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      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  * Copyright 2009 Pierre Ossman <ossman (at) cendio.se> for Cendio AB
      7  * libjpeg-turbo Modifications:
      8  * Copyright (C) 2009, 2011, 2014 D. R. Commander.
      9  * Copyright (C) 2013, Linaro Limited.
     10  * For conditions of distribution and use, see the accompanying README file.
     11  *
     12  * This file contains code for merged upsampling/color conversion.
     13  *
     14  * This file combines functions from jdsample.c and jdcolor.c;
     15  * read those files first to understand what's going on.
     16  *
     17  * When the chroma components are to be upsampled by simple replication
     18  * (ie, box filtering), we can save some work in color conversion by
     19  * calculating all the output pixels corresponding to a pair of chroma
     20  * samples at one time.  In the conversion equations
     21  *      R = Y           + K1 * Cr
     22  *      G = Y + K2 * Cb + K3 * Cr
     23  *      B = Y + K4 * Cb
     24  * only the Y term varies among the group of pixels corresponding to a pair
     25  * of chroma samples, so the rest of the terms can be calculated just once.
     26  * At typical sampling ratios, this eliminates half or three-quarters of the
     27  * multiplications needed for color conversion.
     28  *
     29  * This file currently provides implementations for the following cases:
     30  *      YCbCr => RGB color conversion only.
     31  *      Sampling ratios of 2h1v or 2h2v.
     32  *      No scaling needed at upsample time.
     33  *      Corner-aligned (non-CCIR601) sampling alignment.
     34  * Other special cases could be added, but in most applications these are
     35  * the only common cases.  (For uncommon cases we fall back on the more
     36  * general code in jdsample.c and jdcolor.c.)
     37  */
     38 
     39 #define JPEG_INTERNALS
     40 #include "jinclude.h"
     41 #include "jpeglib.h"
     42 #include "jsimd.h"
     43 #include "jconfigint.h"
     44 
     45 #ifdef UPSAMPLE_MERGING_SUPPORTED
     46 
     47 
     48 /* Private subobject */
     49 
     50 typedef struct {
     51   struct jpeg_upsampler pub;    /* public fields */
     52 
     53   /* Pointer to routine to do actual upsampling/conversion of one row group */
     54   void (*upmethod) (j_decompress_ptr cinfo, JSAMPIMAGE input_buf,
     55                     JDIMENSION in_row_group_ctr, JSAMPARRAY output_buf);
     56 
     57   /* Private state for YCC->RGB conversion */
     58   int * Cr_r_tab;               /* => table for Cr to R conversion */
     59   int * Cb_b_tab;               /* => table for Cb to B conversion */
     60   INT32 * Cr_g_tab;             /* => table for Cr to G conversion */
     61   INT32 * Cb_g_tab;             /* => table for Cb to G conversion */
     62 
     63   /* For 2:1 vertical sampling, we produce two output rows at a time.
     64    * We need a "spare" row buffer to hold the second output row if the
     65    * application provides just a one-row buffer; we also use the spare
     66    * to discard the dummy last row if the image height is odd.
     67    */
     68   JSAMPROW spare_row;
     69   boolean spare_full;           /* T if spare buffer is occupied */
     70 
     71   JDIMENSION out_row_width;     /* samples per output row */
     72   JDIMENSION rows_to_go;        /* counts rows remaining in image */
     73 } my_upsampler;
     74 
     75 typedef my_upsampler * my_upsample_ptr;
     76 
     77 #define SCALEBITS       16      /* speediest right-shift on some machines */
     78 #define ONE_HALF        ((INT32) 1 << (SCALEBITS-1))
     79 #define FIX(x)          ((INT32) ((x) * (1L<<SCALEBITS) + 0.5))
     80 
     81 
     82 /* Include inline routines for colorspace extensions */
     83 
     84 #include "jdmrgext.c"
     85 #undef RGB_RED
     86 #undef RGB_GREEN
     87 #undef RGB_BLUE
     88 #undef RGB_PIXELSIZE
     89 
     90 #define RGB_RED EXT_RGB_RED
     91 #define RGB_GREEN EXT_RGB_GREEN
     92 #define RGB_BLUE EXT_RGB_BLUE
     93 #define RGB_PIXELSIZE EXT_RGB_PIXELSIZE
     94 #define h2v1_merged_upsample_internal extrgb_h2v1_merged_upsample_internal
     95 #define h2v2_merged_upsample_internal extrgb_h2v2_merged_upsample_internal
     96 #include "jdmrgext.c"
     97 #undef RGB_RED
     98 #undef RGB_GREEN
     99 #undef RGB_BLUE
    100 #undef RGB_PIXELSIZE
    101 #undef h2v1_merged_upsample_internal
    102 #undef h2v2_merged_upsample_internal
    103 
    104 #define RGB_RED EXT_RGBX_RED
    105 #define RGB_GREEN EXT_RGBX_GREEN
    106 #define RGB_BLUE EXT_RGBX_BLUE
    107 #define RGB_ALPHA 3
    108 #define RGB_PIXELSIZE EXT_RGBX_PIXELSIZE
    109 #define h2v1_merged_upsample_internal extrgbx_h2v1_merged_upsample_internal
    110 #define h2v2_merged_upsample_internal extrgbx_h2v2_merged_upsample_internal
    111 #include "jdmrgext.c"
    112 #undef RGB_RED
    113 #undef RGB_GREEN
    114 #undef RGB_BLUE
    115 #undef RGB_ALPHA
    116 #undef RGB_PIXELSIZE
    117 #undef h2v1_merged_upsample_internal
    118 #undef h2v2_merged_upsample_internal
    119 
    120 #define RGB_RED EXT_BGR_RED
    121 #define RGB_GREEN EXT_BGR_GREEN
    122 #define RGB_BLUE EXT_BGR_BLUE
    123 #define RGB_PIXELSIZE EXT_BGR_PIXELSIZE
    124 #define h2v1_merged_upsample_internal extbgr_h2v1_merged_upsample_internal
    125 #define h2v2_merged_upsample_internal extbgr_h2v2_merged_upsample_internal
    126 #include "jdmrgext.c"
    127 #undef RGB_RED
    128 #undef RGB_GREEN
    129 #undef RGB_BLUE
    130 #undef RGB_PIXELSIZE
    131 #undef h2v1_merged_upsample_internal
    132 #undef h2v2_merged_upsample_internal
    133 
    134 #define RGB_RED EXT_BGRX_RED
    135 #define RGB_GREEN EXT_BGRX_GREEN
    136 #define RGB_BLUE EXT_BGRX_BLUE
    137 #define RGB_ALPHA 3
    138 #define RGB_PIXELSIZE EXT_BGRX_PIXELSIZE
    139 #define h2v1_merged_upsample_internal extbgrx_h2v1_merged_upsample_internal
    140 #define h2v2_merged_upsample_internal extbgrx_h2v2_merged_upsample_internal
    141 #include "jdmrgext.c"
    142 #undef RGB_RED
    143 #undef RGB_GREEN
    144 #undef RGB_BLUE
    145 #undef RGB_ALPHA
    146 #undef RGB_PIXELSIZE
    147 #undef h2v1_merged_upsample_internal
    148 #undef h2v2_merged_upsample_internal
    149 
    150 #define RGB_RED EXT_XBGR_RED
    151 #define RGB_GREEN EXT_XBGR_GREEN
    152 #define RGB_BLUE EXT_XBGR_BLUE
    153 #define RGB_ALPHA 0
    154 #define RGB_PIXELSIZE EXT_XBGR_PIXELSIZE
    155 #define h2v1_merged_upsample_internal extxbgr_h2v1_merged_upsample_internal
    156 #define h2v2_merged_upsample_internal extxbgr_h2v2_merged_upsample_internal
    157 #include "jdmrgext.c"
    158 #undef RGB_RED
    159 #undef RGB_GREEN
    160 #undef RGB_BLUE
    161 #undef RGB_ALPHA
    162 #undef RGB_PIXELSIZE
    163 #undef h2v1_merged_upsample_internal
    164 #undef h2v2_merged_upsample_internal
    165 
    166 #define RGB_RED EXT_XRGB_RED
    167 #define RGB_GREEN EXT_XRGB_GREEN
    168 #define RGB_BLUE EXT_XRGB_BLUE
    169 #define RGB_ALPHA 0
    170 #define RGB_PIXELSIZE EXT_XRGB_PIXELSIZE
    171 #define h2v1_merged_upsample_internal extxrgb_h2v1_merged_upsample_internal
    172 #define h2v2_merged_upsample_internal extxrgb_h2v2_merged_upsample_internal
    173 #include "jdmrgext.c"
    174 #undef RGB_RED
    175 #undef RGB_GREEN
    176 #undef RGB_BLUE
    177 #undef RGB_ALPHA
    178 #undef RGB_PIXELSIZE
    179 #undef h2v1_merged_upsample_internal
    180 #undef h2v2_merged_upsample_internal
    181 
    182 
    183 /*
    184  * Initialize tables for YCC->RGB colorspace conversion.
    185  * This is taken directly from jdcolor.c; see that file for more info.
    186  */
    187 
    188 LOCAL(void)
    189 build_ycc_rgb_table (j_decompress_ptr cinfo)
    190 {
    191   my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
    192   int i;
    193   INT32 x;
    194   SHIFT_TEMPS
    195 
    196   upsample->Cr_r_tab = (int *)
    197     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
    198                                 (MAXJSAMPLE+1) * sizeof(int));
    199   upsample->Cb_b_tab = (int *)
    200     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
    201                                 (MAXJSAMPLE+1) * sizeof(int));
    202   upsample->Cr_g_tab = (INT32 *)
    203     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
    204                                 (MAXJSAMPLE+1) * sizeof(INT32));
    205   upsample->Cb_g_tab = (INT32 *)
    206     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
    207                                 (MAXJSAMPLE+1) * sizeof(INT32));
    208 
    209   for (i = 0, x = -CENTERJSAMPLE; i <= MAXJSAMPLE; i++, x++) {
    210     /* i is the actual input pixel value, in the range 0..MAXJSAMPLE */
    211     /* The Cb or Cr value we are thinking of is x = i - CENTERJSAMPLE */
    212     /* Cr=>R value is nearest int to 1.40200 * x */
    213     upsample->Cr_r_tab[i] = (int)
    214                     RIGHT_SHIFT(FIX(1.40200) * x + ONE_HALF, SCALEBITS);
    215     /* Cb=>B value is nearest int to 1.77200 * x */
    216     upsample->Cb_b_tab[i] = (int)
    217                     RIGHT_SHIFT(FIX(1.77200) * x + ONE_HALF, SCALEBITS);
    218     /* Cr=>G value is scaled-up -0.71414 * x */
    219     upsample->Cr_g_tab[i] = (- FIX(0.71414)) * x;
    220     /* Cb=>G value is scaled-up -0.34414 * x */
    221     /* We also add in ONE_HALF so that need not do it in inner loop */
    222     upsample->Cb_g_tab[i] = (- FIX(0.34414)) * x + ONE_HALF;
    223   }
    224 }
    225 
    226 
    227 /*
    228  * Initialize for an upsampling pass.
    229  */
    230 
    231 METHODDEF(void)
    232 start_pass_merged_upsample (j_decompress_ptr cinfo)
    233 {
    234   my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
    235 
    236   /* Mark the spare buffer empty */
    237   upsample->spare_full = FALSE;
    238   /* Initialize total-height counter for detecting bottom of image */
    239   upsample->rows_to_go = cinfo->output_height;
    240 }
    241 
    242 
    243 /*
    244  * Control routine to do upsampling (and color conversion).
    245  *
    246  * The control routine just handles the row buffering considerations.
    247  */
    248 
    249 METHODDEF(void)
    250 merged_2v_upsample (j_decompress_ptr cinfo,
    251                     JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
    252                     JDIMENSION in_row_groups_avail,
    253                     JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
    254                     JDIMENSION out_rows_avail)
    255 /* 2:1 vertical sampling case: may need a spare row. */
    256 {
    257   my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
    258   JSAMPROW work_ptrs[2];
    259   JDIMENSION num_rows;          /* number of rows returned to caller */
    260 
    261   if (upsample->spare_full) {
    262     /* If we have a spare row saved from a previous cycle, just return it. */
    263     JDIMENSION size = upsample->out_row_width;
    264     if (cinfo->out_color_space == JCS_RGB565)
    265       size = cinfo->output_width * 2;
    266     jcopy_sample_rows(& upsample->spare_row, 0, output_buf + *out_row_ctr, 0,
    267                       1, size);
    268     num_rows = 1;
    269     upsample->spare_full = FALSE;
    270   } else {
    271     /* Figure number of rows to return to caller. */
    272     num_rows = 2;
    273     /* Not more than the distance to the end of the image. */
    274     if (num_rows > upsample->rows_to_go)
    275       num_rows = upsample->rows_to_go;
    276     /* And not more than what the client can accept: */
    277     out_rows_avail -= *out_row_ctr;
    278     if (num_rows > out_rows_avail)
    279       num_rows = out_rows_avail;
    280     /* Create output pointer array for upsampler. */
    281     work_ptrs[0] = output_buf[*out_row_ctr];
    282     if (num_rows > 1) {
    283       work_ptrs[1] = output_buf[*out_row_ctr + 1];
    284     } else {
    285       work_ptrs[1] = upsample->spare_row;
    286       upsample->spare_full = TRUE;
    287     }
    288     /* Now do the upsampling. */
    289     (*upsample->upmethod) (cinfo, input_buf, *in_row_group_ctr, work_ptrs);
    290   }
    291 
    292   /* Adjust counts */
    293   *out_row_ctr += num_rows;
    294   upsample->rows_to_go -= num_rows;
    295   /* When the buffer is emptied, declare this input row group consumed */
    296   if (! upsample->spare_full)
    297     (*in_row_group_ctr)++;
    298 }
    299 
    300 
    301 METHODDEF(void)
    302 merged_1v_upsample (j_decompress_ptr cinfo,
    303                     JSAMPIMAGE input_buf, JDIMENSION *in_row_group_ctr,
    304                     JDIMENSION in_row_groups_avail,
    305                     JSAMPARRAY output_buf, JDIMENSION *out_row_ctr,
    306                     JDIMENSION out_rows_avail)
    307 /* 1:1 vertical sampling case: much easier, never need a spare row. */
    308 {
    309   my_upsample_ptr upsample = (my_upsample_ptr) cinfo->upsample;
    310 
    311   /* Just do the upsampling. */
    312   (*upsample->upmethod) (cinfo, input_buf, *in_row_group_ctr,
    313                          output_buf + *out_row_ctr);
    314   /* Adjust counts */
    315   (*out_row_ctr)++;
    316   (*in_row_group_ctr)++;
    317 }
    318 
    319 
    320 /*
    321  * These are the routines invoked by the control routines to do
    322  * the actual upsampling/conversion.  One row group is processed per call.
    323  *
    324  * Note: since we may be writing directly into application-supplied buffers,
    325  * we have to be honest about the output width; we can't assume the buffer
    326  * has been rounded up to an even width.
    327  */
    328 
    329 
    330 /*
    331  * Upsample and color convert for the case of 2:1 horizontal and 1:1 vertical.
    332  */
    333 
    334 METHODDEF(void)
    335 h2v1_merged_upsample (j_decompress_ptr cinfo,
    336                       JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
    337                       JSAMPARRAY output_buf)
    338 {
    339   switch (cinfo->out_color_space) {
    340     case JCS_EXT_RGB:
    341       extrgb_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    342                                            output_buf);
    343       break;
    344     case JCS_EXT_RGBX:
    345     case JCS_EXT_RGBA:
    346       extrgbx_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    347                                             output_buf);
    348       break;
    349     case JCS_EXT_BGR:
    350       extbgr_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    351                                            output_buf);
    352       break;
    353     case JCS_EXT_BGRX:
    354     case JCS_EXT_BGRA:
    355       extbgrx_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    356                                             output_buf);
    357       break;
    358     case JCS_EXT_XBGR:
    359     case JCS_EXT_ABGR:
    360       extxbgr_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    361                                             output_buf);
    362       break;
    363     case JCS_EXT_XRGB:
    364     case JCS_EXT_ARGB:
    365       extxrgb_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    366                                             output_buf);
    367       break;
    368     default:
    369       h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    370                                     output_buf);
    371       break;
    372   }
    373 }
    374 
    375 
    376 /*
    377  * Upsample and color convert for the case of 2:1 horizontal and 2:1 vertical.
    378  */
    379 
    380 METHODDEF(void)
    381 h2v2_merged_upsample (j_decompress_ptr cinfo,
    382                       JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
    383                       JSAMPARRAY output_buf)
    384 {
    385   switch (cinfo->out_color_space) {
    386     case JCS_EXT_RGB:
    387       extrgb_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    388                                            output_buf);
    389       break;
    390     case JCS_EXT_RGBX:
    391     case JCS_EXT_RGBA:
    392       extrgbx_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    393                                             output_buf);
    394       break;
    395     case JCS_EXT_BGR:
    396       extbgr_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    397                                            output_buf);
    398       break;
    399     case JCS_EXT_BGRX:
    400     case JCS_EXT_BGRA:
    401       extbgrx_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    402                                             output_buf);
    403       break;
    404     case JCS_EXT_XBGR:
    405     case JCS_EXT_ABGR:
    406       extxbgr_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    407                                             output_buf);
    408       break;
    409     case JCS_EXT_XRGB:
    410     case JCS_EXT_ARGB:
    411       extxrgb_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    412                                             output_buf);
    413       break;
    414     default:
    415       h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,
    416                                     output_buf);
    417       break;
    418   }
    419 }
    420 
    421 
    422 /*
    423  * RGB565 conversion
    424  */
    425 
    426 #define PACK_SHORT_565_LE(r, g, b)   ((((r) << 8) & 0xF800) |  \
    427                                       (((g) << 3) & 0x7E0) | ((b) >> 3))
    428 #define PACK_SHORT_565_BE(r, g, b)   (((r) & 0xF8) | ((g) >> 5) |  \
    429                                       (((g) << 11) & 0xE000) |  \
    430                                       (((b) << 5) & 0x1F00))
    431 
    432 #define PACK_TWO_PIXELS_LE(l, r)     ((r << 16) | l)
    433 #define PACK_TWO_PIXELS_BE(l, r)     ((l << 16) | r)
    434 
    435 #define PACK_NEED_ALIGNMENT(ptr)  (((size_t)(ptr)) & 3)
    436 
    437 #define WRITE_TWO_PIXELS_LE(addr, pixels) {  \
    438   ((INT16*)(addr))[0] = (pixels);  \
    439   ((INT16*)(addr))[1] = (pixels) >> 16;  \
    440 }
    441 #define WRITE_TWO_PIXELS_BE(addr, pixels) {  \
    442   ((INT16*)(addr))[1] = (pixels);  \
    443   ((INT16*)(addr))[0] = (pixels) >> 16;  \
    444 }
    445 
    446 #define DITHER_565_R(r, dither)  ((r) + ((dither) & 0xFF))
    447 #define DITHER_565_G(g, dither)  ((g) + (((dither) & 0xFF) >> 1))
    448 #define DITHER_565_B(b, dither)  ((b) + ((dither) & 0xFF))
    449 
    450 
    451 /* Declarations for ordered dithering
    452  *
    453  * We use a 4x4 ordered dither array packed into 32 bits.  This array is
    454  * sufficent for dithering RGB888 to RGB565.
    455  */
    456 
    457 #define DITHER_MASK       0x3
    458 #define DITHER_ROTATE(x)  (((x) << 24) | (((x) >> 8) & 0x00FFFFFF))
    459 static const INT32 dither_matrix[4] = {
    460   0x0008020A,
    461   0x0C040E06,
    462   0x030B0109,
    463   0x0F070D05
    464 };
    465 
    466 
    467 /* Include inline routines for RGB565 conversion */
    468 
    469 #define PACK_SHORT_565 PACK_SHORT_565_LE
    470 #define PACK_TWO_PIXELS PACK_TWO_PIXELS_LE
    471 #define WRITE_TWO_PIXELS WRITE_TWO_PIXELS_LE
    472 #define h2v1_merged_upsample_565_internal h2v1_merged_upsample_565_le
    473 #define h2v1_merged_upsample_565D_internal h2v1_merged_upsample_565D_le
    474 #define h2v2_merged_upsample_565_internal h2v2_merged_upsample_565_le
    475 #define h2v2_merged_upsample_565D_internal h2v2_merged_upsample_565D_le
    476 #include "jdmrg565.c"
    477 #undef PACK_SHORT_565
    478 #undef PACK_TWO_PIXELS
    479 #undef WRITE_TWO_PIXELS
    480 #undef h2v1_merged_upsample_565_internal
    481 #undef h2v1_merged_upsample_565D_internal
    482 #undef h2v2_merged_upsample_565_internal
    483 #undef h2v2_merged_upsample_565D_internal
    484 
    485 #define PACK_SHORT_565 PACK_SHORT_565_BE
    486 #define PACK_TWO_PIXELS PACK_TWO_PIXELS_BE
    487 #define WRITE_TWO_PIXELS WRITE_TWO_PIXELS_BE
    488 #define h2v1_merged_upsample_565_internal h2v1_merged_upsample_565_be
    489 #define h2v1_merged_upsample_565D_internal h2v1_merged_upsample_565D_be
    490 #define h2v2_merged_upsample_565_internal h2v2_merged_upsample_565_be
    491 #define h2v2_merged_upsample_565D_internal h2v2_merged_upsample_565D_be
    492 #include "jdmrg565.c"
    493 #undef PACK_SHORT_565
    494 #undef PACK_TWO_PIXELS
    495 #undef WRITE_TWO_PIXELS
    496 #undef h2v1_merged_upsample_565_internal
    497 #undef h2v1_merged_upsample_565D_internal
    498 #undef h2v2_merged_upsample_565_internal
    499 #undef h2v2_merged_upsample_565D_internal
    500 
    501 
    502 static INLINE boolean is_big_endian(void)
    503 {
    504   int test_value = 1;
    505   if(*(char *)&test_value != 1)
    506     return TRUE;
    507   return FALSE;
    508 }
    509 
    510 
    511 METHODDEF(void)
    512 h2v1_merged_upsample_565 (j_decompress_ptr cinfo,
    513                           JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
    514                           JSAMPARRAY output_buf)
    515 {
    516   if (is_big_endian())
    517     h2v1_merged_upsample_565_be(cinfo, input_buf, in_row_group_ctr,
    518                                 output_buf);
    519   else
    520     h2v1_merged_upsample_565_le(cinfo, input_buf, in_row_group_ctr,
    521                                 output_buf);
    522  }
    523 
    524 
    525 METHODDEF(void)
    526 h2v1_merged_upsample_565D (j_decompress_ptr cinfo,
    527                            JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
    528                            JSAMPARRAY output_buf)
    529 {
    530   if (is_big_endian())
    531     h2v1_merged_upsample_565D_be(cinfo, input_buf, in_row_group_ctr,
    532                                  output_buf);
    533   else
    534     h2v1_merged_upsample_565D_le(cinfo, input_buf, in_row_group_ctr,
    535                                  output_buf);
    536 }
    537 
    538 
    539 METHODDEF(void)
    540 h2v2_merged_upsample_565 (j_decompress_ptr cinfo,
    541                           JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
    542                           JSAMPARRAY output_buf)
    543 {
    544   if (is_big_endian())
    545     h2v2_merged_upsample_565_be(cinfo, input_buf, in_row_group_ctr,
    546                                 output_buf);
    547   else
    548     h2v2_merged_upsample_565_le(cinfo, input_buf, in_row_group_ctr,
    549                                 output_buf);
    550 }
    551 
    552 
    553 METHODDEF(void)
    554 h2v2_merged_upsample_565D (j_decompress_ptr cinfo,
    555                            JSAMPIMAGE input_buf, JDIMENSION in_row_group_ctr,
    556                            JSAMPARRAY output_buf)
    557 {
    558   if (is_big_endian())
    559     h2v2_merged_upsample_565D_be(cinfo, input_buf, in_row_group_ctr,
    560                                  output_buf);
    561   else
    562     h2v2_merged_upsample_565D_le(cinfo, input_buf, in_row_group_ctr,
    563                                  output_buf);
    564 }
    565 
    566 
    567 /*
    568  * Module initialization routine for merged upsampling/color conversion.
    569  *
    570  * NB: this is called under the conditions determined by use_merged_upsample()
    571  * in jdmaster.c.  That routine MUST correspond to the actual capabilities
    572  * of this module; no safety checks are made here.
    573  */
    574 
    575 GLOBAL(void)
    576 jinit_merged_upsampler (j_decompress_ptr cinfo)
    577 {
    578   my_upsample_ptr upsample;
    579 
    580   upsample = (my_upsample_ptr)
    581     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
    582                                 sizeof(my_upsampler));
    583   cinfo->upsample = (struct jpeg_upsampler *) upsample;
    584   upsample->pub.start_pass = start_pass_merged_upsample;
    585   upsample->pub.need_context_rows = FALSE;
    586 
    587   upsample->out_row_width = cinfo->output_width * cinfo->out_color_components;
    588 
    589   if (cinfo->max_v_samp_factor == 2) {
    590     upsample->pub.upsample = merged_2v_upsample;
    591     if (jsimd_can_h2v2_merged_upsample())
    592       upsample->upmethod = jsimd_h2v2_merged_upsample;
    593     else
    594       upsample->upmethod = h2v2_merged_upsample;
    595     if (cinfo->out_color_space == JCS_RGB565) {
    596       if (cinfo->dither_mode != JDITHER_NONE) {
    597         upsample->upmethod = h2v2_merged_upsample_565D;
    598       } else {
    599         upsample->upmethod = h2v2_merged_upsample_565;
    600       }
    601     }
    602     /* Allocate a spare row buffer */
    603     upsample->spare_row = (JSAMPROW)
    604       (*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
    605                 (size_t) (upsample->out_row_width * sizeof(JSAMPLE)));
    606   } else {
    607     upsample->pub.upsample = merged_1v_upsample;
    608     if (jsimd_can_h2v1_merged_upsample())
    609       upsample->upmethod = jsimd_h2v1_merged_upsample;
    610     else
    611       upsample->upmethod = h2v1_merged_upsample;
    612     if (cinfo->out_color_space == JCS_RGB565) {
    613       if (cinfo->dither_mode != JDITHER_NONE) {
    614         upsample->upmethod = h2v1_merged_upsample_565D;
    615       } else {
    616         upsample->upmethod = h2v1_merged_upsample_565;
    617       }
    618     }
    619     /* No spare row needed */
    620     upsample->spare_row = NULL;
    621   }
    622 
    623   build_ycc_rgb_table(cinfo);
    624 }
    625 
    626 #endif /* UPSAMPLE_MERGING_SUPPORTED */
    627