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Added optional emulation of the jpeg-7 or jpeg-8b API/ABI's

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This commit is contained in:
DRC
2010-10-08 08:05:44 +00:00
parent 0b1530e1e3
commit d0d0f09d40
19 changed files with 632 additions and 103 deletions
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94
jdinput.c
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@@ -2,6 +2,8 @@
* jdinput.c
*
* Copyright (C) 1991-1997, Thomas G. Lane.
* Modified 2002-2009 by Guido Vollbeding.
* Copyright (C) 2010, D. R. Commander.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
@@ -14,6 +16,7 @@
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
#include "jpegcomp.h"
/* Private state */
@@ -35,6 +38,79 @@ METHODDEF(int) consume_markers JPP((j_decompress_ptr cinfo));
* Routines to calculate various quantities related to the size of the image.
*/
#if JPEG_LIB_VERSION >= 80
/*
* Compute output image dimensions and related values.
* NOTE: this is exported for possible use by application.
* Hence it mustn't do anything that can't be done twice.
*/
GLOBAL(void)
jpeg_core_output_dimensions (j_decompress_ptr cinfo)
/* Do computations that are needed before master selection phase.
* This function is used for transcoding and full decompression.
*/
{
#ifdef IDCT_SCALING_SUPPORTED
int ci;
jpeg_component_info *compptr;
/* Compute actual output image dimensions and DCT scaling choices. */
if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom) {
/* Provide 1/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width, (long) cinfo->block_size);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height, (long) cinfo->block_size);
cinfo->min_DCT_h_scaled_size = 1;
cinfo->min_DCT_v_scaled_size = 1;
} else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 2) {
/* Provide 2/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * 2L, (long) cinfo->block_size);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * 2L, (long) cinfo->block_size);
cinfo->min_DCT_h_scaled_size = 2;
cinfo->min_DCT_v_scaled_size = 2;
} else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 4) {
/* Provide 4/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * 4L, (long) cinfo->block_size);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * 4L, (long) cinfo->block_size);
cinfo->min_DCT_h_scaled_size = 4;
cinfo->min_DCT_v_scaled_size = 4;
} else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 8) {
/* Provide 8/block_size scaling */
cinfo->output_width = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * 8L, (long) cinfo->block_size);
cinfo->output_height = (JDIMENSION)
jdiv_round_up((long) cinfo->image_height * 8L, (long) cinfo->block_size);
cinfo->min_DCT_h_scaled_size = 8;
cinfo->min_DCT_v_scaled_size = 8;
}
/* Recompute dimensions of components */
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
compptr->DCT_h_scaled_size = cinfo->min_DCT_h_scaled_size;
compptr->DCT_v_scaled_size = cinfo->min_DCT_v_scaled_size;
}
#else /* !IDCT_SCALING_SUPPORTED */
/* Hardwire it to "no scaling" */
cinfo->output_width = cinfo->image_width;
cinfo->output_height = cinfo->image_height;
/* jdinput.c has already initialized DCT_scaled_size,
* and has computed unscaled downsampled_width and downsampled_height.
*/
#endif /* IDCT_SCALING_SUPPORTED */
}
#endif
LOCAL(void)
initial_setup (j_decompress_ptr cinfo)
/* Called once, when first SOS marker is reached */
@@ -70,16 +146,30 @@ initial_setup (j_decompress_ptr cinfo)
compptr->v_samp_factor);
}
#if JPEG_LIB_VERSION >=80
cinfo->block_size = DCTSIZE;
cinfo->natural_order = jpeg_natural_order;
cinfo->lim_Se = DCTSIZE2-1;
#endif
/* We initialize DCT_scaled_size and min_DCT_scaled_size to DCTSIZE.
* In the full decompressor, this will be overridden by jdmaster.c;
* but in the transcoder, jdmaster.c is not used, so we must do it here.
*/
#if JPEG_LIB_VERSION >= 70
cinfo->min_DCT_h_scaled_size = cinfo->min_DCT_v_scaled_size = DCTSIZE;
#else
cinfo->min_DCT_scaled_size = DCTSIZE;
#endif
/* Compute dimensions of components */
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++) {
#if JPEG_LIB_VERSION >= 70
compptr->DCT_h_scaled_size = compptr->DCT_v_scaled_size = DCTSIZE;
#else
compptr->DCT_scaled_size = DCTSIZE;
#endif
/* Size in DCT blocks */
compptr->width_in_blocks = (JDIMENSION)
jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor,
@@ -138,7 +228,7 @@ per_scan_setup (j_decompress_ptr cinfo)
compptr->MCU_width = 1;
compptr->MCU_height = 1;
compptr->MCU_blocks = 1;
compptr->MCU_sample_width = compptr->DCT_scaled_size;
compptr->MCU_sample_width = _DCT_scaled_size;
compptr->last_col_width = 1;
/* For noninterleaved scans, it is convenient to define last_row_height
* as the number of block rows present in the last iMCU row.
@@ -174,7 +264,7 @@ per_scan_setup (j_decompress_ptr cinfo)
compptr->MCU_width = compptr->h_samp_factor;
compptr->MCU_height = compptr->v_samp_factor;
compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height;
compptr->MCU_sample_width = compptr->MCU_width * compptr->DCT_scaled_size;
compptr->MCU_sample_width = compptr->MCU_width * _DCT_scaled_size;
/* Figure number of non-dummy blocks in last MCU column & row */
tmp = (int) (compptr->width_in_blocks % compptr->MCU_width);
if (tmp == 0) tmp = compptr->MCU_width;