ref: 023f5eca58471db968aee3de7729c1c9b0540952
dir: /sys/src/cmd/gs/jpeg/transupp.c/
/* * 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 } }