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5829cb2398
libjpeg-turbo/transupp.c
Guido Vollbeding 5829cb2398 The Independent JPEG Group's JPEG software v8d
2015-07-27 13:50:34 -05:00

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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);
/* Save x/y offsets measured in iMCUs */
info->x_crop_offset = xoffset / info->iMCU_sample_width;
info->y_crop_offset = yoffset / info->iMCU_sample_height;
} else {
info->x_crop_offset = 0;
info->y_crop_offset = 0;
}
/* Figure out whether we need workspace arrays,
* and if so whether they are transposed relative to the source.
*/
need_workspace = FALSE;
transpose_it = FALSE;
switch (info->transform) {
case JXFORM_NONE:
if (info->x_crop_offset != 0 || info->y_crop_offset != 0)
need_workspace = TRUE;
/* No workspace needed if neither cropping nor transforming */
break;
case JXFORM_FLIP_H:
if (info->trim)
trim_right_edge(info, srcinfo->output_width);
if (info->y_crop_offset != 0)
need_workspace = TRUE;
/* do_flip_h_no_crop doesn't need a workspace array */
break;
case JXFORM_FLIP_V:
if (info->trim)
trim_bottom_edge(info, srcinfo->output_height);
/* Need workspace arrays having same dimensions as source image. */
need_workspace = TRUE;
break;
case JXFORM_TRANSPOSE:
/* transpose does NOT have to trim anything */
/* Need workspace arrays having transposed dimensions. */
need_workspace = TRUE;
transpose_it = TRUE;
break;
case JXFORM_TRANSVERSE:
if (info->trim) {
trim_right_edge(info, srcinfo->output_height);
trim_bottom_edge(info, srcinfo->output_width);
}
/* Need workspace arrays having transposed dimensions. */
need_workspace = TRUE;
transpose_it = TRUE;
break;
case JXFORM_ROT_90:
if (info->trim)
trim_right_edge(info, srcinfo->output_height);
/* Need workspace arrays having transposed dimensions. */
need_workspace = TRUE;
transpose_it = TRUE;
break;
case JXFORM_ROT_180:
if (info->trim) {
trim_right_edge(info, srcinfo->output_width);
trim_bottom_edge(info, srcinfo->output_height);
}
/* Need workspace arrays having same dimensions as source image. */
need_workspace = TRUE;
break;
case JXFORM_ROT_270:
if (info->trim)
trim_bottom_edge(info, srcinfo->output_width);
/* Need workspace arrays having transposed dimensions. */
need_workspace = TRUE;
transpose_it = TRUE;
break;
}
/* Allocate workspace if needed.
* Note that we allocate arrays padded out to the next iMCU boundary,
* so that transform routines need not worry about missing edge blocks.
*/
if (need_workspace) {
coef_arrays = (jvirt_barray_ptr *)
(*srcinfo->mem->alloc_small) ((j_common_ptr) srcinfo, JPOOL_IMAGE,
SIZEOF(jvirt_barray_ptr) * info->num_components);
width_in_iMCUs = (JDIMENSION)
jdiv_round_up((long) info->output_width,
(long) info->iMCU_sample_width);
height_in_iMCUs = (JDIMENSION)
jdiv_round_up((long) info->output_height,
(long) info->iMCU_sample_height);
for (ci = 0; ci < info->num_components; ci++) {
compptr = srcinfo->comp_info + ci;
if (info->num_components == 1) {
/* we're going to force samp factors to 1x1 in this case */
h_samp_factor = v_samp_factor = 1;
} else if (transpose_it) {
h_samp_factor = compptr->v_samp_factor;
v_samp_factor = compptr->h_samp_factor;
} else {
h_samp_factor = compptr->h_samp_factor;
v_samp_factor = compptr->v_samp_factor;
}
width_in_blocks = width_in_iMCUs * h_samp_factor;
height_in_blocks = height_in_iMCUs * v_samp_factor;
coef_arrays[ci] = (*srcinfo->mem->request_virt_barray)
((j_common_ptr) srcinfo, JPOOL_IMAGE, FALSE,
width_in_blocks, height_in_blocks, (JDIMENSION) v_samp_factor);
}
info->workspace_coef_arrays = coef_arrays;
} else
info->workspace_coef_arrays = NULL;
return TRUE;
}
/* Transpose destination image parameters */
LOCAL(void)
transpose_critical_parameters (j_compress_ptr dstinfo)
{
int tblno, i, j, ci, itemp;
jpeg_component_info *compptr;
JQUANT_TBL *qtblptr;
JDIMENSION jtemp;
UINT16 qtemp;
/* Transpose image dimensions */
jtemp = dstinfo->image_width;
dstinfo->image_width = dstinfo->image_height;
dstinfo->image_height = jtemp;
itemp = dstinfo->min_DCT_h_scaled_size;
dstinfo->min_DCT_h_scaled_size = dstinfo->min_DCT_v_scaled_size;
dstinfo->min_DCT_v_scaled_size = itemp;
/* Transpose sampling factors */
for (ci = 0; ci < dstinfo->num_components; ci++) {
compptr = dstinfo->comp_info + ci;
itemp = compptr->h_samp_factor;
compptr->h_samp_factor = compptr->v_samp_factor;
compptr->v_samp_factor = itemp;
}
/* Transpose quantization tables */
for (tblno = 0; tblno < NUM_QUANT_TBLS; tblno++) {
qtblptr = dstinfo->quant_tbl_ptrs[tblno];
if (qtblptr != NULL) {
for (i = 0; i < DCTSIZE; i++) {
for (j = 0; j < i; j++) {
qtemp = qtblptr->quantval[i*DCTSIZE+j];
qtblptr->quantval[i*DCTSIZE+j] = qtblptr->quantval[j*DCTSIZE+i];
qtblptr->quantval[j*DCTSIZE+i] = qtemp;
}
}
}
}
}
/* Adjust Exif image parameters.
*
* We try to adjust the Tags ExifImageWidth and ExifImageHeight if possible.
*/
LOCAL(void)
adjust_exif_parameters (JOCTET FAR * data, unsigned int length,
JDIMENSION new_width, JDIMENSION new_height)
{
boolean is_motorola; /* Flag for byte order */
unsigned int number_of_tags, tagnum;
unsigned int firstoffset, offset;
JDIMENSION new_value;
if (length < 12) return; /* Length of an IFD entry */
/* Discover byte order */
if (GETJOCTET(data[0]) == 0x49 && GETJOCTET(data[1]) == 0x49)
is_motorola = FALSE;
else if (GETJOCTET(data[0]) == 0x4D && GETJOCTET(data[1]) == 0x4D)
is_motorola = TRUE;
else
return;
/* Check Tag Mark */
if (is_motorola) {
if (GETJOCTET(data[2]) != 0) return;
if (GETJOCTET(data[3]) != 0x2A) return;
} else {
if (GETJOCTET(data[3]) != 0) return;
if (GETJOCTET(data[2]) != 0x2A) return;
}
/* Get first IFD offset (offset to IFD0) */
if (is_motorola) {
if (GETJOCTET(data[4]) != 0) return;
if (GETJOCTET(data[5]) != 0) return;
firstoffset = GETJOCTET(data[6]);
firstoffset <<= 8;
firstoffset += GETJOCTET(data[7]);
} else {
if (GETJOCTET(data[7]) != 0) return;
if (GETJOCTET(data[6]) != 0) return;
firstoffset = GETJOCTET(data[5]);
firstoffset <<= 8;
firstoffset += GETJOCTET(data[4]);
}
if (firstoffset > length - 2) return; /* check end of data segment */
/* Get the number of directory entries contained in this IFD */
if (is_motorola) {
number_of_tags = GETJOCTET(data[firstoffset]);
number_of_tags <<= 8;
number_of_tags += GETJOCTET(data[firstoffset+1]);
} else {
number_of_tags = GETJOCTET(data[firstoffset+1]);
number_of_tags <<= 8;
number_of_tags += GETJOCTET(data[firstoffset]);
}
if (number_of_tags == 0) return;
firstoffset += 2;
/* Search for ExifSubIFD offset Tag in IFD0 */
for (;;) {
if (firstoffset > length - 12) return; /* check end of data segment */
/* Get Tag number */
if (is_motorola) {
tagnum = GETJOCTET(data[firstoffset]);
tagnum <<= 8;
tagnum += GETJOCTET(data[firstoffset+1]);
} else {
tagnum = GETJOCTET(data[firstoffset+1]);
tagnum <<= 8;
tagnum += GETJOCTET(data[firstoffset]);
}
if (tagnum == 0x8769) break; /* found ExifSubIFD offset Tag */
if (--number_of_tags == 0) return;
firstoffset += 12;
}
/* Get the ExifSubIFD offset */
if (is_motorola) {
if (GETJOCTET(data[firstoffset+8]) != 0) return;
if (GETJOCTET(data[firstoffset+9]) != 0) return;
offset = GETJOCTET(data[firstoffset+10]);
offset <<= 8;
offset += GETJOCTET(data[firstoffset+11]);
} else {
if (GETJOCTET(data[firstoffset+11]) != 0) return;
if (GETJOCTET(data[firstoffset+10]) != 0) return;
offset = GETJOCTET(data[firstoffset+9]);
offset <<= 8;
offset += GETJOCTET(data[firstoffset+8]);
}
if (offset > length - 2) return; /* check end of data segment */
/* Get the number of directory entries contained in this SubIFD */
if (is_motorola) {
number_of_tags = GETJOCTET(data[offset]);
number_of_tags <<= 8;
number_of_tags += GETJOCTET(data[offset+1]);
} else {
number_of_tags = GETJOCTET(data[offset+1]);
number_of_tags <<= 8;
number_of_tags += GETJOCTET(data[offset]);
}
if (number_of_tags < 2) return;
offset += 2;
/* Search for ExifImageWidth and ExifImageHeight Tags in this SubIFD */
do {
if (offset > length - 12) return; /* check end of data segment */
/* Get Tag number */
if (is_motorola) {
tagnum = GETJOCTET(data[offset]);
tagnum <<= 8;
tagnum += GETJOCTET(data[offset+1]);
} else {
tagnum = GETJOCTET(data[offset+1]);
tagnum <<= 8;
tagnum += GETJOCTET(data[offset]);
}
if (tagnum == 0xA002 || tagnum == 0xA003) {
if (tagnum == 0xA002)
new_value = new_width; /* ExifImageWidth Tag */
else
new_value = new_height; /* ExifImageHeight Tag */
if (is_motorola) {
data[offset+2] = 0; /* Format = unsigned long (4 octets) */
data[offset+3] = 4;
data[offset+4] = 0; /* Number Of Components = 1 */
data[offset+5] = 0;
data[offset+6] = 0;
data[offset+7] = 1;
data[offset+8] = 0;
data[offset+9] = 0;
data[offset+10] = (JOCTET)((new_value >> 8) & 0xFF);
data[offset+11] = (JOCTET)(new_value & 0xFF);
} else {
data[offset+2] = 4; /* Format = unsigned long (4 octets) */
data[offset+3] = 0;
data[offset+4] = 1; /* Number Of Components = 1 */
data[offset+5] = 0;
data[offset+6] = 0;
data[offset+7] = 0;
data[offset+8] = (JOCTET)(new_value & 0xFF);
data[offset+9] = (JOCTET)((new_value >> 8) & 0xFF);
data[offset+10] = 0;
data[offset+11] = 0;
}
}
offset += 12;
} while (--number_of_tags);
}
/* Adjust output image parameters as needed.
*
* This must be called after jpeg_copy_critical_parameters()
* and before jpeg_write_coefficients().
*
* The return value is the set of virtual coefficient arrays to be written
* (either the ones allocated by jtransform_request_workspace, or the
* original source data arrays). The caller will need to pass this value
* to jpeg_write_coefficients().
*/
GLOBAL(jvirt_barray_ptr *)
jtransform_adjust_parameters (j_decompress_ptr srcinfo,
j_compress_ptr dstinfo,
jvirt_barray_ptr *src_coef_arrays,
jpeg_transform_info *info)
{
/* If force-to-grayscale is requested, adjust destination parameters */
if (info->force_grayscale) {
/* First, ensure we have YCbCr or grayscale data, and that the source's
* Y channel is full resolution. (No reasonable person would make Y
* be less than full resolution, so actually coping with that case
* isn't worth extra code space. But we check it to avoid crashing.)
*/
if (((dstinfo->jpeg_color_space == JCS_YCbCr &&
dstinfo->num_components == 3) ||
(dstinfo->jpeg_color_space == JCS_GRAYSCALE &&
dstinfo->num_components == 1)) &&
srcinfo->comp_info[0].h_samp_factor == srcinfo->max_h_samp_factor &&
srcinfo->comp_info[0].v_samp_factor == srcinfo->max_v_samp_factor) {
/* We use jpeg_set_colorspace to make sure subsidiary settings get fixed
* properly. Among other things, it sets the target h_samp_factor &
* v_samp_factor to 1, which typically won't match the source.
* We have to preserve the source's quantization table number, however.
*/
int sv_quant_tbl_no = dstinfo->comp_info[0].quant_tbl_no;
jpeg_set_colorspace(dstinfo, JCS_GRAYSCALE);
dstinfo->comp_info[0].quant_tbl_no = sv_quant_tbl_no;
} else {
/* Sorry, can't do it */
ERREXIT(dstinfo, JERR_CONVERSION_NOTIMPL);
}
} else if (info->num_components == 1) {
/* For a single-component source, we force the destination sampling factors
* to 1x1, with or without force_grayscale. This is useful because some
* decoders choke on grayscale images with other sampling factors.
*/
dstinfo->comp_info[0].h_samp_factor = 1;
dstinfo->comp_info[0].v_samp_factor = 1;
}
/* Correct the destination's image dimensions as necessary
* for rotate/flip, resize, and crop operations.
*/
dstinfo->jpeg_width = info->output_width;
dstinfo->jpeg_height = info->output_height;
/* Transpose destination image parameters */
switch (info->transform) {
case JXFORM_TRANSPOSE:
case JXFORM_TRANSVERSE:
case JXFORM_ROT_90:
case JXFORM_ROT_270:
transpose_critical_parameters(dstinfo);
break;
default:
break;
}
/* Adjust Exif properties */
if (srcinfo->marker_list != NULL &&
srcinfo->marker_list->marker == JPEG_APP0+1 &&
srcinfo->marker_list->data_length >= 6 &&
GETJOCTET(srcinfo->marker_list->data[0]) == 0x45 &&
GETJOCTET(srcinfo->marker_list->data[1]) == 0x78 &&
GETJOCTET(srcinfo->marker_list->data[2]) == 0x69 &&
GETJOCTET(srcinfo->marker_list->data[3]) == 0x66 &&
GETJOCTET(srcinfo->marker_list->data[4]) == 0 &&
GETJOCTET(srcinfo->marker_list->data[5]) == 0) {
/* Suppress output of JFIF marker */
dstinfo->write_JFIF_header = FALSE;
/* Adjust Exif image parameters */
if (dstinfo->jpeg_width != srcinfo->image_width ||
dstinfo->jpeg_height != srcinfo->image_height)
/* Align data segment to start of TIFF structure for parsing */
adjust_exif_parameters(srcinfo->marker_list->data + 6,
srcinfo->marker_list->data_length - 6,
dstinfo->jpeg_width, dstinfo->jpeg_height);
}
/* Return the appropriate output data set */
if (info->workspace_coef_arrays != NULL)
return info->workspace_coef_arrays;
return src_coef_arrays;
}
/* Execute the actual transformation, if any.
*
* This must be called *after* jpeg_write_coefficients, because it depends
* on jpeg_write_coefficients to have computed subsidiary values such as
* the per-component width and height fields in the destination object.
*
* Note that some transformations will modify the source data arrays!
*/
GLOBAL(void)
jtransform_execute_transform (j_decompress_ptr srcinfo,
j_compress_ptr dstinfo,
jvirt_barray_ptr *src_coef_arrays,
jpeg_transform_info *info)
{
jvirt_barray_ptr *dst_coef_arrays = info->workspace_coef_arrays;
/* Note: conditions tested here should match those in switch statement
* in jtransform_request_workspace()
*/
switch (info->transform) {
case JXFORM_NONE:
if (info->x_crop_offset != 0 || info->y_crop_offset != 0)
do_crop(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
src_coef_arrays, dst_coef_arrays);
break;
case JXFORM_FLIP_H:
if (info->y_crop_offset != 0)
do_flip_h(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
src_coef_arrays, dst_coef_arrays);
else
do_flip_h_no_crop(srcinfo, dstinfo, info->x_crop_offset,
src_coef_arrays);
break;
case JXFORM_FLIP_V:
do_flip_v(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
src_coef_arrays, dst_coef_arrays);
break;
case JXFORM_TRANSPOSE:
do_transpose(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
src_coef_arrays, dst_coef_arrays);
break;
case JXFORM_TRANSVERSE:
do_transverse(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
src_coef_arrays, dst_coef_arrays);
break;
case JXFORM_ROT_90:
do_rot_90(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
src_coef_arrays, dst_coef_arrays);
break;
case JXFORM_ROT_180:
do_rot_180(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
src_coef_arrays, dst_coef_arrays);
break;
case JXFORM_ROT_270:
do_rot_270(srcinfo, dstinfo, info->x_crop_offset, info->y_crop_offset,
src_coef_arrays, dst_coef_arrays);
break;
}
}
/* jtransform_perfect_transform
*
* Determine whether lossless transformation is perfectly
* possible for a specified image and transformation.
*
* Inputs:
* image_width, image_height: source image dimensions.
* MCU_width, MCU_height: pixel dimensions of MCU.
* transform: transformation identifier.
* Parameter sources from initialized jpeg_struct
* (after reading source header):
* image_width = cinfo.image_width
* image_height = cinfo.image_height
* MCU_width = cinfo.max_h_samp_factor * cinfo.block_size
* MCU_height = cinfo.max_v_samp_factor * cinfo.block_size
* Result:
* TRUE = perfect transformation possible
* FALSE = perfect transformation not possible
* (may use custom action then)
*/
GLOBAL(boolean)
jtransform_perfect_transform(JDIMENSION image_width, JDIMENSION image_height,
int MCU_width, int MCU_height,
JXFORM_CODE transform)
{
boolean result = TRUE; /* initialize TRUE */
switch (transform) {
case JXFORM_FLIP_H:
case JXFORM_ROT_270:
if (image_width % (JDIMENSION) MCU_width)
result = FALSE;
break;
case JXFORM_FLIP_V:
case JXFORM_ROT_90:
if (image_height % (JDIMENSION) MCU_height)
result = FALSE;
break;
case JXFORM_TRANSVERSE:
case JXFORM_ROT_180:
if (image_width % (JDIMENSION) MCU_width)
result = FALSE;
if (image_height % (JDIMENSION) MCU_height)
result = FALSE;
break;
default:
break;
}
return result;
}
#endif /* TRANSFORMS_SUPPORTED */
/* Setup decompression object to save desired markers in memory.
* This must be called before jpeg_read_header() to have the desired effect.
*/
GLOBAL(void)
jcopy_markers_setup (j_decompress_ptr srcinfo, JCOPY_OPTION option)
{
#ifdef SAVE_MARKERS_SUPPORTED
int m;
/* Save comments except under NONE option */
if (option != JCOPYOPT_NONE) {
jpeg_save_markers(srcinfo, JPEG_COM, 0xFFFF);
}
/* Save all types of APPn markers iff ALL option */
if (option == JCOPYOPT_ALL) {
for (m = 0; m < 16; m++)
jpeg_save_markers(srcinfo, JPEG_APP0 + m, 0xFFFF);
}
#endif /* SAVE_MARKERS_SUPPORTED */
}
/* Copy markers saved in the given source object to the destination object.
* This should be called just after jpeg_start_compress() or
* jpeg_write_coefficients().
* Note that those routines will have written the SOI, and also the
* JFIF APP0 or Adobe APP14 markers if selected.
*/
GLOBAL(void)
jcopy_markers_execute (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
JCOPY_OPTION option)
{
jpeg_saved_marker_ptr marker;
/* In the current implementation, we don't actually need to examine the
* option flag here; we just copy everything that got saved.
* But to avoid confusion, we do not output JFIF and Adobe APP14 markers
* if the encoder library already wrote one.
*/
for (marker = srcinfo->marker_list; marker != NULL; marker = marker->next) {
if (dstinfo->write_JFIF_header &&
marker->marker == JPEG_APP0 &&
marker->data_length >= 5 &&
GETJOCTET(marker->data[0]) == 0x4A &&
GETJOCTET(marker->data[1]) == 0x46 &&
GETJOCTET(marker->data[2]) == 0x49 &&
GETJOCTET(marker->data[3]) == 0x46 &&
GETJOCTET(marker->data[4]) == 0)
continue; /* reject duplicate JFIF */
if (dstinfo->write_Adobe_marker &&
marker->marker == JPEG_APP0+14 &&
marker->data_length >= 5 &&
GETJOCTET(marker->data[0]) == 0x41 &&
GETJOCTET(marker->data[1]) == 0x64 &&
GETJOCTET(marker->data[2]) == 0x6F &&
GETJOCTET(marker->data[3]) == 0x62 &&
GETJOCTET(marker->data[4]) == 0x65)
continue; /* reject duplicate Adobe */
#ifdef NEED_FAR_POINTERS
/* We could use jpeg_write_marker if the data weren't FAR... */
{
unsigned int i;
jpeg_write_m_header(dstinfo, marker->marker, marker->data_length);
for (i = 0; i < marker->data_length; i++)
jpeg_write_m_byte(dstinfo, marker->data[i]);
}
#else
jpeg_write_marker(dstinfo, marker->marker,
marker->data, marker->data_length);
#endif
}
}
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