/*

 * transupp.c

 *

 * Copyright (C) 1997-2009, Thomas G. Lane, Guido Vollbeding.

 * This file is part of the Independent JPEG Group's software.

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

 *

 * This file contains image transformation routines and other utility code

 * used by the jpegtran sample application.  These are NOT part of the core

 * JPEG library.  But we keep these routines separate from jpegtran.c to

 * ease the task of maintaining jpegtran-like programs that have other user

 * interfaces.

 */

/* Although this file really shouldn't have access to the library internals,

 * it's helpful to let it call jround_up() and jcopy_block_row().

 */

#define JPEG_INTERNALS

// LibJPEG includes

extern "C"

{

#include "jinclude.h"

#include "jpeglib.h"

}

// Local includes

#include "transupp.h"		/* My own external interface */

#include <ctype.h>		/* to declare isdigit() */

namespace KIPIJPEGLossLessPlugin

{

#if TRANSFORMS_SUPPORTED

/*

 * Lossless image transformation routines.  These routines work on DCT

 * coefficient arrays and thus do not require any lossy decompression

 * or recompression of the image.

 * Thanks to Guido Vollbeding for the initial design and code of this feature,

 * and to Ben Jackson for introducing the cropping feature.

 *

 * Horizontal flipping is done in-place, using a single top-to-bottom

 * pass through the virtual source array.  It will thus be much the

 * fastest option for images larger than main memory.

 *

 * The other routines require a set of destination virtual arrays, so they

 * need twice as much memory as jpegtran normally does.  The destination

 * arrays are always written in normal scan order (top to bottom) because

 * the virtual array manager expects this.  The source arrays will be scanned

 * in the corresponding order, which means multiple passes through the source

 * arrays for most of the transforms.  That could result in much thrashing

 * if the image is larger than main memory.

 *

 * If cropping or trimming is involved, the destination arrays may be smaller

 * than the source arrays.  Note it is not possible to do horizontal flip

 * in-place when a nonzero Y crop offset is specified, since we'd have to move

 * data from one block row to another but the virtual array manager doesn't

 * guarantee we can touch more than one row at a time.  So in that case,

 * we have to use a separate destination array.

 *

 * Some notes about the operating environment of the individual transform

 * routines:

 * 1. Both the source and destination virtual arrays are allocated from the

 *    source JPEG object, and therefore should be manipulated by calling the

 *    source's memory manager.

 * 2. The destination's component count should be used.  It may be smaller

 *    than the source's when forcing to grayscale.

 * 3. Likewise the destination's sampling factors should be used.  When

 *    forcing to grayscale the destination's sampling factors will be all 1,

 *    and we may as well take that as the effective iMCU size.

 * 4. When "trim" is in effect, the destination's dimensions will be the

 *    trimmed values but the source's will be untrimmed.

 * 5. When "crop" is in effect, the destination's dimensions will be the

 *    cropped values but the source's will be uncropped.  Each transform

 *    routine is responsible for picking up source data starting at the

 *    correct X and Y offset for the crop region.  (The X and Y offsets

 *    passed to the transform routines are measured in iMCU blocks of the

 *    destination.)

 * 6. All the routines assume that the source and destination buffers are

 *    padded out to a full iMCU boundary.  This is true, although for the

 *    source buffer it is an undocumented property of jdcoefct.c.

 */

LOCAL(void)

do_crop (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,

	 JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,

	 jvirt_barray_ptr *src_coef_arrays,

	 jvirt_barray_ptr *dst_coef_arrays)

/* Crop.  This is only used when no rotate/flip is requested with the crop. */

{

  JDIMENSION dst_blk_y, x_crop_blocks, y_crop_blocks;

  int ci, offset_y;

  JBLOCKARRAY src_buffer, dst_buffer;

  jpeg_component_info *compptr;

  /* We simply have to copy the right amount of data (the destination's

   * image size) starting at the given X and Y offsets in the source.

   */

  for (ci = 0; ci < dstinfo->num_components; ci++) {

    compptr = dstinfo->comp_info + ci;

    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;

    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;

    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;

	 dst_blk_y += compptr->v_samp_factor) {

      dst_buffer = (*srcinfo->mem->access_virt_barray)

	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,

	 (JDIMENSION) compptr->v_samp_factor, TRUE);

      src_buffer = (*srcinfo->mem->access_virt_barray)

	((j_common_ptr) srcinfo, src_coef_arrays[ci],

	 dst_blk_y + y_crop_blocks,

	 (JDIMENSION) compptr->v_samp_factor, FALSE);

      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {

	jcopy_block_row(src_buffer[offset_y] + x_crop_blocks,

			dst_buffer[offset_y],

			compptr->width_in_blocks);

      }

    }

  }

}

LOCAL(void)

do_flip_h_no_crop (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,

		   JDIMENSION x_crop_offset,

		   jvirt_barray_ptr *src_coef_arrays)

/* Horizontal flip; done in-place, so no separate dest array is required.

 * NB: this only works when y_crop_offset is zero.

 */

{

  JDIMENSION MCU_cols, comp_width, blk_x, blk_y, x_crop_blocks;

  int ci, k, offset_y;

  JBLOCKARRAY buffer;

  JCOEFPTR ptr1, ptr2;

  JCOEF temp1, temp2;

  jpeg_component_info *compptr;

  /* Horizontal mirroring of DCT blocks is accomplished by swapping

   * pairs of blocks in-place.  Within a DCT block, we perform horizontal

   * mirroring by changing the signs of odd-numbered columns.

   * Partial iMCUs at the right edge are left untouched.

   */

  MCU_cols = srcinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {

    compptr = dstinfo->comp_info + ci;

    comp_width = MCU_cols * compptr->h_samp_factor;

    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;

    for (blk_y = 0; blk_y < compptr->height_in_blocks;

	 blk_y += compptr->v_samp_factor) {

      buffer = (*srcinfo->mem->access_virt_barray)

	((j_common_ptr) srcinfo, src_coef_arrays[ci], blk_y,

	 (JDIMENSION) compptr->v_samp_factor, TRUE);

      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {

	/* Do the mirroring */

	for (blk_x = 0; blk_x * 2 < comp_width; blk_x++) {

	  ptr1 = buffer[offset_y][blk_x];

	  ptr2 = buffer[offset_y][comp_width - blk_x - 1];

	  /* this unrolled loop doesn't need to know which row it's on... */

	  for (k = 0; k < DCTSIZE2; k += 2) {

	    temp1 = *ptr1;	/* swap even column */

	    temp2 = *ptr2;

	    *ptr1++ = temp2;

	    *ptr2++ = temp1;

	    temp1 = *ptr1;	/* swap odd column with sign change */

	    temp2 = *ptr2;

	    *ptr1++ = -temp2;

	    *ptr2++ = -temp1;

	  }

	}

	if (x_crop_blocks > 0) {

	  /* Now left-justify the portion of the data to be kept.

	   * We can't use a single jcopy_block_row() call because that routine

	   * depends on memcpy(), whose behavior is unspecified for overlapping

	   * source and destination areas.  Sigh.

	   */

	  for (blk_x = 0; blk_x < compptr->width_in_blocks; blk_x++) {

	    jcopy_block_row(buffer[offset_y] + blk_x + x_crop_blocks,

			    buffer[offset_y] + blk_x,

			    (JDIMENSION) 1);

	  }

	}

      }

    }

  }

}

LOCAL(void)

do_flip_h (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,

	   JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,

	   jvirt_barray_ptr *src_coef_arrays,

	   jvirt_barray_ptr *dst_coef_arrays)

/* Horizontal flip in general cropping case */

{

  JDIMENSION MCU_cols, comp_width, dst_blk_x, dst_blk_y;

  JDIMENSION x_crop_blocks, y_crop_blocks;

  int ci, k, offset_y;

  JBLOCKARRAY src_buffer, dst_buffer;

  JBLOCKROW src_row_ptr, dst_row_ptr;

  JCOEFPTR src_ptr, dst_ptr;

  jpeg_component_info *compptr;

  /* Here we must output into a separate array because we can't touch

   * different rows of a single virtual array simultaneously.  Otherwise,

   * this is essentially the same as the routine above.

   */

  MCU_cols = srcinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {

    compptr = dstinfo->comp_info + ci;

    comp_width = MCU_cols * compptr->h_samp_factor;

    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;

    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;

    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;

	 dst_blk_y += compptr->v_samp_factor) {

      dst_buffer = (*srcinfo->mem->access_virt_barray)

	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,

	 (JDIMENSION) compptr->v_samp_factor, TRUE);

      src_buffer = (*srcinfo->mem->access_virt_barray)

	((j_common_ptr) srcinfo, src_coef_arrays[ci],

	 dst_blk_y + y_crop_blocks,

	 (JDIMENSION) compptr->v_samp_factor, FALSE);

      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {

	dst_row_ptr = dst_buffer[offset_y];

	src_row_ptr = src_buffer[offset_y];

	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {

	  if (x_crop_blocks + dst_blk_x < comp_width) {

	    /* Do the mirrorable blocks */

	    dst_ptr = dst_row_ptr[dst_blk_x];

	    src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];

	    /* this unrolled loop doesn't need to know which row it's on... */

	    for (k = 0; k < DCTSIZE2; k += 2) {

	      *dst_ptr++ = *src_ptr++;	 /* copy even column */

	      *dst_ptr++ = - *src_ptr++; /* copy odd column with sign change */

	    }

	  } else {

	    /* Copy last partial block(s) verbatim */

	    jcopy_block_row(src_row_ptr + dst_blk_x + x_crop_blocks,

			    dst_row_ptr + dst_blk_x,

			    (JDIMENSION) 1);

	  }

	}

      }

    }

  }

}

LOCAL(void)

do_flip_v (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,

	   JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,

	   jvirt_barray_ptr *src_coef_arrays,

	   jvirt_barray_ptr *dst_coef_arrays)

/* Vertical flip */

{

  JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;

  JDIMENSION x_crop_blocks, y_crop_blocks;

  int ci, i, j, offset_y;

  JBLOCKARRAY src_buffer, dst_buffer;

  JBLOCKROW src_row_ptr, dst_row_ptr;

  JCOEFPTR src_ptr, dst_ptr;

  jpeg_component_info *compptr;

  /* We output into a separate array because we can't touch different

   * rows of the source virtual array simultaneously.  Otherwise, this

   * is a pretty straightforward analog of horizontal flip.

   * Within a DCT block, vertical mirroring is done by changing the signs

   * of odd-numbered rows.

   * Partial iMCUs at the bottom edge are copied verbatim.

   */

  MCU_rows = srcinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {

    compptr = dstinfo->comp_info + ci;

    comp_height = MCU_rows * compptr->v_samp_factor;

    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;

    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;

    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;

	 dst_blk_y += compptr->v_samp_factor) {

      dst_buffer = (*srcinfo->mem->access_virt_barray)

	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,

	 (JDIMENSION) compptr->v_samp_factor, TRUE);

      if (y_crop_blocks + dst_blk_y < comp_height) {

	/* Row is within the mirrorable area. */

	src_buffer = (*srcinfo->mem->access_virt_barray)

	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],

	   comp_height - y_crop_blocks - dst_blk_y -

	   (JDIMENSION) compptr->v_samp_factor,

	   (JDIMENSION) compptr->v_samp_factor, FALSE);

      } else {

	/* Bottom-edge blocks will be copied verbatim. */

	src_buffer = (*srcinfo->mem->access_virt_barray)

	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],

	   dst_blk_y + y_crop_blocks,

	   (JDIMENSION) compptr->v_samp_factor, FALSE);

      }

      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {

	if (y_crop_blocks + dst_blk_y < comp_height) {

	  /* Row is within the mirrorable area. */

	  dst_row_ptr = dst_buffer[offset_y];

	  src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];

	  src_row_ptr += x_crop_blocks;

	  for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;

	       dst_blk_x++) {

	    dst_ptr = dst_row_ptr[dst_blk_x];

	    src_ptr = src_row_ptr[dst_blk_x];

	    for (i = 0; i < DCTSIZE; i += 2) {

	      /* copy even row */

	      for (j = 0; j < DCTSIZE; j++)

		*dst_ptr++ = *src_ptr++;

	      /* copy odd row with sign change */

	      for (j = 0; j < DCTSIZE; j++)

		*dst_ptr++ = - *src_ptr++;

	    }

	  }

	} else {

	  /* Just copy row verbatim. */

	  jcopy_block_row(src_buffer[offset_y] + x_crop_blocks,

			  dst_buffer[offset_y],

			  compptr->width_in_blocks);

	}

      }

    }

  }

}

LOCAL(void)

do_transpose (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,

	      JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,

	      jvirt_barray_ptr *src_coef_arrays,

	      jvirt_barray_ptr *dst_coef_arrays)

/* Transpose source into destination */

{

  JDIMENSION dst_blk_x, dst_blk_y, x_crop_blocks, y_crop_blocks;

  int ci, i, j, offset_x, offset_y;

  JBLOCKARRAY src_buffer, dst_buffer;

  JCOEFPTR src_ptr, dst_ptr;

  jpeg_component_info *compptr;

  /* Transposing pixels within a block just requires transposing the

   * DCT coefficients.

   * Partial iMCUs at the edges require no special treatment; we simply

   * process all the available DCT blocks for every component.

   */

  for (ci = 0; ci < dstinfo->num_components; ci++) {

    compptr = dstinfo->comp_info + ci;

    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;

    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;

    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;

	 dst_blk_y += compptr->v_samp_factor) {

      dst_buffer = (*srcinfo->mem->access_virt_barray)

	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,

	 (JDIMENSION) compptr->v_samp_factor, TRUE);

      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {

	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;

	     dst_blk_x += compptr->h_samp_factor) {

	  src_buffer = (*srcinfo->mem->access_virt_barray)

	    ((j_common_ptr) srcinfo, src_coef_arrays[ci],

	     dst_blk_x + x_crop_blocks,

	     (JDIMENSION) compptr->h_samp_factor, FALSE);

	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {

	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];

	    src_ptr = src_buffer[offset_x][dst_blk_y + offset_y + y_crop_blocks];

	    for (i = 0; i < DCTSIZE; i++)

	      for (j = 0; j < DCTSIZE; j++)

		dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];

	  }

	}

      }

    }

  }

}

LOCAL(void)

do_rot_90 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,

	   JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,

	   jvirt_barray_ptr *src_coef_arrays,

	   jvirt_barray_ptr *dst_coef_arrays)

/* 90 degree rotation is equivalent to

 *   1. Transposing the image;

 *   2. Horizontal mirroring.

 * These two steps are merged into a single processing routine.

 */

{

  JDIMENSION MCU_cols, comp_width, dst_blk_x, dst_blk_y;

  JDIMENSION x_crop_blocks, y_crop_blocks;

  int ci, i, j, offset_x, offset_y;

  JBLOCKARRAY src_buffer, dst_buffer;

  JCOEFPTR src_ptr, dst_ptr;

  jpeg_component_info *compptr;

  /* Because of the horizontal mirror step, we can't process partial iMCUs

   * at the (output) right edge properly.  They just get transposed and

   * not mirrored.

   */

  MCU_cols = srcinfo->image_height / (dstinfo->max_h_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {

    compptr = dstinfo->comp_info + ci;

    comp_width = MCU_cols * compptr->h_samp_factor;

    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;

    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;

    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;

	 dst_blk_y += compptr->v_samp_factor) {

      dst_buffer = (*srcinfo->mem->access_virt_barray)

	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,

	 (JDIMENSION) compptr->v_samp_factor, TRUE);

      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {

	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;

	     dst_blk_x += compptr->h_samp_factor) {

	  if (x_crop_blocks + dst_blk_x < comp_width) {

	    /* Block is within the mirrorable area. */

	    src_buffer = (*srcinfo->mem->access_virt_barray)

	      ((j_common_ptr) srcinfo, src_coef_arrays[ci],

	       comp_width - x_crop_blocks - dst_blk_x -

	       (JDIMENSION) compptr->h_samp_factor,

	       (JDIMENSION) compptr->h_samp_factor, FALSE);

	  } else {

	    /* Edge blocks are transposed but not mirrored. */

	    src_buffer = (*srcinfo->mem->access_virt_barray)

	      ((j_common_ptr) srcinfo, src_coef_arrays[ci],

	       dst_blk_x + x_crop_blocks,

	       (JDIMENSION) compptr->h_samp_factor, FALSE);

	  }

	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {

	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];

	    if (x_crop_blocks + dst_blk_x < comp_width) {

	      /* Block is within the mirrorable area. */

	      src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]

		[dst_blk_y + offset_y + y_crop_blocks];

	      for (i = 0; i < DCTSIZE; i++) {

		for (j = 0; j < DCTSIZE; j++)

		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];

		i++;

		for (j = 0; j < DCTSIZE; j++)

		  dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];

	      }

	    } else {

	      /* Edge blocks are transposed but not mirrored. */

	      src_ptr = src_buffer[offset_x]

		[dst_blk_y + offset_y + y_crop_blocks];

	      for (i = 0; i < DCTSIZE; i++)

		for (j = 0; j < DCTSIZE; j++)

		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];

	    }

	  }

	}

      }

    }

  }

}

LOCAL(void)

do_rot_270 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,

	    JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,

	    jvirt_barray_ptr *src_coef_arrays,

	    jvirt_barray_ptr *dst_coef_arrays)

/* 270 degree rotation is equivalent to

 *   1. Horizontal mirroring;

 *   2. Transposing the image.

 * These two steps are merged into a single processing routine.

 */

{

  JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;

  JDIMENSION x_crop_blocks, y_crop_blocks;

  int ci, i, j, offset_x, offset_y;

  JBLOCKARRAY src_buffer, dst_buffer;

  JCOEFPTR src_ptr, dst_ptr;

  jpeg_component_info *compptr;

  /* Because of the horizontal mirror step, we can't process partial iMCUs

   * at the (output) bottom edge properly.  They just get transposed and

   * not mirrored.

   */

  MCU_rows = srcinfo->image_width / (dstinfo->max_v_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {

    compptr = dstinfo->comp_info + ci;

    comp_height = MCU_rows * compptr->v_samp_factor;

    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;

    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;

    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;

	 dst_blk_y += compptr->v_samp_factor) {

      dst_buffer = (*srcinfo->mem->access_virt_barray)

	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,

	 (JDIMENSION) compptr->v_samp_factor, TRUE);

      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {

	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;

	     dst_blk_x += compptr->h_samp_factor) {

	  src_buffer = (*srcinfo->mem->access_virt_barray)

	    ((j_common_ptr) srcinfo, src_coef_arrays[ci],

	     dst_blk_x + x_crop_blocks,

	     (JDIMENSION) compptr->h_samp_factor, FALSE);

	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {

	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];

	    if (y_crop_blocks + dst_blk_y < comp_height) {

	      /* Block is within the mirrorable area. */

	      src_ptr = src_buffer[offset_x]

		[comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];

	      for (i = 0; i < DCTSIZE; i++) {

		for (j = 0; j < DCTSIZE; j++) {

		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];

		  j++;

		  dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];

		}

	      }

	    } else {

	      /* Edge blocks are transposed but not mirrored. */

	      src_ptr = src_buffer[offset_x]

		[dst_blk_y + offset_y + y_crop_blocks];

	      for (i = 0; i < DCTSIZE; i++)

		for (j = 0; j < DCTSIZE; j++)

		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];

	    }

	  }

	}

      }

    }

  }

}

LOCAL(void)

do_rot_180 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,

	    JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,

	    jvirt_barray_ptr *src_coef_arrays,

	    jvirt_barray_ptr *dst_coef_arrays)

/* 180 degree rotation is equivalent to

 *   1. Vertical mirroring;

 *   2. Horizontal mirroring.

 * These two steps are merged into a single processing routine.

 */

{

  JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;

  JDIMENSION x_crop_blocks, y_crop_blocks;

  int ci, i, j, offset_y;

  JBLOCKARRAY src_buffer, dst_buffer;

  JBLOCKROW src_row_ptr, dst_row_ptr;

  JCOEFPTR src_ptr, dst_ptr;

  jpeg_component_info *compptr;

  MCU_cols = srcinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);

  MCU_rows = srcinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {

    compptr = dstinfo->comp_info + ci;

    comp_width = MCU_cols * compptr->h_samp_factor;

    comp_height = MCU_rows * compptr->v_samp_factor;

    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;

    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;

    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;

	 dst_blk_y += compptr->v_samp_factor) {

      dst_buffer = (*srcinfo->mem->access_virt_barray)

	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,

	 (JDIMENSION) compptr->v_samp_factor, TRUE);

      if (y_crop_blocks + dst_blk_y < comp_height) {

	/* Row is within the vertically mirrorable area. */

	src_buffer = (*srcinfo->mem->access_virt_barray)

	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],

	   comp_height - y_crop_blocks - dst_blk_y -

	   (JDIMENSION) compptr->v_samp_factor,

	   (JDIMENSION) compptr->v_samp_factor, FALSE);

      } else {

	/* Bottom-edge rows are only mirrored horizontally. */

	src_buffer = (*srcinfo->mem->access_virt_barray)

	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],

	   dst_blk_y + y_crop_blocks,

	   (JDIMENSION) compptr->v_samp_factor, FALSE);

      }

      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {

	dst_row_ptr = dst_buffer[offset_y];

	if (y_crop_blocks + dst_blk_y < comp_height) {

	  /* Row is within the mirrorable area. */

	  src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];

	  for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {

	    dst_ptr = dst_row_ptr[dst_blk_x];

	    if (x_crop_blocks + dst_blk_x < comp_width) {

	      /* Process the blocks that can be mirrored both ways. */

	      src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];

	      for (i = 0; i < DCTSIZE; i += 2) {

		/* For even row, negate every odd column. */

		for (j = 0; j < DCTSIZE; j += 2) {

		  *dst_ptr++ = *src_ptr++;

		  *dst_ptr++ = - *src_ptr++;

		}

		/* For odd row, negate every even column. */

		for (j = 0; j < DCTSIZE; j += 2) {

		  *dst_ptr++ = - *src_ptr++;

		  *dst_ptr++ = *src_ptr++;

		}

	      }

	    } else {

	      /* Any remaining right-edge blocks are only mirrored vertically. */

	      src_ptr = src_row_ptr[x_crop_blocks + dst_blk_x];

	      for (i = 0; i < DCTSIZE; i += 2) {

		for (j = 0; j < DCTSIZE; j++)

		  *dst_ptr++ = *src_ptr++;

		for (j = 0; j < DCTSIZE; j++)

		  *dst_ptr++ = - *src_ptr++;

	      }

	    }

	  }

	} else {

	  /* Remaining rows are just mirrored horizontally. */

	  src_row_ptr = src_buffer[offset_y];

	  for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {

	    if (x_crop_blocks + dst_blk_x < comp_width) {

	      /* Process the blocks that can be mirrored. */

	      dst_ptr = dst_row_ptr[dst_blk_x];

	      src_ptr = src_row_ptr[comp_width - x_crop_blocks - dst_blk_x - 1];

	      for (i = 0; i < DCTSIZE2; i += 2) {

		*dst_ptr++ = *src_ptr++;

		*dst_ptr++ = - *src_ptr++;

	      }

	    } else {

	      /* Any remaining right-edge blocks are only copied. */

	      jcopy_block_row(src_row_ptr + dst_blk_x + x_crop_blocks,

			      dst_row_ptr + dst_blk_x,

			      (JDIMENSION) 1);

	    }

	  }

	}

      }

    }

  }

}

LOCAL(void)

do_transverse (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,

	       JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,

	       jvirt_barray_ptr *src_coef_arrays,

	       jvirt_barray_ptr *dst_coef_arrays)

/* Transverse transpose is equivalent to

 *   1. 180 degree rotation;

 *   2. Transposition;

 * or

 *   1. Horizontal mirroring;

 *   2. Transposition;

 *   3. Horizontal mirroring.

 * These steps are merged into a single processing routine.

 */

{

  JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;

  JDIMENSION x_crop_blocks, y_crop_blocks;

  int ci, i, j, offset_x, offset_y;

  JBLOCKARRAY src_buffer, dst_buffer;

  JCOEFPTR src_ptr, dst_ptr;

  jpeg_component_info *compptr;

  MCU_cols = srcinfo->image_height / (dstinfo->max_h_samp_factor * DCTSIZE);

  MCU_rows = srcinfo->image_width / (dstinfo->max_v_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {

    compptr = dstinfo->comp_info + ci;

    comp_width = MCU_cols * compptr->h_samp_factor;

    comp_height = MCU_rows * compptr->v_samp_factor;

    x_crop_blocks = x_crop_offset * compptr->h_samp_factor;

    y_crop_blocks = y_crop_offset * compptr->v_samp_factor;

    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;

	 dst_blk_y += compptr->v_samp_factor) {

      dst_buffer = (*srcinfo->mem->access_virt_barray)

	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,

	 (JDIMENSION) compptr->v_samp_factor, TRUE);

      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {

	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;

	     dst_blk_x += compptr->h_samp_factor) {

	  if (x_crop_blocks + dst_blk_x < comp_width) {

	    /* Block is within the mirrorable area. */

	    src_buffer = (*srcinfo->mem->access_virt_barray)

	      ((j_common_ptr) srcinfo, src_coef_arrays[ci],

	       comp_width - x_crop_blocks - dst_blk_x -

	       (JDIMENSION) compptr->h_samp_factor,

	       (JDIMENSION) compptr->h_samp_factor, FALSE);

	  } else {

	    src_buffer = (*srcinfo->mem->access_virt_barray)

	      ((j_common_ptr) srcinfo, src_coef_arrays[ci],

	       dst_blk_x + x_crop_blocks,

	       (JDIMENSION) compptr->h_samp_factor, FALSE);

	  }

	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {

	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];

	    if (y_crop_blocks + dst_blk_y < comp_height) {

	      if (x_crop_blocks + dst_blk_x < comp_width) {

		/* Block is within the mirrorable area. */

		src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]

		  [comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];

		for (i = 0; i < DCTSIZE; i++) {

		  for (j = 0; j < DCTSIZE; j++) {

		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];

		    j++;

		    dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];

		  }

		  i++;

		  for (j = 0; j < DCTSIZE; j++) {

		    dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];

		    j++;

		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];

		  }

		}

	      } else {

		/* Right-edge blocks are mirrored in y only */

		src_ptr = src_buffer[offset_x]

		  [comp_height - y_crop_blocks - dst_blk_y - offset_y - 1];

		for (i = 0; i < DCTSIZE; i++) {

		  for (j = 0; j < DCTSIZE; j++) {

		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];

		    j++;

		    dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];

		  }

		}

	      }

	    } else {

	      if (x_crop_blocks + dst_blk_x < comp_width) {

		/* Bottom-edge blocks are mirrored in x only */

		src_ptr = src_buffer[compptr->h_samp_factor - offset_x - 1]

		  [dst_blk_y + offset_y + y_crop_blocks];

		for (i = 0; i < DCTSIZE; i++) {

		  for (j = 0; j < DCTSIZE; j++)

		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];

		  i++;

		  for (j = 0; j < DCTSIZE; j++)

		    dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];

		}

	      } else {

		/* At lower right corner, just transpose, no mirroring */

		src_ptr = src_buffer[offset_x]

		  [dst_blk_y + offset_y + y_crop_blocks];

		for (i = 0; i < DCTSIZE; i++)

		  for (j = 0; j < DCTSIZE; j++)

		    dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];

	      }

	    }

	  }

	}

      }

    }

  }

}

/* Parse an unsigned integer: subroutine for jtransform_parse_crop_spec.

 * Returns TRUE if valid integer found, FALSE if not.

 * *strptr is advanced over the digit string, and *result is set to its value.

 */

LOCAL(boolean)

jt_read_integer (const char ** strptr, JDIMENSION * result)

{

  const char * ptr = *strptr;

  JDIMENSION val = 0;

  for (; isdigit(*ptr); ptr++) {

    val = val * 10 + (JDIMENSION) (*ptr - '0');

  }

  *result = val;

  if (ptr == *strptr)

    return FALSE;		/* oops, no digits */

  *strptr = ptr;

  return TRUE;

}

/* Parse a crop specification (written in X11 geometry style).

 * The routine returns TRUE if the spec string is valid, FALSE if not.

 *

 * The crop spec string should have the format

 *	<width>x<height>{+-}<xoffset>{+-}<yoffset>

 * where width, height, xoffset, and yoffset are unsigned integers.

 * Each of the elements can be omitted to indicate a default value.

 * (A weakness of this style is that it is not possible to omit xoffset

 * while specifying yoffset, since they look alike.)

 *

 * This code is loosely based on XParseGeometry from the X11 distribution.

 */

GLOBAL(boolean)

jtransform_parse_crop_spec (jpeg_transform_info *info, const char *spec)

{

  info->crop = FALSE;

  info->crop_width_set = JCROP_UNSET;

  info->crop_height_set = JCROP_UNSET;

  info->crop_xoffset_set = JCROP_UNSET;

  info->crop_yoffset_set = JCROP_UNSET;

  if (isdigit(*spec)) {

    /* fetch width */

    if (! jt_read_integer(&spec, &info->crop_width))

      return FALSE;

    info->crop_width_set = JCROP_POS;

  }

  if (*spec == 'x' || *spec == 'X') {	

    /* fetch height */

    spec++;

    if (! jt_read_integer(&spec, &info->crop_height))

      return FALSE;

    info->crop_height_set = JCROP_POS;

  }

  if (*spec == '+' || *spec == '-') {

    /* fetch xoffset */

    info->crop_xoffset_set = (*spec == '-') ? JCROP_NEG : JCROP_POS;

    spec++;

    if (! jt_read_integer(&spec, &info->crop_xoffset))

      return FALSE;

  }

  if (*spec == '+' || *spec == '-') {

    /* fetch yoffset */

    info->crop_yoffset_set = (*spec == '-') ? JCROP_NEG : JCROP_POS;

    spec++;

    if (! jt_read_integer(&spec, &info->crop_yoffset))

      return FALSE;

  }

  /* We had better have gotten to the end of the string. */

  if (*spec != '\0')

    return FALSE;

  info->crop = TRUE;

  return TRUE;

}

/* Trim off any partial iMCUs on the indicated destination edge */

LOCAL(void)

trim_right_edge (jpeg_transform_info *info, JDIMENSION full_width)

{

  JDIMENSION MCU_cols;

  MCU_cols = info->output_width / (info->iMCU_sample_width);

  if (MCU_cols > 0 && info->x_crop_offset + MCU_cols ==

      full_width / (info->iMCU_sample_width))

    info->output_width = MCU_cols * (info->iMCU_sample_width);

}

LOCAL(void)

trim_bottom_edge (jpeg_transform_info *info, JDIMENSION full_height)

{

  JDIMENSION MCU_rows;

  MCU_rows = info->output_height / (info->iMCU_sample_height);

  if (MCU_rows > 0 && info->y_crop_offset + MCU_rows ==

      full_height / (info->iMCU_sample_height))

    info->output_height = MCU_rows * (info->iMCU_sample_height);

}

/* Request any required workspace.

 *

 * This routine figures out the size that the output image will be

 * (which implies that all the transform parameters must be set before

 * it is called).

 *

 * We allocate the workspace virtual arrays from the source decompression

 * object, so that all the arrays (both the original data and the workspace)

 * will be taken into account while making memory management decisions.

 * Hence, this routine must be called after jpeg_read_header (which reads

 * the image dimensions) and before jpeg_read_coefficients (which realizes

 * the source's virtual arrays).

 */

// NB: changed from transupp.c in libjpeg

GLOBAL(boolean)

jtransform_request_workspace (j_decompress_ptr srcinfo,

			      jpeg_transform_info *info)

{

  jvirt_barray_ptr *coef_arrays = NULL;

  boolean need_workspace, transpose_it;

  jpeg_component_info *compptr;

  JDIMENSION xoffset, yoffset, width_in_iMCUs, height_in_iMCUs;

  JDIMENSION width_in_blocks, height_in_blocks;

  int ci, h_samp_factor, v_samp_factor;

  /* Determine number of components in output image */

  if (info->force_grayscale &&

      srcinfo->jpeg_color_space == JCS_YCbCr &&

      srcinfo->num_components == 3) {

    /* We'll only process the first component */

    info->num_components = 1;

  } else {

    /* Process all the components */

    info->num_components = srcinfo->num_components;

  }

  /* If there is only one output component, force the iMCU size to be 1;

   * else use the source iMCU size.  (This allows us to do the right thing

   * when reducing color to grayscale, and also provides a handy way of

   * cleaning up "funny" grayscale images whose sampling factors are not 1x1.)

   */

  switch (info->transform) {

  case JXFORM_TRANSPOSE:

  case JXFORM_TRANSVERSE:

  case JXFORM_ROT_90:

  case JXFORM_ROT_270:

    info->output_width = srcinfo->image_height;

    info->output_height = srcinfo->image_width;

    if (info->num_components == 1) {

      info->iMCU_sample_width = DCTSIZE;

      info->iMCU_sample_height = DCTSIZE;

    } else {

      info->iMCU_sample_width =

          srcinfo->max_v_samp_factor * DCTSIZE;

      info->iMCU_sample_height =

          srcinfo->max_h_samp_factor * DCTSIZE;

    }

    break;

  default:

    info->output_width = srcinfo->image_width;

    info->output_height = srcinfo->image_height;

    if (info->num_components == 1) {

      info->iMCU_sample_width = DCTSIZE;

      info->iMCU_sample_height = DCTSIZE;

    } else {

      info->iMCU_sample_width =

          srcinfo->max_h_samp_factor * DCTSIZE;

      info->iMCU_sample_height =

          srcinfo->max_v_samp_factor * DCTSIZE;

    }

    break;

  }

  /* If cropping has been requested, compute the crop area's position and

   * dimensions, ensuring that its upper left corner falls at an iMCU boundary.

   */

  if (info->crop) {

    /* Insert default values for unset crop parameters */

    if (info->crop_xoffset_set == JCROP_UNSET)

      info->crop_xoffset = 0;	/* default to +0 */

    if (info->crop_yoffset_set == JCROP_UNSET)

      info->crop_yoffset = 0;	/* default to +0 */

    if (info->crop_xoffset >= info->output_width ||

	info->crop_yoffset >= info->output_height)

      ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);

    if (info->crop_width_set == JCROP_UNSET)

      info->crop_width = info->output_width - info->crop_xoffset;

    if (info->crop_height_set == JCROP_UNSET)

      info->crop_height = info->output_height - info->crop_yoffset;

    /* Ensure parameters are valid */

    if (info->crop_width <= 0 || info->crop_width > info->output_width ||

	info->crop_height <= 0 || info->crop_height > info->output_height ||

	info->crop_xoffset > info->output_width - info->crop_width ||

	info->crop_yoffset > info->output_height - info->crop_height)

      ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);

    /* Convert negative crop offsets into regular offsets */

    if (info->crop_xoffset_set == JCROP_NEG)

      xoffset = info->output_width - info->crop_width - info->crop_xoffset;

    else

      xoffset = info->crop_xoffset;

    if (info->crop_yoffset_set == JCROP_NEG)

      yoffset = info->output_height - info->crop_height - info->crop_yoffset;

    else

      yoffset = info->crop_yoffset;

    /* Now adjust so that upper left corner falls at an iMCU boundary */

    info->output_width =

      info->crop_width + (xoffset % (info->iMCU_sample_width));

    info->output_height =

      info->crop_height + (yoffset % (info->iMCU_sample_height));

    /* Save x/y offsets measured in iMCUs */

    info->x_crop_offset = xoffset / (info->iMCU_sample_width);

    info->y_crop_offset = yoffset / (info->iMCU_sample_height);

  } else {

    info->x_crop_offset = 0;

    info->y_crop_offset = 0;

  }

  /* Figure out whether we need workspace arrays,

   * and if so whether they are transposed relative to the source.

   */

  need_workspace = FALSE;

  transpose_it = FALSE;

  switch (info->transform) {

  case JXFORM_NONE:

    if (info->x_crop_offset != 0 || info->y_crop_offset != 0)

      need_workspace = TRUE;

    /* No workspace needed if neither cropping nor transforming */

    break;

  case JXFORM_FLIP_H:

    if (info->trim)

      trim_right_edge(info, srcinfo->image_width);

    if (info->y_crop_offset != 0)

      need_workspace = TRUE;

    /* do_flip_h_no_crop doesn't need a workspace array */

    break;

  case JXFORM_FLIP_V:

    if (info->trim)

      trim_bottom_edge(info, srcinfo->image_height);

    /* Need workspace arrays having same dimensions as source image. */

    need_workspace = TRUE;

    break;

  case JXFORM_TRANSPOSE:

    /* transpose does NOT have to trim anything */

    /* Need workspace arrays having transposed dimensions. */

    need_workspace = TRUE;

    transpose_it = TRUE;

    break;

  case JXFORM_TRANSVERSE:

    if (info->trim) {

      trim_right_edge(info, srcinfo->image_height);

      trim_bottom_edge(info, srcinfo->image_width);

    }

    /* Need workspace arrays having transposed dimensions. */

    need_workspace = TRUE;

    transpose_it = TRUE;

    break;

  case JXFORM_ROT_90:

    if (info->trim)

      trim_right_edge(info, srcinfo->image_height);

    /* Need workspace arrays having transposed dimensions. */

    need_workspace = TRUE;

    transpose_it = TRUE;

    break;

  case JXFORM_ROT_180:

    if (info->trim) {

      trim_right_edge(info, srcinfo->image_width);

      trim_bottom_edge(info, srcinfo->image_height);

    }

    /* Need workspace arrays having same dimensions as source image. */

    need_workspace = TRUE;

    break;

  case JXFORM_ROT_270:

    if (info->trim)

      trim_bottom_edge(info, srcinfo->image_width);

    /* Need workspace arrays having transposed dimensions. */

    need_workspace = TRUE;

    transpose_it = TRUE;

    break;

  }

  /* Allocate workspace if needed.

   * Note that we allocate arrays padded out to the next iMCU boundary,

   * so that transform routines need not worry about missing edge blocks.

   */

  if (need_workspace) {

    coef_arrays = (jvirt_barray_ptr *)

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

		SIZEOF(jvirt_barray_ptr) * info->num_components);

    width_in_iMCUs = (JDIMENSION)

      jdiv_round_up((long) info->output_width,

		    (long) (info->iMCU_sample_width));

    height_in_iMCUs = (JDIMENSION)

      jdiv_round_up((long) info->output_height,

		    (long) (info->iMCU_sample_height));

    for (ci = 0; ci < info->num_components; ci++) {

      compptr = srcinfo->comp_info + ci;

      if (info->num_components == 1) {

	/* we're going to force samp factors to 1x1 in this case */

	h_samp_factor = v_samp_factor = 1;

      } else if (transpose_it) {

	h_samp_factor = compptr->v_samp_factor;

	v_samp_factor = compptr->h_samp_factor;

      } else {

	h_samp_factor = compptr->h_samp_factor;

	v_samp_factor = compptr->v_samp_factor;

      }

      width_in_blocks = width_in_iMCUs * h_samp_factor;

      height_in_blocks = height_in_iMCUs * v_samp_factor;

      coef_arrays[ci] = (*srcinfo->mem->request_virt_barray)

	((j_common_ptr) srcinfo, JPOOL_IMAGE, FALSE,

	 width_in_blocks, height_in_blocks, (JDIMENSION) v_samp_factor);

    }

  }

  info->workspace_coef_arrays = coef_arrays;

  return TRUE;

}

/* Transpose destination image parameters */

LOCAL(void)

transpose_critical_parameters (j_compress_ptr dstinfo)

{

  int tblno, i, j, ci, itemp;

  jpeg_component_info *compptr;

  JQUANT_TBL *qtblptr;

  UINT16 qtemp;

  /* Transpose sampling factors */

  for (ci = 0; ci < dstinfo->num_components; ci++) {

    compptr = dstinfo->comp_info + ci;

    itemp = compptr->h_samp_factor;

    compptr->h_samp_factor = compptr->v_samp_factor;

    compptr->v_samp_factor = itemp;

  }

  /* Transpose quantization tables */

  for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {

    qtblptr = dstinfo->quant_tbl_ptrs[tblno];

    if (qtblptr != NULL) {

      for (i = 0; i < DCTSIZE; i++) {

	for (j = 0; j < i; j++) {

	  qtemp = qtblptr->quantval[i*DCTSIZE+j];

	  qtblptr->quantval[i*DCTSIZE+j] = qtblptr->quantval[j*DCTSIZE+i];

	  qtblptr->quantval[j*DCTSIZE+i] = qtemp;

	}

      }

    }

  }

}

/* Adjust Exif image parameters.

 *

 * We try to adjust the Tags ExifImageWidth and ExifImageHeight if possible.

 */

LOCAL(void)

adjust_exif_parameters (JOCTET FAR * data, unsigned int length,

			JDIMENSION new_width, JDIMENSION new_height)

{

  boolean is_motorola; /* Flag for byte order */

  unsigned int number_of_tags, tagnum;

  unsigned int firstoffset, offset;

  JDIMENSION new_value;

  if (length < 12) return; /* Length of an IFD entry */

  /* Discover byte order */

  if (GETJOCTET(data[0]) == 0x49 && GETJOCTET(data[1]) == 0x49)

    is_motorola = FALSE;

  else if (GETJOCTET(data[0]) == 0x4D && GETJOCTET(data[1]) == 0x4D)

    is_motorola = TRUE;

  else

    return;

  /* Check Tag Mark */

  if (is_motorola) {

    if (GETJOCTET(data[2]) != 0) return;

    if (GETJOCTET(data[3]) != 0x2A) return;

  } else {

    if (GETJOCTET(data[3]) != 0) return;

    if (GETJOCTET(data[2]) != 0x2A) return;

  }

  /* Get first IFD offset (offset to IFD0) */

  if (is_motorola) {

    if (GETJOCTET(data[4]) != 0) return;

    if (GETJOCTET(data[5]) != 0) return;

    firstoffset = GETJOCTET(data[6]);

    firstoffset <<= 8;

    firstoffset += GETJOCTET(data[7]);

  } else {

    if (GETJOCTET(data[7]) != 0) return;

    if (GETJOCTET(data[6]) != 0) return;

    firstoffset = GETJOCTET(data[5]);

    firstoffset <<= 8;

    firstoffset += GETJOCTET(data[4]);

  }

  if (firstoffset > length - 2) return; /* check end of data segment */

  /* Get the number of directory entries contained in this IFD */

  if (is_motorola) {

    number_of_tags = GETJOCTET(data[firstoffset]);

    number_of_tags <<= 8;

    number_of_tags += GETJOCTET(data[firstoffset+1]);

  } else {

    number_of_tags = GETJOCTET(data[firstoffset+1]);

    number_of_tags <<= 8;

    number_of_tags += GETJOCTET(data[firstoffset]);

  }

  if (number_of_tags == 0) return;

  firstoffset += 2;

  /* Search for ExifSubIFD offset Tag in IFD0 */

  for (;;) {

    if (firstoffset > length - 12) return; /* check end of data segment */

    /* Get Tag number */

    if (is_motorola) {

      tagnum = GETJOCTET(data[firstoffset]);

      tagnum <<= 8;

      tagnum += GETJOCTET(data[firstoffset+1]);

    } else {

      tagnum = GETJOCTET(data[firstoffset+1]);

      tagnum <<= 8;

      tagnum += GETJOCTET(data[firstoffset]);

    }

    if (tagnum == 0x8769) break; /* found ExifSubIFD offset Tag */

    if (--number_of_tags == 0) return;

    firstoffset += 12;

  }

  /* Get the ExifSubIFD offset */

  if (is_motorola) {

    if (GETJOCTET(data[firstoffset+8]) != 0) return;

    if (GETJOCTET(data[firstoffset+9]) != 0) return;

    offset = GETJOCTET(data[firstoffset+10]);

    offset <<= 8;

    offset += GETJOCTET(data[firstoffset+11]);

  } else {

    if (GETJOCTET(data[firstoffset+11]) != 0) return;

    if (GETJOCTET(data[firstoffset+10]) != 0) return;

    offset = GETJOCTET(data[firstoffset+9]);

    offset <<= 8;

    offset += GETJOCTET(data[firstoffset+8]);

  }

  if (offset > length - 2) return; /* check end of data segment */

  /* Get the number of directory entries contained in this SubIFD */

  if (is_motorola) {

    number_of_tags = GETJOCTET(data[offset]);

    number_of_tags <<= 8;

    number_of_tags += GETJOCTET(data[offset+1]);

  } else {

    number_of_tags = GETJOCTET(data[offset+1]);

    number_of_tags <<= 8;

    number_of_tags += GETJOCTET(data[offset]);

  }

  if (number_of_tags < 2) return;

  offset += 2;

  /* Search for ExifImageWidth and ExifImageHeight Tags in this SubIFD */

  do {

    if (offset > length - 12) return; /* check end of data segment */

    /* Get Tag number */

    if (is_motorola) {

      tagnum = GETJOCTET(data[offset]);

      tagnum <<= 8;

      tagnum += GETJOCTET(data[offset+1]);

    } else {

      tagnum = GETJOCTET(data[offset+1]);

      tagnum <<= 8;

      tagnum += GETJOCTET(data[offset]);

    }

    if (tagnum == 0xA002 || tagnum == 0xA003) {

      if (tagnum == 0xA002)

	new_value = new_width; /* ExifImageWidth Tag */

      else

	new_value = new_height; /* ExifImageHeight Tag */

      if (is_motorola) {

	data[offset+2] = 0; /* Format = unsigned long (4 octets) */

	data[offset+3] = 4;

	data[offset+4] = 0; /* Number Of Components = 1 */

	data[offset+5] = 0;

	data[offset+6] = 0;

	data[offset+7] = 1;

	data[offset+8] = 0;

	data[offset+9] = 0;

	data[offset+10] = (JOCTET)((new_value >> 8) & 0xFF);

	data[offset+11] = (JOCTET)(new_value & 0xFF);

      } else {

	data[offset+2] = 4; /* Format = unsigned long (4 octets) */

	data[offset+3] = 0;

	data[offset+4] = 1; /* Number Of Components = 1 */

	data[offset+5] = 0;

	data[offset+6] = 0;

	data[offset+7] = 0;

	data[offset+8] = (JOCTET)(new_value & 0xFF);

	data[offset+9] = (JOCTET)((new_value >> 8) & 0xFF);

	data[offset+10] = 0;

	data[offset+11] = 0;

      }

    }

    offset += 12;

  } while (--number_of_tags);

}

/* Adjust output image parameters as needed.

 *

 * This must be called after jpeg_copy_critical_parameters()

 * and before jpeg_write_coefficients().

 *

 * The return value is the set of virtual coefficient arrays to be written

 * (either the ones allocated by jtransform_request_workspace, or the

 * original source data arrays).  The caller will need to pass this value

 * to jpeg_write_coefficients().

 */

GLOBAL(jvirt_barray_ptr *)

jtransform_adjust_parameters (j_decompress_ptr srcinfo,

			      j_compress_ptr dstinfo,

			      jvirt_barray_ptr *src_coef_arrays,

			      jpeg_transform_info *info)

{

  /* If force-to-grayscale is requested, adjust destination parameters */

  if (info->force_grayscale) {

    /* First, ensure we have YCbCr or grayscale data, and that the source's

     * Y channel is full resolution.  (No reasonable person would make Y

     * be less than full resolution, so actually coping with that case

     * isn't worth extra code space.  But we check it to avoid crashing.)

     */

    if (((dstinfo->jpeg_color_space == JCS_YCbCr &&

	  dstinfo->num_components == 3) ||

	 (dstinfo->jpeg_color_space == JCS_GRAYSCALE &&

	  dstinfo->num_components == 1)) &&

	srcinfo->comp_info[0].h_samp_factor == srcinfo->max_h_samp_factor &&

	srcinfo->comp_info[0].v_samp_factor == srcinfo->max_v_samp_factor) {

      /* We use jpeg_set_colorspace to make sure subsidiary settings get fixed

       * properly.  Among other things, it sets the target h_samp_factor &

       * v_samp_factor to 1, which typically won't match the source.

       * We have to preserve the source's quantization table number, however.

       */

      int sv_quant_tbl_no = dstinfo->comp_info[0].quant_tbl_no;

      jpeg_set_colorspace(dstinfo, JCS_GRAYSCALE);

      dstinfo->comp_info[0].quant_tbl_no = sv_quant_tbl_no;

    } else {

      /* Sorry, can't do it */

      ERREXIT(dstinfo, JERR_CONVERSION_NOTIMPL);

    }

  } else if (info->num_components == 1) {

    /* For a single-component source, we force the destination sampling factors

     * to 1x1, with or without force_grayscale.  This is useful because some

     * decoders choke on grayscale images with other sampling factors.

     */

    dstinfo->comp_info[0].h_samp_factor = 1;

    dstinfo->comp_info[0].v_samp_factor = 1;

  }

  /* Correct the destination's image dimensions as necessary

   * for crop and rotate/flip operations.

   */

  dstinfo->image_width = info->output_width;

  dstinfo->image_height = info->output_height;

  /* Transpose destination image parameters */

  switch (info->transform) {

  case JXFORM_TRANSPOSE:

  case JXFORM_TRANSVERSE:

  case JXFORM_ROT_90:

  case JXFORM_ROT_270:

    transpose_critical_parameters(dstinfo);

    break;

  default:

    break;

  }

  /* Adjust Exif properties */

  if (srcinfo->marker_list != NULL &&

      srcinfo->marker_list->marker == JPEG_APP0+1 &&

      srcinfo->marker_list->data_length >= 6 &&

      GETJOCTET(srcinfo->marker_list->data[0]) == 0x45 &&

      GETJOCTET(srcinfo->marker_list->data[1]) == 0x78 &&

      GETJOCTET(srcinfo->marker_list->data[2]) == 0x69 &&

      GETJOCTET(srcinfo->marker_list->data[3]) == 0x66 &&

      GETJOCTET(srcinfo->marker_list->data[4]) == 0 &&

      GETJOCTET(srcinfo->marker_list->data[5]) == 0) {

    /* Suppress output of JFIF marker */

    dstinfo->write_JFIF_header = FALSE;

    /* Adjust Exif image parameters */

    if (dstinfo->image_width != srcinfo->image_width ||

	dstinfo->image_height != srcinfo->image_height)

      /* Align data segment to start of TIFF structure for parsing */

      adjust_exif_parameters(srcinfo->marker_list->data + 6,

	srcinfo->marker_list->data_length - 6,

	dstinfo->image_width, dstinfo->image_height);

  }

  /* Return the appropriate output data set */

  if (info->workspace_coef_arrays != NULL)

    return info->workspace_coef_arrays;

  return src_coef_arrays;

}

/* Execute the actual transformation, if any.

 *

 * This must be called *after* jpeg_write_coefficients, because it depends

 * on jpeg_write_coefficients to have computed subsidiary values such as

 * the per-component width and height fields in the destination object.

 *

 * Note that some transformations will modify the source data arrays!

 */

GLOBAL(void)

jtransform_execute_transform (j_decompress_ptr srcinfo,

			      j_compress_ptr dstinfo,

			      jvirt_barray_ptr *src_coef_arrays,

			      jpeg_transform_info *info)

{

  jvirt_barray_ptr *dst_coef_arrays = info->workspace_coef_arrays;

  /* Note: conditions tested here should match those in switch statement

   * in jtransform_request_workspace()

   */

  switch (info->transform) {

  case JXFORM_NONE:

    if (info->x_crop_offset != 0 || info->y_crop_offset != 0)

      do_crop(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,

	      src_coef_arrays, dst_coef_arrays);

    break;

  case JXFORM_FLIP_H:

    if (info->y_crop_offset != 0)

      do_flip_h(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,

		src_coef_arrays, dst_coef_arrays);

    else

      do_flip_h_no_crop(srcinfo, dstinfo, info->x_crop_offset,

			src_coef_arrays);

    break;

  case JXFORM_FLIP_V:

    do_flip_v(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,

	      src_coef_arrays, dst_coef_arrays);

    break;

  case JXFORM_TRANSPOSE:

    do_transpose(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,

		 src_coef_arrays, dst_coef_arrays);

    break;

  case JXFORM_TRANSVERSE:

    do_transverse(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,

		  src_coef_arrays, dst_coef_arrays);

    break;

  case JXFORM_ROT_90:

    do_rot_90(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,

	      src_coef_arrays, dst_coef_arrays);

    break;

  case JXFORM_ROT_180:

    do_rot_180(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,

	       src_coef_arrays, dst_coef_arrays);

    break;

  case JXFORM_ROT_270:

    do_rot_270(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,

	       src_coef_arrays, dst_coef_arrays);

    break;

  }

}

/* jtransform_perfect_transform

 *

 * Determine whether lossless transformation is perfectly

 * possible for a specified image and transformation.

 *

 * Inputs:

 *   image_width, image_height: source image dimensions.

 *   MCU_width, MCU_height: pixel dimensions of MCU.

 *   transform: transformation identifier.

 * Parameter sources from initialized jpeg_struct

 * (after reading source header):

 *   image_width = cinfo.image_width

 *   image_height = cinfo.image_height

 *   MCU_width = cinfo.max_h_samp_factor * DCTSIZE

 *   MCU_height = cinfo.max_v_samp_factor * DCTSIZE

 * Result:

 *   TRUE = perfect transformation possible

 *   FALSE = perfect transformation not possible

 *           (may use custom action then)

 */

GLOBAL(boolean)

jtransform_perfect_transform(JDIMENSION image_width, JDIMENSION image_height,

			     int MCU_width, int MCU_height,

			     JXFORM_CODE transform)

{

  boolean result = TRUE; /* initialize TRUE */

  switch (transform) {

  case JXFORM_FLIP_H:

  case JXFORM_ROT_270:

    if (image_width % (JDIMENSION) MCU_width)

      result = FALSE;

    break;

  case JXFORM_FLIP_V:

  case JXFORM_ROT_90:

    if (image_height % (JDIMENSION) MCU_height)

      result = FALSE;

    break;

  case JXFORM_TRANSVERSE:

  case JXFORM_ROT_180:

    if (image_width % (JDIMENSION) MCU_width)

      result = FALSE;

    if (image_height % (JDIMENSION) MCU_height)

      result = FALSE;

    break;

  default:

    break;

  }

  return result;

}

#endif /* TRANSFORMS_SUPPORTED */

/* Setup decompression object to save desired markers in memory.

 * This must be called before jpeg_read_header() to have the desired effect.

 */

GLOBAL(void)

jcopy_markers_setup (j_decompress_ptr srcinfo, JCOPY_OPTION option)

{

#ifdef SAVE_MARKERS_SUPPORTED

  int m;

  /* Save comments except under NONE option */

  if (option != JCOPYOPT_NONE) {

    jpeg_save_markers(srcinfo, JPEG_COM, 0xFFFF);

  }

  /* Save all types of APPn markers iff ALL option */

  if (option == JCOPYOPT_ALL) {

    for (m = 0; m < 16; m++)

      jpeg_save_markers(srcinfo, JPEG_APP0 + m, 0xFFFF);

  }

#endif /* SAVE_MARKERS_SUPPORTED */

}

/* Copy markers saved in the given source object to the destination object.

 * This should be called just after jpeg_start_compress() or

 * jpeg_write_coefficients().

 * Note that those routines will have written the SOI, and also the

 * JFIF APP0 or Adobe APP14 markers if selected.

 */

GLOBAL(void)

jcopy_markers_execute (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,

		       JCOPY_OPTION option)

{

  jpeg_saved_marker_ptr marker;

  /* In the current implementation, we don't actually need to examine the

   * option flag here; we just copy everything that got saved.

   * But to avoid confusion, we do not output JFIF and Adobe APP14 markers

   * if the encoder library already wrote one.

   */

  for (marker = srcinfo->marker_list; marker != NULL; marker = marker->next) {

    if (dstinfo->write_JFIF_header &&

	marker->marker == JPEG_APP0 &&

	marker->data_length >= 5 &&

	GETJOCTET(marker->data[0]) == 0x4A &&

	GETJOCTET(marker->data[1]) == 0x46 &&

	GETJOCTET(marker->data[2]) == 0x49 &&

	GETJOCTET(marker->data[3]) == 0x46 &&

	GETJOCTET(marker->data[4]) == 0)

      continue;			/* reject duplicate JFIF */

    if (dstinfo->write_Adobe_marker &&

	marker->marker == JPEG_APP0+14 &&

	marker->data_length >= 5 &&

	GETJOCTET(marker->data[0]) == 0x41 &&

	GETJOCTET(marker->data[1]) == 0x64 &&

	GETJOCTET(marker->data[2]) == 0x6F &&

	GETJOCTET(marker->data[3]) == 0x62 &&

	GETJOCTET(marker->data[4]) == 0x65)

      continue;			/* reject duplicate Adobe */

#ifdef NEED_FAR_POINTERS

    /* We could use jpeg_write_marker if the data weren't FAR... */

    {

      unsigned int i;

      jpeg_write_m_header(dstinfo, marker->marker, marker->data_length);

      for (i = 0; i < marker->data_length; i++)

	jpeg_write_m_byte(dstinfo, marker->data[i]);

    }

#else

    jpeg_write_marker(dstinfo, marker->marker,

		      marker->data, marker->data_length);

#endif

  }

}

} // namespace KIPIJPEGLossLessPlugin

/*

 * transupp.c

 *

 * Copyright (C) 1997, Thomas G. Lane.

 * This file is part of the Independent JPEG Group's software.

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

 *

 * This file contains image transformation routines and other utility code

 * used by the jpegtran sample application.  These are NOT part of the core

 * JPEG library.  But we keep these routines separate from jpegtran.c to

 * ease the task of maintaining jpegtran-like programs that have other user

 * interfaces.

 */

// Local includes

#include "transupp.h"		/* My own external interface */

namespace KIPIJPEGLossLessPlugin

{

#if TRANSFORMS_SUPPORTED

/*

 * Lossless image transformation routines.  These routines work on DCT

 * coefficient arrays and thus do not require any lossy decompression

 * or recompression of the image.

 * Thanks to Guido Vollbeding for the initial design and code of this feature.

 *

 * Horizontal flipping is done in-place, using a single top-to-bottom

 * pass through the virtual source array.  It will thus be much the

 * fastest option for images larger than main memory.

 *

 * The other routines require a set of destination virtual arrays, so they

 * need twice as much memory as jpegtran normally does.  The destination

 * arrays are always written in normal scan order (top to bottom) because

 * the virtual array manager expects this.  The source arrays will be scanned

 * in the corresponding order, which means multiple passes through the source

 * arrays for most of the transforms.  That could result in much thrashing

 * if the image is larger than main memory.

 *

 * Some notes about the operating environment of the individual transform

 * routines:

 * 1. Both the source and destination virtual arrays are allocated from the

 *    source JPEG object, and therefore should be manipulated by calling the

 *    source's memory manager.

 * 2. The destination's component count should be used.  It may be smaller

 *    than the source's when forcing to grayscale.

 * 3. Likewise the destination's sampling factors should be used.  When

 *    forcing to grayscale the destination's sampling factors will be all 1,

 *    and we may as well take that as the effective iMCU size.

 * 4. When "trim" is in effect, the destination's dimensions will be the

 *    trimmed values but the source's will be untrimmed.

 * 5. All the routines assume that the source and destination buffers are

 *    padded out to a full iMCU boundary.  This is true, although for the

 *    source buffer it is an undocumented property of jdcoefct.c.

 * Notes 2,3,4 boil down to this: generally we should use the destination's

 * dimensions and ignore the source's.

 */

LOCAL(void)

do_flip_h (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,

	   jvirt_barray_ptr *src_coef_arrays)

/* Horizontal flip; done in-place, so no separate dest array is required */

{

  JDIMENSION MCU_cols, comp_width, blk_x, blk_y;

  int ci, k, offset_y;

  JBLOCKARRAY buffer;

  JCOEFPTR ptr1, ptr2;

  JCOEF temp1, temp2;

  jpeg_component_info *compptr;

  /* Horizontal mirroring of DCT blocks is accomplished by swapping

   * pairs of blocks in-place.  Within a DCT block, we perform horizontal

   * mirroring by changing the signs of odd-numbered columns.

   * Partial iMCUs at the right edge are left untouched.

   */

  MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {

    compptr = dstinfo->comp_info + ci;

    comp_width = MCU_cols * compptr->h_samp_factor;

    for (blk_y = 0; blk_y < compptr->height_in_blocks;

	 blk_y += compptr->v_samp_factor) {

      buffer = (*srcinfo->mem->access_virt_barray)

	((j_common_ptr) srcinfo, src_coef_arrays[ci], blk_y,

	 (JDIMENSION) compptr->v_samp_factor, TRUE);

      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {

	for (blk_x = 0; blk_x * 2 < comp_width; blk_x++) {

	  ptr1 = buffer[offset_y][blk_x];

	  ptr2 = buffer[offset_y][comp_width - blk_x - 1];

	  /* this unrolled loop doesn't need to know which row it's on... */

	  for (k = 0; k < DCTSIZE2; k += 2) {

	    temp1 = *ptr1;	/* swap even column */

	    temp2 = *ptr2;

	    *ptr1++ = temp2;

	    *ptr2++ = temp1;

	    temp1 = *ptr1;	/* swap odd column with sign change */

	    temp2 = *ptr2;

	    *ptr1++ = -temp2;

	    *ptr2++ = -temp1;

	  }

	}

      }

    }

  }

}

LOCAL(void)

do_flip_v (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,

	   jvirt_barray_ptr *src_coef_arrays,

	   jvirt_barray_ptr *dst_coef_arrays)

/* Vertical flip */

{

  JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;

  int ci, i, j, offset_y;

  JBLOCKARRAY src_buffer, dst_buffer;

  JBLOCKROW src_row_ptr, dst_row_ptr;

  JCOEFPTR src_ptr, dst_ptr;

  jpeg_component_info *compptr;

  /* We output into a separate array because we can't touch different

   * rows of the source virtual array simultaneously.  Otherwise, this

   * is a pretty straightforward analog of horizontal flip.

   * Within a DCT block, vertical mirroring is done by changing the signs

   * of odd-numbered rows.

   * Partial iMCUs at the bottom edge are copied verbatim.

   */

  MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {

    compptr = dstinfo->comp_info + ci;

    comp_height = MCU_rows * compptr->v_samp_factor;

    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;

	 dst_blk_y += compptr->v_samp_factor) {

      dst_buffer = (*srcinfo->mem->access_virt_barray)

	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,

	 (JDIMENSION) compptr->v_samp_factor, TRUE);

      if (dst_blk_y < comp_height) {

	/* Row is within the mirrorable area. */

	src_buffer = (*srcinfo->mem->access_virt_barray)

	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],

	   comp_height - dst_blk_y - (JDIMENSION) compptr->v_samp_factor,

	   (JDIMENSION) compptr->v_samp_factor, FALSE);

      } else {

	/* Bottom-edge blocks will be copied verbatim. */

	src_buffer = (*srcinfo->mem->access_virt_barray)

	  ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_y,

	   (JDIMENSION) compptr->v_samp_factor, FALSE);

      }

      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {

	if (dst_blk_y < comp_height) {

	  /* Row is within the mirrorable area. */

	  dst_row_ptr = dst_buffer[offset_y];

	  src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];

	  for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;

	       dst_blk_x++) {

	    dst_ptr = dst_row_ptr[dst_blk_x];

	    src_ptr = src_row_ptr[dst_blk_x];

	    for (i = 0; i < DCTSIZE; i += 2) {

	      /* copy even row */

	      for (j = 0; j < DCTSIZE; j++)

		*dst_ptr++ = *src_ptr++;

	      /* copy odd row with sign change */

	      for (j = 0; j < DCTSIZE; j++)

		*dst_ptr++ = - *src_ptr++;

	    }

	  }

	} else {

	  /* Just copy row verbatim. */

	  jcopy_block_row(src_buffer[offset_y], dst_buffer[offset_y],

			  compptr->width_in_blocks);

	}

      }

    }

  }

}

LOCAL(void)

do_transpose (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,

	      jvirt_barray_ptr *src_coef_arrays,

	      jvirt_barray_ptr *dst_coef_arrays)

/* Transpose source into destination */

{

  JDIMENSION dst_blk_x, dst_blk_y;

  int ci, i, j, offset_x, offset_y;

  JBLOCKARRAY src_buffer, dst_buffer;

  JCOEFPTR src_ptr, dst_ptr;

  jpeg_component_info *compptr;

  /* Transposing pixels within a block just requires transposing the

   * DCT coefficients.

   * Partial iMCUs at the edges require no special treatment; we simply

   * process all the available DCT blocks for every component.

   */

  for (ci = 0; ci < dstinfo->num_components; ci++) {

    compptr = dstinfo->comp_info + ci;

    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;

	 dst_blk_y += compptr->v_samp_factor) {

      dst_buffer = (*srcinfo->mem->access_virt_barray)

	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,

	 (JDIMENSION) compptr->v_samp_factor, TRUE);

      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {

	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;

	     dst_blk_x += compptr->h_samp_factor) {

	  src_buffer = (*srcinfo->mem->access_virt_barray)

	    ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,

	     (JDIMENSION) compptr->h_samp_factor, FALSE);

	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {

	    src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];

	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];

	    for (i = 0; i < DCTSIZE; i++)

	      for (j = 0; j < DCTSIZE; j++)

		dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];

	  }

	}

      }

    }

  }

}

LOCAL(void)

do_rot_90 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,

	   jvirt_barray_ptr *src_coef_arrays,

	   jvirt_barray_ptr *dst_coef_arrays)

/* 90 degree rotation is equivalent to

 *   1. Transposing the image;

 *   2. Horizontal mirroring.

 * These two steps are merged into a single processing routine.

 */

{

  JDIMENSION MCU_cols, comp_width, dst_blk_x, dst_blk_y;

  int ci, i, j, offset_x, offset_y;

  JBLOCKARRAY src_buffer, dst_buffer;

  JCOEFPTR src_ptr, dst_ptr;

  jpeg_component_info *compptr;

  /* Because of the horizontal mirror step, we can't process partial iMCUs

   * at the (output) right edge properly.  They just get transposed and

   * not mirrored.

   */

  MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {

    compptr = dstinfo->comp_info + ci;

    comp_width = MCU_cols * compptr->h_samp_factor;

    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;

	 dst_blk_y += compptr->v_samp_factor) {

      dst_buffer = (*srcinfo->mem->access_virt_barray)

	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,

	 (JDIMENSION) compptr->v_samp_factor, TRUE);

      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {

	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;

	     dst_blk_x += compptr->h_samp_factor) {

	  src_buffer = (*srcinfo->mem->access_virt_barray)

	    ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,

	     (JDIMENSION) compptr->h_samp_factor, FALSE);

	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {

	    src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];

	    if (dst_blk_x < comp_width) {

	      /* Block is within the mirrorable area. */

	      dst_ptr = dst_buffer[offset_y]

		[comp_width - dst_blk_x - offset_x - 1];

	      for (i = 0; i < DCTSIZE; i++) {

		for (j = 0; j < DCTSIZE; j++)

		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];

		i++;

		for (j = 0; j < DCTSIZE; j++)

		  dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];

	      }

	    } else {

	      /* Edge blocks are transposed but not mirrored. */

	      dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];

	      for (i = 0; i < DCTSIZE; i++)

		for (j = 0; j < DCTSIZE; j++)

		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];

	    }

	  }

	}

      }

    }

  }

}

LOCAL(void)

do_rot_270 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,

	    jvirt_barray_ptr *src_coef_arrays,

	    jvirt_barray_ptr *dst_coef_arrays)

/* 270 degree rotation is equivalent to

 *   1. Horizontal mirroring;

 *   2. Transposing the image.

 * These two steps are merged into a single processing routine.

 */

{

  JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;

  int ci, i, j, offset_x, offset_y;

  JBLOCKARRAY src_buffer, dst_buffer;

  JCOEFPTR src_ptr, dst_ptr;

  jpeg_component_info *compptr;

  /* Because of the horizontal mirror step, we can't process partial iMCUs

   * at the (output) bottom edge properly.  They just get transposed and

   * not mirrored.

   */

  MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {

    compptr = dstinfo->comp_info + ci;

    comp_height = MCU_rows * compptr->v_samp_factor;

    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;

	 dst_blk_y += compptr->v_samp_factor) {

      dst_buffer = (*srcinfo->mem->access_virt_barray)

	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,

	 (JDIMENSION) compptr->v_samp_factor, TRUE);

      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {

	for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;

	     dst_blk_x += compptr->h_samp_factor) {

	  src_buffer = (*srcinfo->mem->access_virt_barray)

	    ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,

	     (JDIMENSION) compptr->h_samp_factor, FALSE);

	  for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {

	    dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];

	    if (dst_blk_y < comp_height) {

	      /* Block is within the mirrorable area. */

	      src_ptr = src_buffer[offset_x]

		[comp_height - dst_blk_y - offset_y - 1];

	      for (i = 0; i < DCTSIZE; i++) {

		for (j = 0; j < DCTSIZE; j++) {

		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];

		  j++;

		  dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];

		}

	      }

	    } else {

	      /* Edge blocks are transposed but not mirrored. */

	      src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];

	      for (i = 0; i < DCTSIZE; i++)

		for (j = 0; j < DCTSIZE; j++)

		  dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];

	    }

	  }

	}

      }

    }

  }

}

LOCAL(void)

do_rot_180 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,

	    jvirt_barray_ptr *src_coef_arrays,

	    jvirt_barray_ptr *dst_coef_arrays)

/* 180 degree rotation is equivalent to

 *   1. Vertical mirroring;

 *   2. Horizontal mirroring.

 * These two steps are merged into a single processing routine.

 */

{

  JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;

  int ci, i, j, offset_y;

  JBLOCKARRAY src_buffer, dst_buffer;

  JBLOCKROW src_row_ptr, dst_row_ptr;

  JCOEFPTR src_ptr, dst_ptr;

  jpeg_component_info *compptr;

  MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);

  MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);

  for (ci = 0; ci < dstinfo->num_components; ci++) {

    compptr = dstinfo->comp_info + ci;

    comp_width = MCU_cols * compptr->h_samp_factor;

    comp_height = MCU_rows * compptr->v_samp_factor;

    for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;

	 dst_blk_y += compptr->v_samp_factor) {

      dst_buffer = (*srcinfo->mem->access_virt_barray)

	((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,

	 (JDIMENSION) compptr->v_samp_factor, TRUE);

      if (dst_blk_y < comp_height) {

	/* Row is within the vertically mirrorable area. */

	src_buffer = (*srcinfo->mem->access_virt_barray)

	  ((j_common_ptr) srcinfo, src_coef_arrays[ci],

	   comp_height - dst_blk_y - (JDIMENSION) compptr->v_samp_factor,

	   (JDIMENSION) compptr->v_samp_factor, FALSE);

      } else {

	/* Bottom-edge rows are only mirrored horizontally. */

	src_buffer = (*srcinfo->mem->access_virt_barray)

	  ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_y,

	   (JDIMENSION) compptr->v_samp_factor, FALSE);

      }

      for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {

	if (dst_blk_y < comp_height) {

	  /* Row is within the mirrorable area. */

	  dst_row_ptr = dst_buffer[offset_y];

	  src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];

	  /* Process the blocks that can be mirrored both ways. */

	  for (dst_blk_x = 0; dst_blk_x < comp_width; dst_blk_x++) {

	    dst_ptr = dst_row_ptr[dst_blk_x];

	    src_ptr = src_row_ptr[comp_width - dst_blk_x - 1];

	    for (i = 0; i < DCTSIZE; i += 2) {

	      /* For even row, negate every odd column. */

	      for (j = 0; j < DCTSIZE; j += 2) {

		*dst_ptr++ = *src_ptr++;

		*dst_ptr++ = - *src_ptr++;

	      }

	      /* For odd row, negate every even column. */

	      for (j = 0; j < DCTSIZE; j += 2) {

		*dst_ptr++ = - *src_ptr++;

		*dst_ptr++ = *src_ptr++;

	      }

	    }