--- /dev/null
+/*
+ * transupp.c
+ *
+ * Copyright (C) 1997, Thomas G. Lane.
+ * This file is part of the Independent JPEG Group's software.
+ * For conditions of distribution and use, see the accompanying README file.
+ *
+ * This file contains image transformation routines and other utility code
+ * used by the jpegtran sample application. These are NOT part of the core
+ * JPEG library. But we keep these routines separate from jpegtran.c to
+ * ease the task of maintaining jpegtran-like programs that have other user
+ * interfaces.
+ */
+
+/* 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 */
+
+
+#if TRANSFORMS_SUPPORTED
+
+/*
+ * Lossless image transformation routines. These routines work on DCT
+ * coefficient arrays and thus do not require any lossy decompression
+ * or recompression of the image.
+ * Thanks to Guido Vollbeding for the initial design and code of this feature.
+ *
+ * Horizontal flipping is done in-place, using a single top-to-bottom
+ * pass through the virtual source array. It will thus be much the
+ * fastest option for images larger than main memory.
+ *
+ * The other routines require a set of destination virtual arrays, so they
+ * need twice as much memory as jpegtran normally does. The destination
+ * arrays are always written in normal scan order (top to bottom) because
+ * the virtual array manager expects this. The source arrays will be scanned
+ * in the corresponding order, which means multiple passes through the source
+ * arrays for most of the transforms. That could result in much thrashing
+ * if the image is larger than main memory.
+ *
+ * Some notes about the operating environment of the individual transform
+ * routines:
+ * 1. Both the source and destination virtual arrays are allocated from the
+ * source JPEG object, and therefore should be manipulated by calling the
+ * source's memory manager.
+ * 2. The destination's component count should be used. It may be smaller
+ * than the source's when forcing to grayscale.
+ * 3. Likewise the destination's sampling factors should be used. When
+ * forcing to grayscale the destination's sampling factors will be all 1,
+ * and we may as well take that as the effective iMCU size.
+ * 4. When "trim" is in effect, the destination's dimensions will be the
+ * trimmed values but the source's will be untrimmed.
+ * 5. All the routines assume that the source and destination buffers are
+ * padded out to a full iMCU boundary. This is true, although for the
+ * source buffer it is an undocumented property of jdcoefct.c.
+ * Notes 2,3,4 boil down to this: generally we should use the destination's
+ * dimensions and ignore the source's.
+ */
+
+
+LOCAL(void)
+do_flip_h (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+ jvirt_barray_ptr *src_coef_arrays)
+/* Horizontal flip; done in-place, so no separate dest array is required */
+{
+ JDIMENSION MCU_cols, comp_width, blk_x, blk_y;
+ int ci, k, offset_y;
+ JBLOCKARRAY buffer;
+ JCOEFPTR ptr1, ptr2;
+ JCOEF temp1, temp2;
+ jpeg_component_info *compptr;
+
+ /* Horizontal mirroring of DCT blocks is accomplished by swapping
+ * pairs of blocks in-place. Within a DCT block, we perform horizontal
+ * mirroring by changing the signs of odd-numbered columns.
+ * Partial iMCUs at the right edge are left untouched.
+ */
+ MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
+
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ compptr = dstinfo->comp_info + ci;
+ comp_width = MCU_cols * compptr->h_samp_factor;
+ for (blk_y = 0; blk_y < compptr->height_in_blocks;
+ blk_y += compptr->v_samp_factor) {
+ buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci], blk_y,
+ (JDIMENSION) compptr->v_samp_factor, TRUE);
+ for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+ for (blk_x = 0; blk_x * 2 < comp_width; blk_x++) {
+ ptr1 = buffer[offset_y][blk_x];
+ ptr2 = buffer[offset_y][comp_width - blk_x - 1];
+ /* this unrolled loop doesn't need to know which row it's on... */
+ for (k = 0; k < DCTSIZE2; k += 2) {
+ temp1 = *ptr1; /* swap even column */
+ temp2 = *ptr2;
+ *ptr1++ = temp2;
+ *ptr2++ = temp1;
+ temp1 = *ptr1; /* swap odd column with sign change */
+ temp2 = *ptr2;
+ *ptr1++ = -temp2;
+ *ptr2++ = -temp1;
+ }
+ }
+ }
+ }
+ }
+}
+
+
+LOCAL(void)
+do_flip_v (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+ jvirt_barray_ptr *src_coef_arrays,
+ jvirt_barray_ptr *dst_coef_arrays)
+/* Vertical flip */
+{
+ JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
+ int ci, i, j, offset_y;
+ JBLOCKARRAY src_buffer, dst_buffer;
+ JBLOCKROW src_row_ptr, dst_row_ptr;
+ JCOEFPTR src_ptr, dst_ptr;
+ jpeg_component_info *compptr;
+
+ /* We output into a separate array because we can't touch different
+ * rows of the source virtual array simultaneously. Otherwise, this
+ * is a pretty straightforward analog of horizontal flip.
+ * Within a DCT block, vertical mirroring is done by changing the signs
+ * of odd-numbered rows.
+ * Partial iMCUs at the bottom edge are copied verbatim.
+ */
+ MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
+
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ compptr = dstinfo->comp_info + ci;
+ comp_height = MCU_rows * compptr->v_samp_factor;
+ for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+ dst_blk_y += compptr->v_samp_factor) {
+ dst_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+ (JDIMENSION) compptr->v_samp_factor, TRUE);
+ if (dst_blk_y < comp_height) {
+ /* Row is within the mirrorable area. */
+ src_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+ comp_height - dst_blk_y - (JDIMENSION) compptr->v_samp_factor,
+ (JDIMENSION) compptr->v_samp_factor, FALSE);
+ } else {
+ /* Bottom-edge blocks will be copied verbatim. */
+ src_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_y,
+ (JDIMENSION) compptr->v_samp_factor, FALSE);
+ }
+ for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+ if (dst_blk_y < comp_height) {
+ /* Row is within the mirrorable area. */
+ dst_row_ptr = dst_buffer[offset_y];
+ src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
+ for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
+ dst_blk_x++) {
+ dst_ptr = dst_row_ptr[dst_blk_x];
+ src_ptr = src_row_ptr[dst_blk_x];
+ for (i = 0; i < DCTSIZE; i += 2) {
+ /* copy even row */
+ for (j = 0; j < DCTSIZE; j++)
+ *dst_ptr++ = *src_ptr++;
+ /* copy odd row with sign change */
+ for (j = 0; j < DCTSIZE; j++)
+ *dst_ptr++ = - *src_ptr++;
+ }
+ }
+ } else {
+ /* Just copy row verbatim. */
+ jcopy_block_row(src_buffer[offset_y], dst_buffer[offset_y],
+ compptr->width_in_blocks);
+ }
+ }
+ }
+ }
+}
+
+
+LOCAL(void)
+do_transpose (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+ jvirt_barray_ptr *src_coef_arrays,
+ jvirt_barray_ptr *dst_coef_arrays)
+/* Transpose source into destination */
+{
+ JDIMENSION dst_blk_x, dst_blk_y;
+ int ci, i, j, offset_x, offset_y;
+ JBLOCKARRAY src_buffer, dst_buffer;
+ JCOEFPTR src_ptr, dst_ptr;
+ jpeg_component_info *compptr;
+
+ /* Transposing pixels within a block just requires transposing the
+ * DCT coefficients.
+ * Partial iMCUs at the edges require no special treatment; we simply
+ * process all the available DCT blocks for every component.
+ */
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ compptr = dstinfo->comp_info + ci;
+ for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+ dst_blk_y += compptr->v_samp_factor) {
+ dst_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+ (JDIMENSION) compptr->v_samp_factor, TRUE);
+ for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+ for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
+ dst_blk_x += compptr->h_samp_factor) {
+ src_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
+ (JDIMENSION) compptr->h_samp_factor, FALSE);
+ for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
+ src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
+ dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+ for (i = 0; i < DCTSIZE; i++)
+ for (j = 0; j < DCTSIZE; j++)
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ }
+ }
+ }
+ }
+ }
+}
+
+
+LOCAL(void)
+do_rot_90 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+ jvirt_barray_ptr *src_coef_arrays,
+ jvirt_barray_ptr *dst_coef_arrays)
+/* 90 degree rotation is equivalent to
+ * 1. Transposing the image;
+ * 2. Horizontal mirroring.
+ * These two steps are merged into a single processing routine.
+ */
+{
+ JDIMENSION MCU_cols, comp_width, dst_blk_x, dst_blk_y;
+ int ci, i, j, offset_x, offset_y;
+ JBLOCKARRAY src_buffer, dst_buffer;
+ JCOEFPTR src_ptr, dst_ptr;
+ jpeg_component_info *compptr;
+
+ /* Because of the horizontal mirror step, we can't process partial iMCUs
+ * at the (output) right edge properly. They just get transposed and
+ * not mirrored.
+ */
+ MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
+
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ compptr = dstinfo->comp_info + ci;
+ comp_width = MCU_cols * compptr->h_samp_factor;
+ for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+ dst_blk_y += compptr->v_samp_factor) {
+ dst_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+ (JDIMENSION) compptr->v_samp_factor, TRUE);
+ for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+ for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
+ dst_blk_x += compptr->h_samp_factor) {
+ src_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
+ (JDIMENSION) compptr->h_samp_factor, FALSE);
+ for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
+ src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
+ if (dst_blk_x < comp_width) {
+ /* Block is within the mirrorable area. */
+ dst_ptr = dst_buffer[offset_y]
+ [comp_width - dst_blk_x - offset_x - 1];
+ for (i = 0; i < DCTSIZE; i++) {
+ for (j = 0; j < DCTSIZE; j++)
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ i++;
+ for (j = 0; j < DCTSIZE; j++)
+ dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
+ }
+ } else {
+ /* Edge blocks are transposed but not mirrored. */
+ dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+ for (i = 0; i < DCTSIZE; i++)
+ for (j = 0; j < DCTSIZE; j++)
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ }
+ }
+ }
+ }
+ }
+ }
+}
+
+
+LOCAL(void)
+do_rot_270 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+ jvirt_barray_ptr *src_coef_arrays,
+ jvirt_barray_ptr *dst_coef_arrays)
+/* 270 degree rotation is equivalent to
+ * 1. Horizontal mirroring;
+ * 2. Transposing the image.
+ * These two steps are merged into a single processing routine.
+ */
+{
+ JDIMENSION MCU_rows, comp_height, dst_blk_x, dst_blk_y;
+ int ci, i, j, offset_x, offset_y;
+ JBLOCKARRAY src_buffer, dst_buffer;
+ JCOEFPTR src_ptr, dst_ptr;
+ jpeg_component_info *compptr;
+
+ /* Because of the horizontal mirror step, we can't process partial iMCUs
+ * at the (output) bottom edge properly. They just get transposed and
+ * not mirrored.
+ */
+ MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
+
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ compptr = dstinfo->comp_info + ci;
+ comp_height = MCU_rows * compptr->v_samp_factor;
+ for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+ dst_blk_y += compptr->v_samp_factor) {
+ dst_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+ (JDIMENSION) compptr->v_samp_factor, TRUE);
+ for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+ for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
+ dst_blk_x += compptr->h_samp_factor) {
+ src_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
+ (JDIMENSION) compptr->h_samp_factor, FALSE);
+ for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
+ dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+ if (dst_blk_y < comp_height) {
+ /* Block is within the mirrorable area. */
+ src_ptr = src_buffer[offset_x]
+ [comp_height - dst_blk_y - offset_y - 1];
+ for (i = 0; i < DCTSIZE; i++) {
+ for (j = 0; j < DCTSIZE; j++) {
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ j++;
+ dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
+ }
+ }
+ } else {
+ /* Edge blocks are transposed but not mirrored. */
+ src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
+ for (i = 0; i < DCTSIZE; i++)
+ for (j = 0; j < DCTSIZE; j++)
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ }
+ }
+ }
+ }
+ }
+ }
+}
+
+
+LOCAL(void)
+do_rot_180 (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+ jvirt_barray_ptr *src_coef_arrays,
+ jvirt_barray_ptr *dst_coef_arrays)
+/* 180 degree rotation is equivalent to
+ * 1. Vertical mirroring;
+ * 2. Horizontal mirroring.
+ * These two steps are merged into a single processing routine.
+ */
+{
+ JDIMENSION MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y;
+ int ci, i, j, offset_y;
+ JBLOCKARRAY src_buffer, dst_buffer;
+ JBLOCKROW src_row_ptr, dst_row_ptr;
+ JCOEFPTR src_ptr, dst_ptr;
+ jpeg_component_info *compptr;
+
+ MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
+ MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
+
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ compptr = dstinfo->comp_info + ci;
+ comp_width = MCU_cols * compptr->h_samp_factor;
+ comp_height = MCU_rows * compptr->v_samp_factor;
+ for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+ dst_blk_y += compptr->v_samp_factor) {
+ dst_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+ (JDIMENSION) compptr->v_samp_factor, TRUE);
+ if (dst_blk_y < comp_height) {
+ /* Row is within the vertically mirrorable area. */
+ src_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci],
+ comp_height - dst_blk_y - (JDIMENSION) compptr->v_samp_factor,
+ (JDIMENSION) compptr->v_samp_factor, FALSE);
+ } else {
+ /* Bottom-edge rows are only mirrored horizontally. */
+ src_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_y,
+ (JDIMENSION) compptr->v_samp_factor, FALSE);
+ }
+ for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+ if (dst_blk_y < comp_height) {
+ /* Row is within the mirrorable area. */
+ dst_row_ptr = dst_buffer[offset_y];
+ src_row_ptr = src_buffer[compptr->v_samp_factor - offset_y - 1];
+ /* Process the blocks that can be mirrored both ways. */
+ for (dst_blk_x = 0; dst_blk_x < comp_width; dst_blk_x++) {
+ dst_ptr = dst_row_ptr[dst_blk_x];
+ src_ptr = src_row_ptr[comp_width - dst_blk_x - 1];
+ for (i = 0; i < DCTSIZE; i += 2) {
+ /* For even row, negate every odd column. */
+ for (j = 0; j < DCTSIZE; j += 2) {
+ *dst_ptr++ = *src_ptr++;
+ *dst_ptr++ = - *src_ptr++;
+ }
+ /* For odd row, negate every even column. */
+ for (j = 0; j < DCTSIZE; j += 2) {
+ *dst_ptr++ = - *src_ptr++;
+ *dst_ptr++ = *src_ptr++;
+ }
+ }
+ }
+ /* Any remaining right-edge blocks are only mirrored vertically. */
+ for (; 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) {
+ 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. */
+ dst_row_ptr = dst_buffer[offset_y];
+ src_row_ptr = src_buffer[offset_y];
+ /* Process the blocks that can be mirrored. */
+ for (dst_blk_x = 0; dst_blk_x < comp_width; dst_blk_x++) {
+ dst_ptr = dst_row_ptr[dst_blk_x];
+ src_ptr = src_row_ptr[comp_width - dst_blk_x - 1];
+ for (i = 0; i < DCTSIZE2; i += 2) {
+ *dst_ptr++ = *src_ptr++;
+ *dst_ptr++ = - *src_ptr++;
+ }
+ }
+ /* Any remaining right-edge blocks are only copied. */
+ for (; 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 < DCTSIZE2; i++)
+ *dst_ptr++ = *src_ptr++;
+ }
+ }
+ }
+ }
+ }
+}
+
+
+LOCAL(void)
+do_transverse (j_decompress_ptr srcinfo, j_compress_ptr dstinfo,
+ 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;
+ int ci, i, j, offset_x, offset_y;
+ JBLOCKARRAY src_buffer, dst_buffer;
+ JCOEFPTR src_ptr, dst_ptr;
+ jpeg_component_info *compptr;
+
+ MCU_cols = dstinfo->image_width / (dstinfo->max_h_samp_factor * DCTSIZE);
+ MCU_rows = dstinfo->image_height / (dstinfo->max_v_samp_factor * DCTSIZE);
+
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ compptr = dstinfo->comp_info + ci;
+ comp_width = MCU_cols * compptr->h_samp_factor;
+ comp_height = MCU_rows * compptr->v_samp_factor;
+ for (dst_blk_y = 0; dst_blk_y < compptr->height_in_blocks;
+ dst_blk_y += compptr->v_samp_factor) {
+ dst_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, dst_coef_arrays[ci], dst_blk_y,
+ (JDIMENSION) compptr->v_samp_factor, TRUE);
+ for (offset_y = 0; offset_y < compptr->v_samp_factor; offset_y++) {
+ for (dst_blk_x = 0; dst_blk_x < compptr->width_in_blocks;
+ dst_blk_x += compptr->h_samp_factor) {
+ src_buffer = (*srcinfo->mem->access_virt_barray)
+ ((j_common_ptr) srcinfo, src_coef_arrays[ci], dst_blk_x,
+ (JDIMENSION) compptr->h_samp_factor, FALSE);
+ for (offset_x = 0; offset_x < compptr->h_samp_factor; offset_x++) {
+ if (dst_blk_y < comp_height) {
+ src_ptr = src_buffer[offset_x]
+ [comp_height - dst_blk_y - offset_y - 1];
+ if (dst_blk_x < comp_width) {
+ /* Block is within the mirrorable area. */
+ dst_ptr = dst_buffer[offset_y]
+ [comp_width - dst_blk_x - offset_x - 1];
+ for (i = 0; i < DCTSIZE; i++) {
+ for (j = 0; j < DCTSIZE; j++) {
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ 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 */
+ dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+ for (i = 0; i < DCTSIZE; i++) {
+ for (j = 0; j < DCTSIZE; j++) {
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ j++;
+ dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
+ }
+ }
+ }
+ } else {
+ src_ptr = src_buffer[offset_x][dst_blk_y + offset_y];
+ if (dst_blk_x < comp_width) {
+ /* Bottom-edge blocks are mirrored in x only */
+ dst_ptr = dst_buffer[offset_y]
+ [comp_width - dst_blk_x - offset_x - 1];
+ for (i = 0; i < DCTSIZE; i++) {
+ for (j = 0; j < DCTSIZE; j++)
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ i++;
+ for (j = 0; j < DCTSIZE; j++)
+ dst_ptr[j*DCTSIZE+i] = -src_ptr[i*DCTSIZE+j];
+ }
+ } else {
+ /* At lower right corner, just transpose, no mirroring */
+ dst_ptr = dst_buffer[offset_y][dst_blk_x + offset_x];
+ for (i = 0; i < DCTSIZE; i++)
+ for (j = 0; j < DCTSIZE; j++)
+ dst_ptr[j*DCTSIZE+i] = src_ptr[i*DCTSIZE+j];
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+}
+
+
+/* Request any required workspace.
+ *
+ * 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).
+ */
+
+GLOBAL(void)
+jtransform_request_workspace (j_decompress_ptr srcinfo,
+ jpeg_transform_info *info)
+{
+ jvirt_barray_ptr *coef_arrays = NULL;
+ jpeg_component_info *compptr;
+ int ci;
+
+ 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;
+ }
+
+ switch (info->transform) {
+ case JXFORM_NONE:
+ case JXFORM_FLIP_H:
+ /* Don't need a workspace array */
+ break;
+ case JXFORM_FLIP_V:
+ case JXFORM_ROT_180:
+ /* Need workspace arrays having same dimensions as source image.
+ * Note that we allocate arrays padded out to the next iMCU boundary,
+ * so that transform routines need not worry about missing edge blocks.
+ */
+ coef_arrays = (jvirt_barray_ptr *)
+ (*srcinfo->mem->alloc_small) ((j_common_ptr) srcinfo, JPOOL_IMAGE,
+ SIZEOF(jvirt_barray_ptr) * info->num_components);
+ for (ci = 0; ci < info->num_components; ci++) {
+ compptr = srcinfo->comp_info + ci;
+ coef_arrays[ci] = (*srcinfo->mem->request_virt_barray)
+ ((j_common_ptr) srcinfo, JPOOL_IMAGE, FALSE,
+ (JDIMENSION) jround_up((long) compptr->width_in_blocks,
+ (long) compptr->h_samp_factor),
+ (JDIMENSION) jround_up((long) compptr->height_in_blocks,
+ (long) compptr->v_samp_factor),
+ (JDIMENSION) compptr->v_samp_factor);
+ }
+ break;
+ case JXFORM_TRANSPOSE:
+ case JXFORM_TRANSVERSE:
+ case JXFORM_ROT_90:
+ case JXFORM_ROT_270:
+ /* Need workspace arrays having transposed dimensions.
+ * Note that we allocate arrays padded out to the next iMCU boundary,
+ * so that transform routines need not worry about missing edge blocks.
+ */
+ coef_arrays = (jvirt_barray_ptr *)
+ (*srcinfo->mem->alloc_small) ((j_common_ptr) srcinfo, JPOOL_IMAGE,
+ SIZEOF(jvirt_barray_ptr) * info->num_components);
+ for (ci = 0; ci < info->num_components; ci++) {
+ compptr = srcinfo->comp_info + ci;
+ coef_arrays[ci] = (*srcinfo->mem->request_virt_barray)
+ ((j_common_ptr) srcinfo, JPOOL_IMAGE, FALSE,
+ (JDIMENSION) jround_up((long) compptr->height_in_blocks,
+ (long) compptr->v_samp_factor),
+ (JDIMENSION) jround_up((long) compptr->width_in_blocks,
+ (long) compptr->h_samp_factor),
+ (JDIMENSION) compptr->h_samp_factor);
+ }
+ break;
+ }
+ info->workspace_coef_arrays = coef_arrays;
+}
+
+
+/* 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 dtemp;
+ UINT16 qtemp;
+
+ /* Transpose basic image dimensions */
+ dtemp = dstinfo->image_width;
+ dstinfo->image_width = dstinfo->image_height;
+ dstinfo->image_height = dtemp;
+
+ /* 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;
+ }
+ }
+ }
+ }
+}
+
+
+/* Trim off any partial iMCUs on the indicated destination edge */
+
+LOCAL(void)
+trim_right_edge (j_compress_ptr dstinfo)
+{
+ int ci, max_h_samp_factor;
+ JDIMENSION MCU_cols;
+
+ /* We have to compute max_h_samp_factor ourselves,
+ * because it hasn't been set yet in the destination
+ * (and we don't want to use the source's value).
+ */
+ max_h_samp_factor = 1;
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ int h_samp_factor = dstinfo->comp_info[ci].h_samp_factor;
+ max_h_samp_factor = MAX(max_h_samp_factor, h_samp_factor);
+ }
+ MCU_cols = dstinfo->image_width / (max_h_samp_factor * DCTSIZE);
+ if (MCU_cols > 0) /* can't trim to 0 pixels */
+ dstinfo->image_width = MCU_cols * (max_h_samp_factor * DCTSIZE);
+}
+
+LOCAL(void)
+trim_bottom_edge (j_compress_ptr dstinfo)
+{
+ int ci, max_v_samp_factor;
+ JDIMENSION MCU_rows;
+
+ /* We have to compute max_v_samp_factor ourselves,
+ * because it hasn't been set yet in the destination
+ * (and we don't want to use the source's value).
+ */
+ max_v_samp_factor = 1;
+ for (ci = 0; ci < dstinfo->num_components; ci++) {
+ int v_samp_factor = dstinfo->comp_info[ci].v_samp_factor;
+ max_v_samp_factor = MAX(max_v_samp_factor, v_samp_factor);
+ }
+ MCU_rows = dstinfo->image_height / (max_v_samp_factor * DCTSIZE);
+ if (MCU_rows > 0) /* can't trim to 0 pixels */
+ dstinfo->image_height = MCU_rows * (max_v_samp_factor * DCTSIZE);
+}
+
+
+/* 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) {
+ /* We use jpeg_set_colorspace to make sure subsidiary settings get fixed
+ * properly. Among other things, the target h_samp_factor & v_samp_factor
+ * will get set to 1, which typically won't match the source.
+ * In fact we do this even if the source is already grayscale; that
+ * provides an easy way of coercing a grayscale JPEG with funny sampling
+ * factors to the customary 1,1. (Some decoders fail on other factors.)
+ */
+ if ((dstinfo->jpeg_color_space == JCS_YCbCr &&
+ dstinfo->num_components == 3) ||
+ (dstinfo->jpeg_color_space == JCS_GRAYSCALE &&
+ dstinfo->num_components == 1)) {
+ /* We have to preserve the source's quantization table number. */
+ 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);
+ }
+ }
+
+ /* Correct the destination's image dimensions etc if necessary */
+ switch (info->transform) {
+ case JXFORM_NONE:
+ /* Nothing to do */
+ break;
+ case JXFORM_FLIP_H:
+ if (info->trim)
+ trim_right_edge(dstinfo);
+ break;
+ case JXFORM_FLIP_V:
+ if (info->trim)
+ trim_bottom_edge(dstinfo);
+ break;
+ case JXFORM_TRANSPOSE:
+ transpose_critical_parameters(dstinfo);
+ /* transpose does NOT have to trim anything */
+ break;
+ case JXFORM_TRANSVERSE:
+ transpose_critical_parameters(dstinfo);
+ if (info->trim) {
+ trim_right_edge(dstinfo);
+ trim_bottom_edge(dstinfo);
+ }
+ break;
+ case JXFORM_ROT_90:
+ transpose_critical_parameters(dstinfo);
+ if (info->trim)
+ trim_right_edge(dstinfo);
+ break;
+ case JXFORM_ROT_180:
+ if (info->trim) {
+ trim_right_edge(dstinfo);
+ trim_bottom_edge(dstinfo);
+ }
+ break;
+ case JXFORM_ROT_270:
+ transpose_critical_parameters(dstinfo);
+ if (info->trim)
+ trim_bottom_edge(dstinfo);
+ break;
+ }
+
+ /* 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_transformation (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;
+
+ switch (info->transform) {
+ case JXFORM_NONE:
+ break;
+ case JXFORM_FLIP_H:
+ do_flip_h(srcinfo, dstinfo, src_coef_arrays);
+ break;
+ case JXFORM_FLIP_V:
+ do_flip_v(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+ break;
+ case JXFORM_TRANSPOSE:
+ do_transpose(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+ break;
+ case JXFORM_TRANSVERSE:
+ do_transverse(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+ break;
+ case JXFORM_ROT_90:
+ do_rot_90(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+ break;
+ case JXFORM_ROT_180:
+ do_rot_180(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+ break;
+ case JXFORM_ROT_270:
+ do_rot_270(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
+ break;
+ }
+}
+
+#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
+ }
+}
projects / synfig.git / blobdiff