Mercurial > hgrepos > Python2 > PyMuPDF
diff mupdf-source/thirdparty/libjpeg/jcinit.c @ 2:b50eed0cc0ef upstream
ADD: MuPDF v1.26.7: the MuPDF source as downloaded by a default build of PyMuPDF 1.26.4.
The directory name has changed: no version number in the expanded directory now.
| author | Franz Glasner <fzglas.hg@dom66.de> |
|---|---|
| date | Mon, 15 Sep 2025 11:43:07 +0200 |
| parents | |
| children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mupdf-source/thirdparty/libjpeg/jcinit.c Mon Sep 15 11:43:07 2025 +0200 @@ -0,0 +1,249 @@ +/* + * 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); +}
