr = compptr->downsampled_width - 2; colctr > 0; colctr--) {
   1.380 +	/* General case: 3/4 * nearer pixel + 1/4 * further pixel in each */
   1.381 +	/* dimension, thus 9/16, 3/16, 3/16, 1/16 overall */
   1.382 +	nextcolsum = GETJSAMPLE(*inptr0++) * 3 + GETJSAMPLE(*inptr1++);
   1.383 +	*outptr++ = (JSAMPLE) ((thiscolsum * 3 + lastcolsum + 8) >> 4);
   1.384 +	*outptr++ = (JSAMPLE) ((thiscolsum * 3 + nextcolsum + 7) >> 4);
   1.385 +	lastcolsum = thiscolsum; thiscolsum = nextcolsum;
   1.386 +      }
   1.387 +
   1.388 +      /* Special case for last column */
   1.389 +      *outptr++ = (JSAMPLE) ((thiscolsum * 3 + lastcolsum + 8) >> 4);
   1.390 +      *outptr++ = (JSAMPLE) ((thiscolsum * 4 + 7) >> 4);
   1.391 +    }
   1.392 +    inrow++;
   1.393 +  }
   1.394 +}
   1.395 +
   1.396 +
   1.397 +/*
   1.398 + * Module initialization routine for upsampling.
   1.399 + */
   1.400 +
   1.401 +GLOBAL(void)
   1.402 +jinit_upsampler (j_decompress_ptr cinfo)
   1.403 +{
   1.404 +  my_upsample_ptr upsample;
   1.405 +  int ci;
   1.406 +  jpeg_component_info * compptr;
   1.407 +  boolean need_buffer, do_fancy;
   1.408 +  int h_in_group, v_in_group, h_out_group, v_out_group;
   1.409 +
   1.410 +  upsample = (my_upsample_ptr)
   1.411 +    (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
   1.412 +				SIZEOF(my_upsampler));
   1.413 +  cinfo->upsample = (struct jpeg_upsampler *) upsample;
   1.414 +  upsample->pub.start_pass = start_pass_upsample;
   1.415 +  upsample->pub.upsample = sep_upsample;
   1.416 +  upsample->pub.need_context_rows = FALSE; /* until we find out differently */
   1.417 +
   1.418 +  if (cinfo->CCIR601_sampling)	/* this isn't supported */
   1.419 +    ERREXIT(cinfo, JERR_CCIR601_NOTIMPL);
   1.420 +
   1.421 +  /* jdmainct.c doesn't support context rows when min_DCT_scaled_size = 1,
   1.422 +   * so don't ask for it.
   1.423 +   */
   1.424 +  do_fancy = cinfo->do_fancy_upsampling && cinfo->min_DCT_scaled_size > 1;
   1.425 +
   1.426 +  /* Verify we can handle the sampling factors, select per-component methods,
   1.427 +   * and create storage as needed.
   1.428 +   */
   1.429 +  for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
   1.430 +       ci++, compptr++) {
   1.431 +    /* Compute size of an "input group" after IDCT scaling.  This many samples
   1.432 +     * are to be converted to max_h_samp_factor * max_v_samp_factor pixels.
   1.433 +     */
   1.434 +    h_in_group = (compptr->h_samp_factor * compptr->DCT_scaled_size) /
   1.435 +		 cinfo->min_DCT_scaled_size;
   1.436 +    v_in_group = (compptr->v_samp_factor * compptr->DCT_scaled_size) /
   1.437 +		 cinfo->min_DCT_scaled_size;
   1.438 +    h_out_group = cinfo->max_h_samp_factor;
   1.439 +    v_out_group = cinfo->max_v_samp_factor;
   1.440 +    upsample->rowgroup_height[ci] = v_in_group; /* save for use later */
   1.441 +    need_buffer = TRUE;
   1.442 +    if (! compptr->component_needed) {
   1.443 +      /* Don't bother to upsample an uninteresting component. */
   1.444 +      upsample->methods[ci] = noop_upsample;
   1.445 +      need_buffer = FALSE;
   1.446 +    } else if (h_in_group == h_out_group && v_in_group == v_out_group) {
   1.447 +      /* Fullsize components can be processed without any work. */
   1.448 +      upsample->methods[ci] = fullsize_upsample;
   1.449 +      need_buffer = FALSE;
   1.450 +    } else if (h_in_group * 2 == h_out_group &&
   1.451 +	       v_in_group == v_out_group) {
   1.452 +      /* Special cases for 2h1v upsampling */
   1.453 +      if (do_fancy && compptr->downsampled_width > 2)
   1.454 +	upsample->methods[ci] = h2v1_fancy_upsample;
   1.455 +      else
   1.456 +	upsample->methods[ci] = h2v1_upsample;
   1.457 +    } else if (h_in_group * 2 == h_out_group &&
   1.458 +	       v_in_group * 2 == v_out_group) {
   1.459 +      /* Special cases for 2h2v upsampling */
   1.460 +      if (do_fancy && compptr->downsampled_width > 2) {
   1.461 +	upsample->methods[ci] = h2v2_fancy_upsample;
   1.462 +	upsample->pub.need_context_rows = TRUE;
   1.463 +      } else
   1.464 +	upsample->methods[ci] = h2v2_upsample;
   1.465 +    } else if ((h_out_group % h_in_group) == 0 &&
   1.466 +	       (v_out_group % v_in_group) == 0) {
   1.467 +      /* Generic integral-factors upsampling method */
   1.468 +      upsample->methods[ci] = int_upsample;
   1.469 +      upsample->h_expand[ci] = (UINT8) (h_out_group / h_in_group);
   1.470 +      upsample->v_expand[ci] = (UINT8) (v_out_group / v_in_group);
   1.471 +    } else
   1.472 +      ERREXIT(cinfo, JERR_FRACT_SAMPLE_NOTIMPL);
   1.473 +    if (need_buffer) {
   1.474 +      upsample->color_buf[ci] = (*cinfo->mem->alloc_sarray)
   1.475 +	((j_common_ptr) cinfo, JPOOL_IMAGE,
   1.476 +	 (JDIMENSION) jround_up((long) cinfo->output_width,
   1.477 +				(long) cinfo->max_h_samp_factor),
   1.478 +	 (JDIMENSION) cinfo->max_v_samp_factor);
   1.479 +    }
   1.480 +  }
   1.481 +}