250 lines
10 KiB
C
250 lines
10 KiB
C
/*
|
|
* jcinit.c
|
|
*
|
|
* Copyright (C) 1991-1997, Thomas G. Lane.
|
|
* Modified 2003-2017 by Guido Vollbeding.
|
|
* 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 initialization logic for the JPEG compressor.
|
|
* This routine is in charge of selecting the modules to be executed and
|
|
* making an initialization call to each one.
|
|
*
|
|
* Logically, this code belongs in jcmaster.c. It's split out because
|
|
* linking this routine implies linking the entire compression library.
|
|
* For a transcoding-only application, we want to be able to use jcmaster.c
|
|
* without linking in the whole library.
|
|
*/
|
|
|
|
#define JPEG_INTERNALS
|
|
#include "jinclude.h"
|
|
#include "jpeglib.h"
|
|
|
|
|
|
/*
|
|
* Compute JPEG 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_calc_jpeg_dimensions (j_compress_ptr cinfo)
|
|
/* Do computations that are needed before master selection phase */
|
|
{
|
|
/* Sanity check on input image dimensions to prevent overflow in
|
|
* following calculations.
|
|
* We do check jpeg_width and jpeg_height in initial_setup in jcmaster.c,
|
|
* but image_width and image_height can come from arbitrary data,
|
|
* and we need some space for multiplication by block_size.
|
|
*/
|
|
if (((long) cinfo->image_width >> 24) || ((long) cinfo->image_height >> 24))
|
|
ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);
|
|
|
|
#ifdef DCT_SCALING_SUPPORTED
|
|
|
|
/* Compute actual JPEG image dimensions and DCT scaling choices. */
|
|
if (cinfo->scale_num >= cinfo->scale_denom * cinfo->block_size) {
|
|
/* Provide block_size/1 scaling */
|
|
cinfo->jpeg_width = cinfo->image_width * cinfo->block_size;
|
|
cinfo->jpeg_height = cinfo->image_height * cinfo->block_size;
|
|
cinfo->min_DCT_h_scaled_size = 1;
|
|
cinfo->min_DCT_v_scaled_size = 1;
|
|
} else if (cinfo->scale_num * 2 >= cinfo->scale_denom * cinfo->block_size) {
|
|
/* Provide block_size/2 scaling */
|
|
cinfo->jpeg_width = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 2L);
|
|
cinfo->jpeg_height = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 2L);
|
|
cinfo->min_DCT_h_scaled_size = 2;
|
|
cinfo->min_DCT_v_scaled_size = 2;
|
|
} else if (cinfo->scale_num * 3 >= cinfo->scale_denom * cinfo->block_size) {
|
|
/* Provide block_size/3 scaling */
|
|
cinfo->jpeg_width = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 3L);
|
|
cinfo->jpeg_height = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 3L);
|
|
cinfo->min_DCT_h_scaled_size = 3;
|
|
cinfo->min_DCT_v_scaled_size = 3;
|
|
} else if (cinfo->scale_num * 4 >= cinfo->scale_denom * cinfo->block_size) {
|
|
/* Provide block_size/4 scaling */
|
|
cinfo->jpeg_width = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 4L);
|
|
cinfo->jpeg_height = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 4L);
|
|
cinfo->min_DCT_h_scaled_size = 4;
|
|
cinfo->min_DCT_v_scaled_size = 4;
|
|
} else if (cinfo->scale_num * 5 >= cinfo->scale_denom * cinfo->block_size) {
|
|
/* Provide block_size/5 scaling */
|
|
cinfo->jpeg_width = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 5L);
|
|
cinfo->jpeg_height = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 5L);
|
|
cinfo->min_DCT_h_scaled_size = 5;
|
|
cinfo->min_DCT_v_scaled_size = 5;
|
|
} else if (cinfo->scale_num * 6 >= cinfo->scale_denom * cinfo->block_size) {
|
|
/* Provide block_size/6 scaling */
|
|
cinfo->jpeg_width = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 6L);
|
|
cinfo->jpeg_height = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 6L);
|
|
cinfo->min_DCT_h_scaled_size = 6;
|
|
cinfo->min_DCT_v_scaled_size = 6;
|
|
} else if (cinfo->scale_num * 7 >= cinfo->scale_denom * cinfo->block_size) {
|
|
/* Provide block_size/7 scaling */
|
|
cinfo->jpeg_width = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 7L);
|
|
cinfo->jpeg_height = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 7L);
|
|
cinfo->min_DCT_h_scaled_size = 7;
|
|
cinfo->min_DCT_v_scaled_size = 7;
|
|
} else if (cinfo->scale_num * 8 >= cinfo->scale_denom * cinfo->block_size) {
|
|
/* Provide block_size/8 scaling */
|
|
cinfo->jpeg_width = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 8L);
|
|
cinfo->jpeg_height = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 8L);
|
|
cinfo->min_DCT_h_scaled_size = 8;
|
|
cinfo->min_DCT_v_scaled_size = 8;
|
|
} else if (cinfo->scale_num * 9 >= cinfo->scale_denom * cinfo->block_size) {
|
|
/* Provide block_size/9 scaling */
|
|
cinfo->jpeg_width = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 9L);
|
|
cinfo->jpeg_height = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 9L);
|
|
cinfo->min_DCT_h_scaled_size = 9;
|
|
cinfo->min_DCT_v_scaled_size = 9;
|
|
} else if (cinfo->scale_num * 10 >= cinfo->scale_denom * cinfo->block_size) {
|
|
/* Provide block_size/10 scaling */
|
|
cinfo->jpeg_width = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 10L);
|
|
cinfo->jpeg_height = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 10L);
|
|
cinfo->min_DCT_h_scaled_size = 10;
|
|
cinfo->min_DCT_v_scaled_size = 10;
|
|
} else if (cinfo->scale_num * 11 >= cinfo->scale_denom * cinfo->block_size) {
|
|
/* Provide block_size/11 scaling */
|
|
cinfo->jpeg_width = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 11L);
|
|
cinfo->jpeg_height = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 11L);
|
|
cinfo->min_DCT_h_scaled_size = 11;
|
|
cinfo->min_DCT_v_scaled_size = 11;
|
|
} else if (cinfo->scale_num * 12 >= cinfo->scale_denom * cinfo->block_size) {
|
|
/* Provide block_size/12 scaling */
|
|
cinfo->jpeg_width = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 12L);
|
|
cinfo->jpeg_height = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 12L);
|
|
cinfo->min_DCT_h_scaled_size = 12;
|
|
cinfo->min_DCT_v_scaled_size = 12;
|
|
} else if (cinfo->scale_num * 13 >= cinfo->scale_denom * cinfo->block_size) {
|
|
/* Provide block_size/13 scaling */
|
|
cinfo->jpeg_width = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 13L);
|
|
cinfo->jpeg_height = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 13L);
|
|
cinfo->min_DCT_h_scaled_size = 13;
|
|
cinfo->min_DCT_v_scaled_size = 13;
|
|
} else if (cinfo->scale_num * 14 >= cinfo->scale_denom * cinfo->block_size) {
|
|
/* Provide block_size/14 scaling */
|
|
cinfo->jpeg_width = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 14L);
|
|
cinfo->jpeg_height = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 14L);
|
|
cinfo->min_DCT_h_scaled_size = 14;
|
|
cinfo->min_DCT_v_scaled_size = 14;
|
|
} else if (cinfo->scale_num * 15 >= cinfo->scale_denom * cinfo->block_size) {
|
|
/* Provide block_size/15 scaling */
|
|
cinfo->jpeg_width = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 15L);
|
|
cinfo->jpeg_height = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 15L);
|
|
cinfo->min_DCT_h_scaled_size = 15;
|
|
cinfo->min_DCT_v_scaled_size = 15;
|
|
} else {
|
|
/* Provide block_size/16 scaling */
|
|
cinfo->jpeg_width = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_width * cinfo->block_size, 16L);
|
|
cinfo->jpeg_height = (JDIMENSION)
|
|
jdiv_round_up((long) cinfo->image_height * cinfo->block_size, 16L);
|
|
cinfo->min_DCT_h_scaled_size = 16;
|
|
cinfo->min_DCT_v_scaled_size = 16;
|
|
}
|
|
|
|
#else /* !DCT_SCALING_SUPPORTED */
|
|
|
|
/* Hardwire it to "no scaling" */
|
|
cinfo->jpeg_width = cinfo->image_width;
|
|
cinfo->jpeg_height = cinfo->image_height;
|
|
cinfo->min_DCT_h_scaled_size = DCTSIZE;
|
|
cinfo->min_DCT_v_scaled_size = DCTSIZE;
|
|
|
|
#endif /* DCT_SCALING_SUPPORTED */
|
|
}
|
|
|
|
|
|
/*
|
|
* Master selection of compression modules.
|
|
* This is done once at the start of processing an image. We determine
|
|
* which modules will be used and give them appropriate initialization calls.
|
|
*/
|
|
|
|
GLOBAL(void)
|
|
jinit_compress_master (j_compress_ptr cinfo)
|
|
{
|
|
long samplesperrow;
|
|
JDIMENSION jd_samplesperrow;
|
|
|
|
/* For now, precision must match compiled-in value... */
|
|
if (cinfo->data_precision != BITS_IN_JSAMPLE)
|
|
ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision);
|
|
|
|
/* Sanity check on input image dimensions */
|
|
if (cinfo->image_height <= 0 || cinfo->image_width <= 0 ||
|
|
cinfo->input_components <= 0)
|
|
ERREXIT(cinfo, JERR_EMPTY_IMAGE);
|
|
|
|
/* Width of an input scanline must be representable as JDIMENSION. */
|
|
samplesperrow = (long) cinfo->image_width * (long) cinfo->input_components;
|
|
jd_samplesperrow = (JDIMENSION) samplesperrow;
|
|
if ((long) jd_samplesperrow != samplesperrow)
|
|
ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);
|
|
|
|
/* Compute JPEG image dimensions and related values. */
|
|
jpeg_calc_jpeg_dimensions(cinfo);
|
|
|
|
/* Initialize master control (includes parameter checking/processing) */
|
|
jinit_c_master_control(cinfo, FALSE /* full compression */);
|
|
|
|
/* Preprocessing */
|
|
if (! cinfo->raw_data_in) {
|
|
jinit_color_converter(cinfo);
|
|
jinit_downsampler(cinfo);
|
|
jinit_c_prep_controller(cinfo, FALSE /* never need full buffer here */);
|
|
}
|
|
/* Forward DCT */
|
|
jinit_forward_dct(cinfo);
|
|
/* Entropy encoding: either Huffman or arithmetic coding. */
|
|
if (cinfo->arith_code)
|
|
jinit_arith_encoder(cinfo);
|
|
else {
|
|
jinit_huff_encoder(cinfo);
|
|
}
|
|
|
|
/* Need a full-image coefficient buffer in any multi-pass mode. */
|
|
jinit_c_coef_controller(cinfo,
|
|
(boolean) (cinfo->num_scans > 1 || cinfo->optimize_coding));
|
|
jinit_c_main_controller(cinfo, FALSE /* never need full buffer here */);
|
|
|
|
jinit_marker_writer(cinfo);
|
|
|
|
/* We can now tell the memory manager to allocate virtual arrays. */
|
|
(*cinfo->mem->realize_virt_arrays) ((j_common_ptr) cinfo);
|
|
|
|
/* Write the datastream header (SOI) immediately.
|
|
* Frame and scan headers are postponed till later.
|
|
* This lets application insert special markers after the SOI.
|
|
*/
|
|
(*cinfo->marker->write_file_header) (cinfo);
|
|
}
|