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transupp.c
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/*
* 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);