Python2/PyMuPDF: mupdf-source/thirdparty/libjpeg/transupp.c comparison

comparison mupdf-source/thirdparty/libjpeg/transupp.c @ 2:b50eed0cc0ef upstream

ADD: MuPDF v1.26.7: the MuPDF source as downloaded by a default build of PyMuPDF 1.26.4. The directory name has changed: no version number in the expanded directory now.

author	Franz Glasner <fzglas.hg@dom66.de>
date	Mon, 15 Sep 2025 11:43:07 +0200
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-:1d09e1dec1d9
+:b50eed0cc0ef
+/*
+* transupp.c
+*
+* Copyright (C) 1997-2023, 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().
+* Also, the (switchable) virtual memory adaptation code for
+* the drop feature has dependencies on library internals.
+*/
+#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.
+*/
+/* Drop code may be used with or without virtual memory adaptation code.
+* This code has some dependencies on internal library behavior, so you
+* may choose to disable it.  For example, it doesn't make a difference
+* if you only use jmemnobs anyway.
+*/
+#ifndef DROP_REQUEST_FROM_SRC
+#define DROP_REQUEST_FROM_SRC 1		/* 0 disables adaptation */
+#endif
+#if DROP_REQUEST_FROM_SRC
+/* Force jpeg_read_coefficients to request
+* the virtual coefficient arrays from
+* the source decompression object.
+*/
+METHODDEF(jvirt_barray_ptr)
+drop_request_virt_barray (j_common_ptr cinfo, int pool_id, boolean pre_zero,
+			  JDIMENSION blocksperrow, JDIMENSION numrows,
+			  JDIMENSION maxaccess)
+{
+j_common_ptr srcinfo = (j_common_ptr) cinfo->client_data;
+return (*srcinfo->mem->request_virt_barray)
+	  (srcinfo, pool_id, pre_zero,
+	   blocksperrow, numrows, maxaccess);
+}
+/* Force jpeg_read_coefficients to return
+* after requesting and before accessing
+* the virtual coefficient arrays.
+*/
+METHODDEF(int)
+drop_consume_input (j_decompress_ptr cinfo)
+{
+return JPEG_SUSPENDED;
+}
+METHODDEF(void)
+drop_start_input_pass (j_decompress_ptr cinfo)
+{
+cinfo->inputctl->consume_input = drop_consume_input;
+}
+LOCAL(void)
+drop_request_from_src (j_decompress_ptr dropinfo, j_decompress_ptr srcinfo)
+{
+void *save_client_data;
+JMETHOD(jvirt_barray_ptr, save_request_virt_barray,
+	  (j_common_ptr cinfo, int pool_id, boolean pre_zero,
+	   JDIMENSION blocksperrow, JDIMENSION numrows, JDIMENSION maxaccess));
+JMETHOD(void, save_start_input_pass, (j_decompress_ptr cinfo));
+/* Set custom method pointers, save original pointers */
+save_client_data = dropinfo->client_data;
+dropinfo->client_data = (void *) srcinfo;
+save_request_virt_barray = dropinfo->mem->request_virt_barray;
+dropinfo->mem->request_virt_barray = drop_request_virt_barray;
+save_start_input_pass = dropinfo->inputctl->start_input_pass;
+dropinfo->inputctl->start_input_pass = drop_start_input_pass;
+/* Execute only initialization part.
+* Requested coefficient arrays will be realized later by the srcinfo object.
+* Next call to the same function will then do the actual data reading.
+* NB: since we request the coefficient arrays from another object,
+* the inherent realization call is effectively a no-op.
+*/
+(void) jpeg_read_coefficients(dropinfo);
+/* Reset method pointers */
+dropinfo->client_data = save_client_data;
+dropinfo->mem->request_virt_barray = save_request_virt_barray;
+dropinfo->inputctl->start_input_pass = save_start_input_pass;
+/* Do input initialization for first scan now,
+* which also resets the consume_input method.
+*/
+(*save_start_input_pass)(dropinfo);
+}
+#endif /* DROP_REQUEST_FROM_SRC */
+LOCAL(void)
+dequant_comp (j_decompress_ptr cinfo, jpeg_component_info *compptr,
+	      jvirt_barray_ptr coef_array, JQUANT_TBL *qtblptr1)
+{
+JDIMENSION blk_x, blk_y;
+int offset_y, k;
+JQUANT_TBL *qtblptr;
+JBLOCKARRAY buffer;
+JBLOCKROW block;
+JCOEFPTR ptr;
+qtblptr = compptr->quant_table;
+for (blk_y = 0; blk_y < compptr->height_in_blocks;
+blk_y += compptr->v_samp_factor) {
+buffer = (*cinfo->mem->access_virt_barray)
+((j_common_ptr) cinfo, coef_array, blk_y,
+(JDIMENSION) compptr->v_samp_factor, TRUE);
+for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+block = buffer[offset_y];
+for (blk_x = 0; blk_x < compptr->width_in_blocks; blk_x++) {
+	ptr = block[blk_x];
+	for (k = 0; k < DCTSIZE2; k++)
+	  if (qtblptr->quantval[k] != qtblptr1->quantval[k])
+	    ptr[k] *= qtblptr->quantval[k] / qtblptr1->quantval[k];
+}
+}
+}
+}
+LOCAL(void)
+requant_comp (j_decompress_ptr cinfo, jpeg_component_info *compptr,
+	      jvirt_barray_ptr coef_array, JQUANT_TBL *qtblptr1)
+{
+JDIMENSION blk_x, blk_y;
+int offset_y, k, temp, qval;
+JQUANT_TBL *qtblptr;
+JBLOCKARRAY buffer;
+JBLOCKROW block;
+JCOEFPTR ptr;
+qtblptr = compptr->quant_table;
+for (blk_y = 0; blk_y < compptr->height_in_blocks;
+blk_y += compptr->v_samp_factor) {
+buffer = (*cinfo->mem->access_virt_barray)
+((j_common_ptr) cinfo, coef_array, blk_y,
+(JDIMENSION) compptr->v_samp_factor, TRUE);
+for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+block = buffer[offset_y];
+for (blk_x = 0; blk_x < compptr->width_in_blocks; blk_x++) {
+	ptr = block[blk_x];
+	for (k = 0; k < DCTSIZE2; k++) {
+	  qval = qtblptr1->quantval[k];
+	  if (qval == 0) continue;
+	  temp = qtblptr->quantval[k];
+	  if (temp == qval) continue;
+	  temp *= ptr[k];
+	  /* The following quantization code is a copy from jcdctmgr.c */
+#ifdef FAST_DIVIDE
+#define DIVIDE_BY(a,b)	a /= b
+#else
+#define DIVIDE_BY(a,b)	if (a >= b) a /= b; else a = 0
+#endif
+	  if (temp < 0) {
+	    temp = -temp;
+	    temp += qval>>1;	/* for rounding */
+	    DIVIDE_BY(temp, qval);
+	    temp = -temp;
+	  } else {
+	    temp += qval>>1;	/* for rounding */
+	    DIVIDE_BY(temp, qval);
+	  }
+	  ptr[k] = (JCOEF) temp;
+	}
+}
+}
+}
+}
+/* Calculate largest common denominator with Euclid's algorithm.
+*/
+LOCAL(JCOEF)
+largest_common_denominator(JCOEF a, JCOEF b)
+{
+JCOEF c;
+while (b) {
+c = a % b;
+a = b;
+b = c;
+}
+return a;
+}
+LOCAL(void)
+adjust_quant(j_decompress_ptr srcinfo, jvirt_barray_ptr *src_coef_arrays,
+	     j_decompress_ptr dropinfo, jvirt_barray_ptr *drop_coef_arrays,
+	     boolean trim, j_compress_ptr dstinfo)
+{
+jpeg_component_info *compptr1, *compptr2;
+JQUANT_TBL *qtblptr1, *qtblptr2, *qtblptr3;
+int ci, k;
+for (ci = 0; ci < dstinfo->num_components &&
+	       ci < dropinfo->num_components; ci++) {
+compptr1 = srcinfo->comp_info + ci;
+compptr2 = dropinfo->comp_info + ci;
+qtblptr1 = compptr1->quant_table;
+qtblptr2 = compptr2->quant_table;
+for (k = 0; k < DCTSIZE2; k++) {
+if (qtblptr1->quantval[k] != qtblptr2->quantval[k]) {
+	if (trim)
+	  requant_comp(dropinfo, compptr2, drop_coef_arrays[ci], qtblptr1);
+	else {
+	  qtblptr3 = dstinfo->quant_tbl_ptrs[compptr1->quant_tbl_no];
+	  for (k = 0; k < DCTSIZE2; k++)
+	    if (qtblptr1->quantval[k] != qtblptr2->quantval[k])
+	      qtblptr3->quantval[k] = largest_common_denominator
+		(qtblptr1->quantval[k], qtblptr2->quantval[k]);
+	  dequant_comp(srcinfo, compptr1, src_coef_arrays[ci], qtblptr3);
+	  dequant_comp(dropinfo, compptr2, drop_coef_arrays[ci], qtblptr3);
+	}
+	break;
+}
+}
+}
+}
+LOCAL(void)
+do_drop (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+	 JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
+	 jvirt_barray_ptr *src_coef_arrays,
+	 j_decompress_ptr dropinfo, jvirt_barray_ptr *drop_coef_arrays,
+	 JDIMENSION drop_width, JDIMENSION drop_height)
+/* Drop.  If the dropinfo component number is smaller than the destination's,
+* we fill in the remaining components with zero.  This provides the feature
+* of dropping grayscale into (arbitrarily sampled) color images.
+*/
+{
+JDIMENSION comp_width, comp_height;
+JDIMENSION blk_y, x_drop_blocks, y_drop_blocks;
+int ci, offset_y;
+JBLOCKARRAY src_buffer, dst_buffer;
+jpeg_component_info *compptr;
+for (ci = 0; ci < dstinfo->num_components; ci++) {
+compptr = dstinfo->comp_info + ci;
+comp_width = drop_width * compptr->h_samp_factor;
+comp_height = drop_height * compptr->v_samp_factor;
+x_drop_blocks = x_crop_offset * compptr->h_samp_factor;
+y_drop_blocks = y_crop_offset * compptr->v_samp_factor;
+for (blk_y = 0; blk_y < comp_height; blk_y += compptr->v_samp_factor) {
+dst_buffer = (*srcinfo->mem->access_virt_barray)
+	((j_common_ptr) srcinfo, src_coef_arrays[ci], blk_y + y_drop_blocks,
+	 (JDIMENSION) compptr->v_samp_factor, TRUE);
+if (ci < dropinfo->num_components) {
+#if DROP_REQUEST_FROM_SRC
+	src_buffer = (*srcinfo->mem->access_virt_barray)
+	  ((j_common_ptr) srcinfo, drop_coef_arrays[ci], blk_y,
+#else
+	src_buffer = (*dropinfo->mem->access_virt_barray)
+	  ((j_common_ptr) dropinfo, drop_coef_arrays[ci], blk_y,
+#endif
+	   (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],
+			  dst_buffer[offset_y] + x_drop_blocks,
+			  comp_width);
+	}
+} else {
+	for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+	  FMEMZERO(dst_buffer[offset_y] + x_drop_blocks,
+		   comp_width * SIZEOF(JBLOCK));
+	}
+}
+}
+}
+}
+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_crop_ext_zero (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.
+* Extension: If the destination size is larger than the source, we fill in
+* the extra area with zero (neutral gray).  Note we also have to zero partial
+* iMCUs at the right and bottom edge of the source image area in this case.
+*/
+{
+JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height;
+JDIMENSION dst_blk_y, x_crop_blocks, y_crop_blocks;
+int ci, offset_y;
+JBLOCKARRAY src_buffer, dst_buffer;
+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 (dstinfo->jpeg_height > srcinfo->output_height) {
+	if (dst_blk_y < y_crop_blocks ||
+	    dst_blk_y >= y_crop_blocks + comp_height) {
+	  for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+	    FMEMZERO(dst_buffer[offset_y],
+		     compptr->width_in_blocks * SIZEOF(JBLOCK));
+	  }
+	  continue;
+	}
+	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);
+} else {
+	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 (dstinfo->jpeg_width > srcinfo->output_width) {
+	  if (x_crop_blocks > 0) {
+	    FMEMZERO(dst_buffer[offset_y],
+		     x_crop_blocks * SIZEOF(JBLOCK));
+	  }
+	  jcopy_block_row(src_buffer[offset_y],
+			  dst_buffer[offset_y] + x_crop_blocks,
+			  comp_width);
+	  if (compptr->width_in_blocks > x_crop_blocks + comp_width) {
+	    FMEMZERO(dst_buffer[offset_y] +
+		       x_crop_blocks + comp_width,
+		     (compptr->width_in_blocks -
+		       x_crop_blocks - comp_width) * SIZEOF(JBLOCK));
+	  }
+	} else {
+	  jcopy_block_row(src_buffer[offset_y] + x_crop_blocks,
+			  dst_buffer[offset_y],
+			  compptr->width_in_blocks);
+	}
+}
+}
+}
+}
+LOCAL(void)
+do_crop_ext_flat (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.
+* Extension: The destination width is larger than the source and we fill in
+* the extra area with the DC of the adjacent block.  Note we also have to
+* fill partial iMCUs at the right and bottom edge of the source image area
+* in this case.
+*/
+{
+JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height;
+JDIMENSION dst_blk_x, dst_blk_y, x_crop_blocks, y_crop_blocks;
+int ci, offset_y;
+JCOEF dc;
+JBLOCKARRAY src_buffer, dst_buffer;
+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 (dstinfo->jpeg_height > srcinfo->output_height) {
+	if (dst_blk_y < y_crop_blocks ||
+	    dst_blk_y >= y_crop_blocks + comp_height) {
+	  for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+	    FMEMZERO(dst_buffer[offset_y],
+		     compptr->width_in_blocks * SIZEOF(JBLOCK));
+	  }
+	  continue;
+	}
+	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);
+} else {
+	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 (x_crop_blocks > 0) {
+	  FMEMZERO(dst_buffer[offset_y],
+		   x_crop_blocks * SIZEOF(JBLOCK));
+	  dc = src_buffer[offset_y][0][0];
+	  for (dst_blk_x = 0; dst_blk_x < x_crop_blocks; dst_blk_x++) {
+	    dst_buffer[offset_y][dst_blk_x][0] = dc;
+	  }
+	}
+	jcopy_block_row(src_buffer[offset_y],
+			dst_buffer[offset_y] + x_crop_blocks,
+			comp_width);
+	if (compptr->width_in_blocks > x_crop_blocks + comp_width) {
+	  FMEMZERO(dst_buffer[offset_y] +
+		     x_crop_blocks + comp_width,
+		   (compptr->width_in_blocks -
+		     x_crop_blocks - comp_width) * SIZEOF(JBLOCK));
+	  dc = src_buffer[offset_y][comp_width - 1][0];
+	  for (dst_blk_x = x_crop_blocks + comp_width;
+	       dst_blk_x < compptr->width_in_blocks; dst_blk_x++) {
+	    dst_buffer[offset_y][dst_blk_x][0] = dc;
+	  }
+	}
+}
+}
+}
+}
+LOCAL(void)
+do_crop_ext_reflect (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.
+* Extension: The destination width is larger than the source and we fill in
+* the extra area with repeated reflections of the source region.  Note we
+* also have to fill partial iMCUs at the right and bottom edge of the source
+* image area in this case.
+*/
+{
+JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, src_blk_x;
+JDIMENSION dst_blk_x, dst_blk_y, 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;
+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 (dstinfo->jpeg_height > srcinfo->output_height) {
+	if (dst_blk_y < y_crop_blocks ||
+	    dst_blk_y >= y_crop_blocks + comp_height) {
+	  for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+	    FMEMZERO(dst_buffer[offset_y],
+		     compptr->width_in_blocks * SIZEOF(JBLOCK));
+	  }
+	  continue;
+	}
+	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);
+} else {
+	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++) {
+	/* Copy source region */
+	jcopy_block_row(src_buffer[offset_y],
+			dst_buffer[offset_y] + x_crop_blocks,
+			comp_width);
+	if (x_crop_blocks > 0) {
+	  /* Reflect to left */
+	  dst_row_ptr = dst_buffer[offset_y] + x_crop_blocks;
+	  for (dst_blk_x = x_crop_blocks; dst_blk_x > 0;) {
+	    src_row_ptr = dst_row_ptr;	   /* (re)set axis of reflection */
+	    for (src_blk_x = comp_width; src_blk_x > 0 && dst_blk_x > 0;
+		 src_blk_x--, dst_blk_x--) {
+	      dst_ptr = *--dst_row_ptr;	   /* destination goes left */
+	      src_ptr = *src_row_ptr++;	   /* source goes right */
+	      /* 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 */
+	      }
+	    }
+	  }
+	}
+	if (compptr->width_in_blocks > x_crop_blocks + comp_width) {
+	  /* Reflect to right */
+	  dst_row_ptr = dst_buffer[offset_y] + x_crop_blocks + comp_width;
+	  for (dst_blk_x = compptr->width_in_blocks - x_crop_blocks - comp_width;
+	       dst_blk_x > 0;) {
+	    src_row_ptr = dst_row_ptr;	   /* (re)set axis of reflection */
+	    for (src_blk_x = comp_width; src_blk_x > 0 && dst_blk_x > 0;
+		 src_blk_x--, dst_blk_x--) {
+	      dst_ptr = *dst_row_ptr++;	   /* destination goes right */
+	      src_ptr = *--src_row_ptr;	   /* source goes left */
+	      /* 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 */
+	      }
+	    }
+	  }
+	}
+}
+}
+}
+}
+LOCAL(void)
+do_wipe (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+	 JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
+	 jvirt_barray_ptr *src_coef_arrays,
+	 JDIMENSION drop_width, JDIMENSION drop_height)
+/* Wipe - drop content of specified area, fill with zero (neutral gray) */
+{
+JDIMENSION x_wipe_blocks, wipe_width;
+JDIMENSION y_wipe_blocks, wipe_bottom;
+int ci, offset_y;
+JBLOCKARRAY buffer;
+jpeg_component_info *compptr;
+for (ci = 0; ci < dstinfo->num_components; ci++) {
+compptr = dstinfo->comp_info + ci;
+x_wipe_blocks = x_crop_offset * compptr->h_samp_factor;
+wipe_width = drop_width * compptr->h_samp_factor;
+y_wipe_blocks = y_crop_offset * compptr->v_samp_factor;
+wipe_bottom = drop_height * compptr->v_samp_factor + y_wipe_blocks;
+for (; y_wipe_blocks < wipe_bottom;
+	 y_wipe_blocks += compptr->v_samp_factor) {
+buffer = (*srcinfo->mem->access_virt_barray)
+	((j_common_ptr) srcinfo, src_coef_arrays[ci], y_wipe_blocks,
+	 (JDIMENSION) compptr->v_samp_factor, TRUE);
+for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+	FMEMZERO(buffer[offset_y] + x_wipe_blocks,
+		 wipe_width * SIZEOF(JBLOCK));
+}
+}
+}
+}
+LOCAL(void)
+do_flatten (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+	    JDIMENSION x_crop_offset, JDIMENSION y_crop_offset,
+	    jvirt_barray_ptr *src_coef_arrays,
+	    JDIMENSION drop_width, JDIMENSION drop_height)
+/* Flatten - drop content of specified area, similar to wipe,
+* but fill with average of adjacent blocks, instead of zero.
+*/
+{
+JDIMENSION x_wipe_blocks, wipe_width, wipe_right;
+JDIMENSION y_wipe_blocks, wipe_bottom, blk_x;
+int ci, offset_y, dc_left_value, dc_right_value, average;
+JBLOCKARRAY buffer;
+jpeg_component_info *compptr;
+for (ci = 0; ci < dstinfo->num_components; ci++) {
+compptr = dstinfo->comp_info + ci;
+x_wipe_blocks = x_crop_offset * compptr->h_samp_factor;
+wipe_width = drop_width * compptr->h_samp_factor;
+wipe_right = wipe_width + x_wipe_blocks;
+y_wipe_blocks = y_crop_offset * compptr->v_samp_factor;
+wipe_bottom = drop_height * compptr->v_samp_factor + y_wipe_blocks;
+for (; y_wipe_blocks < wipe_bottom;
+	 y_wipe_blocks += compptr->v_samp_factor) {
+buffer = (*srcinfo->mem->access_virt_barray)
+	((j_common_ptr) srcinfo, src_coef_arrays[ci], y_wipe_blocks,
+	 (JDIMENSION) compptr->v_samp_factor, TRUE);
+for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+	FMEMZERO(buffer[offset_y] + x_wipe_blocks,
+		 wipe_width * SIZEOF(JBLOCK));
+	if (x_wipe_blocks > 0) {
+	  dc_left_value = buffer[offset_y][x_wipe_blocks - 1][0];
+	  if (wipe_right < compptr->width_in_blocks) {
+	    dc_right_value = buffer[offset_y][wipe_right][0];
+	    average = (dc_left_value + dc_right_value) >> 1;
+	  } else {
+	    average = dc_left_value;
+	  }
+	} else if (wipe_right < compptr->width_in_blocks) {
+	  average = buffer[offset_y][wipe_right][0];
+	} else continue;
+	for (blk_x = x_wipe_blocks; blk_x < wipe_right; blk_x++) {
+	  buffer[offset_y][blk_x][0] = (JCOEF) average;
+	}
+}
+}
+}
+}
+LOCAL(void)
+do_reflect (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+	    JDIMENSION x_crop_offset,
+	    jvirt_barray_ptr *src_coef_arrays,
+	    JDIMENSION drop_width, JDIMENSION drop_height)
+/* Reflect - drop content of specified area, similar to wipe, but
+* fill with repeated reflections of the outside area, instead of zero.
+* NB: y_crop_offset is assumed to be zero.
+*/
+{
+JDIMENSION x_wipe_blocks, wipe_width;
+JDIMENSION y_wipe_blocks, wipe_bottom;
+JDIMENSION src_blk_x, dst_blk_x;
+int ci, k, offset_y;
+JBLOCKARRAY buffer;
+JBLOCKROW src_row_ptr, dst_row_ptr;
+JCOEFPTR src_ptr, dst_ptr;
+jpeg_component_info *compptr;
+for (ci = 0; ci < dstinfo->num_components; ci++) {
+compptr = dstinfo->comp_info + ci;
+x_wipe_blocks = x_crop_offset * compptr->h_samp_factor;
+wipe_width = drop_width * compptr->h_samp_factor;
+wipe_bottom = drop_height * compptr->v_samp_factor;
+for (y_wipe_blocks = 0; y_wipe_blocks < wipe_bottom;
+	 y_wipe_blocks += compptr->v_samp_factor) {
+buffer = (*srcinfo->mem->access_virt_barray)
+	((j_common_ptr) srcinfo, src_coef_arrays[ci], y_wipe_blocks,
+	 (JDIMENSION) compptr->v_samp_factor, TRUE);
+for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+	if (x_wipe_blocks > 0) {
+	  /* Reflect from left */
+	  dst_row_ptr = buffer[offset_y] + x_wipe_blocks;
+	  for (dst_blk_x = wipe_width; dst_blk_x > 0;) {
+	    src_row_ptr = dst_row_ptr;	   /* (re)set axis of reflection */
+	    for (src_blk_x = x_wipe_blocks;
+		 src_blk_x > 0 && dst_blk_x > 0; src_blk_x--, dst_blk_x--) {
+	      dst_ptr = *dst_row_ptr++;	   /* destination goes right */
+	      src_ptr = *--src_row_ptr;	   /* source goes left */
+	      /* 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 if (compptr->width_in_blocks > x_wipe_blocks + wipe_width) {
+	  /* Reflect from right */
+	  dst_row_ptr = buffer[offset_y] + x_wipe_blocks + wipe_width;
+	  for (dst_blk_x = wipe_width; dst_blk_x > 0;) {
+	    src_row_ptr = dst_row_ptr;	   /* (re)set axis of reflection */
+	    src_blk_x = compptr->width_in_blocks - x_wipe_blocks - wipe_width;
+	    for (; src_blk_x > 0 && dst_blk_x > 0; src_blk_x--, dst_blk_x--) {
+	      dst_ptr = *--dst_row_ptr;	   /* destination goes left */
+	      src_ptr = *src_row_ptr++;	   /* source goes right */
+	      /* 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 {
+	  FMEMZERO(buffer[offset_y] + x_wipe_blocks,
+		   wipe_width * SIZEOF(JBLOCK));
+	}
+}
+}
+}
+}
+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>[{fr}]x<height>[{fr}]{+-}<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 if (*spec == 'r' || *spec == 'R') {
+spec++;
+info->crop_width_set = JCROP_REFLECT;
+} 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 if (*spec == 'r' || *spec == 'R') {
+spec++;
+info->crop_height_set = JCROP_REFLECT;
+} 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, dtemp;
+JDIMENSION width_in_iMCUs, height_in_iMCUs;
+JDIMENSION width_in_blocks, height_in_blocks;
+int itemp, 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->jpeg_color_space == JCS_BG_YCC) &&
+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;
+}
+}
+/* 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_width_set == JCROP_UNSET) {
+if (info->crop_xoffset >= info->output_width)
+	ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
+info->crop_width = info->output_width - info->crop_xoffset;
+} else {
+/* Check for crop extension */
+if (info->crop_width > info->output_width) {
+	/* Crop extension does not work when transforming! */
+	if (info->transform != JXFORM_NONE ||
+	    info->crop_xoffset >= info->crop_width ||
+	    info->crop_xoffset > info->crop_width - info->output_width)
+	  ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
+} else {
+	if (info->crop_xoffset >= info->output_width ||
+	    info->crop_width <= 0 ||
+	    info->crop_xoffset > info->output_width - info->crop_width)
+	  ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
+}
+}
+if (info->crop_height_set == JCROP_UNSET) {
+if (info->crop_yoffset >= info->output_height)
+	ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
+info->crop_height = info->output_height - info->crop_yoffset;
+} else {
+/* Check for crop extension */
+if (info->crop_height > info->output_height) {
+	/* Crop extension does not work when transforming! */
+	if (info->transform != JXFORM_NONE ||
+	    info->crop_yoffset >= info->crop_height ||
+	    info->crop_yoffset > info->crop_height - info->output_height)
+	  ERREXIT(srcinfo, JERR_BAD_CROP_SPEC);
+} else {
+	if (info->crop_yoffset >= info->output_height ||
+	    info->crop_height <= 0 ||
+	    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->crop_xoffset;
+else if (info->crop_width > info->output_width) /* crop extension */
+xoffset = info->crop_width - info->output_width - info->crop_xoffset;
+else
+xoffset = info->output_width - info->crop_width - info->crop_xoffset;
+if (info->crop_yoffset_set != JCROP_NEG)
+yoffset = info->crop_yoffset;
+else if (info->crop_height > info->output_height) /* crop extension */
+yoffset = info->crop_height - info->output_height - info->crop_yoffset;
+else
+yoffset = info->output_height - info->crop_height - info->crop_yoffset;
+/* Now adjust so that upper left corner falls at an iMCU boundary */
+switch (info->transform) {
+case JXFORM_DROP:
+/* Ensure the effective drop region will not exceed the requested */
+itemp = info->iMCU_sample_width;
+dtemp = itemp - 1 - ((xoffset + itemp - 1) % itemp);
+xoffset += dtemp;
+if (info->crop_width <= dtemp)
+	info->drop_width = 0;
+else if (xoffset + info->crop_width - dtemp == info->output_width)
+	/* Matching right edge: include partial iMCU */
+	info->drop_width = (info->crop_width - dtemp + itemp - 1) / itemp;
+else
+	info->drop_width = (info->crop_width - dtemp) / itemp;
+itemp = info->iMCU_sample_height;
+dtemp = itemp - 1 - ((yoffset + itemp - 1) % itemp);
+yoffset += dtemp;
+if (info->crop_height <= dtemp)
+	info->drop_height = 0;
+else if (yoffset + info->crop_height - dtemp == info->output_height)
+	/* Matching bottom edge: include partial iMCU */
+	info->drop_height = (info->crop_height - dtemp + itemp - 1) / itemp;
+else
+	info->drop_height = (info->crop_height - dtemp) / itemp;
+/* Check if sampling factors match for dropping */
+if (info->drop_width != 0 && info->drop_height != 0)
+	for (ci = 0; ci < info->num_components &&
+		     ci < info->drop_ptr->num_components; ci++) {
+	  if (info->drop_ptr->comp_info[ci].h_samp_factor *
+	      srcinfo->max_h_samp_factor !=
+	      srcinfo->comp_info[ci].h_samp_factor *
+	      info->drop_ptr->max_h_samp_factor)
+	    ERREXIT6(srcinfo, JERR_BAD_DROP_SAMPLING, ci,
+	      info->drop_ptr->comp_info[ci].h_samp_factor,
+	      info->drop_ptr->max_h_samp_factor,
+	      srcinfo->comp_info[ci].h_samp_factor,
+	      srcinfo->max_h_samp_factor, 'h');
+	  if (info->drop_ptr->comp_info[ci].v_samp_factor *
+	      srcinfo->max_v_samp_factor !=
+	      srcinfo->comp_info[ci].v_samp_factor *
+	      info->drop_ptr->max_v_samp_factor)
+	    ERREXIT6(srcinfo, JERR_BAD_DROP_SAMPLING, ci,
+	      info->drop_ptr->comp_info[ci].v_samp_factor,
+	      info->drop_ptr->max_v_samp_factor,
+	      srcinfo->comp_info[ci].v_samp_factor,
+	      srcinfo->max_v_samp_factor, 'v');
+	}
+break;
+case JXFORM_WIPE:
+/* Ensure the effective wipe region will cover the requested */
+info->drop_width = (JDIMENSION) jdiv_round_up
+	((long) (info->crop_width + (xoffset % info->iMCU_sample_width)),
+	 (long) info->iMCU_sample_width);
+info->drop_height = (JDIMENSION) jdiv_round_up
+	((long) (info->crop_height + (yoffset % info->iMCU_sample_height)),
+	 (long) info->iMCU_sample_height);
+break;
+default:
+/* Ensure the effective crop region will cover the requested */
+if (info->crop_width_set == JCROP_FORCE ||
+	  info->crop_width > info->output_width)
+	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->crop_height > info->output_height)
+	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 ||
+	info->output_width > srcinfo->output_width ||
+	info->output_height > srcinfo->output_height)
+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;
+case JXFORM_WIPE:
+break;
+case JXFORM_DROP:
+#if DROP_REQUEST_FROM_SRC
+drop_request_from_src(info->drop_ptr, srcinfo);
+#endif
+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 YCC 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->jpeg_color_space == JCS_BG_YCC) &&
+	  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, adjust quantization */
+switch (info->transform) {
+case JXFORM_TRANSPOSE:
+case JXFORM_TRANSVERSE:
+case JXFORM_ROT_90:
+case JXFORM_ROT_270:
+transpose_critical_parameters(dstinfo);
+break;
+case JXFORM_DROP:
+if (info->drop_width != 0 && info->drop_height != 0)
+adjust_quant(srcinfo, src_coef_arrays,
+		   info->drop_ptr, info->drop_coef_arrays,
+		   info->trim, 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->output_width > srcinfo->output_width ||
+	info->output_height > srcinfo->output_height) {
+if (info->output_width > srcinfo->output_width &&
+	  info->crop_width_set == JCROP_REFLECT)
+	do_crop_ext_reflect(srcinfo, dstinfo,
+			    info->x_crop_offset, info->y_crop_offset,
+			    src_coef_arrays, dst_coef_arrays);
+else if (info->output_width > srcinfo->output_width &&
+	       info->crop_width_set == JCROP_FORCE)
+	do_crop_ext_flat(srcinfo, dstinfo,
+			 info->x_crop_offset, info->y_crop_offset,
+			 src_coef_arrays, dst_coef_arrays);
+else
+	do_crop_ext_zero(srcinfo, dstinfo,
+			 info->x_crop_offset, info->y_crop_offset,
+			 src_coef_arrays, dst_coef_arrays);
+} else 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;
+case JXFORM_WIPE:
+if (info->crop_width_set == JCROP_REFLECT &&
+	info->y_crop_offset == 0 && info->drop_height ==
+	(JDIMENSION) jdiv_round_up
+	  ((long) info->output_height, (long) info->iMCU_sample_height) &&
+	(info->x_crop_offset == 0 ||
+	 info->x_crop_offset + info->drop_width ==
+	 (JDIMENSION) jdiv_round_up
+	   ((long) info->output_width, (long) info->iMCU_sample_width)))
+do_reflect(srcinfo, dstinfo, info->x_crop_offset,
+		 src_coef_arrays, info->drop_width, info->drop_height);
+else if (info->crop_width_set == JCROP_FORCE)
+do_flatten(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+		 src_coef_arrays, info->drop_width, info->drop_height);
+else
+do_wipe(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+	      src_coef_arrays, info->drop_width, info->drop_height);
+break;
+case JXFORM_DROP:
+if (info->drop_width != 0 && info->drop_height != 0)
+do_drop(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
+	      src_coef_arrays, info->drop_ptr, info->drop_coef_arrays,
+	      info->drop_width, info->drop_height);
+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
+}
+}

Mercurial > hgrepos > Python2 > PyMuPDF

comparison mupdf-source/thirdparty/libjpeg/transupp.c @ 2:b50eed0cc0ef upstream