/*

 * jdmerge.c

 *

 * This file was part of the Independent JPEG Group's software:

 * Copyright (C) 1994-1996, Thomas G. Lane.

 * libjpeg-turbo Modifications:

 * Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB

 * Copyright (C) 2009, 2011, 2014-2015, 2020, D. R. Commander.

 * Copyright (C) 2013, Linaro Limited.

 * For conditions of distribution and use, see the accompanying README.ijg

 * file.

 *

 * This file contains code for merged upsampling/color conversion.

 *

 * This file combines functions from jdsample.c and jdcolor.c;

 * read those files first to understand what's going on.

 *

 * When the chroma components are to be upsampled by simple replication

 * (ie, box filtering), we can save some work in color conversion by

 * calculating all the output pixels corresponding to a pair of chroma

 * samples at one time.  In the conversion equations

 *      R = Y           + K1 * Cr

 *      G = Y + K2 * Cb + K3 * Cr

 *      B = Y + K4 * Cb

 * only the Y term varies among the group of pixels corresponding to a pair

 * of chroma samples, so the rest of the terms can be calculated just once.

 * At typical sampling ratios, this eliminates half or three-quarters of the

 * multiplications needed for color conversion.

 *

 * This file currently provides implementations for the following cases:

 *      YCbCr => RGB color conversion only.

 *      Sampling ratios of 2h1v or 2h2v.

 *      No scaling needed at upsample time.

 *      Corner-aligned (non-CCIR601) sampling alignment.

 * Other special cases could be added, but in most applications these are

 * the only common cases.  (For uncommon cases we fall back on the more

 * general code in jdsample.c and jdcolor.c.)

 */

#define JPEG_INTERNALS

#include "jinclude.h"

#include "jpeglib.h"

#include "jdmerge.h"

#include "jsimd.h"

#include "jconfigint.h"

#ifdef UPSAMPLE_MERGING_SUPPORTED

#define SCALEBITS       16      /* speediest right-shift on some machines */

#define ONE_HALF        ((JLONG)1 << (SCALEBITS - 1))

#define FIX(x)          ((JLONG)((x) * (1L << SCALEBITS) + 0.5))

/* Include inline routines for colorspace extensions */

#include "jdmrgext.c"

#undef RGB_RED

#undef RGB_GREEN

#undef RGB_BLUE

#undef RGB_PIXELSIZE

#define RGB_RED  EXT_RGB_RED

#define RGB_GREEN  EXT_RGB_GREEN

#define RGB_BLUE  EXT_RGB_BLUE

#define RGB_PIXELSIZE  EXT_RGB_PIXELSIZE

#define h2v1_merged_upsample_internal  extrgb_h2v1_merged_upsample_internal

#define h2v2_merged_upsample_internal  extrgb_h2v2_merged_upsample_internal

#include "jdmrgext.c"

#undef RGB_RED

#undef RGB_GREEN

#undef RGB_BLUE

#undef RGB_PIXELSIZE

#undef h2v1_merged_upsample_internal

#undef h2v2_merged_upsample_internal

#define RGB_RED  EXT_RGBX_RED

#define RGB_GREEN  EXT_RGBX_GREEN

#define RGB_BLUE  EXT_RGBX_BLUE

#define RGB_ALPHA  3

#define RGB_PIXELSIZE  EXT_RGBX_PIXELSIZE

#define h2v1_merged_upsample_internal  extrgbx_h2v1_merged_upsample_internal

#define h2v2_merged_upsample_internal  extrgbx_h2v2_merged_upsample_internal

#include "jdmrgext.c"

#undef RGB_RED

#undef RGB_GREEN

#undef RGB_BLUE

#undef RGB_ALPHA

#undef RGB_PIXELSIZE

#undef h2v1_merged_upsample_internal

#undef h2v2_merged_upsample_internal

#define RGB_RED  EXT_BGR_RED

#define RGB_GREEN  EXT_BGR_GREEN

#define RGB_BLUE  EXT_BGR_BLUE

#define RGB_PIXELSIZE  EXT_BGR_PIXELSIZE

#define h2v1_merged_upsample_internal  extbgr_h2v1_merged_upsample_internal

#define h2v2_merged_upsample_internal  extbgr_h2v2_merged_upsample_internal

#include "jdmrgext.c"

#undef RGB_RED

#undef RGB_GREEN

#undef RGB_BLUE

#undef RGB_PIXELSIZE

#undef h2v1_merged_upsample_internal

#undef h2v2_merged_upsample_internal

#define RGB_RED  EXT_BGRX_RED

#define RGB_GREEN  EXT_BGRX_GREEN

#define RGB_BLUE  EXT_BGRX_BLUE

#define RGB_ALPHA  3

#define RGB_PIXELSIZE  EXT_BGRX_PIXELSIZE

#define h2v1_merged_upsample_internal  extbgrx_h2v1_merged_upsample_internal

#define h2v2_merged_upsample_internal  extbgrx_h2v2_merged_upsample_internal

#include "jdmrgext.c"

#undef RGB_RED

#undef RGB_GREEN

#undef RGB_BLUE

#undef RGB_ALPHA

#undef RGB_PIXELSIZE

#undef h2v1_merged_upsample_internal

#undef h2v2_merged_upsample_internal

#define RGB_RED  EXT_XBGR_RED

#define RGB_GREEN  EXT_XBGR_GREEN

#define RGB_BLUE  EXT_XBGR_BLUE

#define RGB_ALPHA  0

#define RGB_PIXELSIZE  EXT_XBGR_PIXELSIZE

#define h2v1_merged_upsample_internal  extxbgr_h2v1_merged_upsample_internal

#define h2v2_merged_upsample_internal  extxbgr_h2v2_merged_upsample_internal

#include "jdmrgext.c"

#undef RGB_RED

#undef RGB_GREEN

#undef RGB_BLUE

#undef RGB_ALPHA

#undef RGB_PIXELSIZE

#undef h2v1_merged_upsample_internal

#undef h2v2_merged_upsample_internal

#define RGB_RED  EXT_XRGB_RED

#define RGB_GREEN  EXT_XRGB_GREEN

#define RGB_BLUE  EXT_XRGB_BLUE

#define RGB_ALPHA  0

#define RGB_PIXELSIZE  EXT_XRGB_PIXELSIZE

#define h2v1_merged_upsample_internal  extxrgb_h2v1_merged_upsample_internal

#define h2v2_merged_upsample_internal  extxrgb_h2v2_merged_upsample_internal

#include "jdmrgext.c"

#undef RGB_RED

#undef RGB_GREEN

#undef RGB_BLUE

#undef RGB_ALPHA

#undef RGB_PIXELSIZE

#undef h2v1_merged_upsample_internal

#undef h2v2_merged_upsample_internal

/*

 * Initialize tables for YCC->RGB colorspace conversion.

 * This is taken directly from jdcolor.c; see that file for more info.

 */

LOCAL(void)

build_ycc_rgb_table(j_decompress_ptr cinfo)

{

  my_merged_upsample_ptr upsample = (my_merged_upsample_ptr)cinfo->upsample;

  int i;

  JLONG x;

  SHIFT_TEMPS

  upsample->Cr_r_tab = (int *)

    (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,

                                (MAXJSAMPLE + 1) * sizeof(int));

  upsample->Cb_b_tab = (int *)

    (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,

                                (MAXJSAMPLE + 1) * sizeof(int));

  upsample->Cr_g_tab = (JLONG *)

    (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,

                                (MAXJSAMPLE + 1) * sizeof(JLONG));

  upsample->Cb_g_tab = (JLONG *)

    (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,

                                (MAXJSAMPLE + 1) * sizeof(JLONG));

  for (i = 0, x = -CENTERJSAMPLE; i <= MAXJSAMPLE; i++, x++) {

    /* i is the actual input pixel value, in the range 0..MAXJSAMPLE */

    /* The Cb or Cr value we are thinking of is x = i - CENTERJSAMPLE */

    /* Cr=>R value is nearest int to 1.40200 * x */

    upsample->Cr_r_tab[i] = (int)

                    RIGHT_SHIFT(FIX(1.40200) * x + ONE_HALF, SCALEBITS);

    /* Cb=>B value is nearest int to 1.77200 * x */

    upsample->Cb_b_tab[i] = (int)

                    RIGHT_SHIFT(FIX(1.77200) * x + ONE_HALF, SCALEBITS);

    /* Cr=>G value is scaled-up -0.71414 * x */

    upsample->Cr_g_tab[i] = (-FIX(0.71414)) * x;

    /* Cb=>G value is scaled-up -0.34414 * x */

    /* We also add in ONE_HALF so that need not do it in inner loop */

    upsample->Cb_g_tab[i] = (-FIX(0.34414)) * x + ONE_HALF;

  }

}

/*

 * Initialize for an upsampling pass.

 */

METHODDEF(void)

start_pass_merged_upsample(j_decompress_ptr cinfo)

{

  my_merged_upsample_ptr upsample = (my_merged_upsample_ptr)cinfo->upsample;

  /* Mark the spare buffer empty */

  upsample->spare_full = FALSE;

  /* Initialize total-height counter for detecting bottom of image */

  upsample->rows_to_go = cinfo->output_height;

}

/*

 * Control routine to do upsampling (and color conversion).

 *

 * The control routine just handles the row buffering considerations.

 */

METHODDEF(void)

merged_2v_upsample(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,

                   JDIMENSION *in_row_group_ctr,

                   JDIMENSION in_row_groups_avail, JSAMPARRAY output_buf,

                   JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail)

/* 2:1 vertical sampling case: may need a spare row. */

{

  my_merged_upsample_ptr upsample = (my_merged_upsample_ptr)cinfo->upsample;

  JSAMPROW work_ptrs[2];

  JDIMENSION num_rows;          /* number of rows returned to caller */

  if (upsample->spare_full) {

    /* If we have a spare row saved from a previous cycle, just return it. */

    JDIMENSION size = upsample->out_row_width;

    if (cinfo->out_color_space == JCS_RGB565)

      size = cinfo->output_width * 2;

    jcopy_sample_rows(&upsample->spare_row, 0, output_buf + *out_row_ctr, 0, 1,

                      size);

    num_rows = 1;

    upsample->spare_full = FALSE;

  } else {

    /* Figure number of rows to return to caller. */

    num_rows = 2;

    /* Not more than the distance to the end of the image. */

    if (num_rows > upsample->rows_to_go)

      num_rows = upsample->rows_to_go;

    /* And not more than what the client can accept: */

    out_rows_avail -= *out_row_ctr;

    if (num_rows > out_rows_avail)

      num_rows = out_rows_avail;

    /* Create output pointer array for upsampler. */

    work_ptrs[0] = output_buf[*out_row_ctr];

    if (num_rows > 1) {

      work_ptrs[1] = output_buf[*out_row_ctr + 1];

    } else {

      work_ptrs[1] = upsample->spare_row;

      upsample->spare_full = TRUE;

    }

    /* Now do the upsampling. */

    (*upsample->upmethod) (cinfo, input_buf, *in_row_group_ctr, work_ptrs);

  }

  /* Adjust counts */

  *out_row_ctr += num_rows;

  upsample->rows_to_go -= num_rows;

  /* When the buffer is emptied, declare this input row group consumed */

  if (!upsample->spare_full)

    (*in_row_group_ctr)++;

}

METHODDEF(void)

merged_1v_upsample(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,

                   JDIMENSION *in_row_group_ctr,

                   JDIMENSION in_row_groups_avail, JSAMPARRAY output_buf,

                   JDIMENSION *out_row_ctr, JDIMENSION out_rows_avail)

/* 1:1 vertical sampling case: much easier, never need a spare row. */

{

  my_merged_upsample_ptr upsample = (my_merged_upsample_ptr)cinfo->upsample;

  /* Just do the upsampling. */

  (*upsample->upmethod) (cinfo, input_buf, *in_row_group_ctr,

                         output_buf + *out_row_ctr);

  /* Adjust counts */

  (*out_row_ctr)++;

  (*in_row_group_ctr)++;

}

/*

 * These are the routines invoked by the control routines to do

 * the actual upsampling/conversion.  One row group is processed per call.

 *

 * Note: since we may be writing directly into application-supplied buffers,

 * we have to be honest about the output width; we can't assume the buffer

 * has been rounded up to an even width.

 */

/*

 * Upsample and color convert for the case of 2:1 horizontal and 1:1 vertical.

 */

METHODDEF(void)

h2v1_merged_upsample(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,

                     JDIMENSION in_row_group_ctr, JSAMPARRAY output_buf)

{

  switch (cinfo->out_color_space) {

  case JCS_EXT_RGB:

    extrgb_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,

                                         output_buf);

    break;

  case JCS_EXT_RGBX:

  case JCS_EXT_RGBA:

    extrgbx_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,

                                          output_buf);

    break;

  case JCS_EXT_BGR:

    extbgr_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,

                                         output_buf);

    break;

  case JCS_EXT_BGRX:

  case JCS_EXT_BGRA:

    extbgrx_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,

                                          output_buf);

    break;

  case JCS_EXT_XBGR:

  case JCS_EXT_ABGR:

    extxbgr_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,

                                          output_buf);

    break;

  case JCS_EXT_XRGB:

  case JCS_EXT_ARGB:

    extxrgb_h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,

                                          output_buf);

    break;

  default:

    h2v1_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,

                                  output_buf);

    break;

  }

}

/*

 * Upsample and color convert for the case of 2:1 horizontal and 2:1 vertical.

 */

METHODDEF(void)

h2v2_merged_upsample(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,

                     JDIMENSION in_row_group_ctr, JSAMPARRAY output_buf)

{

  switch (cinfo->out_color_space) {

  case JCS_EXT_RGB:

    extrgb_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,

                                         output_buf);

    break;

  case JCS_EXT_RGBX:

  case JCS_EXT_RGBA:

    extrgbx_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,

                                          output_buf);

    break;

  case JCS_EXT_BGR:

    extbgr_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,

                                         output_buf);

    break;

  case JCS_EXT_BGRX:

  case JCS_EXT_BGRA:

    extbgrx_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,

                                          output_buf);

    break;

  case JCS_EXT_XBGR:

  case JCS_EXT_ABGR:

    extxbgr_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,

                                          output_buf);

    break;

  case JCS_EXT_XRGB:

  case JCS_EXT_ARGB:

    extxrgb_h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,

                                          output_buf);

    break;

  default:

    h2v2_merged_upsample_internal(cinfo, input_buf, in_row_group_ctr,

                                  output_buf);

    break;

  }

}

/*

 * RGB565 conversion

 */

#define PACK_SHORT_565_LE(r, g, b) \

  ((((r) << 8) & 0xF800) | (((g) << 3) & 0x7E0) | ((b) >> 3))

#define PACK_SHORT_565_BE(r, g, b) \

  (((r) & 0xF8) | ((g) >> 5) | (((g) << 11) & 0xE000) | (((b) << 5) & 0x1F00))

#define PACK_TWO_PIXELS_LE(l, r)    ((r << 16) | l)

#define PACK_TWO_PIXELS_BE(l, r)    ((l << 16) | r)

#define WRITE_TWO_PIXELS_LE(addr, pixels) { \

  ((INT16 *)(addr))[0] = (INT16)(pixels); \

  ((INT16 *)(addr))[1] = (INT16)((pixels) >> 16); \

}

#define WRITE_TWO_PIXELS_BE(addr, pixels) { \

  ((INT16 *)(addr))[1] = (INT16)(pixels); \

  ((INT16 *)(addr))[0] = (INT16)((pixels) >> 16); \

}

#define DITHER_565_R(r, dither)  ((r) + ((dither) & 0xFF))

#define DITHER_565_G(g, dither)  ((g) + (((dither) & 0xFF) >> 1))

#define DITHER_565_B(b, dither)  ((b) + ((dither) & 0xFF))

/* Declarations for ordered dithering

 *

 * We use a 4x4 ordered dither array packed into 32 bits.  This array is

 * sufficient for dithering RGB888 to RGB565.

 */

#define DITHER_MASK       0x3

#define DITHER_ROTATE(x)  ((((x) & 0xFF) << 24) | (((x) >> 8) & 0x00FFFFFF))

static const JLONG dither_matrix[4] = {

  0x0008020A,

  0x0C040E06,

  0x030B0109,

  0x0F070D05

};

/* Include inline routines for RGB565 conversion */

#define PACK_SHORT_565  PACK_SHORT_565_LE

#define PACK_TWO_PIXELS  PACK_TWO_PIXELS_LE

#define WRITE_TWO_PIXELS  WRITE_TWO_PIXELS_LE

#define h2v1_merged_upsample_565_internal  h2v1_merged_upsample_565_le

#define h2v1_merged_upsample_565D_internal  h2v1_merged_upsample_565D_le

#define h2v2_merged_upsample_565_internal  h2v2_merged_upsample_565_le

#define h2v2_merged_upsample_565D_internal  h2v2_merged_upsample_565D_le

#include "jdmrg565.c"

#undef PACK_SHORT_565

#undef PACK_TWO_PIXELS

#undef WRITE_TWO_PIXELS

#undef h2v1_merged_upsample_565_internal

#undef h2v1_merged_upsample_565D_internal

#undef h2v2_merged_upsample_565_internal

#undef h2v2_merged_upsample_565D_internal

#define PACK_SHORT_565  PACK_SHORT_565_BE

#define PACK_TWO_PIXELS  PACK_TWO_PIXELS_BE

#define WRITE_TWO_PIXELS  WRITE_TWO_PIXELS_BE

#define h2v1_merged_upsample_565_internal  h2v1_merged_upsample_565_be

#define h2v1_merged_upsample_565D_internal  h2v1_merged_upsample_565D_be

#define h2v2_merged_upsample_565_internal  h2v2_merged_upsample_565_be

#define h2v2_merged_upsample_565D_internal  h2v2_merged_upsample_565D_be

#include "jdmrg565.c"

#undef PACK_SHORT_565

#undef PACK_TWO_PIXELS

#undef WRITE_TWO_PIXELS

#undef h2v1_merged_upsample_565_internal

#undef h2v1_merged_upsample_565D_internal

#undef h2v2_merged_upsample_565_internal

#undef h2v2_merged_upsample_565D_internal

static INLINE boolean is_big_endian(void)

{

  int test_value = 1;

  if (*(char *)&test_value != 1)

    return TRUE;

  return FALSE;

}

METHODDEF(void)

h2v1_merged_upsample_565(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,

                         JDIMENSION in_row_group_ctr, JSAMPARRAY output_buf)

{

  if (is_big_endian())

    h2v1_merged_upsample_565_be(cinfo, input_buf, in_row_group_ctr,

                                output_buf);

  else

    h2v1_merged_upsample_565_le(cinfo, input_buf, in_row_group_ctr,

                                output_buf);

}

METHODDEF(void)

h2v1_merged_upsample_565D(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,

                          JDIMENSION in_row_group_ctr, JSAMPARRAY output_buf)

{

  if (is_big_endian())

    h2v1_merged_upsample_565D_be(cinfo, input_buf, in_row_group_ctr,

                                 output_buf);

  else

    h2v1_merged_upsample_565D_le(cinfo, input_buf, in_row_group_ctr,

                                 output_buf);

}

METHODDEF(void)

h2v2_merged_upsample_565(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,

                         JDIMENSION in_row_group_ctr, JSAMPARRAY output_buf)

{

  if (is_big_endian())

    h2v2_merged_upsample_565_be(cinfo, input_buf, in_row_group_ctr,

                                output_buf);

  else

    h2v2_merged_upsample_565_le(cinfo, input_buf, in_row_group_ctr,

                                output_buf);

}

METHODDEF(void)

h2v2_merged_upsample_565D(j_decompress_ptr cinfo, JSAMPIMAGE input_buf,

                          JDIMENSION in_row_group_ctr, JSAMPARRAY output_buf)

{

  if (is_big_endian())

    h2v2_merged_upsample_565D_be(cinfo, input_buf, in_row_group_ctr,

                                 output_buf);

  else

    h2v2_merged_upsample_565D_le(cinfo, input_buf, in_row_group_ctr,

                                 output_buf);

}

/*

 * Module initialization routine for merged upsampling/color conversion.

 *

 * NB: this is called under the conditions determined by use_merged_upsample()

 * in jdmaster.c.  That routine MUST correspond to the actual capabilities

 * of this module; no safety checks are made here.

 */

GLOBAL(void)

jinit_merged_upsampler(j_decompress_ptr cinfo)

{

  my_merged_upsample_ptr upsample;

  upsample = (my_merged_upsample_ptr)

    (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,

                                sizeof(my_merged_upsampler));

  cinfo->upsample = (struct jpeg_upsampler *)upsample;

  upsample->pub.start_pass = start_pass_merged_upsample;

  upsample->pub.need_context_rows = FALSE;

  upsample->out_row_width = cinfo->output_width * cinfo->out_color_components;

  if (cinfo->max_v_samp_factor == 2) {

    upsample->pub.upsample = merged_2v_upsample;

    if (jsimd_can_h2v2_merged_upsample())

      upsample->upmethod = jsimd_h2v2_merged_upsample;

    else

      upsample->upmethod = h2v2_merged_upsample;

    if (cinfo->out_color_space == JCS_RGB565) {

      if (cinfo->dither_mode != JDITHER_NONE) {

        upsample->upmethod = h2v2_merged_upsample_565D;

      } else {

        upsample->upmethod = h2v2_merged_upsample_565;

      }

    }

    /* Allocate a spare row buffer */

    upsample->spare_row = (JSAMPROW)

      (*cinfo->mem->alloc_large) ((j_common_ptr)cinfo, JPOOL_IMAGE,

                (size_t)(upsample->out_row_width * sizeof(JSAMPLE)));

  } else {

    upsample->pub.upsample = merged_1v_upsample;

    if (jsimd_can_h2v1_merged_upsample())

      upsample->upmethod = jsimd_h2v1_merged_upsample;

    else

      upsample->upmethod = h2v1_merged_upsample;

    if (cinfo->out_color_space == JCS_RGB565) {

      if (cinfo->dither_mode != JDITHER_NONE) {

        upsample->upmethod = h2v1_merged_upsample_565D;

      } else {

        upsample->upmethod = h2v1_merged_upsample_565;

      }

    }

    /* No spare row needed */

    upsample->spare_row = NULL;

  }

  build_ycc_rgb_table(cinfo);

}

#endif /* UPSAMPLE_MERGING_SUPPORTED */