/* * transupp.c * * Copyright (C) 1997-2001, 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 */ #include /* 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->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; 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->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; 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->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; 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->image_height / (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; 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->image_width / (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; 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->image_width / (dstinfo->max_h_samp_factor * DCTSIZE); MCU_rows = srcinfo->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; 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->image_height / (dstinfo->max_h_samp_factor * DCTSIZE); MCU_rows = srcinfo->image_width / (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; 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 * x{+-}{+-} * 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; info->crop_width_set = JCROP_POS; } if (*spec == 'x' || *spec == 'X') { /* fetch height */ spec++; if (! jt_read_integer(&spec, &info->crop_height)) return FALSE; 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->max_h_samp_factor * DCTSIZE); if (MCU_cols > 0 && info->x_crop_offset + MCU_cols == full_width / (info->max_h_samp_factor * DCTSIZE)) info->output_width = MCU_cols * (info->max_h_samp_factor * DCTSIZE); } LOCAL(void) trim_bottom_edge (jpeg_transform_info *info, JDIMENSION full_height) { JDIMENSION MCU_rows; MCU_rows = info->output_height / (info->max_v_samp_factor * DCTSIZE); if (MCU_rows > 0 && info->y_crop_offset + MCU_rows == full_height / (info->max_v_samp_factor * DCTSIZE)) info->output_height = MCU_rows * (info->max_v_samp_factor * DCTSIZE); } /* 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). */ GLOBAL(void) jtransform_request_workspace (j_decompress_ptr srcinfo, jpeg_transform_info *info) { jvirt_barray_ptr *coef_arrays = NULL; boolean need_workspace, transpose_it; jpeg_component_info *compptr; JDIMENSION xoffset, yoffset, 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; } /* 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->image_height; info->output_height = srcinfo->image_width; if (info->num_components == 1) { info->max_h_samp_factor = 1; info->max_v_samp_factor = 1; } else { info->max_h_samp_factor = srcinfo->max_v_samp_factor; info->max_v_samp_factor = srcinfo->max_h_samp_factor; } break; default: info->output_width = srcinfo->image_width; info->output_height = srcinfo->image_height; if (info->num_components == 1) { info->max_h_samp_factor = 1; info->max_v_samp_factor = 1; } else { info->max_h_samp_factor = srcinfo->max_h_samp_factor; info->max_v_samp_factor = srcinfo->max_v_samp_factor; } 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 */ info->output_width = info->crop_width + (xoffset % (info->max_h_samp_factor * DCTSIZE)); info->output_height = info->crop_height + (yoffset % (info->max_v_samp_factor * DCTSIZE)); /* Save x/y offsets measured in iMCUs */ info->x_crop_offset = xoffset / (info->max_h_samp_factor * DCTSIZE); info->y_crop_offset = yoffset / (info->max_v_samp_factor * DCTSIZE); } 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->image_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->image_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->image_height); trim_bottom_edge(info, srcinfo->image_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->image_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->image_width); trim_bottom_edge(info, srcinfo->image_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->image_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->max_h_samp_factor * DCTSIZE)); height_in_iMCUs = (JDIMENSION) jdiv_round_up((long) info->output_height, (long) (info->max_v_samp_factor * DCTSIZE)); 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; } /* 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; UINT16 qtemp; /* 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 crop and rotate/flip operations. */ dstinfo->image_width = info->output_width; dstinfo->image_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->image_width != srcinfo->image_width || dstinfo->image_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->image_width, dstinfo->image_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 * DCTSIZE * MCU_height = cinfo.max_v_samp_factor * DCTSIZE * 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 } }