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jdmerge.c (19979B)


      1 /*
      2 * jdmerge.c
      3 *
      4 * This file was part of the Independent JPEG Group's software:
      5 * Copyright (C) 1994-1996, Thomas G. Lane.
      6 * libjpeg-turbo Modifications:
      7 * Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
      8 * Copyright (C) 2009, 2011, 2014-2015, 2020, 2022, D. R. Commander.
      9 * Copyright (C) 2013, Linaro Limited.
     10 * For conditions of distribution and use, see the accompanying README.ijg
     11 * file.
     12 *
     13 * This file contains code for merged upsampling/color conversion.
     14 *
     15 * This file combines functions from jdsample.c and jdcolor.c;
     16 * read those files first to understand what's going on.
     17 *
     18 * When the chroma components are to be upsampled by simple replication
     19 * (ie, box filtering), we can save some work in color conversion by
     20 * calculating all the output pixels corresponding to a pair of chroma
     21 * samples at one time.  In the conversion equations
     22 *      R = Y           + K1 * Cr
     23 *      G = Y + K2 * Cb + K3 * Cr
     24 *      B = Y + K4 * Cb
     25 * only the Y term varies among the group of pixels corresponding to a pair
     26 * of chroma samples, so the rest of the terms can be calculated just once.
     27 * At typical sampling ratios, this eliminates half or three-quarters of the
     28 * multiplications needed for color conversion.
     29 *
     30 * This file currently provides implementations for the following cases:
     31 *      YCbCr => RGB color conversion only.
     32 *      Sampling ratios of 2h1v or 2h2v.
     33 *      No scaling needed at upsample time.
     34 *      Corner-aligned (non-CCIR601) sampling alignment.
     35 * Other special cases could be added, but in most applications these are
     36 * the only common cases.  (For uncommon cases we fall back on the more
     37 * general code in jdsample.c and jdcolor.c.)
     38 */
     39 
     40 #define JPEG_INTERNALS
     41 #include "jinclude.h"
     42 #include "jpeglib.h"
     43 #include "jdmerge.h"
     44 #include "jsimd.h"
     45 
     46 #ifdef UPSAMPLE_MERGING_SUPPORTED
     47 
     48 
     49 #define SCALEBITS       16      /* speediest right-shift on some machines */
     50 #define ONE_HALF        ((JLONG)1 << (SCALEBITS - 1))
     51 #define FIX(x)          ((JLONG)((x) * (1L << SCALEBITS) + 0.5))
     52 
     53 
     54 /* Include inline routines for colorspace extensions */
     55 
     56 #include "jdmrgext.c"
     57 #undef RGB_RED
     58 #undef RGB_GREEN
     59 #undef RGB_BLUE
     60 #undef RGB_PIXELSIZE
     61 
     62 #define RGB_RED  EXT_RGB_RED
     63 #define RGB_GREEN  EXT_RGB_GREEN
     64 #define RGB_BLUE  EXT_RGB_BLUE
     65 #define RGB_PIXELSIZE  EXT_RGB_PIXELSIZE
     66 #define h2v1_merged_upsample_internal  extrgb_h2v1_merged_upsample_internal
     67 #define h2v2_merged_upsample_internal  extrgb_h2v2_merged_upsample_internal
     68 #include "jdmrgext.c"
     69 #undef RGB_RED
     70 #undef RGB_GREEN
     71 #undef RGB_BLUE
     72 #undef RGB_PIXELSIZE
     73 #undef h2v1_merged_upsample_internal
     74 #undef h2v2_merged_upsample_internal
     75 
     76 #define RGB_RED  EXT_RGBX_RED
     77 #define RGB_GREEN  EXT_RGBX_GREEN
     78 #define RGB_BLUE  EXT_RGBX_BLUE
     79 #define RGB_ALPHA  3
     80 #define RGB_PIXELSIZE  EXT_RGBX_PIXELSIZE
     81 #define h2v1_merged_upsample_internal  extrgbx_h2v1_merged_upsample_internal
     82 #define h2v2_merged_upsample_internal  extrgbx_h2v2_merged_upsample_internal
     83 #include "jdmrgext.c"
     84 #undef RGB_RED
     85 #undef RGB_GREEN
     86 #undef RGB_BLUE
     87 #undef RGB_ALPHA
     88 #undef RGB_PIXELSIZE
     89 #undef h2v1_merged_upsample_internal
     90 #undef h2v2_merged_upsample_internal
     91 
     92 #define RGB_RED  EXT_BGR_RED
     93 #define RGB_GREEN  EXT_BGR_GREEN
     94 #define RGB_BLUE  EXT_BGR_BLUE
     95 #define RGB_PIXELSIZE  EXT_BGR_PIXELSIZE
     96 #define h2v1_merged_upsample_internal  extbgr_h2v1_merged_upsample_internal
     97 #define h2v2_merged_upsample_internal  extbgr_h2v2_merged_upsample_internal
     98 #include "jdmrgext.c"
     99 #undef RGB_RED
    100 #undef RGB_GREEN
    101 #undef RGB_BLUE
    102 #undef RGB_PIXELSIZE
    103 #undef h2v1_merged_upsample_internal
    104 #undef h2v2_merged_upsample_internal
    105 
    106 #define RGB_RED  EXT_BGRX_RED
    107 #define RGB_GREEN  EXT_BGRX_GREEN
    108 #define RGB_BLUE  EXT_BGRX_BLUE
    109 #define RGB_ALPHA  3
    110 #define RGB_PIXELSIZE  EXT_BGRX_PIXELSIZE
    111 #define h2v1_merged_upsample_internal  extbgrx_h2v1_merged_upsample_internal
    112 #define h2v2_merged_upsample_internal  extbgrx_h2v2_merged_upsample_internal
    113 #include "jdmrgext.c"
    114 #undef RGB_RED
    115 #undef RGB_GREEN
    116 #undef RGB_BLUE
    117 #undef RGB_ALPHA
    118 #undef RGB_PIXELSIZE
    119 #undef h2v1_merged_upsample_internal
    120 #undef h2v2_merged_upsample_internal
    121 
    122 #define RGB_RED  EXT_XBGR_RED
    123 #define RGB_GREEN  EXT_XBGR_GREEN
    124 #define RGB_BLUE  EXT_XBGR_BLUE
    125 #define RGB_ALPHA  0
    126 #define RGB_PIXELSIZE  EXT_XBGR_PIXELSIZE
    127 #define h2v1_merged_upsample_internal  extxbgr_h2v1_merged_upsample_internal
    128 #define h2v2_merged_upsample_internal  extxbgr_h2v2_merged_upsample_internal
    129 #include "jdmrgext.c"
    130 #undef RGB_RED
    131 #undef RGB_GREEN
    132 #undef RGB_BLUE
    133 #undef RGB_ALPHA
    134 #undef RGB_PIXELSIZE
    135 #undef h2v1_merged_upsample_internal
    136 #undef h2v2_merged_upsample_internal
    137 
    138 #define RGB_RED  EXT_XRGB_RED
    139 #define RGB_GREEN  EXT_XRGB_GREEN
    140 #define RGB_BLUE  EXT_XRGB_BLUE
    141 #define RGB_ALPHA  0
    142 #define RGB_PIXELSIZE  EXT_XRGB_PIXELSIZE
    143 #define h2v1_merged_upsample_internal  extxrgb_h2v1_merged_upsample_internal
    144 #define h2v2_merged_upsample_internal  extxrgb_h2v2_merged_upsample_internal
    145 #include "jdmrgext.c"
    146 #undef RGB_RED
    147 #undef RGB_GREEN
    148 #undef RGB_BLUE
    149 #undef RGB_ALPHA
    150 #undef RGB_PIXELSIZE
    151 #undef h2v1_merged_upsample_internal
    152 #undef h2v2_merged_upsample_internal
    153 
    154 
    155 /*
    156 * Initialize tables for YCC->RGB colorspace conversion.
    157 * This is taken directly from jdcolor.c; see that file for more info.
    158 */
    159 
    160 LOCAL(void)
    161 build_ycc_rgb_table(j_decompress_ptr cinfo)
    162 {
    163  my_merged_upsample_ptr upsample = (my_merged_upsample_ptr)cinfo->upsample;
    164  int i;
    165  JLONG x;
    166  SHIFT_TEMPS
    167 
    168  upsample->Cr_r_tab = (int *)
    169    (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
    170                                (_MAXJSAMPLE + 1) * sizeof(int));
    171  upsample->Cb_b_tab = (int *)
    172    (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
    173                                (_MAXJSAMPLE + 1) * sizeof(int));
    174  upsample->Cr_g_tab = (JLONG *)
    175    (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
    176                                (_MAXJSAMPLE + 1) * sizeof(JLONG));
    177  upsample->Cb_g_tab = (JLONG *)
    178    (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
    179                                (_MAXJSAMPLE + 1) * sizeof(JLONG));
    180 
    181  for (i = 0, x = -_CENTERJSAMPLE; i <= _MAXJSAMPLE; i++, x++) {
    182    /* i is the actual input pixel value, in the range 0.._MAXJSAMPLE */
    183    /* The Cb or Cr value we are thinking of is x = i - _CENTERJSAMPLE */
    184    /* Cr=>R value is nearest int to 1.40200 * x */
    185    upsample->Cr_r_tab[i] = (int)
    186                    RIGHT_SHIFT(FIX(1.40200) * x + ONE_HALF, SCALEBITS);
    187    /* Cb=>B value is nearest int to 1.77200 * x */
    188    upsample->Cb_b_tab[i] = (int)
    189                    RIGHT_SHIFT(FIX(1.77200) * x + ONE_HALF, SCALEBITS);
    190    /* Cr=>G value is scaled-up -0.71414 * x */
    191    upsample->Cr_g_tab[i] = (-FIX(0.71414)) * x;
    192    /* Cb=>G value is scaled-up -0.34414 * x */
    193    /* We also add in ONE_HALF so that need not do it in inner loop */
    194    upsample->Cb_g_tab[i] = (-FIX(0.34414)) * x + ONE_HALF;
    195  }
    196 }
    197 
    198 
    199 /*
    200 * Initialize for an upsampling pass.
    201 */
    202 
    203 METHODDEF(void)
    204 start_pass_merged_upsample(j_decompress_ptr cinfo)
    205 {
    206  my_merged_upsample_ptr upsample = (my_merged_upsample_ptr)cinfo->upsample;
    207 
    208  /* Mark the spare buffer empty */
    209  upsample->spare_full = FALSE;
    210  /* Initialize total-height counter for detecting bottom of image */
    211  upsample->rows_to_go = cinfo->output_height;
    212 }
    213 
    214 
    215 /*
    216 * Control routine to do upsampling (and color conversion).
    217 *
    218 * The control routine just handles the row buffering considerations.
    219 */
    220 
    221 METHODDEF(void)
    222 merged_2v_upsample(j_decompress_ptr cinfo, _JSAMPIMAGE input_buf,
    223                   JDIMENSION *in_row_group_ctr,
    224                   JDIMENSION in_row_groups_avail, _JSAMPARRAY output_buf,
    225                   JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail)
    226 /* 2:1 vertical sampling case: may need a spare row. */
    227 {
    228  my_merged_upsample_ptr upsample = (my_merged_upsample_ptr)cinfo->upsample;
    229  _JSAMPROW work_ptrs[2];
    230  JDIMENSION num_rows;          /* number of rows returned to caller */
    231 
    232  if (upsample->spare_full) {
    233    /* If we have a spare row saved from a previous cycle, just return it. */
    234    JDIMENSION size = upsample->out_row_width;
    235    if (cinfo->out_color_space == JCS_RGB565)
    236      size = cinfo->output_width * 2;
    237    _jcopy_sample_rows(&upsample->spare_row, 0, output_buf + *out_row_ctr, 0,
    238                       1, size);
    239    num_rows = 1;
    240    upsample->spare_full = FALSE;
    241  } else {
    242    /* Figure number of rows to return to caller. */
    243    num_rows = 2;
    244    /* Not more than the distance to the end of the image. */
    245    if (num_rows > upsample->rows_to_go)
    246      num_rows = upsample->rows_to_go;
    247    /* And not more than what the client can accept: */
    248    out_rows_avail -= *out_row_ctr;
    249    if (num_rows > out_rows_avail)
    250      num_rows = out_rows_avail;
    251    /* Create output pointer array for upsampler. */
    252    work_ptrs[0] = output_buf[*out_row_ctr];
    253    if (num_rows > 1) {
    254      work_ptrs[1] = output_buf[*out_row_ctr + 1];
    255    } else {
    256      work_ptrs[1] = upsample->spare_row;
    257      upsample->spare_full = TRUE;
    258    }
    259    /* Now do the upsampling. */
    260    (*upsample->upmethod) (cinfo, input_buf, *in_row_group_ctr, work_ptrs);
    261  }
    262 
    263  /* Adjust counts */
    264  *out_row_ctr += num_rows;
    265  upsample->rows_to_go -= num_rows;
    266  /* When the buffer is emptied, declare this input row group consumed */
    267  if (!upsample->spare_full)
    268    (*in_row_group_ctr)++;
    269 }
    270 
    271 
    272 METHODDEF(void)
    273 merged_1v_upsample(j_decompress_ptr cinfo, _JSAMPIMAGE input_buf,
    274                   JDIMENSION *in_row_group_ctr,
    275                   JDIMENSION in_row_groups_avail, _JSAMPARRAY output_buf,
    276                   JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail)
    277 /* 1:1 vertical sampling case: much easier, never need a spare row. */
    278 {
    279  my_merged_upsample_ptr upsample = (my_merged_upsample_ptr)cinfo->upsample;
    280 
    281  /* Just do the upsampling. */
    282  (*upsample->upmethod) (cinfo, input_buf, *in_row_group_ctr,
    283                         output_buf + *out_row_ctr);
    284  /* Adjust counts */
    285  (*out_row_ctr)++;
    286  (*in_row_group_ctr)++;
    287 }
    288 
    289 
    290 /*
    291 * These are the routines invoked by the control routines to do
    292 * the actual upsampling/conversion.  One row group is processed per call.
    293 *
    294 * Note: since we may be writing directly into application-supplied buffers,
    295 * we have to be honest about the output width; we can't assume the buffer
    296 * has been rounded up to an even width.
    297 */
    298 
    299 
    300 /*
    301 * Upsample and color convert for the case of 2:1 horizontal and 1:1 vertical.
    302 */
    303 
    304 METHODDEF(void)
    305 h2v1_merged_upsample(j_decompress_ptr cinfo, _JSAMPIMAGE input_buf,
    306                     JDIMENSION in_row_group_ctr, _JSAMPARRAY output_buf)
    307 {
    308  switch (cinfo->out_color_space) {
    309  case JCS_EXT_RGB:
    310    extrgb_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    311                                         output_buf);
    312    break;
    313  case JCS_EXT_RGBX:
    314  case JCS_EXT_RGBA:
    315    extrgbx_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    316                                          output_buf);
    317    break;
    318  case JCS_EXT_BGR:
    319    extbgr_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    320                                         output_buf);
    321    break;
    322  case JCS_EXT_BGRX:
    323  case JCS_EXT_BGRA:
    324    extbgrx_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    325                                          output_buf);
    326    break;
    327  case JCS_EXT_XBGR:
    328  case JCS_EXT_ABGR:
    329    extxbgr_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    330                                          output_buf);
    331    break;
    332  case JCS_EXT_XRGB:
    333  case JCS_EXT_ARGB:
    334    extxrgb_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    335                                          output_buf);
    336    break;
    337  default:
    338    h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    339                                  output_buf);
    340    break;
    341  }
    342 }
    343 
    344 
    345 /*
    346 * Upsample and color convert for the case of 2:1 horizontal and 2:1 vertical.
    347 */
    348 
    349 METHODDEF(void)
    350 h2v2_merged_upsample(j_decompress_ptr cinfo, _JSAMPIMAGE input_buf,
    351                     JDIMENSION in_row_group_ctr, _JSAMPARRAY output_buf)
    352 {
    353  switch (cinfo->out_color_space) {
    354  case JCS_EXT_RGB:
    355    extrgb_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    356                                         output_buf);
    357    break;
    358  case JCS_EXT_RGBX:
    359  case JCS_EXT_RGBA:
    360    extrgbx_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    361                                          output_buf);
    362    break;
    363  case JCS_EXT_BGR:
    364    extbgr_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    365                                         output_buf);
    366    break;
    367  case JCS_EXT_BGRX:
    368  case JCS_EXT_BGRA:
    369    extbgrx_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    370                                          output_buf);
    371    break;
    372  case JCS_EXT_XBGR:
    373  case JCS_EXT_ABGR:
    374    extxbgr_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    375                                          output_buf);
    376    break;
    377  case JCS_EXT_XRGB:
    378  case JCS_EXT_ARGB:
    379    extxrgb_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    380                                          output_buf);
    381    break;
    382  default:
    383    h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    384                                  output_buf);
    385    break;
    386  }
    387 }
    388 
    389 
    390 /*
    391 * RGB565 conversion
    392 */
    393 
    394 #define PACK_SHORT_565_LE(r, g, b) \
    395  ((((r) << 8) & 0xF800) | (((g) << 3) & 0x7E0) | ((b) >> 3))
    396 #define PACK_SHORT_565_BE(r, g, b) \
    397  (((r) & 0xF8) | ((g) >> 5) | (((g) << 11) & 0xE000) | (((b) << 5) & 0x1F00))
    398 
    399 #define PACK_TWO_PIXELS_LE(l, r)    ((r << 16) | l)
    400 #define PACK_TWO_PIXELS_BE(l, r)    ((l << 16) | r)
    401 
    402 #define WRITE_TWO_PIXELS_LE(addr, pixels) { \
    403  ((INT16 *)(addr))[0] = (INT16)(pixels); \
    404  ((INT16 *)(addr))[1] = (INT16)((pixels) >> 16); \
    405 }
    406 #define WRITE_TWO_PIXELS_BE(addr, pixels) { \
    407  ((INT16 *)(addr))[1] = (INT16)(pixels); \
    408  ((INT16 *)(addr))[0] = (INT16)((pixels) >> 16); \
    409 }
    410 
    411 #define DITHER_565_R(r, dither)  ((r) + ((dither) & 0xFF))
    412 #define DITHER_565_G(g, dither)  ((g) + (((dither) & 0xFF) >> 1))
    413 #define DITHER_565_B(b, dither)  ((b) + ((dither) & 0xFF))
    414 
    415 
    416 /* Declarations for ordered dithering
    417 *
    418 * We use a 4x4 ordered dither array packed into 32 bits.  This array is
    419 * sufficient for dithering RGB888 to RGB565.
    420 */
    421 
    422 #define DITHER_MASK       0x3
    423 #define DITHER_ROTATE(x)  ((((x) & 0xFF) << 24) | (((x) >> 8) & 0x00FFFFFF))
    424 static const JLONG dither_matrix[4] = {
    425  0x0008020A,
    426  0x0C040E06,
    427  0x030B0109,
    428  0x0F070D05
    429 };
    430 
    431 
    432 /* Include inline routines for RGB565 conversion */
    433 
    434 #define PACK_SHORT_565  PACK_SHORT_565_LE
    435 #define PACK_TWO_PIXELS  PACK_TWO_PIXELS_LE
    436 #define WRITE_TWO_PIXELS  WRITE_TWO_PIXELS_LE
    437 #define h2v1_merged_upsample_565_internal  h2v1_merged_upsample_565_le
    438 #define h2v1_merged_upsample_565D_internal  h2v1_merged_upsample_565D_le
    439 #define h2v2_merged_upsample_565_internal  h2v2_merged_upsample_565_le
    440 #define h2v2_merged_upsample_565D_internal  h2v2_merged_upsample_565D_le
    441 #include "jdmrg565.c"
    442 #undef PACK_SHORT_565
    443 #undef PACK_TWO_PIXELS
    444 #undef WRITE_TWO_PIXELS
    445 #undef h2v1_merged_upsample_565_internal
    446 #undef h2v1_merged_upsample_565D_internal
    447 #undef h2v2_merged_upsample_565_internal
    448 #undef h2v2_merged_upsample_565D_internal
    449 
    450 #define PACK_SHORT_565  PACK_SHORT_565_BE
    451 #define PACK_TWO_PIXELS  PACK_TWO_PIXELS_BE
    452 #define WRITE_TWO_PIXELS  WRITE_TWO_PIXELS_BE
    453 #define h2v1_merged_upsample_565_internal  h2v1_merged_upsample_565_be
    454 #define h2v1_merged_upsample_565D_internal  h2v1_merged_upsample_565D_be
    455 #define h2v2_merged_upsample_565_internal  h2v2_merged_upsample_565_be
    456 #define h2v2_merged_upsample_565D_internal  h2v2_merged_upsample_565D_be
    457 #include "jdmrg565.c"
    458 #undef PACK_SHORT_565
    459 #undef PACK_TWO_PIXELS
    460 #undef WRITE_TWO_PIXELS
    461 #undef h2v1_merged_upsample_565_internal
    462 #undef h2v1_merged_upsample_565D_internal
    463 #undef h2v2_merged_upsample_565_internal
    464 #undef h2v2_merged_upsample_565D_internal
    465 
    466 
    467 static INLINE boolean is_big_endian(void)
    468 {
    469  int test_value = 1;
    470  if (*(char *)&test_value != 1)
    471    return TRUE;
    472  return FALSE;
    473 }
    474 
    475 
    476 METHODDEF(void)
    477 h2v1_merged_upsample_565(j_decompress_ptr cinfo, _JSAMPIMAGE input_buf,
    478                         JDIMENSION in_row_group_ctr, _JSAMPARRAY output_buf)
    479 {
    480  if (is_big_endian())
    481    h2v1_merged_upsample_565_be(cinfo, input_buf, in_row_group_ctr,
    482                                output_buf);
    483  else
    484    h2v1_merged_upsample_565_le(cinfo, input_buf, in_row_group_ctr,
    485                                output_buf);
    486 }
    487 
    488 
    489 METHODDEF(void)
    490 h2v1_merged_upsample_565D(j_decompress_ptr cinfo, _JSAMPIMAGE input_buf,
    491                          JDIMENSION in_row_group_ctr, _JSAMPARRAY output_buf)
    492 {
    493  if (is_big_endian())
    494    h2v1_merged_upsample_565D_be(cinfo, input_buf, in_row_group_ctr,
    495                                 output_buf);
    496  else
    497    h2v1_merged_upsample_565D_le(cinfo, input_buf, in_row_group_ctr,
    498                                 output_buf);
    499 }
    500 
    501 
    502 METHODDEF(void)
    503 h2v2_merged_upsample_565(j_decompress_ptr cinfo, _JSAMPIMAGE input_buf,
    504                         JDIMENSION in_row_group_ctr, _JSAMPARRAY output_buf)
    505 {
    506  if (is_big_endian())
    507    h2v2_merged_upsample_565_be(cinfo, input_buf, in_row_group_ctr,
    508                                output_buf);
    509  else
    510    h2v2_merged_upsample_565_le(cinfo, input_buf, in_row_group_ctr,
    511                                output_buf);
    512 }
    513 
    514 
    515 METHODDEF(void)
    516 h2v2_merged_upsample_565D(j_decompress_ptr cinfo, _JSAMPIMAGE input_buf,
    517                          JDIMENSION in_row_group_ctr, _JSAMPARRAY output_buf)
    518 {
    519  if (is_big_endian())
    520    h2v2_merged_upsample_565D_be(cinfo, input_buf, in_row_group_ctr,
    521                                 output_buf);
    522  else
    523    h2v2_merged_upsample_565D_le(cinfo, input_buf, in_row_group_ctr,
    524                                 output_buf);
    525 }
    526 
    527 
    528 /*
    529 * Module initialization routine for merged upsampling/color conversion.
    530 *
    531 * NB: this is called under the conditions determined by use_merged_upsample()
    532 * in jdmaster.c.  That routine MUST correspond to the actual capabilities
    533 * of this module; no safety checks are made here.
    534 */
    535 
    536 GLOBAL(void)
    537 _jinit_merged_upsampler(j_decompress_ptr cinfo)
    538 {
    539  my_merged_upsample_ptr upsample;
    540 
    541  if (cinfo->data_precision != BITS_IN_JSAMPLE)
    542    ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
    543 
    544  upsample = (my_merged_upsample_ptr)
    545    (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
    546                                sizeof(my_merged_upsampler));
    547  cinfo->upsample = (struct jpeg_upsampler *)upsample;
    548  upsample->pub.start_pass = start_pass_merged_upsample;
    549  upsample->pub.need_context_rows = FALSE;
    550 
    551  upsample->out_row_width = cinfo->output_width * cinfo->out_color_components;
    552 
    553  if (cinfo->max_v_samp_factor == 2) {
    554    upsample->pub._upsample = merged_2v_upsample;
    555 #ifdef WITH_SIMD
    556    if (jsimd_can_h2v2_merged_upsample())
    557      upsample->upmethod = jsimd_h2v2_merged_upsample;
    558    else
    559 #endif
    560      upsample->upmethod = h2v2_merged_upsample;
    561    if (cinfo->out_color_space == JCS_RGB565) {
    562      if (cinfo->dither_mode != JDITHER_NONE) {
    563        upsample->upmethod = h2v2_merged_upsample_565D;
    564      } else {
    565        upsample->upmethod = h2v2_merged_upsample_565;
    566      }
    567    }
    568    /* Allocate a spare row buffer */
    569    upsample->spare_row = (_JSAMPROW)
    570      (*cinfo->mem->alloc_large) ((j_common_ptr)cinfo, JPOOL_IMAGE,
    571                (size_t)(upsample->out_row_width * sizeof(_JSAMPLE)));
    572  } else {
    573    upsample->pub._upsample = merged_1v_upsample;
    574 #ifdef WITH_SIMD
    575    if (jsimd_can_h2v1_merged_upsample())
    576      upsample->upmethod = jsimd_h2v1_merged_upsample;
    577    else
    578 #endif
    579      upsample->upmethod = h2v1_merged_upsample;
    580    if (cinfo->out_color_space == JCS_RGB565) {
    581      if (cinfo->dither_mode != JDITHER_NONE) {
    582        upsample->upmethod = h2v1_merged_upsample_565D;
    583      } else {
    584        upsample->upmethod = h2v1_merged_upsample_565;
    585      }
    586    }
    587    /* No spare row needed */
    588    upsample->spare_row = NULL;
    589  }
    590 
    591  build_ycc_rgb_table(cinfo);
    592 }
    593 
    594 #endif /* UPSAMPLE_MERGING_SUPPORTED */