?? transupp.c
字號:
* 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);
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