Remove damned ancient DOS line endings from Irrlicht. Hopefully I did not go overboard.

1 files changed, 1597 insertions, 1597 deletions

diff --git a/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/transupp.c b/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/transupp.c
index fe34a3a..016f383 100644
--- a/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/transupp.c
+++ b/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/transupp.c
@@ -1,1597 +1,1597 @@
-/*

- * transupp.c

- *

- * Copyright (C) 1997-2011, 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

-

-#include "jinclude.h"

-#include "jpeglib.h"

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

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

-

-

-#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->output_width /

-    (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);

-

-  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->output_width /

-    (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);

-

-  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->output_height /

-    (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);

-

-  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->output_height /

-    (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);

-

-  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->output_width /

-    (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);

-

-  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->output_width /

-    (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);

-  MCU_rows = srcinfo->output_height /

-    (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);

-

-  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->output_height /

-    (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);

-  MCU_rows = srcinfo->output_width /

-    (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);

-

-  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>[f]x<height>[f]{+-}<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;

-    if (*spec == 'f' || *spec == 'F') {

-      spec++;

-      info->crop_width_set = JCROP_FORCE;

-    } else

-      info->crop_width_set = JCROP_POS;

-  }

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

-    /* fetch height */

-    spec++;

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

-      return FALSE;

-    if (*spec == 'f' || *spec == 'F') {

-      spec++;

-      info->crop_height_set = JCROP_FORCE;

-    } else

-      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).

- *

- * This function returns FALSE right away if -perfect is given

- * and transformation is not perfect.  Otherwise returns TRUE.

- */

-

-GLOBAL(boolean)

-jtransform_request_workspace (j_decompress_ptr srcinfo,

-                              jpeg_transform_info *info)

-{

-  jvirt_barray_ptr *coef_arrays;

-  boolean need_workspace, transpose_it;

-  jpeg_component_info *compptr;

-  JDIMENSION xoffset, yoffset;

-  JDIMENSION 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;

-

-  /* Compute output image dimensions and related values. */

-  jpeg_core_output_dimensions(srcinfo);

-

-  /* Return right away if -perfect is given and transformation is not perfect.

-   */

-  if (info->perfect) {

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

-      if (!jtransform_perfect_transform(srcinfo->output_width,

-          srcinfo->output_height,

-          srcinfo->min_DCT_h_scaled_size,

-          srcinfo->min_DCT_v_scaled_size,

-          info->transform))

-        return FALSE;

-    } else {

-      if (!jtransform_perfect_transform(srcinfo->output_width,

-          srcinfo->output_height,

-          srcinfo->max_h_samp_factor * srcinfo->min_DCT_h_scaled_size,

-          srcinfo->max_v_samp_factor * srcinfo->min_DCT_v_scaled_size,

-          info->transform))

-        return FALSE;

-    }

-  }

-

-  /* 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->output_height;

-    info->output_height = srcinfo->output_width;

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

-      info->iMCU_sample_width = srcinfo->min_DCT_v_scaled_size;

-      info->iMCU_sample_height = srcinfo->min_DCT_h_scaled_size;

-    } else {

-      info->iMCU_sample_width =

-        srcinfo->max_v_samp_factor * srcinfo->min_DCT_v_scaled_size;

-      info->iMCU_sample_height =

-        srcinfo->max_h_samp_factor * srcinfo->min_DCT_h_scaled_size;

-    }

-    break;

-  default:

-    info->output_width = srcinfo->output_width;

-    info->output_height = srcinfo->output_height;

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

-      info->iMCU_sample_width = srcinfo->min_DCT_h_scaled_size;

-      info->iMCU_sample_height = srcinfo->min_DCT_v_scaled_size;

-    } else {

-      info->iMCU_sample_width =

-        srcinfo->max_h_samp_factor * srcinfo->min_DCT_h_scaled_size;

-      info->iMCU_sample_height =

-        srcinfo->max_v_samp_factor * srcinfo->min_DCT_v_scaled_size;

-    }

-    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 */

-    if (info->crop_width_set == JCROP_FORCE)

-      info->output_width = info->crop_width;

-    else

-      info->output_width =

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

-    if (info->crop_height_set == JCROP_FORCE)

-      info->output_height = info->crop_height;

-    else

-      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->output_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->output_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->output_height);

-      trim_bottom_edge(info, srcinfo->output_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->output_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->output_width);

-      trim_bottom_edge(info, srcinfo->output_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->output_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;

-  } else

-    info->workspace_coef_arrays = NULL;

-

-  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;

-  JDIMENSION jtemp;

-  UINT16 qtemp;

-

-  /* Transpose image dimensions */

-  jtemp = dstinfo->image_width;

-  dstinfo->image_width = dstinfo->image_height;

-  dstinfo->image_height = jtemp;

-  itemp = dstinfo->min_DCT_h_scaled_size;

-  dstinfo->min_DCT_h_scaled_size = dstinfo->min_DCT_v_scaled_size;

-  dstinfo->min_DCT_v_scaled_size = itemp;

-

-  /* 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 rotate/flip, resize, and crop operations.

-   */

-  dstinfo->jpeg_width = info->output_width;

-  dstinfo->jpeg_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->jpeg_width != srcinfo->image_width ||

-        dstinfo->jpeg_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->jpeg_width, dstinfo->jpeg_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 * cinfo.block_size

- *   MCU_height = cinfo.max_v_samp_factor * cinfo.block_size

- * 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

-  }

-}

+/*
+ * transupp.c
+ *
+ * Copyright (C) 1997-2011, 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
+
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "transupp.h"           /* My own external interface */
+#include <ctype.h>              /* to declare isdigit() */
+
+
+#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->output_width /
+    (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
+
+  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->output_width /
+    (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
+
+  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->output_height /
+    (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
+
+  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->output_height /
+    (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
+
+  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->output_width /
+    (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
+
+  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->output_width /
+    (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
+  MCU_rows = srcinfo->output_height /
+    (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
+
+  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->output_height /
+    (dstinfo->max_h_samp_factor * dstinfo->min_DCT_h_scaled_size);
+  MCU_rows = srcinfo->output_width /
+    (dstinfo->max_v_samp_factor * dstinfo->min_DCT_v_scaled_size);
+
+  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>[f]x<height>[f]{+-}<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;
+    if (*spec == 'f' || *spec == 'F') {
+      spec++;
+      info->crop_width_set = JCROP_FORCE;
+    } else
+      info->crop_width_set = JCROP_POS;
+  }
+  if (*spec == 'x' || *spec == 'X') {
+    /* fetch height */
+    spec++;
+    if (! jt_read_integer(&spec, &info->crop_height))
+      return FALSE;
+    if (*spec == 'f' || *spec == 'F') {
+      spec++;
+      info->crop_height_set = JCROP_FORCE;
+    } else
+      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).
+ *
+ * This function returns FALSE right away if -perfect is given
+ * and transformation is not perfect.  Otherwise returns TRUE.
+ */
+
+GLOBAL(boolean)
+jtransform_request_workspace (j_decompress_ptr srcinfo,
+                              jpeg_transform_info *info)
+{
+  jvirt_barray_ptr *coef_arrays;
+  boolean need_workspace, transpose_it;
+  jpeg_component_info *compptr;
+  JDIMENSION xoffset, yoffset;
+  JDIMENSION 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;
+
+  /* Compute output image dimensions and related values. */
+  jpeg_core_output_dimensions(srcinfo);
+
+  /* Return right away if -perfect is given and transformation is not perfect.
+   */
+  if (info->perfect) {
+    if (info->num_components == 1) {
+      if (!jtransform_perfect_transform(srcinfo->output_width,
+          srcinfo->output_height,
+          srcinfo->min_DCT_h_scaled_size,
+          srcinfo->min_DCT_v_scaled_size,
+          info->transform))
+        return FALSE;
+    } else {
+      if (!jtransform_perfect_transform(srcinfo->output_width,
+          srcinfo->output_height,
+          srcinfo->max_h_samp_factor * srcinfo->min_DCT_h_scaled_size,
+          srcinfo->max_v_samp_factor * srcinfo->min_DCT_v_scaled_size,
+          info->transform))
+        return FALSE;
+    }
+  }
+
+  /* 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->output_height;
+    info->output_height = srcinfo->output_width;
+    if (info->num_components == 1) {
+      info->iMCU_sample_width = srcinfo->min_DCT_v_scaled_size;
+      info->iMCU_sample_height = srcinfo->min_DCT_h_scaled_size;
+    } else {
+      info->iMCU_sample_width =
+        srcinfo->max_v_samp_factor * srcinfo->min_DCT_v_scaled_size;
+      info->iMCU_sample_height =
+        srcinfo->max_h_samp_factor * srcinfo->min_DCT_h_scaled_size;
+    }
+    break;
+  default:
+    info->output_width = srcinfo->output_width;
+    info->output_height = srcinfo->output_height;
+    if (info->num_components == 1) {
+      info->iMCU_sample_width = srcinfo->min_DCT_h_scaled_size;
+      info->iMCU_sample_height = srcinfo->min_DCT_v_scaled_size;
+    } else {
+      info->iMCU_sample_width =
+        srcinfo->max_h_samp_factor * srcinfo->min_DCT_h_scaled_size;
+      info->iMCU_sample_height =
+        srcinfo->max_v_samp_factor * srcinfo->min_DCT_v_scaled_size;
+    }
+    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 */
+    if (info->crop_width_set == JCROP_FORCE)
+      info->output_width = info->crop_width;
+    else
+      info->output_width =
+        info->crop_width + (xoffset % info->iMCU_sample_width);
+    if (info->crop_height_set == JCROP_FORCE)
+      info->output_height = info->crop_height;
+    else
+      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->output_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->output_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->output_height);
+      trim_bottom_edge(info, srcinfo->output_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->output_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->output_width);
+      trim_bottom_edge(info, srcinfo->output_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->output_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;
+  } else
+    info->workspace_coef_arrays = NULL;
+
+  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;
+  JDIMENSION jtemp;
+  UINT16 qtemp;
+
+  /* Transpose image dimensions */
+  jtemp = dstinfo->image_width;
+  dstinfo->image_width = dstinfo->image_height;
+  dstinfo->image_height = jtemp;
+  itemp = dstinfo->min_DCT_h_scaled_size;
+  dstinfo->min_DCT_h_scaled_size = dstinfo->min_DCT_v_scaled_size;
+  dstinfo->min_DCT_v_scaled_size = itemp;
+
+  /* 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 rotate/flip, resize, and crop operations.
+   */
+  dstinfo->jpeg_width = info->output_width;
+  dstinfo->jpeg_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->jpeg_width != srcinfo->image_width ||
+        dstinfo->jpeg_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->jpeg_width, dstinfo->jpeg_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 * cinfo.block_size
+ *   MCU_height = cinfo.max_v_samp_factor * cinfo.block_size
+ * 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
+  }
+}