Unit transupp;
{* transupp.c
* transupp.h
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.
NOTE: all the routines declared here have very specific requirements
about when they are to be executed during the reading and writing of the
source and destination files. See the comments in transupp.c, or see
jpegtran.c for an example of correct usage. }
interface
{$I jconfig.inc}
uses
jmorecfg,
jinclude,
jpeglib;
{ Short forms of external names for systems with brain-damaged linkers. }
{$ifdef NEED_SHORT_EXTERNAL_NAMES}
jtransform_request_workspace jTrRequest
jtransform_adjust_parameters jTrAdjust
jtransform_execute_transformation jTrExec
jcopy_markers_setup jCMrkSetup
jcopy_markers_execute jCMrkExec
{$endif} { NEED_SHORT_EXTERNAL_NAMES }
{ Codes for supported types of image transformations. }
type
JXFORM_CODE = (
JXFORM_NONE, { no transformation }
{$ifdef CROP_SUPPORTED}
JXFORM_CUT, { cut out part of the image }
{$endif}
JXFORM_FLIP_H, { horizontal flip }
JXFORM_FLIP_V, { vertical flip }
JXFORM_TRANSPOSE, { transpose across UL-to-LR axis }
JXFORM_TRANSVERSE, { transpose across UR-to-LL axis }
JXFORM_ROT_90, { 90-degree clockwise rotation }
JXFORM_ROT_180, { 180-degree rotation }
JXFORM_ROT_270 { 270-degree clockwise (or 90 ccw) }
);
{
Although rotating and flipping data expressed as DCT coefficients is not
hard, there is an asymmetry in the JPEG format specification for images
whose dimensions aren't multiples of the iMCU size. The right and bottom
image edges are padded out to the next iMCU boundary with junk data; but
no padding is possible at the top and left edges. If we were to flip
the whole image including the pad data, then pad garbage would become
visible at the top and/or left, and real pixels would disappear into the
pad margins --- perhaps permanently, since encoders & decoders may not
bother to preserve DCT blocks that appear to be completely outside the
nominal image area. So, we have to exclude any partial iMCUs from the
basic transformation.
Transpose is the only transformation that can handle partial iMCUs at the
right and bottom edges completely cleanly. flip_h can flip partial iMCUs
at the bottom, but leaves any partial iMCUs at the right edge untouched.
Similarly flip_v leaves any partial iMCUs at the bottom edge untouched.
The other transforms are defined as combinations of these basic transforms
and process edge blocks in a way that preserves the equivalence.
The "trim" option causes untransformable partial iMCUs to be dropped;
this is not strictly lossless, but it usually gives the best-looking
result for odd-size images. Note that when this option is active,
the expected mathematical equivalences between the transforms may not hold.
(For example, -rot 270 -trim trims only the bottom edge, but -rot 90 -trim
followed by -rot 180 -trim trims both edges.)
We also offer a "force to grayscale" option, which simply discards the
chrominance channels of a YCbCr image. This is lossless in the sense that
the luminance channel is preserved exactly. It's not the same kind of
thing as the rotate/flip transformations, but it's convenient to handle it
as part of this package, mainly because the transformation routines have to
be aware of the option to know how many components to work on.
}
type
jpeg_transform_info = record
{ Options: set by caller }
transform : JXFORM_CODE; { image transform operator }
trim : boolean; { if TRUE, trim partial MCUs as needed }
force_grayscale : boolean; { if TRUE, convert color image to grayscale }
{$ifdef CROP_SUPPORTED}
xoffs, yoffs, newwidth, newheight : JDIMENSION;
{$endif}
{ Internal workspace: caller should not touch these }
num_components : int; { # of components in workspace }
workspace_coef_arrays : jvirt_barray_tbl_ptr; { workspace for transformations }
end;
{$ifdef TRANSFORMS_SUPPORTED}
{ Request any required workspace }
procedure jtransform_request_workspace(srcinfo : j_decompress_ptr;
var info : jpeg_transform_info);
{ Adjust output image parameters }
function jtransform_adjust_parameters(
srcinfo : j_decompress_ptr;
dstinfo : j_compress_ptr;
src_coef_arrays : jvirt_barray_tbl_ptr;
var info : jpeg_transform_info) : jvirt_barray_tbl_ptr;
{ Execute the actual transformation, if any }
procedure jtransform_execute_transformation(
srcinfo : j_decompress_ptr;
dstinfo : j_compress_ptr;
src_coef_arrays : jvirt_barray_tbl_ptr;
var info : jpeg_transform_info);
{$endif} { TRANSFORMS_SUPPORTED }
{ Support for copying optional markers from source to destination file. }
type
JCOPY_OPTION = (
JCOPYOPT_NONE, { copy no optional markers }
JCOPYOPT_COMMENTS, { copy only comment (COM) markers }
JCOPYOPT_ALL { copy all optional markers }
);
const
JCOPYOPT_DEFAULT = JCOPYOPT_COMMENTS; { recommended default }
{ Setup decompression object to save desired markers in memory }
procedure jcopy_markers_setup(srcinfo : j_decompress_ptr;
option : JCOPY_OPTION);
{ Copy markers saved in the given source object to the destination object }
procedure jcopy_markers_execute(srcinfo : j_decompress_ptr;
dstinfo : j_compress_ptr;
option : JCOPY_OPTION);
implementation
{ Although this file really shouldn't have access to the library internals,
it's helpful to let it call jround_up() and jcopy_block_row(). }
uses
jutils,
jdeferr,
jerror,
{$ifdef SAVE_MARKERS_SUPPORTED}
jdmarker,
{$endif}
jcapimin,
jcparam; { set color space }
{$ifdef 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}
procedure do_flip_h (srcinfo : j_decompress_ptr;
dstinfo : j_compress_ptr;
src_coef_arrays : jvirt_barray_tbl_ptr);
{ Horizontal flip; done in-place, so no separate dest array is required }
var
MCU_cols, comp_width, blk_x, blk_y : JDIMENSION;
ci, k, offset_y : int;
buffer : JBLOCKARRAY;
ptr1, ptr2 : JCOEF_PTR;
temp1, temp2 : JCOEF;
compptr : jpeg_component_info_ptr;
begin
{ 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 div (dstinfo^.max_h_samp_factor * DCTSIZE);
for ci := 0 to dstinfo^.num_components-1 do
begin
compptr := jpeg_component_info_ptr(dstinfo^.comp_info);
Inc(compptr, ci);
comp_width := MCU_cols * compptr^.h_samp_factor;
blk_y := 0;
while (blk_y < compptr^.height_in_blocks) do
begin
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 to compptr^.v_samp_factor-1 do
begin
blk_x := 0;
while (blk_x * 2 < comp_width) do
begin
ptr1 := JCOEF_PTR(@(buffer^[offset_y]^[blk_x]));
ptr2 := JCOEF_PTR(@(buffer^[offset_y]^[comp_width - blk_x - 1]));
{ this unrolled loop doesn't need to know which row it's on... }
k := 0;
while (k < DCTSIZE2) do
begin
temp1 := ptr1^; { swap even column }
temp2 := ptr2^;
ptr1^ := temp2;
Inc(ptr1);
ptr2^ := temp1;
Inc(ptr2);
temp1 := ptr1^; { swap odd column with sign change }
temp2 := ptr2^;
ptr1^ := -temp2;
Inc(ptr1);
ptr2^ := -temp1;
Inc(ptr2);
Inc(k, 2);
end;
Inc(blk_x);
end;
end;
Inc(blk_y, compptr^.v_samp_factor);
end; { while }
end; { for ci }
end; { do_flip_h }
{LOCAL}
procedure do_flip_v (srcinfo : j_decompress_ptr;
dstinfo : j_compress_ptr;
src_coef_arrays : jvirt_barray_tbl_ptr;
dst_coef_arrays : jvirt_barray_tbl_ptr);
{ Vertical flip }
var
MCU_rows, comp_height, dst_blk_x, dst_blk_y : JDIMENSION;
ci, i, j, offset_y : int;
src_buffer, dst_buffer : JBLOCKARRAY;
src_row_ptr, dst_row_ptr : JBLOCKROW;
src_ptr, dst_ptr : JCOEF_PTR;
compptr : jpeg_component_info_ptr;
begin
{ 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 div (dstinfo^.max_v_samp_factor * DCTSIZE);
for ci := 0 to dstinfo^.num_components-1 do
begin
compptr := jpeg_component_info_ptr(dstinfo^.comp_info);
Inc(compptr, ci);
comp_height := MCU_rows * compptr^.v_samp_factor;
dst_blk_y := 0;
while (dst_blk_y < compptr^.height_in_blocks) do
begin
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) then
begin
{ 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);
end
else
begin
{ 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);
end;
for offset_y := 0 to compptr^.v_samp_factor-1 do
begin
if (dst_blk_y < comp_height) then
begin
{ 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 to compptr^.width_in_blocks-1 do
begin
dst_ptr := JCOEF_PTR(@(dst_row_ptr^[dst_blk_x]));
src_ptr := JCOEF_PTR(@(src_row_ptr^[dst_blk_x]));
i := 0;
while (i < DCTSIZE) do
begin
{ copy even row }
for j := 0 to DCTSIZE-1 do
begin
dst_ptr^ := src_ptr^;
Inc(dst_ptr);
Inc(src_ptr);
end;
{ copy odd row with sign change }
for j := 0 to DCTSIZE-1 do
begin
dst_ptr^ := - (src_ptr^);
Inc(dst_ptr);
Inc(src_ptr);
end;
Inc(i, 2);
end;
end;
end
else
begin
{ Just copy row verbatim. }
jcopy_block_row(src_buffer^[offset_y], dst_buffer^[offset_y],
compptr^.width_in_blocks);
end;
end;
Inc(dst_blk_y, compptr^.v_samp_factor);
end; { while }
end; { for ci }
end; { do_flip_v }
{$ifdef CROP_SUPPORTED}
{LOCAL}
procedure do_transform (srcinfo : j_decompress_ptr;
dstinfo : j_compress_ptr;
src_coef_arrays : jvirt_barray_tbl_ptr;
dst_coef_arrays : jvirt_barray_tbl_ptr;
xoffs : JDIMENSION;
yoffs : JDIMENSION);
{ transform src_coef_arrays so that the xoffs,yoffs (rounded to an even
dct block) are the new origin of the image. copy rather than move because
I'd never finish if I tried to understand the byzantine memory management.
}
var
ci : int;
compptr : jpeg_component_info_ptr;
src_buffer, dst_buffer : JBLOCKARRAY;
dst_blk_x, dst_blk_y : JDIMENSION;
begin
xoffs := xoffs div dstinfo^.max_h_samp_factor * DCTSIZE;
yoffs := yoffs div dstinfo^.max_v_samp_factor * DCTSIZE;
for ci := 0 to dstinfo^.num_components-1 do
begin
compptr := jpeg_component_info_ptr(dstinfo^.comp_info);
Inc(compptr, ci);
dst_blk_y := 0;
while (dst_blk_y < compptr^.height_in_blocks) do
begin
dst_buffer := srcinfo^.mem^.access_virt_barray
(j_common_ptr(srcinfo), dst_coef_arrays^[ci], dst_blk_y, 1, TRUE);
src_buffer := srcinfo^.mem^.access_virt_barray
(j_common_ptr(srcinfo), src_coef_arrays^[ci],
dst_blk_y + yoffs * JDIMENSION(compptr^.v_samp_factor), 1, FALSE);
jcopy_block_row(JBLOCKROW(@src_buffer^[0]^[xoffs * compptr^.h_samp_factor]),
dst_buffer^[0], compptr^.width_in_blocks);
Inc(dst_blk_y);
end;
end;
end; { do_transform }
{$endif}
{LOCAL}
procedure do_transpose (srcinfo : j_decompress_ptr;
dstinfo : j_compress_ptr;
src_coef_arrays : jvirt_barray_tbl_ptr;
dst_coef_arrays : jvirt_barray_tbl_ptr);
{ Transpose source into destination }
var
dst_blk_x, dst_blk_y : JDIMENSION;
ci, i, j, offset_x, offset_y : int;
src_buffer, dst_buffer : JBLOCKARRAY;
src_ptr, dst_ptr : JCOEFPTR;
compptr : jpeg_component_info_ptr;
begin
{ 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 to dstinfo^.num_components-1 do
begin
compptr := jpeg_component_info_ptr(dstinfo^.comp_info);
Inc(compptr, ci);
dst_blk_y := 0;
while (dst_blk_y < compptr^.height_in_blocks) do
begin
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 to compptr^.v_samp_factor-1 do
begin
dst_blk_x := 0;
while (dst_blk_x < compptr^.width_in_blocks) do
begin
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 to compptr^.h_samp_factor-1 do
begin
src_ptr := JCOEFPTR(@(src_buffer^[offset_x]^
[dst_blk_y + offset_y]));
dst_ptr := JCOEFPTR(@(dst_buffer^[offset_y]^
[dst_blk_x + offset_x]));
for i := 0 to DCTSIZE-1 do
for j := 0 to DCTSIZE-1 do
dst_ptr^[j*DCTSIZE+i] := src_ptr^[i*DCTSIZE+j];
end;
Inc(dst_blk_x, compptr^.h_samp_factor);
end;
end;
Inc(dst_blk_y, compptr^.v_samp_factor);
end; { while }
end; { for ci }
end; { do_transpose }
{LOCAL}
procedure do_rot_90 (srcinfo : j_decompress_ptr;
dstinfo : j_compress_ptr;
src_coef_arrays : jvirt_barray_tbl_ptr;
dst_coef_arrays : jvirt_barray_tbl_ptr);
{ 90 degree rotation is equivalent to
1. Transposing the image;
2. Horizontal mirroring.
These two steps are merged into a single processing routine. }
var
MCU_cols, comp_width, dst_blk_x, dst_blk_y : JDIMENSION;
ci, i, j, offset_x, offset_y : int;
src_buffer, dst_buffer : JBLOCKARRAY;
src_ptr, dst_ptr : JCOEFPTR;
compptr : jpeg_component_info_ptr;
begin
{ 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 div (dstinfo^.max_h_samp_factor * DCTSIZE);
for ci := 0 to dstinfo^.num_components-1 do
begin
compptr := jpeg_component_info_ptr(dstinfo^.comp_info);
Inc(compptr, ci);
comp_width := MCU_cols * compptr^.h_samp_factor;
dst_blk_y := 0;
while ( dst_blk_y < compptr^.height_in_blocks) do
begin
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 to compptr^.v_samp_factor-1 do
begin
dst_blk_x := 0;
while (dst_blk_x < compptr^.width_in_blocks) do
begin
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 to compptr^.h_samp_factor-1 do
begin
src_ptr := JCOEFPTR(@(src_buffer^[offset_x]^
[dst_blk_y + offset_y]));
if (dst_blk_x < comp_width) then
begin
{ Block is within the mirrorable area. }
dst_ptr := JCOEFPTR(@(dst_buffer^[offset_y]^
[comp_width - dst_blk_x - offset_x - 1]));
i := 0;
while (i < DCTSIZE) do
begin
for j := 0 to DCTSIZE-1 do
dst_ptr^[j*DCTSIZE+i] := src_ptr^[i*DCTSIZE+j];
Inc(i);
for j := 0 to DCTSIZE-1 do
dst_ptr^[j*DCTSIZE+i] := -src_ptr^[i*DCTSIZE+j];
Inc(i);
end;
end
else
begin
{ Edge blocks are transposed but not mirrored. }
dst_ptr := JCOEFPTR(@(dst_buffer^[offset_y]^
[dst_blk_x + offset_x]));
for i := 0 to DCTSIZE-1 do
for j := 0 to DCTSIZE-1 do
dst_ptr^[j*DCTSIZE+i] := src_ptr^[i*DCTSIZE+j];
end;
end;
Inc(dst_blk_x, compptr^.h_samp_factor);
end;
end;
Inc(dst_blk_y, compptr^.v_samp_factor);
end; { while }
end; { for ci }
end; { do_rot_90 }
{LOCAL}
procedure do_rot_270 (srcinfo : j_decompress_ptr;
dstinfo : j_compress_ptr;
src_coef_arrays : jvirt_barray_tbl_ptr;
dst_coef_arrays : jvirt_barray_tbl_ptr);
{ 270 degree rotation is equivalent to
1. Horizontal mirroring;
2. Transposing the image.
These two steps are merged into a single processing routine. }
var
MCU_rows, comp_height, dst_blk_x, dst_blk_y : JDIMENSION;
ci, i, j, offset_x, offset_y : int;
src_buffer, dst_buffer : JBLOCKARRAY;
src_ptr, dst_ptr : JCOEFPTR;
compptr : jpeg_component_info_ptr;
begin
{ 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 div (dstinfo^.max_v_samp_factor * DCTSIZE);
for ci := 0 to dstinfo^.num_components-1 do
begin
compptr := jpeg_component_info_ptr(dstinfo^.comp_info);
Inc(compptr, ci);
comp_height := MCU_rows * compptr^.v_samp_factor;
dst_blk_y := 0;
while (dst_blk_y < compptr^.height_in_blocks) do
begin
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 to compptr^.v_samp_factor-1 do
begin
dst_blk_x := 0;
while (dst_blk_x < compptr^.width_in_blocks) do
begin
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 to compptr^.h_samp_factor-1 do
begin
dst_ptr := JCOEFPTR(@(dst_buffer^[offset_y]^
[dst_blk_x + offset_x]));
if (dst_blk_y < comp_height) then
begin
{ Block is within the mirrorable area. }
src_ptr := JCOEFPTR(@(src_buffer^[offset_x]^
[comp_height - dst_blk_y - offset_y - 1]));
for i := 0 to DCTSIZE-1 do
begin
j := 0;
while (j < DCTSIZE) do
begin
dst_ptr^[j*DCTSIZE+i] := src_ptr^[i*DCTSIZE+j];
Inc(j);
dst_ptr^[j*DCTSIZE+i] := -src_ptr^[i*DCTSIZE+j];
Inc(j);
end;
end;
end
else
begin
{ Edge blocks are transposed but not mirrored. }
src_ptr := JCOEFPTR(@(src_buffer^[offset_x]^
[dst_blk_y + offset_y]));
for i := 0 to DCTSIZE-1 do
for j := 0 to DCTSIZE-1 do
dst_ptr^[j*DCTSIZE+i] := src_ptr^[i*DCTSIZE+j];
end;
end;
Inc(dst_blk_x, compptr^.h_samp_factor);
end;
end;
Inc(dst_blk_y, compptr^.v_samp_factor);
end; { while }
end; { for ci }
end; { do_rot_270 }
{LOCAL}
procedure do_rot_180 (srcinfo : j_decompress_ptr;
dstinfo : j_compress_ptr;
src_coef_arrays : jvirt_barray_tbl_ptr;
dst_coef_arrays : jvirt_barray_tbl_ptr);
{ 180 degree rotation is equivalent to
1. Vertical mirroring;
2. Horizontal mirroring.
These two steps are merged into a single processing routine. }
var
MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y : JDIMENSION;
ci, i, j, offset_y : int;
src_buffer, dst_buffer : JBLOCKARRAY;
src_row_ptr, dst_row_ptr : JBLOCKROW;
src_ptr, dst_ptr : JCOEF_PTR;
compptr : jpeg_component_info_ptr;
begin
MCU_cols := dstinfo^.image_width div (dstinfo^.max_h_samp_factor * DCTSIZE);
MCU_rows := dstinfo^.image_height div (dstinfo^.max_v_samp_factor * DCTSIZE);
for ci := 0 to dstinfo^.num_components-1 do
begin
compptr := jpeg_component_info_ptr(dstinfo^.comp_info);
Inc(compptr, ci);
comp_width := MCU_cols * compptr^.h_samp_factor;
comp_height := MCU_rows * compptr^.v_samp_factor;
dst_blk_y := 0;
while (dst_blk_y < compptr^.height_in_blocks) do
begin
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) then
begin
{ 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);
end
else
begin
{ 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);
end;
for offset_y := 0 to compptr^.v_samp_factor-1 do
begin
if (dst_blk_y < comp_height) then
begin
{ 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 to comp_width-1 do
begin
dst_ptr := JCOEF_PTR(@(dst_row_ptr^[dst_blk_x]));
src_ptr := JCOEF_PTR(@(src_row_ptr^[comp_width - dst_blk_x - 1]));
i := 0;
while (i < DCTSIZE) do
begin
{ For even row, negate every odd column. }
j := 0;
while (j < DCTSIZE) do
begin
dst_ptr^ := src_ptr^;
Inc(dst_ptr);
Inc(src_ptr);
dst_ptr^ := - src_ptr^;
Inc(dst_ptr);
Inc(src_ptr);
Inc(j, 2);
end;
{ For odd row, negate every even column. }
j := 0;
while (j < DCTSIZE) do
begin
dst_ptr^ := - src_ptr^;
Inc(dst_ptr);
Inc(src_ptr);
dst_ptr^ := src_ptr^;
Inc(dst_ptr);
Inc(src_ptr);
Inc(j, 2);
end;
Inc(i, 2);
end; { while i }
end;
{ Any remaining right-edge blocks are only mirrored vertically. }
for dst_blk_x := comp_width to compptr^.width_in_blocks-1 do
begin
dst_ptr := JCOEF_PTR(@(dst_row_ptr^[dst_blk_x]));
src_ptr := JCOEF_PTR(@(src_row_ptr^[dst_blk_x]));
i := 0;
while (i < DCTSIZE) do
begin
for j := 0 to DCTSIZE-1 do
begin
dst_ptr^ := src_ptr^;
Inc(dst_ptr);
Inc(src_ptr);
end;
for j := 0 to DCTSIZE-1 do
begin
dst_ptr^ := - src_ptr^;
Inc(dst_ptr);
Inc(src_ptr);
end;
Inc(i, 2);
end
end
end
else
begin
{ 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 to comp_width-1 do
begin
dst_ptr := JCOEF_PTR(@(dst_row_ptr^[dst_blk_x]));
src_ptr := JCOEF_PTR(@(src_row_ptr^[comp_width - dst_blk_x - 1]));
i := 0;
while (i < DCTSIZE2) do
begin
dst_ptr^ := src_ptr^;
Inc(dst_ptr);
Inc(src_ptr);
dst_ptr^ := - src_ptr^;
Inc(dst_ptr);
Inc(src_ptr);
Inc(i, 2);
end;
end;
{ Any remaining right-edge blocks are only copied. }
for dst_blk_x := comp_width to compptr^.width_in_blocks-1 do
begin
dst_ptr := JCOEF_PTR(@(dst_row_ptr^[dst_blk_x]));
src_ptr := JCOEF_PTR(@(src_row_ptr^[dst_blk_x]));
for i := 0 to DCTSIZE2-1 do
begin
dst_ptr^ := src_ptr^;
Inc(dst_ptr);
Inc(src_ptr);
end;
end;
end;
end;
Inc(dst_blk_y, compptr^.v_samp_factor) ;
end; { while }
end; { for ci }
end; { do_rot_180 }
{LOCAL}
procedure do_transverse (srcinfo : j_decompress_ptr;
dstinfo : j_compress_ptr;
src_coef_arrays : jvirt_barray_tbl_ptr;
dst_coef_arrays : jvirt_barray_tbl_ptr);
{ 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. }
var
MCU_cols, MCU_rows, comp_width, comp_height, dst_blk_x, dst_blk_y : JDIMENSION;
ci, i, j, offset_x, offset_y : int;
src_buffer, dst_buffer : JBLOCKARRAY;
src_ptr, dst_ptr : JCOEFPTR;
compptr : jpeg_component_info_ptr;
begin
MCU_cols := dstinfo^.image_width div (dstinfo^.max_h_samp_factor * DCTSIZE);
MCU_rows := dstinfo^.image_height div (dstinfo^.max_v_samp_factor * DCTSIZE);
for ci := 0 to dstinfo^.num_components-1 do
begin
compptr := jpeg_component_info_ptr(dstinfo^.comp_info);
Inc(compptr, ci);
comp_width := MCU_cols * compptr^.h_samp_factor;
comp_height := MCU_rows * compptr^.v_samp_factor;
dst_blk_y := 0;
while (dst_blk_y < compptr^.height_in_blocks) do
begin
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 to compptr^.v_samp_factor-1 do
begin
dst_blk_x := 0;
while ( dst_blk_x < compptr^.width_in_blocks) do
begin
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 to compptr^.h_samp_factor-1 do
begin
if (dst_blk_y < comp_height) then
begin
src_ptr := JCOEFPTR(@(src_buffer^[offset_x]^
[comp_height - dst_blk_y - offset_y - 1]));
if (dst_blk_x < comp_width) then
begin
{ Block is within the mirrorable area. }
dst_ptr := JCOEFPTR(@(dst_buffer^[offset_y]^
[comp_width - dst_blk_x - offset_x - 1]));
i := 0;
while (i < DCTSIZE) do
begin
j := 0;
while (j < DCTSIZE) do
begin
dst_ptr^[j*DCTSIZE+i] := src_ptr^[i*DCTSIZE+j];
Inc(j);
dst_ptr^[j*DCTSIZE+i] := -src_ptr^[i*DCTSIZE+j];
Inc(j);
end;
Inc(i);
j := 0;
while (j < DCTSIZE) do
begin
dst_ptr^[j*DCTSIZE+i] := -src_ptr^[i*DCTSIZE+j];
Inc(j);
dst_ptr^[j*DCTSIZE+i] := src_ptr^[i*DCTSIZE+j];
Inc(j);
end;
Inc(i);
end
end
else
begin
{ Right-edge blocks are mirrored in y only }
dst_ptr := JCOEFPTR(@(dst_buffer^[offset_y]^
[dst_blk_x + offset_x]));
for i := 0 to DCTSIZE-1 do
begin
j := 0;
while (j < DCTSIZE) do
begin
dst_ptr^[j*DCTSIZE+i] := src_ptr^[i*DCTSIZE+j];
Inc(j);
dst_ptr^[j*DCTSIZE+i] := -src_ptr^[i*DCTSIZE+j];
Inc(j);
end;
end;
end;
end
else
begin
src_ptr := JCOEFPTR(@(src_buffer^[offset_x]^
[dst_blk_y + offset_y]));
if (dst_blk_x < comp_width) then
begin
{ Bottom-edge blocks are mirrored in x only }
dst_ptr := JCOEFPTR(@(dst_buffer^[offset_y]^
[comp_width - dst_blk_x - offset_x - 1]));
i := 0;
while (i < DCTSIZE) do
begin
for j := 0 to DCTSIZE-1 do
dst_ptr^[j*DCTSIZE+i] := src_ptr^[i*DCTSIZE+j];
Inc(i);
for j := 0 to DCTSIZE-1 do
dst_ptr^[j*DCTSIZE+i] := -src_ptr^[i*DCTSIZE+j];
Inc(i);
end;
end
else
begin
{ At lower right corner, just transpose, no mirroring }
dst_ptr := JCOEFPTR(@(dst_buffer^[offset_y]^
[dst_blk_x + offset_x]));
for i := 0 to DCTSIZE-1 do
for j := 0 to DCTSIZE-1 do
dst_ptr^[j*DCTSIZE+i] := src_ptr^[i*DCTSIZE+j];
end;
end;
end;
Inc(dst_blk_x, compptr^.h_samp_factor);
end;
end;
Inc(dst_blk_y, compptr^.v_samp_factor);
end; { while }
end; { for ci }
end; { do_transverse }
{ 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}
procedure jtransform_request_workspace (
srcinfo : j_decompress_ptr;
var info : jpeg_transform_info);
var
coef_arrays : jvirt_barray_tbl_ptr;
compptr : jpeg_component_info_ptr;
ci : int;
begin
coef_arrays := NIL;
if (info.force_grayscale) and (srcinfo^.jpeg_color_space = JCS_YCbCr)
and (srcinfo^.num_components = 3) then
begin
{ We'll only process the first component }
info.num_components := 1;
end
else
begin
{ Process all the components }
info.num_components := srcinfo^.num_components;
end;
case (info.transform) of
JXFORM_NONE,
JXFORM_FLIP_H:;
{ Don't need a workspace array }
{$ifdef CROP_SUPPORTED}
JXFORM_CUT,
{ really cut needs smaller arrays if you want to figure it out }
{$endif}
JXFORM_FLIP_V,
JXFORM_ROT_180:
begin
{ 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_tbl_ptr (
srcinfo^.mem^.alloc_small (j_common_ptr(srcinfo), JPOOL_IMAGE,
SIZEOF(jvirt_barray_ptr) * info.num_components) );
for ci := 0 to info.num_components-1 do
begin
compptr := jpeg_component_info_ptr(srcinfo^.comp_info);
Inc(compptr, 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));
end;
end;
JXFORM_TRANSPOSE,
JXFORM_TRANSVERSE,
JXFORM_ROT_90,
JXFORM_ROT_270:
begin
{ 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_tbl_ptr(
srcinfo^.mem^.alloc_small (j_common_ptr(srcinfo), JPOOL_IMAGE,
SIZEOF(jvirt_barray_ptr) * info.num_components) );
for ci := 0 to info.num_components-1 do
begin
compptr := jpeg_component_info_ptr(srcinfo^.comp_info);
Inc(compptr, 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 ) );
end;
end;
end;
info.workspace_coef_arrays := coef_arrays;
end;
{ Transpose destination image parameters }
{LOCAL}
procedure transpose_critical_parameters (dstinfo : j_compress_ptr);
var
tblno, i, j, ci, itemp : int;
compptr : jpeg_component_info_ptr;
qtblptr : JQUANT_TBL_PTR;
dtemp : JDIMENSION;
qtemp : UINT16;
begin
{ Transpose basic image dimensions }
dtemp := dstinfo^.image_width;
dstinfo^.image_width := dstinfo^.image_height;
dstinfo^.image_height := dtemp;
{ Transpose sampling factors }
for ci := 0 to dstinfo^.num_components-1 do
begin
compptr := jpeg_component_info_ptr(dstinfo^.comp_info);
Inc(compptr, ci);
itemp := compptr^.h_samp_factor;
compptr^.h_samp_factor := compptr^.v_samp_factor;
compptr^.v_samp_factor := itemp;
end;
{ Transpose quantization tables }
for tblno := 0 to NUM_QUANT_TBLS-1 do
begin
qtblptr := dstinfo^.quant_tbl_ptrs[tblno];
if (qtblptr <> NIL) then
begin
for i := 0 to DCTSIZE-1 do
begin
for j := 0 to i-1 do
begin
qtemp := qtblptr^.quantval[i*DCTSIZE+j];
qtblptr^.quantval[i*DCTSIZE+j] := qtblptr^.quantval[j*DCTSIZE+i];
qtblptr^.quantval[j*DCTSIZE+i] := qtemp;
end;
end;
end;
end;
end;
{ Trim off any partial iMCUs on the indicated destination edge }
{LOCAL}
procedure trim_right_edge (dstinfo : j_compress_ptr);
var
ci, max_h_samp_factor : int;
MCU_cols : JDIMENSION;
var
h_samp_factor : int;
begin
{ 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 to dstinfo^.num_components-1 do
begin
h_samp_factor := dstinfo^.comp_info^[ci].h_samp_factor;
{max_h_samp_factor := MAX(max_h_samp_factor, h_samp_factor);}
if h_samp_factor > max_h_samp_factor then
max_h_samp_factor := h_samp_factor;
end;
MCU_cols := dstinfo^.image_width div (max_h_samp_factor * DCTSIZE);
if (MCU_cols > 0) then { can't trim to 0 pixels }
dstinfo^.image_width := MCU_cols * (max_h_samp_factor * DCTSIZE);
end;
{LOCAL}
procedure trim_bottom_edge (dstinfo : j_compress_ptr);
var
ci, max_v_samp_factor : int;
MCU_rows : JDIMENSION;
var
v_samp_factor : int;
begin
{ 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 to dstinfo^.num_components-1 do
begin
v_samp_factor := dstinfo^.comp_info^[ci].v_samp_factor;
{max_v_samp_factor := MAX(max_v_samp_factor, v_samp_factor);}
if v_samp_factor > max_v_samp_factor then
max_v_samp_factor := v_samp_factor;
end;
MCU_rows := dstinfo^.image_height div (max_v_samp_factor * DCTSIZE);
if (MCU_rows > 0) then { can't trim to 0 pixels }
dstinfo^.image_height := MCU_rows * (max_v_samp_factor * DCTSIZE);
end;
{$ifdef CROP_SUPPORTED}
{ For cropping, realize and constrain the target area, and reshape the
dstinfo to hold the resulting image.
Input was supplied as WxH[+-]X[+-]Y offsets. Negative offsets are
relative to the lower righthand corner of the image. The region is
expanded so that all boundaries fall on even MCU blocks by rounding
the offsets *down* (at the do_transform() step) and the size *up*. }
{LOCAL}
procedure set_dest_size(dstinfo : j_compress_ptr;
var info : jpeg_transform_info);
var
ci, max_samp_factor : int;
MCU_size, newsize, offset, factor : JDIMENSION;
var
samp_factor : int;
begin
{ Initially the dstinfo is the same size as the srcinfo.
Use it to constrain the offsets: }
if (info.xoffs < 0) then
Inc(info.xoffs, dstinfo^.image_width);
if (info.yoffs < 0) then
Inc(info.yoffs, dstinfo^.image_height);
if (info.xoffs < 0) or (info.xoffs >= dstinfo^.image_width) or
(info.yoffs < 0) or (info.yoffs >= dstinfo^.image_height) then
begin
{jpegtran_error('-cut offsets fall outside source image');}
ERREXIT(j_common_ptr(dstinfo), JERR_CONVERSION_NOTIMPL);
end;
{ use it to constrain the size: }
if (info.newwidth + info.xoffs > dstinfo^.image_width) then
info.newwidth := dstinfo^.image_width - info.xoffs;
if (info.newheight + info.yoffs > dstinfo^.image_height) then
info.newheight := dstinfo^.image_height - info.yoffs;
{ We have to compute max_v/h_samp_factors ourselves,
because it hasn't been set yet in the destination
(and we don't want to use the source's value). }
max_samp_factor := 1;
for ci := 0 to dstinfo^.num_components-1 do
begin
samp_factor := dstinfo^.comp_info^[ci].v_samp_factor;
{max_samp_factor := MAX(max_samp_factor, samp_factor);}
if (max_samp_factor < samp_factor) then
max_samp_factor := samp_factor;
end;
{ Find original (rounded down) and new (rounded up) heights in full
dct blocks, choose the smaller of the two. }
factor := max_samp_factor * DCTSIZE;
MCU_size := dstinfo^.image_height div factor;
newsize := (info.newheight + (info.yoffs mod factor) + factor - 1) div factor;
{MCU_size := MIN(MCU_size, newsize);}
if (MCU_size > newsize) then
MCU_size := newsize;
if (MCU_size > 0) then { can't trim to 0 pixels }
dstinfo^.image_height := MCU_size * factor
else
begin
{jpegtran_error('degenerate -cut height');}
ERREXIT(j_common_ptr(dstinfo), JERR_CONVERSION_NOTIMPL);
end;
max_samp_factor := 1;
for ci := 0 to dstinfo^.num_components-1 do
begin
samp_factor := dstinfo^.comp_info^[ci].h_samp_factor;
{max_samp_factor := MAX(max_samp_factor, samp_factor);}
if (max_samp_factor < samp_factor) then
max_samp_factor := samp_factor;
end;
{ Find original (rounded down) and new (rounded up) heights in full
dct blocks, choose the smaller of the two. }
factor := max_samp_factor * DCTSIZE;
MCU_size := dstinfo^.image_width div factor;
newsize := (info.newwidth + (info.xoffs mod factor) + factor - 1) div factor;
{MCU_size := MIN(MCU_size, newsize);}
if (MCU_size > newsize) then
MCU_size := newsize;
if (MCU_size > 0) then { can't trim to 0 pixels }
dstinfo^.image_width := MCU_size * factor
else
begin
{jpegtran_error('degenerate -cut width');}
ERREXIT(j_common_ptr(dstinfo), JERR_CONVERSION_NOTIMPL);
end;
end;
{$endif}
{ 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}
function jtransform_adjust_parameters
(srcinfo : j_decompress_ptr;
dstinfo : j_compress_ptr;
src_coef_arrays : jvirt_barray_tbl_ptr;
var info : jpeg_transform_info) : jvirt_barray_tbl_ptr;
var
sv_quant_tbl_no : int;
begin
{ If force-to-grayscale is requested, adjust destination parameters }
if (info.force_grayscale) then
begin
{ 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) and
(dstinfo^.num_components = 3)) or
((dstinfo^.jpeg_color_space = JCS_GRAYSCALE) and
(dstinfo^.num_components = 1)) then
begin
{ We have to preserve the source's quantization table number. }
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;
end
else
begin
{ Sorry, can't do it }
ERREXIT(j_common_ptr(dstinfo), JERR_CONVERSION_NOTIMPL);
end;
end;
{ Correct the destination's image dimensions etc if necessary }
case (info.transform) of
JXFORM_NONE:;
{ Nothing to do }
{$ifdef CROP_SUPPORTED}
JXFORM_CUT:
set_dest_size(dstinfo, info);
{$endif}
JXFORM_FLIP_H:
if (info.trim) then
trim_right_edge(dstinfo);
JXFORM_FLIP_V:
if (info.trim) then
trim_bottom_edge(dstinfo);
JXFORM_TRANSPOSE:
transpose_critical_parameters(dstinfo);
{ transpose does NOT have to trim anything }
JXFORM_TRANSVERSE:
begin
transpose_critical_parameters(dstinfo);
if (info.trim) then
begin
trim_right_edge(dstinfo);
trim_bottom_edge(dstinfo);
end;
end;
JXFORM_ROT_90:
begin
transpose_critical_parameters(dstinfo);
if (info.trim) then
trim_right_edge(dstinfo);
end;
JXFORM_ROT_180:
if (info.trim) then
begin
trim_right_edge(dstinfo);
trim_bottom_edge(dstinfo);
end;
JXFORM_ROT_270:
begin
transpose_critical_parameters(dstinfo);
if (info.trim) then
trim_bottom_edge(dstinfo);
end;
end;
{ Return the appropriate output data set }
if (info.workspace_coef_arrays <> NIL) then
jtransform_adjust_parameters := info.workspace_coef_arrays
else
jtransform_adjust_parameters := src_coef_arrays;
end;
{ 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}
procedure jtransform_execute_transformation (
srcinfo : j_decompress_ptr;
dstinfo : j_compress_ptr;
src_coef_arrays : jvirt_barray_tbl_ptr;
var info : jpeg_transform_info);
var
dst_coef_arrays : jvirt_barray_tbl_ptr;
begin
dst_coef_arrays := info.workspace_coef_arrays;
case (info.transform) of
JXFORM_NONE:;
{$ifdef CROP_SUPPORTED}
JXFORM_CUT:
do_transform(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays,
info.xoffs, info.yoffs);
{$endif}
JXFORM_FLIP_H:
do_flip_h(srcinfo, dstinfo, src_coef_arrays);
JXFORM_FLIP_V:
do_flip_v(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
JXFORM_TRANSPOSE:
do_transpose(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
JXFORM_TRANSVERSE:
do_transverse(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
JXFORM_ROT_90:
do_rot_90(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
JXFORM_ROT_180:
do_rot_180(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
JXFORM_ROT_270:
do_rot_270(srcinfo, dstinfo, src_coef_arrays, dst_coef_arrays);
end;
end;
{$endif} { TRANSFORMS_SUPPORTED }
{ Setup decompression object to save desired markers in memory.
This must be called before jpeg_read_header() to have the desired effect. }
{GLOBAL}
procedure jcopy_markers_setup (srcinfo : j_decompress_ptr;
option : JCOPY_OPTION);
var
m : int;
begin
{$ifdef SAVE_MARKERS_SUPPORTED}
{ Save comments except under NONE option }
if (option <> JCOPYOPT_NONE) then
begin
jpeg_save_markers(srcinfo, JPEG_COM, $FFFF);
end;
{ Save all types of APPn markers iff ALL option }
if (option = JCOPYOPT_ALL) then
begin
for m := 0 to 16-1 do
jpeg_save_markers(srcinfo, JPEG_APP0 + m, $FFFF);
end;
{$endif} { SAVE_MARKERS_SUPPORTED }
end;
{ 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}
procedure jcopy_markers_execute (srcinfo : j_decompress_ptr;
dstinfo : j_compress_ptr;
option : JCOPY_OPTION);
var
marker : jpeg_saved_marker_ptr;
{$ifdef NEED_FAR_POINTERS}
var
i : uint;
{$endif}
begin
{ 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. }
marker := srcinfo^.marker_list;
while (marker <> NIL) do
begin
if (dstinfo^.write_JFIF_header) and
(marker^.marker = JPEG_APP0) and
(marker^.data_length >= 5) and
( GETJOCTET(marker^.data^[0]) = $4A ) and
( GETJOCTET(marker^.data^[1]) = $46 ) and
( GETJOCTET(marker^.data^[2]) = $49 ) and
( GETJOCTET(marker^.data^[3]) = $46 ) and
( GETJOCTET(marker^.data^[4]) = 0 ) then
begin
marker := marker^.next;
continue; { reject duplicate JFIF }
end;
if (dstinfo^.write_Adobe_marker ) and
( marker^.marker = JPEG_APP0+14 ) and
( marker^.data_length >= 5 ) and
( GETJOCTET(marker^.data^[0]) = $41 ) and
( GETJOCTET(marker^.data^[1]) = $64 ) and
( GETJOCTET(marker^.data^[2]) = $6F ) and
( GETJOCTET(marker^.data^[3]) = $62 ) and
( GETJOCTET(marker^.data^[4]) = $65 ) then
begin
marker := marker^.next;
continue; { reject duplicate Adobe }
end;
{$ifdef NEED_FAR_POINTERS}
{ We could use jpeg_write_marker if the data weren't FAR... }
begin
jpeg_write_m_header(dstinfo, marker^.marker, marker^.data_length);
for i := 0 to marker^.data_length-1 do
jpeg_write_m_byte(dstinfo, marker^.data^[i]);
end;
{$else}
jpeg_write_marker(dstinfo, marker^.marker,
JOCTETPTR(marker^.data), marker^.data_length);
{$endif}
marker := marker^.next;
end;
end;
end.
