dbf-halloween2015

annotate libs/libjpeg/jcapistd.c @ 3:c37fe5d8a4ed

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windows port
author John Tsiombikas <nuclear@member.fsf.org>
date Sun, 01 Nov 2015 06:04:28 +0200
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nuclear@1 1 /*
nuclear@1 2 * jcapistd.c
nuclear@1 3 *
nuclear@1 4 * Copyright (C) 1994-1996, Thomas G. Lane.
nuclear@1 5 * This file is part of the Independent JPEG Group's software.
nuclear@1 6 * For conditions of distribution and use, see the accompanying README file.
nuclear@1 7 *
nuclear@1 8 * This file contains application interface code for the compression half
nuclear@1 9 * of the JPEG library. These are the "standard" API routines that are
nuclear@1 10 * used in the normal full-compression case. They are not used by a
nuclear@1 11 * transcoding-only application. Note that if an application links in
nuclear@1 12 * jpeg_start_compress, it will end up linking in the entire compressor.
nuclear@1 13 * We thus must separate this file from jcapimin.c to avoid linking the
nuclear@1 14 * whole compression library into a transcoder.
nuclear@1 15 */
nuclear@1 16
nuclear@1 17 #define JPEG_INTERNALS
nuclear@1 18 #include "jinclude.h"
nuclear@1 19 #include "jpeglib.h"
nuclear@1 20
nuclear@1 21
nuclear@1 22 /*
nuclear@1 23 * Compression initialization.
nuclear@1 24 * Before calling this, all parameters and a data destination must be set up.
nuclear@1 25 *
nuclear@1 26 * We require a write_all_tables parameter as a failsafe check when writing
nuclear@1 27 * multiple datastreams from the same compression object. Since prior runs
nuclear@1 28 * will have left all the tables marked sent_table=TRUE, a subsequent run
nuclear@1 29 * would emit an abbreviated stream (no tables) by default. This may be what
nuclear@1 30 * is wanted, but for safety's sake it should not be the default behavior:
nuclear@1 31 * programmers should have to make a deliberate choice to emit abbreviated
nuclear@1 32 * images. Therefore the documentation and examples should encourage people
nuclear@1 33 * to pass write_all_tables=TRUE; then it will take active thought to do the
nuclear@1 34 * wrong thing.
nuclear@1 35 */
nuclear@1 36
nuclear@1 37 GLOBAL(void)
nuclear@1 38 jpeg_start_compress (j_compress_ptr cinfo, boolean write_all_tables)
nuclear@1 39 {
nuclear@1 40 if (cinfo->global_state != CSTATE_START)
nuclear@1 41 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
nuclear@1 42
nuclear@1 43 if (write_all_tables)
nuclear@1 44 jpeg_suppress_tables(cinfo, FALSE); /* mark all tables to be written */
nuclear@1 45
nuclear@1 46 /* (Re)initialize error mgr and destination modules */
nuclear@1 47 (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo);
nuclear@1 48 (*cinfo->dest->init_destination) (cinfo);
nuclear@1 49 /* Perform master selection of active modules */
nuclear@1 50 jinit_compress_master(cinfo);
nuclear@1 51 /* Set up for the first pass */
nuclear@1 52 (*cinfo->master->prepare_for_pass) (cinfo);
nuclear@1 53 /* Ready for application to drive first pass through jpeg_write_scanlines
nuclear@1 54 * or jpeg_write_raw_data.
nuclear@1 55 */
nuclear@1 56 cinfo->next_scanline = 0;
nuclear@1 57 cinfo->global_state = (cinfo->raw_data_in ? CSTATE_RAW_OK : CSTATE_SCANNING);
nuclear@1 58 }
nuclear@1 59
nuclear@1 60
nuclear@1 61 /*
nuclear@1 62 * Write some scanlines of data to the JPEG compressor.
nuclear@1 63 *
nuclear@1 64 * The return value will be the number of lines actually written.
nuclear@1 65 * This should be less than the supplied num_lines only in case that
nuclear@1 66 * the data destination module has requested suspension of the compressor,
nuclear@1 67 * or if more than image_height scanlines are passed in.
nuclear@1 68 *
nuclear@1 69 * Note: we warn about excess calls to jpeg_write_scanlines() since
nuclear@1 70 * this likely signals an application programmer error. However,
nuclear@1 71 * excess scanlines passed in the last valid call are *silently* ignored,
nuclear@1 72 * so that the application need not adjust num_lines for end-of-image
nuclear@1 73 * when using a multiple-scanline buffer.
nuclear@1 74 */
nuclear@1 75
nuclear@1 76 GLOBAL(JDIMENSION)
nuclear@1 77 jpeg_write_scanlines (j_compress_ptr cinfo, JSAMPARRAY scanlines,
nuclear@1 78 JDIMENSION num_lines)
nuclear@1 79 {
nuclear@1 80 JDIMENSION row_ctr, rows_left;
nuclear@1 81
nuclear@1 82 if (cinfo->global_state != CSTATE_SCANNING)
nuclear@1 83 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
nuclear@1 84 if (cinfo->next_scanline >= cinfo->image_height)
nuclear@1 85 WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
nuclear@1 86
nuclear@1 87 /* Call progress monitor hook if present */
nuclear@1 88 if (cinfo->progress != NULL) {
nuclear@1 89 cinfo->progress->pass_counter = (long) cinfo->next_scanline;
nuclear@1 90 cinfo->progress->pass_limit = (long) cinfo->image_height;
nuclear@1 91 (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
nuclear@1 92 }
nuclear@1 93
nuclear@1 94 /* Give master control module another chance if this is first call to
nuclear@1 95 * jpeg_write_scanlines. This lets output of the frame/scan headers be
nuclear@1 96 * delayed so that application can write COM, etc, markers between
nuclear@1 97 * jpeg_start_compress and jpeg_write_scanlines.
nuclear@1 98 */
nuclear@1 99 if (cinfo->master->call_pass_startup)
nuclear@1 100 (*cinfo->master->pass_startup) (cinfo);
nuclear@1 101
nuclear@1 102 /* Ignore any extra scanlines at bottom of image. */
nuclear@1 103 rows_left = cinfo->image_height - cinfo->next_scanline;
nuclear@1 104 if (num_lines > rows_left)
nuclear@1 105 num_lines = rows_left;
nuclear@1 106
nuclear@1 107 row_ctr = 0;
nuclear@1 108 (*cinfo->main->process_data) (cinfo, scanlines, &row_ctr, num_lines);
nuclear@1 109 cinfo->next_scanline += row_ctr;
nuclear@1 110 return row_ctr;
nuclear@1 111 }
nuclear@1 112
nuclear@1 113
nuclear@1 114 /*
nuclear@1 115 * Alternate entry point to write raw data.
nuclear@1 116 * Processes exactly one iMCU row per call, unless suspended.
nuclear@1 117 */
nuclear@1 118
nuclear@1 119 GLOBAL(JDIMENSION)
nuclear@1 120 jpeg_write_raw_data (j_compress_ptr cinfo, JSAMPIMAGE data,
nuclear@1 121 JDIMENSION num_lines)
nuclear@1 122 {
nuclear@1 123 JDIMENSION lines_per_iMCU_row;
nuclear@1 124
nuclear@1 125 if (cinfo->global_state != CSTATE_RAW_OK)
nuclear@1 126 ERREXIT1(cinfo, JERR_BAD_STATE, cinfo->global_state);
nuclear@1 127 if (cinfo->next_scanline >= cinfo->image_height) {
nuclear@1 128 WARNMS(cinfo, JWRN_TOO_MUCH_DATA);
nuclear@1 129 return 0;
nuclear@1 130 }
nuclear@1 131
nuclear@1 132 /* Call progress monitor hook if present */
nuclear@1 133 if (cinfo->progress != NULL) {
nuclear@1 134 cinfo->progress->pass_counter = (long) cinfo->next_scanline;
nuclear@1 135 cinfo->progress->pass_limit = (long) cinfo->image_height;
nuclear@1 136 (*cinfo->progress->progress_monitor) ((j_common_ptr) cinfo);
nuclear@1 137 }
nuclear@1 138
nuclear@1 139 /* Give master control module another chance if this is first call to
nuclear@1 140 * jpeg_write_raw_data. This lets output of the frame/scan headers be
nuclear@1 141 * delayed so that application can write COM, etc, markers between
nuclear@1 142 * jpeg_start_compress and jpeg_write_raw_data.
nuclear@1 143 */
nuclear@1 144 if (cinfo->master->call_pass_startup)
nuclear@1 145 (*cinfo->master->pass_startup) (cinfo);
nuclear@1 146
nuclear@1 147 /* Verify that at least one iMCU row has been passed. */
nuclear@1 148 lines_per_iMCU_row = cinfo->max_v_samp_factor * DCTSIZE;
nuclear@1 149 if (num_lines < lines_per_iMCU_row)
nuclear@1 150 ERREXIT(cinfo, JERR_BUFFER_SIZE);
nuclear@1 151
nuclear@1 152 /* Directly compress the row. */
nuclear@1 153 if (! (*cinfo->coef->compress_data) (cinfo, data)) {
nuclear@1 154 /* If compressor did not consume the whole row, suspend processing. */
nuclear@1 155 return 0;
nuclear@1 156 }
nuclear@1 157
nuclear@1 158 /* OK, we processed one iMCU row. */
nuclear@1 159 cinfo->next_scanline += lines_per_iMCU_row;
nuclear@1 160 return lines_per_iMCU_row;
nuclear@1 161 }